Download Technical Regulation for Thermal Power Station Units

Technical Regulation for Thermal
Power Station Units of 1.5 MW and higher
Regulation for grid connection TF 3.2.3
Version 5.1
1 October 2008
Revision view
Revision view
Section no.
Sections 2+3+13
Appendix 1
Text
Consolidation Act; Commencement; Measuring and Data Exchange; Layout
of Appendix 1; Regulation notified to the Danish Energy Regulatory Authority
Version
Date
5.1
09/2008
All
Updated after public consultation and registered with the Danish Energy
Regulatory Authority
5
09/2007
All
Updated and harmonised with TF 3.2.4 and submitted for public hearing
4
07/2007
2-3
Updated in connection with translation into English
3
07/2006
All
Updated after public consultation
2
12/2005
All
Updated and submitted for public consultation
1
2005
All
Grid Committee consultation
0
2004
Working group:
Kaj Christensen, Energinet.dk
Jens Peter Kjærgaard, Energinet.dk
Jan Havsager, Energinet.dk
Per Lund, Energinet.dk
Frederik B. Olesen, Energinet.dk (prepared regulation)
Carsten Strunge, Energinet.dk (prepared regulation)
Søren F. Jensen, Energinet.dk (prepared regulation)
For a copy of the regulation, please contact:
Energinet.dk
Fjordvejen 1-11
DK-7000 Fredericia
Tel. +45 70 10 22 44
The regulation can be downloaded from www.energinet.dk
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Summary (not part of the regulation)
Summary (not part of the regulation)
This technical regulation is the Danish Grid Code, which includes provisions for thermal
power station units with an output of 1.5 MW electrical power or higher for connection to the
public electricity supply grid in Denmark.
The regulation applies to new power station units and existing power station units which are
modified.
The regulation includes provisions regarding effective power, tolerance towards voltage and
frequency variations, grid faults, island operation, start and synchronisation, active power
generation and frequency control, system stability, reactive power generation and voltage
control, protection, measurement, communication and data exchange, power station unit
structure, operation and maintenance, verification, documentation and non-performance.
A power station unit must be equipped with synchronous generator according to the
provisions in subsection 10.1.
The regulation replaces previous specifications and recommendations issued by Eltra and
Elkraft, now merged into Energinet.dk, covering Western and Eastern Denmark, respectively.
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Table of contents
Table of contents
Revision view ........................................................................................................... 2
Summary (not part of the regulation) .......................................................................... 3
Table of contents ...................................................................................................... 4
Introduction (not part of the regulation)....................................................................... 5
1.
Definitions....................................................................................................... 6
2.
Objective .......................................................................................................11
3.
Scope ............................................................................................................12
4.
Effective power ...............................................................................................13
5.
Tolerance towards frequency and voltage deviations.............................................15
6.
Tolerance towards grid faults ............................................................................19
7.
Island operation ..............................................................................................22
8.
Start and synchronisation .................................................................................24
9.
Active power production and frequency control ....................................................26
10.
System stability ..............................................................................................30
11.
Reactive power generation and voltage control ....................................................31
12.
Protection ......................................................................................................34
13.
Metering, communication and data exchange ......................................................36
14.
Power station unit structure ..............................................................................37
15.
Operation and maintenance ..............................................................................38
16.
Verification and documentation .........................................................................39
17.
Non-compliance ..............................................................................................43
18.
Exemptions and unforeseen circumstances..........................................................44
Appendix 1: Documentation ......................................................................................45
Appendix 2: Required relay protection at plants with synchronous generator ....................66
Appendix 3: Supplementary relay protection at plants with synchronous generator............67
Appendix 4: Comments (not part of the regulation) ......................................................68
Appendix 5: Previous provisions (not part of the regulation)...........................................84
Appendix 6: Reference list (not part of the regulation) ..................................................85
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Introduction (not part of the regulation)
Introduction (not part of the regulation)
Requirements and delimitation
This technical regulation is part of the complete set of technical regulations issued by
Energinet.dk, the Danish Transmission System Operator (TSO). The technical regulations
comprise technical rules for the players regarding the connection to and operation of the
public electricity supply grid. Together with the market regulations, the technical regulations,
including the system operation regulations, constitute the non-discriminating set of rules to
be complied with by the players. The current version of the technical regulations is available
at www.energinet.dk.
This technical regulation is the Danish Grid Code, which includes provisions for thermal
power station units with an output of 1.5 MW electrical power or higher for connection to the
public electricity supply grid in Denmark. The regulation includes provisions regarding the
properties which the power station units must incorporate and retain throughout their service
lives. System operational conditions for power station units are regulated in other
regulations.
Definitions and comments
This regulation makes extensive use of definitions. These are described in the first section of
the regulation. In the text, definitions are written in italics.
Special reference is made to the section with comments at the end of the document. This
section can contribute to creating an overview of the provisions and an understanding of the
background and consequences of the provisions. This section is not part of the regulation
itself, a fact which can also be seen from the headings.
Responsibility for the regulation
The TSO is responsible for the technical regulations and for ensuring that the regulations are
observed and continuously adapted to the future public electricity supply grid in Denmark.
The technical regulations are enforced by the individual electric power utilities. The TSO can
issue a written permission to depart from the regulations.
Furthermore, reference is made to Section 26(1) of the Danish Electricity Supply
(Consolidation) Act no. 1115 of 8 November 2008, see Section 7 of the Danish
(Consolidation) Act on Transmission System Operation and the Use of the Electricity
Transmission Grid no. 1463 of 19 December 2005.
Authority requirements and standards
All power station units must comply with Danish legislation, including the Danish Heavy
Current Regulation and the Joint Regulation of the electric power utilities. In areas not
covered by Danish legislation or by technical regulation TF 3.2.3, the CENELEC standards
apply, and in areas where there are no such standards, the ISO and IEC standards apply.
In case of any discrepancy between the Danish text and the English translation, the Danish
text shall prevail.
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Definitions
1. Definitions
1.1
1.1.1
Operation
House-load operation
Operating condition in which a power station unit is operated in isolation from the public
electricity supply grid and with its own auxiliary power consumption as the only load.
1.1.2
Ready state
A power station unit is in ready state when it is able to start from a cold/warm state in the
time indicated in Appendix 1 for the power station unit.
Ready state is the basis of the definitions starting time until synchronisation and starting
time until full generation.
1.1.3
External operating conditions
External conditions comprising, for example, cooling water temperature, outdoor
temperature, air pressure, and relative humidity which impact on the effective power and
which cannot be controlled by the power station operator.
1.1.4
Nominal external operating conditions
External operating conditions in which nominal maximum power and nominal minimum
power are stated.
1.1.5
Normal operating condition
The process, configuration and connection for which a power station unit has been designed
and in which a power station unit is normally operated.
The configuration of a plant may deviate from normal operating condition when, for
example, faults occur in parts of the unit, during start-up and shutdown, during house-load
operation, or when the unit operates at overload.
Doubts may arise as to the definition of normal operating condition, if for instance a power
station unit under normal conditions is operated both with and without heat production or
with different fuel types. If there is any doubt about how to define normal operating
condition, the TSO must in consultation with the power station operator decide what is to be
considered normal operating condition and may demand that the provisions in this
regulation be met in different operating conditions.
1.1.6
Isolated island operation
Operating condition that occurs when a power station unit supplies an isolated grid area
either alone or as a significant unit.
1.1.7
Island operation
Mode of operation comprising house-load operation and isolated island operation.
1.2
1.2.1
Power
Effective power
The sum of the active electrical power estimated with signs, which a power station unit
exchanges with the grid at the connecting points. The power flow direction from the power
station unit to the public electricity supply grid is considered to be positive.
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Definitions
1.2.2
Maximum power
The maximum effective power which a power station unit can supply continuously in normal
operating condition under the current external operating conditions and by observing the
full-load voltage frequency range at the connecting points.
It should be noted that the maximum power fluctuates with the external operating
conditions and is thus not a fixed value. See also nominal maximum power.
1.2.3
Highest maximum power
The highest maximum power under typical external operating conditions.
1.2.4
Lowest maximum power
The lowest maximum power under typical external operating conditions.
1.2.5
Nominal maximum power
Maximum effective power which a power station unit can supply continuously in normal
operating condition under nominal external operating conditions and by observing the fullload voltage-frequency range at the connecting points.
Unlike maximum power, nominal maximum power is a fixed number, which is independent
of the external operating conditions.
1.2.6
Minimum power
The minimum effective power which a power station unit can supply continuously in normal
operating condition under the current external operating conditions and by observing the
full-load voltage-frequency range at the connecting points.
It should be noted that the minimum power fluctuates with the external operating
conditions and is thus not a fixed value. See also nominal minimum power.
1.2.7
Nominal minimum power
Minimum effective power which a power station unit can supply continuously in normal
operating condition under nominal external operating conditions and by observing the fullload voltage-frequency range at the connecting points.
Unlike minimum power, nominal minimum power is a fixed number, which is independent of
the external operating conditions.
1.3
1.3.1
Full load
Full-load frequency range
Frequency range in a connecting point at which a power station unit can supply maximum
power.
1.3.2
Full-load voltage-frequency range
Voltage and frequency range in a connecting point at which the frequency lies within the
full-load frequency range, and the voltage lies within the full-load voltage range, and at
which a power station unit can supply maximum power.
1.3.3
Full-load voltage range
Voltage range in a connecting point at which a power station unit can supply maximum
power.
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Definitions
1.4
Generator feeder
Electrical connection that links the generator/machine transformer to the public electricity
supply grid.
1.5
Main fuel
Fuel whose share makes up more than 80% of the total energy input into a power station
unit in normal operating condition.
1.6
Public electricity supply grid
Transmission and distribution grids that transmit electricity for an indefinite group of
suppliers and consumers on the terms dictated by public authorities.
1.7
Short-circuit ratio
The relation between the current in a synchronous generator’s field winding at rated voltage
on an open stator winding and the current in the field winding at rated current on a shortcircuited stator winding.
1.8
Power station unit
A facility which produces three-phase alternating current and where there is a directly
functional correlation between its main components (eg boiler, turbine and generator).
In case of doubt, a facility consisting of two units, each with a boiler, a turbine and a
generator, should be considered as two power station units. A facility consisting of a
combined-cycle plant (combi plant) should be considered as one power station unit. A
facility consisting of three gas engines operating at part load during the shutdown of one or
more of the engines is to be considered as one power station unit.
In case of doubt, the transmission system operator makes the decision based on whether a
facility can be considered as consisting of one or more power station units in accordance
with the rules in this regulation.
1.9
Power station operator
Enterprise that runs a power station unit and is responsible for the operation hereof through
ownership or contractual agreements.
1.10 Power schedule (load plan)
A plan stating the quantity of electricity to be generated in a specific period.
1.11 Load control
Control following a locally ordered change of effective power, ensuring the desired power
generation.
1.12 Point of common coupling (PCC)
Connecting point where the electricity produced is supplied to the public electricity supply
grid. Where installation-connected power station units are concerned, the point of common
coupling is the point where the installation is connected to the public electricity supply grid.
Auxiliary supply facilities can (particularly during start) be connected to a connecting point
that is not the point of common coupling. At small power station units, the point of common
coupling and the connecting point are often the same. See also the definition of connecting
point and the comments in Appendix 4.
1.13 Nominal voltage
The voltage in a connecting point for which the system has been designed.
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Definitions
1.14 Overload capacity
The effective power with the exception of maximum power that a power station unit can
supply to the grid for at least one hour at a time under nominal external operating
conditions, complying with the full-load voltage-frequency range in the connecting points.
Overload capacity can be obtained, for instance, by disconnecting the heat production of a
power station unit normally operated with heat production or by disconnecting highpressure preheaters in a steam power plant. The result of overload operation is often
reduced efficiency, increased costs and/or reduced plant life.
1.15 Power/frequency controller
Control system in a power station unit that quickly and automatically controls the effective
power on the basis of frequency deviations.
1.16 Power frequency control
Automatic control which ensures on a scale of seconds that the frequency is constant and
that production and consumption balance. The control is implemented in the
power/frequency controller in the power station units.
1.17 Secondary control
Control achieved through a locally ordered change of the effective power, which can ensure
the desired power generation and adjust the frequency.
1.18 Starting time until full generation
The time that passes from a power station unit in ready state being ordered to start until
the power station unit supplies maximum power.
1.19 Starting time until synchronisation
The time that passes from a power station unit in ready state being ordered to start until
the generator(s) of the power station unit is/are synchronised and connected to the public
electricity supply grid and can supply active electrical power.
1.20 Droop
Change in rotational speed (or change in frequency) causing the load on the electric
generator’s drive engine to change from idling to full load. Droop is often stated in % of
rated rotational speed (or rated frequency).
1.21 tanφ
Correlation between the reactive electrical power and the active electrical power generated
by a power station unit. Reactive power is supplied to the grid at positive tanφ.
1.22 Thermal power station unit
Power station unit producing three-phase alternating current using a thermodynamic
process.
1.23 Connecting point
The point at which a power station unit has been electrically connected to the public
electricity supply grid. It should be noted that one power station unit may have several
connecting points. See also the definition of point of common coupling and comments in
Appendix 4.
1.23.1 Grid connection
A power station unit is grid connected if the power station unit is connected directly to the
public electricity supply grid.
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Definitions
1.23.2 Installation connection
A power station unit is installation connected if the power station unit is connected to the
public electricity supply grid via a private electrical installation. This also applies even if the
house load, if any, covers the power station unit's entire power generation.
1.24 Typical operating voltage
Typical operating voltage is determined by the electric power utility in the connecting point.
Typical operating voltage is used for determining the full-load voltage range.
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Objective
2. Objective
The objective of this technical regulation TF 3.2.3 is to specify the minimum technical and
design requirements applying to thermal power station units with a nominal maximum power
of 1.5 MW electrical power or higher which are connected to the public electricity supply grid.
Another objective is to ensure the technical quality and balance of the public electricity
supply grid. This includes the fulfilment of two basic technical conditions, namely that power
generation can be adjusted continuously to the consumption and that the voltage can be
maintained.
To obtain a reliable and efficient electricity supply grid it is necessary to have coherent
planning, plant design and operation (from production facilities to consumers).
This regulation outlines the minimum requirements. If better properties can be achieved
without incurring extra costs, it should be done.
2.1
Legislation
The regulation has been drawn up pursuant to Section 26(1) of the Danish Electricity Supply
(Consolidation) Act no. 1115 of 8 November 2005, see Section 7 of the Danish
(Consolidation) Act noon Transmission System Operation and the Use of the Electricity
Transmission Grid . 1463 of 19 December 2005.
2.2
Administration of the regulation
The technical regulations are administered by the electric power utility to whose grid the
power station unit is connected on behalf of the TSO. The TSO may give permission in
writing to depart from the regulation.
2.3
Complaints
This regulation has been registered with the Danish Energy Regulatory Authority. Complaints
about the regulation can be lodged with the Danish Energy Regulatory Authority. Complaints
about the TSO's enforcement of the provisions of the regulation can be lodged with the
Danish Energy Regulatory Authority.
Complaints about how the individual electric power utility's enforcement of the provisions of
the regulation can be lodged with the TSO.
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Scope
3. Scope
Thermal power station units connected to the public electricity supply grid in Denmark in
accordance with sections 3.1 and 3.2 hereof must at any given time comply with the
regulation.
In areas not covered by Danish legislation or by technical regulation TF 3.2.3, the CENELEC
standards apply, and in areas where there are no such standards, the ISO and IEC standards
apply.
3.1
New plants
The regulation applies to all thermal power station units with nominal maximum power of 1.5
MW electrical power or higher which are connected to the public electricity supply grid in
Denmark and commissioned on 1 November 2008 or later.
3.2
Existing plants
Thermal power station units with nominal maximum power of 1.5 MW or higher which were
connected to the public electricity supply grid in Denmark before 1 November 2008 must
comply with the regulation in force at the time of commissioning.
Existing plants which are modified substantially must comply with the provisions in this
regulation relating to the changes. A substantial modification affects one or more of the
properties discussed in this regulation. In cases of doubt, the TSO decides whether a
modification is substantial or not.
3.3
Exemptions
The regulation does not apply to power station units transmitting the electricity generated
via power converters.
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Effective power
4. Effective power
4.1 Maximum power
A power station unit must constantly and continuously be capable of delivering
maximum power, see the explanations below.
For a power station unit with heat-load determined electricity production (eg a backpressure plant), the time in which maximum power can be delivered can be limited by a
small extraction of district heat.
For a power station unit with independent electricity and heat production (eg an
extraction plant), a reduction in the effective power is accepted because of a large
extraction of district heat.
In case of unusual voltages and/or frequencies in the connecting points and following
grid faults, a reduction of the effective power is accepted in accordance with sections 5
and 6 hereof.
Nominal maximum power must be stated in connection with the following nominal
external operating conditions:
-
Steam power plant:
Cooling water temperature at intake 10º C
Outdoor temperature 8º C
-
Gas turbines and gas engines:
Outdoor temperature 15º C
Air pressure 1013 hPa
Relative humidity 60%
-
Other plants:
Outdoor temperature 8º C
Typical mean annual values are used for any other external operating conditions, including
return flow temperature of district heating water.
Lowest maximum power and highest maximum power must be stated in connection with
values of external operating conditions within the following range:
-
Outdoor temperature between -25º C and 35º C
Relative humidity between 40% and 100%
Air pressure between 960 hPa and 1050 hPa
Cooling water temperature at intakes between 0º C and 25º C.
Typical annual extremes are used for any other external operating conditions, including
return flow temperature of district heating water.
4.2
Overload capacity
There are no overload capacity requirements for a power station unit.
According to Appendix 1, a power plant unit must not deliver more effective power than the
sum of the maximum power stated and the overload capacity stated.
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Effective power
4.3
Minimum power
A power station unit must constantly and continuously be capable of delivering minimum
power.
Depending on the power station unit’s thermodynamic process and main fuel, the minimum
power must not exceed the percentage of the maximum power stated in Table 1.
The upper allowable minimum power will be stated by the TSO for plant types and main fuels
that are not stated in Table 1, including power station units with several different main
fuels.
Power station unit type and
main fuel
Minimum power
[%]
Coal dust-fired steam power plant
35
Oil-fired steam power plant
20
Gas-fired steam power plant
20
Bio dust-fired steam power plant
35
Straw-fired steam power plant
50
Wood chip-fired steam power plant
50
Fluid-bed coal-fired steam power plant
50
Waste-fired steam power plant
Gas engine
Gas turbine
Gas-fired combined cycle (combi plant)
Diesel engine
Table 1
70
50 (35% for minimum 5 min.)
20
20% for gas turbine part
75% for steam turbine part
50 (20% for minimum 5 min.)
Upper allowable minimum power stated as a percentage of the maximum power
The minimum power for a power station unit with nominal maximum power up to 25 MW is
allowed to be obtained by starting/stopping several unit components, eg gas engines, to
obtain improved efficiency in the event of reduced effective power. Nevertheless, the power
station unit must be capable of operating at any part load according to section 4.4 hereof.
It must be possible to regulate a power station unit to the minimum power directly from the
start and from a condition with any other effective power.
4.4
Part load
A power station unit must constantly and continuously be capable of delivering any part load
between minimum power and maximum power with the natural limitation attributable to the
process of the power station unit (eg start of coal mills and Benson transition) according to
the following explanations.
For a power station unit with heat-load determined electricity production, the time in which a
given amount of effective power can be delivered can be limited by a small extraction of
district heat.
For a power plant unit with independent electricity and heat production (an extraction plant),
a reduction in the effective power is accepted because of a large extraction of district heat.
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Tolerance towards frequency and voltage deviations
5. Tolerance towards frequency and voltage deviations
A power station unit must be able to withstand voltage and frequency deviations in the
connecting points beyond the full-load voltage-frequency range while reducing the maximum
power as little as possible.
The requirements governing reactive power in case of voltage fluctuations are described in
more detail in section 11 hereof.
Voltage (p.u.)
UEH
Minimum
reduction
UH
1 hour
10% reduction
10 sec. No generation
requirements
UHF
30 min
reduction 15%
at 47.5 Hz
UTYP
30 min
reduction
0%
Continuous
operation
3 min
No generation
requirements
Linear interpolation
ULF
1 hour
10% reduction
UL
Minimum
reduction
UEL
47.0
Figure 1
5.1
47.5
49.0
50.5
51.0
53.0
Frequency
(Hz)
Frequency range, operating time and generation requirements.
Full-load voltage-frequency range
The full-load frequency range is 49.0 Hz-50.5 Hz. In the full-load frequency range it must be
possible to start and operate a power station unit continuously with automatic voltage
control within the full-load voltage range.
The full-load voltage range depends on the nominal voltage for the connecting point as
stated in Table 2 and Table 3.
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Tolerance towards frequency and voltage deviations
Nominal
voltage
Un
Lower
voltage
UL
Lower
full-load
voltage
ULF
Upper
full-load
voltage
UHF
Upper
voltage
UH
[kV]
[kV]
[kV]
[kV]
[kV]
400
320
360
420
440
150
135
146
170
180
132
119
125
145
155
60
54
57
66
72.5
50
45
47.5
55
60.0
Table 2
Full-load voltage range in relation to upper and lower voltage limit.
In Table 2, fixed voltage values determining the full-load voltage range in the point of
common coupling are stated.
For voltages of 132 kV and higher the upper voltage limit is higher than recommended in EN
60038 due to brief high voltages in the event of re-establishment of the grid after blackout.
Nominal
voltage
Un
Typical
operating
voltage
UTYP
Lower
voltage
UL
Lower
full-load
voltage
ULF
Upper
full-load
voltage
UHF
Upper
voltage
UH
[kV]
[kV]
[kV]
[p.u. of Utyp]
[p.u. of Utyp]
[kV]
30
30.0
27.0
0.95
1.05
36.0
20
20.5
18.0
0.95
1.05
22.0
15
15.3
13.5
0.95
1.05
16.5
10
10.5
9.00
0.95
1.05
11.0
0.69
0.69
0.62
0.90
1.05
0.76
0.40
0.40
0.36
0.90
1.05
0.44
Table 3
Full-load voltage range in relation to upper and lower voltage limit.
Table 3 states the typical operating voltage (UTYP). Typical operating voltage varies from one
part of the country to another and is determined by the electric power utility.
The interval between the upper and lower limits of the full-load voltage range measured in
kV (UHF-ULF) must be within the upper and lower voltage limit (UH-UL), respectively.
5.2
5.2.1
Voltage deviations
Low voltages UL
At frequencies in the connecting points within the full-load frequency range, a power station
unit must be able to supply reduced maximum power when the voltage in a connecting point
is between ULF and UL.
A power station unit must be able to supply reduced maximum power for at least one hour at
a time. If low voltage occurs in a connecting point for longer periods of time, the power
station unit must be able to continuously supply reduced maximum power. Whether or not
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Tolerance towards frequency and voltage deviations
low voltage may occur for longer periods of time must be indicated by the electric power
utility to which the power station unit is connected.
The reduction in maximum power must not constitute more than 10% of the nominal
maximum power.
5.2.2
Extra low voltages UEL
A power station unit having a connecting point with a nominal voltage Un lying within the 10
to 20 kV range must supply electricity within the full-load frequency range and within the
range between UL and the extra low voltage UEL as stated in Table 4 while reducing
maximum power as little as possible.
Nominal
voltage
Un
Extra low
voltage
UEL
Extra high
voltage
UEH
[kV]
[kV]
[kV]
20
17.0
24.0
15
12.0
17.5
10
8.50
12.0
Table 4
Extra low and extra high voltage limits.
5.2.3
High voltages UH
If frequencies in the connecting points lie within the full-load frequency range, a power
station unit must be able to supply reduced maximum power when the voltage in a
connecting point is between UHF and UH.
A power station unit must be able to deliver reduced maximum power for at least one hour
at the time, and for connecting points with a nominal voltage Un more than 100 kV for up to
10 hours a year.
The reduction in maximum power must not constitute more than 10% of the nominal
maximum power.
5.2.4
Extra high voltages UEH
A power station unit having a connecting point with a nominal voltage Un lying within the 10
to 20 kV range must supply electricity within the full-load frequency range and within the
range between UH and the extra high voltage UEH as stated in Table 4 while reducing
maximum power as little as possible.
5.2.5
Voltage ramp rate
The voltage deviations mentioned in section 5.2 must be tolerated for connecting points with
a nominal voltage Un of more than 100 kV when the voltage varies up to 10% of nominal
voltage Un for any one-minute interval. Voltage variations for other connecting points must
be tolerated at any voltage ramp rate.
5.2.6
Transient voltages
Conditions in the public electricity supply grid may cause transient voltages in the connecting
point for the power station unit.
Any need for installing surge arresters in order to protect the power station unit must be
assessed in collaboration with the electric power utility.
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Tolerance towards frequency and voltage deviations
5.3
Frequency deviations
5.3.1
Low frequencies
When the frequency is low (below 49.0 Hz) and if voltages in the connecting points lie within
the full-load voltage range, a power station unit must be able to supply reduced maximum
power at frequencies in the connecting points as shown in Table 5.
The reduction in maximum power must make up 15% at the most of nominal maximum
power at 47.5 Hz, 0% of nominal maximum power at 49 Hz, and a value found by linear
interpolation at frequencies between 47.5 Hz and 49 Hz.
There are no requirements as to the maximum power which a power station unit must supply
at extra low frequencies (below 47.5 Hz).
Frequency range
f
[Hz]
Operating time
t
[sec. / min.]
Maximum
power reduction
[%]
f < 47.0 Hz
47.0 ≤ f ≤ 47.5
47.5 < f ≤ 49.0
≥ 300 ms
> 10.0 sec.
> 30 min
No requirements
No requirements
< 15%
49.0 < f ≤ 50.5
Continuous
0%
50.5 < f ≤ 51.0
51.0 < f ≤ 53.0
f > 53.0 Hz
> 30 min
Short (3 min)
≥ 300 ms
0%
No requirements
No requirements
Table 5
Frequency range, operating time and generation requirements.
5.3.2
High frequencies
When the frequency is high (above 50.5 Hz and below 51.0 Hz, and if voltages in the
connecting points lie within the full-load voltage range, a power station unit must be able to
supply reduced maximum power without any reduction, as shown in Table 5.
5.3.3
Extra high frequencies
When the frequency is extra high (above 51.0 Hz), and if voltages in the connecting points
lie within the full-load voltage range, a power station unit must remain connected when
frequencies in the connecting points are as shown in Table 5.
There are no requirements as to the maximum power which a power station unit must supply
at extra high frequencies.
5.3.4
Transient frequencies
The general purpose of the following requirements is to ensure that the power station unit is
designed in such a way that it can continue to operate at transient frequency deviations.
These deviations normally occur in connection with grid faults.
A power station unit must be able to withstand transient frequency gradients (df/dt) of up to
±2.5 Hz/s in the connecting point without disconnecting.
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Tolerance towards grid faults
6. Tolerance towards grid faults
A power station unit, including auxiliary supply system and auxiliary facilities, must stay
connected to the grid during and after a voltage disturbance in the connecting points as
stated in the sections 6.1-6.2 with a subsequent load reduction of maximum 10% in the
effective power.
Whether or not a power station unit must be designed to withstand these voltage sags with
the stated reduction in effective power, the relay settings must be as stated in section 12.
The power station unit is considered to be connected above 100 kV when there is only
electricity consumption in the form of house load for production and grid installations
between the power station unit and the transmission grid above 100 kV.
6.1
Connecting points above 100 kV
A power station unit must be able to withstand a voltage disturbance nearby on the highvoltage side of the generator transformer and in the connecting point as stated in Figure 2
and Figure 3.
6.1.1
Faults near a power station - short-line faults
A voltage disturbance near a power station means a voltage disturbance occurring in such a
distance from a power station unit that, in the event of a three-phase short-circuit, the share
of AC in the initial short-circuit current (IK”) from the power station unit’s generator(s) is
minimum 1.8 times the nominal current of the generator(s).
In the event of three-phase voltage disturbances, the power station unit must be capable of
withstanding a voltage curve in the three phases as stated in Figure 2.
Percentage
of nominal
voltage
Full-load
voltage range
100%
ULF
60%
0%
0
Figure 2
ms
1y5 0
ms
7 0 0 ms
1 5 0 0 ms Time
Three-phase voltage disturbance which must not lead to the disconnection of the power station unit. ULF
designates the lower limit of the full-load voltage range according to Table 2.
In Eastern Denmark, y is required to be 250 ms (in accordance with Nordel), and in Western
Denmark, y is required to be 150 ms (in accordance with the UCTE).
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Tolerance towards grid faults
In the event of one-phase or two-phase voltage disturbances, the power station unit must be
capable of withstanding a voltage curve in the faulty phases as stated in Figure 3 at the
same time as the voltage in the non-faulty phases is between the lower limit for the full-load
voltage range (ULF) and 1.4 times the upper limit for the full-load voltage range (1.4 x UHF)
according to Table 2 and Table 3. The time interval, x, in Figure 3 may vary between 300
ms and 800 ms.
Percentage
of nominal
voltage
Full-load
voltage range
100%
ULF
60%
0%
15 0 ms
x
1 5 0 ms
5 5 0 ms
Time
8 0 0 ms
Figure 3
Phase voltage during faulty phases in the event of one-phase or two-phase voltage disturbances which
must not lead to the disconnection of the power station unit. ULF designates the lower limit of the full-load
voltage range according to Table 2.
6.1.2
Faults occurring far away from a power station
A voltage disturbance occurring far away from a power station means a voltage disturbance
occurring in such a distance from the power station unit that, in the event of a three-phase
short-circuit, the share of AC in the initial short-circuit current (IK”) from the power station
unit’s generator(s) is less than 1.8 times the nominal current of the generator(s).
A power station unit must be capable of tolerating any one-, two- or three-phase voltage
disturbance far away from the power station of up to five seconds in connecting points with
nominal voltage above 100 kV.
6.2
Connection points up to 100 kV
A power station unit must be designed in such a way that the connecting points with nominal
voltage up to 100 kV are able to withstand voltage sags up to 50% of the nominal voltage in
one second in all three phases and voltage sags to 0% voltage during one second in one
phase.
A power station unit must be designed in such a way that the connecting points with nominal
voltage up to 100 kV are able to withstand voltage sags up to U3ϕ in between one and five
seconds in all three phases and a voltage sag up to U1ϕ in between one and five seconds in
one phase. The size of U3ϕ and U1ϕ in p.u. is given at U3ϕ = 1 – (0.5 seconds)/t and U1ϕ = 1 (1 second)/t where t is the duration of the voltage sag (nominal voltage equal to 1 p.u.) as
illustrated in Figure 4.
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Tolerance towards grid faults
Voltage, U
3 -phase
voltage drop
100%
75%
50%
ULF
1 -phase
voltage drop
25%
0%
0
Figure 4
1
2
3
4
5
Duration, t
(s e co nds)
Relationship between duration and range of one-phase and three-phase voltage sags which power station
units connected to up to 100 kV must be able to withstand.
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Island operation
7. Island operation
7.1
7.1.1
Power station units up to 25 MW
House-load operation
For power station units with nominal maximum power up to 25 MW it is acceptable that they
are disconnected at impacts not covered by the specified requirements without switching
from normal operation to house-load operation.
The significance of a system's possible ability to switch from normal operation to house-load
operation is assessed as being modest in relation to the price of ensuring such an operational
property. Efforts should rather be made to ensure short starting times after a disconnection
of the power station unit.
7.1.2
Isolated island operation
A grid fault may cause unintentional isolated island operation. Continued operation of the
power station unit during unintentional isolated island operation should be avoided to the
widest possible extent.
According to section 9, a power station unit must, however, be able to supply a suitable area
during isolated island operation in accordance with a special operational supervisor
agreement.
7.2
Power station units above 25 MW
A power station unit with nominal maximum power above 25 MW must be capable of
switching from normal operation in parallel with the interconnected power supply system to
island operation, maintain island operation and return from island operation as stated in
sections 7.2.1-7.2.3.
7.2.1
Transition to island operation
The transition to house-load operation must be possible from any condition with effective
power from minimum power to maximum power and in case of overload.
Transition to island operation must be effected automatically in the following situations:
-
If the frequency and voltage ranges specified in section 5 in the form of high/low
voltages/frequencies or the times stated in the section are exceeded.
In case of grid faults exceeding the profiles for voltage sags specified in section 6.
At the transition to isolated island operation, a power station unit must be capable of
controlling the system frequency within the full-load frequency range unless this will lead to
the effective power becoming lower than the minimum power or exceeding the maximum
power. According to section 9, this will be effected, in case of transition to isolated island
operation, by the power station unit undertaking control as after a fault and immediately
thereafter undertaking control as during normal operation.
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Island operation
7.2.2
Maintaining island operation
It must be possible to maintain stable and reliable house-load operation for at least two
hours without stopping the power station unit.
It must be possible to maintain continuous, stable and reliable isolated island operation
without stopping the power station unit as long as it is not contrary to the power station
unit’s possible maximum power according to section 4 or tolerance towards voltage and
frequency deviations according to section 5.
For a power station unit with heat-load determined electricity production, the time in which
island operation can be maintained can be limited by a small extraction of district heat.
7.2.3
Return from island operation
A power station unit must be capable of returning directly to normal operation after island
operation without stopping the power station unit according to section 8.3.
A power station unit must be capable of going into isolated island operation, including
energising, without stopping the power station unit according to section 8.3.
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Start and synchronisation
8. Start and synchronisation
8.1
Start
A power station unit must be able to start at frequencies and voltages in the connecting
points lying within the full-load voltage-frequency range. In addition, a power station unit
must in pursuance of section 5.1. also be able to start at voltages down to the lower voltage
level UL.
There are no requirements as to the start of a power station unit of 1.5 MW electric power or
more with a no-voltage public electricity supply grid. It is possible, however, to agree on
additional energising properties with the TSO so that it becomes possible to start from a novoltage grid.
8.2
Starting time
A power station unit must be designed with a starting time that is as short as possible giving
due consideration to the financial consequences, for example with a view to providing fast
reserves and emergency start.
8.2.1
Steam turbine above 25 MW
The starting time until synchronisation and the starting time until full generation must not
exceed the times indicated in Table 6 for a power station unit with a steam turbine with
rated maximum power above 25 MW.
The times for the steam turbine part apply to a combined-cycle unit with rated maximum
power above 25 MW.
Time since last stop
Starting time for
synchronisation
Starting time until
full generation
[min.]
[min.]
Immediately after stop
120
210
Up to 8 hours
180
300
Between 8 and 36 hours
300
480
Over 36 hours (cold start)
600
840
Table 6
8.2.2
Maximum starting time for power station units with nominal maximum power above 25 MW
depending on the time elapsed since the last stop.
Gas turbine above 25 MW
As for a power station unit with a gas turbine that does not produce heat and the nominal
maximum power of which is above 25 MW, the starting time until full generation must not
exceed 3 minutes for gas turbines of the jet type and 10 minutes for gas turbines of the
industrial type, irrespective of the time elapsed since last disconnection.
As for a power station unit with a gas turbine that produces heat, including a power station
unit with combined-cycle gas turbine (combi plant), and the nominal maximum power of
which is above 25 MW, the starting time until synchronisation and the starting time until full
generation for the gas turbine part must not exceed 20 minutes and 45 minutes respectively,
irrespective of the time elapsed since latest disconnection.
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Start and synchronisation
8.2.3
Plant types up to 25 MW
The starting time until synchronisation and the starting time until full generation must not
exceed the times stated in Table 7 for power station units not comprised by sections 8.2.18.2.2 - including power station units with nominal maximum power up to 25 MW.
The starting time will be stated by the TSO for plant types and main fuels not stated in
Table 7, including power station units with several different main fuels.
Starting time
Type/main fuel
of power station unit
Immediately after
disconnection
Eight hours since
disconnection
Until
synchronisation
Until full
generation
Until
synchronisation
Until full
generation
[min.]
[min.]
[min.]
[min.]
Straw-fired steam power plant
75
90
60
120
Wood chip-fired steam power plant
30
45
60
90
Fluid-bed coal-fired steam power
plant
45
60
90
120
Waste-fired steam power plant
No req.
No req.
No req.
No req.
Gas engine
10
20
10
20
Gas turbine
20
30
20
30
Gas-fired combined cycle
(combi plant)
30
40
(steam part
95 min.)
25
35
(steam part
90 min.)
5
15
5
15
Diesel engine
Table 7
8.3
Maximum starting time for power station units not comprised by 8.2.1-8.2.2 – including power station units
with rated maximum power up to 25 MW – depending on the time elapsed since latest disconnection.
Synchronisation
A power station unit must be provided with synchronisation equipment for connection.
The synchronisation equipment must safely and reliably synchronise the power station unit
to the grid – both in case of normal start and in situations with island operation in
accordance with section 7, in situations when voltage and frequency in the connection points
lie within the full-load voltage-frequency area according to section 5.1, and in situations
when voltages go down to the lower voltage limit.
A power station unit that can go into island operation according to section 7 must be capable
of energising a dead grid safely and reliably from situations with house-load operation
according to section 7.2.3 as long as it does not exceed the frequency and voltage limits
specified in sections 5 and 6.
In connecting points with a nominal voltage of 20 kV or less, a power station unit must not
be the cause of inrush currents, etc. of such a magnitude that it causes disruptive temporary
voltage variations in accordance with the DEFU committee report 88, ”Nettilslutning af
decentrale produktionsanlæg” (Grid Connection of Local Power Plants), March 1991.
Transient voltage deviations from inrush currents etc., including from the excitation current
at the synchronisation of a generator transformer, must not exceed 3% of nominal voltage in
connecting points with a nominal voltage above 20 kV.
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Active power production and frequency control
9.
Active power production and frequency control
A power station unit must be designed in such a way that it can be operated in an operating
condition that enables, at a minimum, the supply of the reserves required by Nordel and the
UCTE, respectively, in accordance with the following requirements.
9.1
General requirements of the regulating capability of the power station
unit
The power station unit must be equipped with a fast reacting power/frequency controller
capable of continuously, reliable and safely controlling the effective power and supplying
frequency control.
It must be possible to operate the power station unit in an operating condition allowing for
an instantaneous increase in effective power when the power station unit is supplying
effective power of 50-90% of maximum power in accordance with the following
requirements.
An increase/reduction in the effective power must be at least 5% of the nominal maximum
power in 30 seconds at the limit frequency specified by the TSO.
The power/frequency controller must be capable of continuously controlling the effective
power between minimum power and maximum power with the natural constraints which may
be imposed by the process at the power station unit (eg start of coal mills and Benson
transition).
The accuracy of the power/frequency controller’s frequency metering must be 10 mHz or less
for power station units above 25 MW whereas a resolution of 20 mHz or less is acceptable for
other power station units.
It must be possible to set the power/frequency controller’s reference frequency in the 49.9
Hz to 50.1 Hz range with a resolution of 10 mHz or less.
The power/frequency controller’s droop must be set within the range of 2%-8% with a
resolution of 1% or less.
The power/ frequency controller’s droop part must be equipped with an adjustable dead band
that can be by-passed. It must be possible to set the dead band within the ±0 mHz to ±200
mHz range with a resolution of ±5 mHz or less.
For power station units above 25 MW it must be possible to set the power/frequency
controller individually with limit frequencies for the activation of maximum load variations for
both over- and underfrequencies.
For power station units above 25 MW the power/frequency controller must as a minimum
have two parallel sets of dead band and droop.
The power/frequency controller's time constant must not limit the total control system's
closed loop time constant (regulator + drive engine + generator).
For power station units above 25 MW the setting of reference frequency, dead band and
droop must be remote-controllable during operation via an external signal within the given
limits.
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Active power production and frequency control
9.2
9.2.1
Power control in case of major frequency deviations
Western Denmark – Critical power/frequency control
The power station unit must be capable of providing critical power frequency support in the
event of major frequency deviations.
In the event of momentary frequency drop/increase, the power station unit must be capable
of providing frequency support according to the set point of the droop. The power response
must correspond to what is achievable in the current operating situation.
A power station unit must be capable of supplying secondary regulation immediately after a
momentary increase in the effective power according to section 9.4.
Critical power frequency control for the individual power station unit must only be activated
upon the request of the TSO.
Power station units connected to the grid above 100 kV must always be able to provide
critical power frequency control.
9.2.2
Eastern Denmark – Frequency-controlled disturbance reserve
The increase in the effective power must start in the event of a frequency drop bringing the
frequency under a limit value specified by the TSO. The limit value will typically be 49.9 Hz
(Δfact=100 mHz). The limit value for the frequency at which the increase in effective power
must be fully stepped up is specified by the TSO. The limit value will typically be 49.5 Hz
(Δftrg=500 mHz).
The increase in effective power must be minimum 2.5% of nominal maximum power in 5
seconds in the event of a specified frequency drop relative to the reference frequency
(Nordel recommendation).
In the event of a frequency drop lower than the limit frequency (Δftrg) specified by the TSO,
the power station unit must be capable of providing an increase in effective power as
indicated above, in such a way, however, that the increase in the effective power is scaled
with a factor K:
K=(Δf-Δfact)/( Δftrg-Δfact)
where:
Δf
Δftrg
:
:
Δfact
:
Frequency drop magnitude in Hz
The frequency drop in Hz that triggers the increase in
effective power stated (0.2-0.5 Hz)
The frequency deviation for activation in Hz specified by
the TSO
Apart from the above-mentioned requirements relating to frequency-controlled disturbance
reserves, the power station unit must be capable of providing frequency support according to
the set point of the droop in the event of momentary frequency increase. The power
response must correspond to what is achievable in the current operating situation.
Frequency-controlled disturbance reserves for the individual power station unit must only be
activated upon the request of the TSO.
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Active power production and frequency control
A power station unit must be capable of providing secondary regulation immediately after a
momentary increase/reduction in the effective power according to section 9.4.
9.3
Power control in case of minor frequency deviations
A power station unit with nominal maximum power above 25 MW must be designed so that it
can be operated according to the following requirements.
9.3.1
Western Denmark – Primary control
The increase/reduction in the effective power must start at frequency deviations specified by
the TSO, and it will typically be in the ± 100 mHz range relative to the reference frequency.
The limit frequency at which the increase/reduction in the effective power must be fully
regulated is specified by the TSO and will typically be in the ± 200 mHz range relative to the
reference frequency.
In the event of frequency deviations requiring a power response of less than 50% of the total
reserve capacity, the power response must be supplied within 15 seconds at the most. In the
event of frequency deviations requiring a power response in the 50-100% range of the total
reserve capacity, the part of the power response that is beyond 50% must be supplied
linearly controlled from 50% at 15 seconds to 100% at 30 seconds.
The power response of the power station unit in connection with the requirements in sections
9.2.1 and 9.3.1 must be the highest possible of the requirements mentioned.
9.3.2
Eastern Denmark –Frequency-controlled normal operation reserve
With a dead band set at 0 mHz, the power station unit must be capable of supplying the
reserve capacity agreed with the TSO within 150 seconds in the event of a momentary
frequency drop/increase.
9.4
Load control and secondary control
A power station unit must constantly and safely be able to control the effective power within
the range of minimum power to the highest maximum power. This must be possible both on
the basis of a planned power schedule (load control) and on the basis of centrally ordered
control (secondary control).
It must be possible to control the secondary control from an external signal.
It must be possible to control the effective power by selecting a required effective power in
MW (set point) and a required regulation rate (ramp rate) in MW/min. After that the power
station unit must be capable of controlling production to the selected effective power.
Table 8 shows the rate at which it must be possible to change the effective power at a
minimum expressed in per cent of nominal maximum power per time unit. It is acceptable
that the effective power will be delayed by the natural time constant connected to the
transformation of the fuel for power generation. The rate depends on the current effective
power (power range) expressed in per cent of nominal maximum power as shown in the
table.
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Active power production and frequency control
Type of power station unit
Coal dust-fired steam power plant
Oil-fired steam power plant
Gas-fired steam power plant
Bio dust-fired steam power plant
Straw-fired steam power plant
Wood chip-fired steam power plant
Fluid-bed coal-fired steam power plant
Ramp rate
Power range
[%/minute]
[%]
2
35-50
4
50-90
2
90-100
2
20-50
8
50-90
2
90-100
2
20-50
8
50-90
2
90-100
2
35-50
4
50-90
2
90-100
4
50-90
2
90-100
4
50-90
2
90-100
4
50-90
2
90-100
No reguirement
No reguirement
Gas engine
10
35-100
Gas turbine
10
20-100
Gas-fired combined cycle (combi plant)
10
20-100% for
gas turbine part
75-100% for
steam turbine
part
Diesel engine
20
20-100
Waste-fired steam power plant
Table 8
Minimum requirement in relation to ramp rate for effective power.
In addition to the ramp rates given in Table 8 the following applies: for any overload
capacity the unit must be capable of regulating with minimum 1%/min. in the overload area.
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System stability
10. System stability
A power plant unit must be equipped with one or more synchronous generators delivering
the generated electricity to the public electricity supply grid possibly via one or more grid
transformers (step-up transformer/engine transformer).
10.1 Generator
The generator(s) of a power station unit must comply with the relevant parts of the
specifications of the European standards EN60034-1, ”Rotating electrical machines – Part 1:
Rating and performance”, 2004, and EN60034-3, ”Rotating electrical machines – Part 3:
Specific requirements for turbine-type synchronous machines”, 1995, but in pursuance of the
following requirements.
The reactances of a power station unit's generator(s) must be as low as possible, taking the
technical and financial consequences hereof into account, with the aim of enhancing the
stability of the public electricity supply grid and reactive power control.
For a power station unit connected to a point of common coupling with nominal voltage up to
100 kV, the power station unit’s generator(s) must have a short-circuit ratio of minimum
0.45.
For a power station unit connected to a point of common coupling with nominal voltage up to
100 kV, the power station unit’s generator(s) must have a transient reactance of less than
0.35 p.u.
For a power station unit connected to a point of common coupling with nominal voltage
above 100 kV, minimum requirements are set in relation to short-circuit ratio and transient
reactance by the TSO on the basis of stability analyses according to section 12.
10.2 Step-up transformer
The connection between a power station unit’s generator and the point of common coupling,
including step-up transformer and generator feeder, must have a reactance that is as low as
possible taking into account the technical and financial consequences involved, with a view to
enhancing the stability of the public electricity supply grid and voltage control.
For a power station unit connected to a point of common coupling with nominal voltage up to
100 kV, the power station unit’s step-up transformer(s) must have a short-circuit impedance
as defined in EN60076-1 of less than ez:
ez= 0.07·Sn0.15 p.u.
where
Sn
:
Rated power for the transformer as defined in EN60076-1,
measured in MVA.
For a power station unit connected to a point of common coupling with nominal voltage
above 100 kV, the TSO sets the maximum allowable magnitude of the set-up transformer's
short-circuit reactance as defined in EN60076-1.
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Reactive power generation and voltage control
11. Reactive power generation and voltage control
11.1 Power factor
In the point of common coupling, a power station unit connected to a point of common
coupling with nominal voltage up to 100 kV must be able to use/produce reactive power with
tanφ within the -0.20 to 0.40 range at nominal maximum power and at voltages in the point
of common coupling within the full-load voltage range.
In the point of common coupling, a power station unit connected to a point of common
coupling with nominal voltage up to 100 kV must be able to use/produce reactive power as
indicated by the hatched area in Figure 5 at nominal maximum power and at voltages in the
point of common coupling within the full-load voltage range.
At voltages in the point of common coupling lying outside the full-load voltage range, the
potential reactive power production of a power station unit connected to a point of common
coupling with a nominal voltage above 100 kV must only be reduced to an extent determined
by the fact that the generator’s and the step-up transformer’s thermal limits are not
exceeded and that the generator remains at a stable operating point.
Voltage
UH F
UN
ULF
-0 .2
Figure 5
0
0 .4
ta nϕ
Tanϕ as a function of the voltage in the point of common coupling for a power station unit connected to a
point of common coupling with a nominal voltage above 100 kV.
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Reactive power generation and voltage control
11.2 Excitation system in general
A power station unit must be equipped with a continuously operating automatic excitation
system that ensures a constant voltage in the point of common coupling and increases the
stability of the public electricity supply grid.
It must be possible, by an external signal, to select the reference voltage (set point) of the
voltage control within the full-load voltage range according to section 5.
For a power station unit connected to a point of common coupling with nominal voltage up to
100 kV, the voltage may be controlled on the basis of the voltage on the generator clamps.
For a power station unit connected to a point of common coupling with nominal voltage
above 100 kV, voltage control must take place on the basis of the voltage on the generator
clamps in the point of common coupling or somewhere in between (voltage measurement
with compounding).
The excitation system must be designed in accordance with the European standard
EN60034-16-1 "Rotating electrical machines – Part 16: Excitation systems for synchronous
machines – Chapter 1: Definitions", 1995, and IEC technical report IEC60034-16-3 "Rotating
electrical machines – Part 16: Excitation systems for synchronous machines – Section 3:
Dynamic performance", 1996, but in accordance with sections 11.3 and 11.4.
11.3 Excitation system during normal operation (small-signal performance)
The excitation system’s time response in the event of momentary 10% voltage variation
must be non-oscillating, have a rise time as defined in EN60034-16-1 of no more than 0.3
seconds for a static excitation system, no more than 0.5 seconds for a rotating exciter if the
voltage variation is positive, and no more than 0.8 seconds for a rotating exciter if the
voltage variation is negative.
Overshoot as defined in EN60034-16-1 must not exceed 15% in the event of a momentary
10% voltage variation.
The excitation system’s open-loop frequency response must not have an amplification of
more than 20 dB in the frequency range 0.2-1.5 Hz.
11.4 Excitation system during grid faults (large-signal performance)
The excitation system’s ceiling voltage as defined in EN60034-16-1 must be at least 160% of
nominal excitation voltage.
The excitation system’s voltage response time as defined in IEEE Std. 421.2-1990 and must
not exceed 0.1 second.
The excitation system’s over-excitation protection and other types of protection must be
designed and set so that the generator’s capacity for temporary overload can be utilised
without superseding the generator’s thermal limits.
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Reactive power generation and voltage control
11.5 Equipment for power system stabilisers
A power station unit with nominal maximum power above 25 MW must be provided with
equipment for dampinging power swings (power system stabiliser, PSS).
It must be possible to connect and disconnect the damping equipment.
The damping equipment must have adjustable limits for the output signal.
The damping equipment must also meet specifications as regards control facilities and actual
settings laid down by the TSO in collaboration with the power station operator.
11.6 Automatic voltage control, etc.
The excitation system of a power station unit connected to a point of common coupling with
a nominal voltage above 100 kV must be operated with automatic voltage control according
to section 11.2 unless otherwise prescribed by the TSO.
Apart from automatic voltage control, the excitation system of a power station unit
connected to a point of common coupling with a nominal voltage up to 100 kV must have the
option of operating with automatic regulation of tanφ in accordance with the following
requirements. The form of operation must be specified by the electric power utility to whose
grid the power station unit is connected.
Automatic control of tanφ must be carried out with a resolution of 0.1 or less.
It must be possible to set the time control by external signals and with a time resolution of
at least 15 minutes over one week (weekly clock with a 15-minute resolution).
Irrespective of the control options, it must be possible to automatically and fully
- control tanφ down to a minimum in accordance with section 11.1 if the voltage is higher
than an adjustable value; and
- control tanφ up to a maximum in accordance with section 11.1 if the voltage is lower than
an adjustable value.
The selection of operational mode between automatic voltage control and automatic tanφ as
well as time control must be possible by remote control via external signals within the set
limits.
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Protection
12. Protection
12.1 General
The power station operator is responsible for ensuring that a power station unit is
dimensioned and protected so that:
-
The power station unit is protected against damage resulting from faults and incidents in
the grid.
The public electricity supply grid is secured to the greatest possible extent against
undesirable impacts from the power station unit.
The power station unit is secured against disconnection in non-critical situations.
The TSO and the electric power utility to whose grid a power station unit is connected may
demand that the setting of the power station unit's relay protection, which is important to
the operation of the public electricity supply grid, be changed after commissioning. Such
change must not expose the power station unit to impacts from the public electricity supply
grid that lie outside the design criteria stated in this regulation.
It is the responsibility of the electric power utility to whose grid the power station unit is
connected to indicate the highest and lowest short-circuit current that can be expected in the
connecting points and provide other information about the public electricity supply grid which
is necessary to determine the protection of the power station unit.
12.2 Protection against external faults
For a power station unit connected to a point of common coupling with a nominal voltage of
10-20 kV, the scope and setting of the relay protection must be established as outlined in
DEFU technical report TF 293, 2nd edition, "Relæbeskyttelse ved decentrale
produktionsanlæg med synkrongenerator" (Relay protection at local production plants with
synchronous generators), June 1995, see however:
-
-
-
-
-
The setting of the positive-sequence undervoltage relay is calculated by the electric power
utility to whose grid the power station unit is connected (using the principles in the DEFU
technical report TF 293, second edition) on the basis of generator data supplied by the
power station operator.
Relay protection aimed at internal faults in the power station unit in excess of what is
mentioned in the DEFU technical report 293, 2nd edition, may be established provided it
does not disconnect the power station unit in case of faults or incidents in the grid and
does not prevent the power station unit from complying with the other provisions of this
regulation.
Relay protection in excess to what is stated in DEFU technical report 293, 2nd edition, and
which may disconnect a power station unit at faults or incidents in the grid must only be
established where special local conditions apply and following approval by the TSO and
the electric power utility to whose grid the power station unit is connected. This relay
protection must not prevent the power station unit from complying with the other
provisions of this regulation.
The vector jump protection and the phase shift protection, which are mentioned in the
DEFU technical report 293, 2nd edition, can no longer be used as they result in additional
false trippings of the power station units.
Appendix 2 describes the required relay protection for synchronous generators, while
Appendix 3 outlines the supplementary relay protection.
For a power station unit connected to a point of common coupling with a nominal voltage
above 20 kV and under 100 kV, including power station units connected to a point of
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Protection
common coupling with a nominal voltage of 30-60 kV, the electric power utility to whose grid
the power station unit is connected indicates whether the provisions in DEFU TR 293, 2nd
edition, are applicable or the provisions for power station units connected to a point of
common coupling with nominal voltage above 100 kV must be followed.
For power station units connected to a point of common coupling with a nominal voltage
above 100 kV, the power station operator is responsible for the implementation of stability
and selectivity investigations in collaboration with the TSO and the electric power utility to
whose grid the power station unit is connected with a view to determining the protection of
the power station unit. The purpose of the investigation is to ensure that the power station
unit complies with section 12.1 and that the protection does not prevent the power station
unit from complying with the other provisions in this regulation. The selected relay settings
which are of relevance to the operation of the public electricity supply grid must be approved
by the TSO and the electric power utility to whose grid the power station unit is connected.
12.3 Protection against internal faults
In case of internal short-circuiting in the generator plant, relay protection must be selective
with the grid protection, ie short-circuiting in the generator must be disconnected within 100
ms.
In addition to the relay protections mentioned in Appendices 2 and 3, relay protection can
be established targeting faults in the production plant, including short-circuits, overspeed,
excitation monitoring, reverse power, etc. Such relays must not disconnect the unit in the
event of short-circuits or under normal grid operations.
Relay protection which is not mentioned in Appendices 2 or 3 and which is able to
disconnect in case of short-circuiting or under normal grid operations must only be used if
the local grid has a special structure rendering it necessary. Such relay protection must only
be established with the permission of the electric power utility, and the relay settings must
be approved by the electric power utility.
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Metering, communication and data exchange
13. Metering, communication and data exchange
With a view to ensuring the operation of the public electricity supply grid, telecommunication
must be set up between the operator responsible for the operation of a power station unit
and the TSO in accordance with the regulations issued by the TSO.
Correct metering, communication and data exchange must be maintained under all
circumstances, including situations with shutdown and outage of the power station unit and
situations with a dead grid.
13.1 Metering
A power station unit must be connected to metering equipment in accordance with the
regulations issued by the TSO.
There are two metering regulations that must be observed:
-
metering regulation for settlement purposes, which describes the requirements for electric
energy metering on the basis of quarter-hourly registration; and
metering regulation for the purposes of system operation, which describes the
requirements for electric energy metering on the basis of online metering.
13.2 Communication
It must be possible to connect and disconnect a power station unit externally, and as a
minimum the unit must be able to exchange status and operating states.
In addition, it must be possible to exchange specific requirements as to external signals from
other sections of this regulation with the power station unit.
13.3 Data exchange
The final data exchange must take place pursuant to IEC 61850-7-420 and must be specified
in collaboration with the electric power utility.
If the implementation of the protocol is impossible at the time of commissioning, the protocol
must be registered at a later date. In the intervening period, the protocol must be agreed
upon in cooperation with the electric power utility.
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Power station unit structure
14. Power station unit structure
14.1 Structure
A power station unit must be designed in such a way that it can operate electrically,
mechanically and in all other aspects as a stand-alone unit independently of other power
station units.
14.2 Earthing
At power station units where the generator is connected without step-up transformer, the
generator star point must be earthed in accordance with the specifications issued by the
electric power utility to whose grid the power station unit is connected.
At power station units where the generator is connected via a step-up transformer, the star
point of the step-up transformer must be earthed in accordance with the specifications
issued by the electric power utility to whose grid the power station unit is connected.
14.3 Electrical equipment
Substation equipment, etc., which is installed by the power station operator in a connecting
point and which is comprised by the grid relay protection must comply with the specifications
issued by the electric power utility.
14.4 Disconnection when work is performed on generator plant
The provisions of Sections 551 and 636 of Title 6 of the Danish Heavy Current Regulation
apply to power station units connected to the low voltage grid.
The provisions of Section 6.4.3 of Title 5 of the Danish Heavy Current Regulation apply to
power station units connected to the high voltage grid
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Operation and maintenance
15. Operation and maintenance
During the operation of a power station unit, the power station operator must comply with
the provisions of relevant operation regulations issued by the TSO and agreements between
the power station operator and the TSO. Where no operating regulations exist, the power
station unit must be operated so that the properties indicated in this regulation, including
properties relating to starting times and ramp rates, are observed during operation.
The maintenance of a power station unit must be carried out continuously so that the power
station unit always complies with this regulation and does not constitute a risk to other
installations in the public electricity supply grid.
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Verification and documentation
16. Verification and documentation
16.1 General
All documentation must be supplied to the electric power utility in electronic form.
The electric power utility reviews the documents and provisionally approves the
documentation described in section 16.2 hereof prior to commissioning. The same is done
with the commissioning report, which is described in section 16.3 hereof, after
commissioning.
The electric power utility submits the overall documentation electronically to the TSO for final
approval.
16.2 Prior to commissioning
The following documentation must be provided prior to the commissioning of a new power
station unit:
-
-
Name and address of power station unit
Name of power station owner
Time of commissioning
GSRN number
Name and location of point of common coupling
Nominal voltage for the point of common coupling
Name of electric power utility
Description of type, fuel and power station unit structure
Single-line representation of power station unit with connecting point(s) with indication of
point of common coupling, measuring points, eg settlement metering, limits of owner and
operational supervisor
Description of supply principle for control voltage
Nominal maximum power
Highest maximum power and the equivalent external operating conditions
Lowest maximum power and the equivalent external operating conditions
Maximum effective power in other operating conditions than normal operating condition
Overload capacity
Maximum heat production
Heat accumulator size
PQ diagram of generator and in point of common coupling
Starting time until synchronisation and starting time until full production
Possibility of dead start
Possibility of island operation
Power station unit's tolerance towards grid faults
Maximum ramp rate of effective power
Generator and transformer data
Excitation system data
Operating system data
Power/frequency controller data
Relay protection setting
The stated documentation must be supplied in a self-contained report in the format
described in Appendix 1 of this regulation.
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Verification and documentation
16.3 During commissioning
During the commissioning of a power station unit, a commissioning test must be conducted
by the power station owner to verify that the power station unit complies with the provisions
of this regulation.
The commissioning test cannot be initiated before the electric power utility has provisionally
approved the supplied documentation outlined in 16.2.
The commissioning test must provide documentation of the following properties in the
connecting point:
-
Stable and continuous operation, see 4.1
Nominal maximum power, see 4.1
Overload capacity, see 4.2
Minimum power, see 4.3
Transition to and return from house-load operation, see 7.1-7.2
Starting time, see 8.2.
Power/frequency control, see 9.1
Power control at major frequency deviations, see 9.2.
Power control at minor frequency deviations, see 9.3
Load control and secondary control, see 9.4
Reactive power generation, see 11.1
Voltage control (step response), see 11.3
Power swing damping equipment (commissioning report for the equipment), see 11.5
Relay protection settings and function verification (secondary testing of operating time
and tripping value), see 12.1
Measurement of terminal voltage at maximum production and during no-load
External signals for communication and data exchange, see 13.2.
The commissioning test must be documented in a self-contained report with recorded data
enclosed to document the properties of the power station unit in accordance with the
regulations issued by the TSO.
Where the power station unit is delivered on a turnkey basis and such power station unit
complete with relay protection can be tested in the course of test procedures performed by
the manufacturer, the settings and verification of the relay protection can be implemented
and documented by the manufacturer, section 16.3, as part of a final factory acceptance
test. When the factory tested turnkey unit is commissioned, the relay protection must, at a
minimum, be inspected visually, and it must be documented that the settings are correct.
The commissioning report must be submitted to the electric power utility for preliminary
approval. The electric power utility subsequently grants a temporary operating permit.
Upon final approval of the documentation by the TSO, the electric power utility grants a final
operating permit.
If the electric power utility cannot approve the overall documentation, the plant owner can
be ordered to stop the power station unit.
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Verification and documentation
16.4 During operation
The power station operator must continuously supervise whether the provisions of this
regulation and the stated properties are complied with by the power station unit, including
nominal maximum power and overload capacity.
If the properties of the power station unit are modified permanently thus affecting the
compliance with the provisions of this regulation, the electric power utility must be notified
hereof immediately. In accordance with Appendix 1, updated documentation must be
enclosed.
If the properties of the power station unit with nominal maximum power above 25 MW are
modified temporarily, for example due to part outage, thus affecting the compliance with the
provisions of this regulation, and if the information in section 16.2, including nominal
maximum power and overload capacity, is changed temporarily, the TSO must be notified
hereof immediately.
16.5 During overhaul
A test with documentation of the following properties must be conducted at intervals of
maximum 30 months and after overhaul of a power station unit:
-
Maximum power, see 4.1
Minimum power, see 4.3
Transition to and return from house-load operation, see 7.1-7.2
Power frequency control, see 9.1
The test must be conducted in accordance with the regulation on system operation
concerning operational planning issued by the TSO.
16.6 Modification of power station units
During the implementation of modifications to an existing power station unit, the aspects of
a commissioning test that may be affected by the modifications must be implemented and
documented again in accordance with section 16.3 hereof.
Prior to the commissioning test, updated documentation regarding the modifications to the
power station unit must be prepared and supplied in accordance with section 16.2 hereof.
The commissioning test cannot be initiated before the electric power utility has provisionally
approved the supplied documentation regarding the modifications, in accordance with 16.2
hereof.
The commissioning report must be submitted to the electric power utility for preliminary
approval. The electric power utility subsequently grants a temporary operating permit.
Upon final approval of the documentation by the TSO, the electric power utility grants a final
operating permit.
If the electric power utility cannot approve the overall documentation, the plant owner can
be ordered to stop the power station unit.
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Verification and documentation
16.7 Request for meter data and documentation
At any given time, the electric power utility and the TSO must be able to request information
about a power station unit in addition to what is specified in sections 16.2 and 16.3 hereof
that may be relevant to system operation.
It must be possible for the TSO to request going three months back in time meter data and
fault registrations collected for the power station unit even if the data is included in the
online metering already made available to the TSO.
At any given time, the electric power utility and the TSO may request verification and
documentation to the effect that a power station unit complies with the provisions of this
regulation. This must be based on metering and/or calculations as specified by the electric
power utility or the TSO.
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Non-compliance
17. Non-compliance
Unless otherwise expressly stated, it is the responsibility of the power station operator to
ensure that the provisions of this regulation are complied with.
Unless otherwise expressly stated, expenses related to ensuring compliance with the
provisions of this regulation are the responsibility of the power station operator.
If a power station unit does not comply with the provisions of this regulation, the electric
power utility is entitled to cut off the electrical connection to the power station unit.
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Exemptions and unforeseen circumstances
18. Exemptions and unforeseen circumstances
The TSO may grant exemption from specific requirements in this regulation.
In order for an exemption to be granted:
-
It must be a matter of particular conditions, eg of local character
The deviation must not cause appreciable deterioration of the technical quality and
balance of the public electricity supply grid
The deviation must not be inappropriate from a socioeconomic viewpoint.
Exemption is granted by virtue of a written application to the electric power utility indicating
which provision the exemption concerns and the reason for the exemption. The electric
power utility has the right to comment on the application before it is submitted to the TSO.
In the event of circumstances not foreseen in this technical regulation occurring, the TSO
must consult the parties involved with the purpose of deciding what to do. If an agreement
cannot be reached, the TSO must decide what to do. The decision is made from what is
equitable and where possible taking the views of the parties involved into consideration. The
decisions of the TSO can be lodged with the Danish Energy Regulatory Authority.
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Documentation
Appendix 1: Documentation
The appendix comprises the documentation which a power station unit must supply to the
TSO.
Table of contents for Appendix 1
B1.1.1.
B1.1.2.
B1.1.3.
B1.1.4.
B1.1.5.
B1.1.6.
B1.1.7.
B1.1.8.
B1.1.9.
B1.1.10.
B1.1.11.
B1.1.12.
B1.1.13.
B1.1.14.
B1.1.15.
B1.1.16.
B1.1.17.
B1.1.18.
B1.1.19.
B1.1.20.
B1.2.1.
B1.2.2.
B1.2.3.
B1.2.4.
B1.2.5.
B1.2.6.
B1.2.7.
B1.2.8.
Identification..........................................................................47
Point of common coupling ........................................................47
Other connecting points ...........................................................47
Description of power station unit ...............................................48
Maximum power and normal operating condition .........................48
Minimum power ......................................................................49
Overload capacity ...................................................................49
Maximum power in other operating conditions.............................50
Heat production ......................................................................50
Start .....................................................................................50
Island operation .....................................................................51
Tolerance towards voltage deviations.........................................51
Tolerance towards grid faults....................................................52
Ramp rate .............................................................................52
Generator ..............................................................................53
Step-up transformer................................................................55
Excitation system....................................................................56
Power/frequency controller.......................................................56
Operating system ...................................................................57
Relay protection .....................................................................58
Power station unit flow chart ....................................................63
Single-line representation with indication of settlement
metering and operational supervisor limit ...................................63
PQ diagram for generator.........................................................63
No-load and short-circuit characteristic for the generator..............63
Generator datasheet ...............................................................63
Block diagrams and parameter values for voltage regulator,
tanφ-regulator, power system stabiliser, under-excitation
limiters and over-excitation limiters...........................................63
Block diagrams and parameter values for power/frequency ...............
controller
..........65
Block diagrams and parameter values for operating system ..........65
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Documentation
B1.1. Appendices
The appendix comes in the shape of a form covering the main part of the expected
documentation for a power station unit. The form must be filled in electronically, and
associated appendices from various suppliers must be attached as self-containing
documents.
Only tables relevant to the individual power station unit must be filled in. If, for example,
there is no step-up transformer, the table need not be filled in and can be deleted from the
appendix. Accordingly, only the tables for relay protection relevant to the individual power
station units must be filled in.
All documentation must be stated as commissioning data applying to the power station unit
at the time of commissioning. If information is changed after commissioning, updated
documentation must be forward.
The revision view in the appendix must be updated each time new information about the
power station unit is submitted. The text must clearly indicate the status of the appendix
(preliminary/version, commissioning/version, final/version). If several versions with the
same text are required, version numbers must be used.
Revision view
Appendix 1
Text
Document no. 43436-08_v5.1
Version
Date
46/85
Documentation
B1.1.1.
Identification
No.
Description
A.1
Name of power station unit
A.2
Address of power station unit
A.3
Name of power station owner
A.4
A.5
A.99
B1.1.2.
No.
B.1
B.2
B.3
B.4
B.5
B.6
B.99
Value
Time of commissioning (yyyymm-dd)
GSRN number (all numbers for
facilities/plants must be
provided)
Comments
Point of common coupling
Description
Value
Name of point of common
coupling
Location of point of common
coupling
Nominal voltage (kV) of point of
common coupling in kV
Name of electric power utility
Name of nearest 30-60 kV
substation*
Name of nearest 132-150 kV
substation
Comments
*Can be stated by the electric power utility to whose grid the power station unit is
connected.
B1.1.3.
No.
C.1
C.2
C.99
Other connecting points
Description
Are there other connecting points
than the point of common
coupling?
Description of other connecting
points including voltage
Value
Yes
No
Comments
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Documentation
B1.1.4.
Description of power station unit
No.
Description
D.1
Type
D.2
Specification of combustible
D.3
D.4
D.99
Value
Steam turbine
Gas turbine
Combi plant
Gas engine
Diesel engine
Other
Description of process and
structure of power station unit
Description of supply principle for
control voltage
Comments*
*Specify type of plant, if “Other” was chosen in D.1.
The following appendices must be attached:
-
B1.2.1 Power station unit process diagram
B1.2.2 Single-line representation with indication of settlement metering and operational
supervisor limit.
B1.1.5.
Maximum power and normal operating condition
No.
Description
Symbol
Unit
E.1
Nominal maximum power
Pn
MW
E.2
Is there simultaneous heat
generation in normal operating
condition?
-
-
E.3
Highest maximum power
Pn,max
MW
E.4
Lowest maximum power
Pn,min
MW
Tout, n
°C
Tout,max
°C
Tout,min
°C
Pn
hPa
Pmax
hPa
Pmin
hPa
E.5.1
E.5.2
E.5.3
E.6.1
E.6.2
E.6.3
Outdoor temperature at nominal
maximum power*
Outdoor temperature at highest
maximum power*
Outdoor temperature at lowest
maximum power*
Air pressure at nominal
maximum power*
Air pressure at highest maximum
power*
Air pressure at lowest maximum
power*
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Yes
No
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Documentation
Relative air humidity at nominal
maximum power*
Relative air humidity at highest
E.7.2
maximum power*
Relative air humidity at lowest
E.7.3
maximum power*
Cooling water temperature at
E.8.1
inlet at nominal maximum
power*
Cooling water temperature at
E.8.2
inlet at highest maximum
power*
Cooling water temperature at
E.8.3
inlet at lowest maximum power*
* See provisions in section 4
E.7.1
No.
E.7
E.8
E.9
E.10
E.99
B1.1.6.
Description
%
RHmin
%
Tcw, n
°C
Tcw, max
°C
Tcw, min
°C
Value
Minimum power
F.1
Nominal minimum power
Symbol
Unit
Pmin
MW
Symbol
Unit
Value
Comments
Overload capacity
No.
Description
G.1
Is there any overload capacity?
G.2
Overload capacity (apart from
nominal maximum power)
G.99
RHmax
Comments
Description
B1.1.7.
%
Description of normal operating
condition
Any other external operating
conditions at nominal maximum
power
Any other external operating
conditions at highest maximum
power
Any other external operating
conditions at lowest maximum
power
No.
F.99
RHn
Value
Yes
No
Poverload
MW
Comments
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Documentation
B1.1.8.
Maximum power in other operating conditions
Descriptions of any other operating conditions than normal operating condition which may
occur during continuous operation must be given here.
No.
H.1
H.2
H.3
H.4
H.5
H.6
H.99
B1.1.9.
Description
Description of operating condition
1
Maximum effective power in
operating condition 1 in MW
Description of operating condition
2
Maximum effective power in
operating condition 2 in MW
Description of operating condition
3
Maximum effective power in
operating condition 3 in MW
Comments
Heat production
No.
Description
I.1
Maximum heat production
I.2
Volume of heat accumulation
tank
I.99
Value
Symbol
Unit
Wheat
MJ/s
Eacc
MJ
Value
Comments
B1.1.10. Start
No.
K.1
K.2
K.3
K.4
K.5
K.6
K.7
K.99
Description
Starting time until synchronisation from
order immediately after disconnection
Starting time until full generation from
order immediately after disconnection
Starting time until synchronisation from
order at 8 hours since last disconnection
Starting time until full production from
order at 8 hours after last disconnection
Starting time until synchronisation from
order to connection at cold start
Starting time from order to maximum
power at cold start
Possibility of starting from no-voltage
grid (black start)
Symbol
Unit
Tin0
min.
Tfull0
min.
Tin,cold
min.
Tfull,cold
min.
-
-
Value
Yes
No
Comments
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Documentation
B1.1.11. Island operation
No.
L.1
L.2
L.99
Description
Value
Can the unit change to and be
operated in house-load operation
Can the unit change to and be
operated in isolated island operation
Yes
No
Yes
No
Comments
B1.1.12. Tolerance towards voltage deviations
No.
Description
Symbol
Unit
M.1
Lower limit for full-load voltage range
ULF
kV
M.2
Upper limit for full-load voltage range
UHF
kV
M.3
Maximum operating voltage
UH
kV
M.4
Minimum operating voltage
UL
kV
M.5
Is the time with minimum operating
voltage limited?
-
-
M.6
If yes, how much time is allowed?
TL
Min
PL, reduc
MW
-
-
TH
Min
PH,reduc
MW
M.7
M.8
M.9
Reduction of nominal maximum power at
minimum operating voltage
Is the time with maximum operating
voltage limited?
If yes, how much time is allowed?
M.10
Reduction of nominal maximum power at
maximum operating voltage
M.11
Extra high voltage
UEH
kV
M.12
Extra low voltage
UEL
kV
M.13
Is the time with extra low voltage
limited?
-
-
M.14
If yes, how much time is allowed?
TEL
Min
PEL,reduc
MW
-
-
TEH
Min
PH,reduc
MW
M.15
M.16
Reduction of nominal maximum power at
extra low voltage
Is the time with extra high voltage
limited?
M.17
If yes, how much time is allowed?
M.18
Reduction of nominal maximum power at
extra high voltage
M.99
Comments
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Value
Yes
No
Yes
No
Yes
No
Yes
No
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Documentation
B1.1.13. Tolerance towards grid faults
No.
Description
N.1
Can power station unit remain
synchronised during voltage
disturbances
N.2
Documentation that generator
can resist voltage disturbances
without disconnecting (dynamic
stability analysis or declaration
from supplier)
N.3
Documentation that auxiliary
supply plant can withstand
voltage disturbances (calculations
or design philosophy)
N.99
Value
Yes
No
Comments
B1.1.14. Ramp rate
This section indicates the power station unit’s ramp rate divided into different power ranges
according to section 9. Divide into necessary number of power ranges.
Power range 1:
No.
Description
Symbol
Unit
O.1.1
Lower limit of power range 1
PL1
% of Pn
O.1.2
Upper limit of power range 1
PU1
% of Pn
O.1.3
Maximum ramp rate for effective
power in power range 1
(ΔP/Δt)1
%/min
Symbol
Unit
Value
Power range 2:
No.
Description
O.2.1
Lower limit of power range 2
PL2
% of Pn
O.2.2
Upper limit of power range 2
PU2
% of Pn
O.2.3
Maximum ramp rate for effective
power in power range 2
(ΔP/Δt)2
%/min
Symbol
Unit
Value
Power range 3:
No.
Description
O.3.1
Lower limit of power range 3
PL3
% of Pn
O.3.2
Upper limit of power range 3
PU3
% of Pn
O.3.3
Maximum ramp rate for effective
power in power range 3
(ΔP/Δt)3
%/min
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Value
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Documentation
Power range 4:
No.
Description
Symbol
Unit
Value
O.4.1
Lower limit of power range 4
PL4
% of Pn
O.4.2
Upper limit of power range 4
PU4
% of Pn
O.4.3
Maximum ramp rate for effective
power in power range 4
(ΔP/Δt)4
%/min
Symbol
Unit
Power range 5:
No.
Description
Value
O.5.1
Lower limit of power range 5
PL5
% of Pn
O.5.2
Upper limit of power range 5
PU5
% of Pn
O.5.3
Maximum ramp rate for effective
power in power range 5
(ΔP/Δt)5
%/min
General:
No.
Description
O.6
Maximum ramp rate for overload
O.99
Symbol
Unit
(ΔP/Δt)overload
%
Comments
Value
-
B1.1.15. Generator
No.
Description
Q.1
Identification
Q.2
Type
Q.3
Power station owner
Q.99
Comments
No.
Description
Q.4
Value
Symbol
Unit
Nominal apparent power (1 p.u.)
Sn
MVA
Q.5
Nominal voltage (1 p.u.)
Un
kV
Q.6
Nominal frequency
fn
Hz
Q.7
Nominal power factor (cosφ)
cosφn
-
Qmin,n
Mvar
Qmax,n
Mvar
Q.8
Q.9
Nominal minimum reactive power
generation from PQ diagram
Nominal maximum reactive power
generation from PQ diagram
Q.10
Synchronous speed
nn
Rpm
Q.11
Total moment of inertia for rotating
mass (generator, operating system,
etc.)
Jtot
kg⋅m2
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Value
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Documentation
Q.11.1
Moment of inertia for generator
JG
kg⋅m2
Q.11.2
Moment of inertia for operating
system
JD
kg⋅m2
Q.12
Rotor type
-
-
Q.13
Stator resistance per phase
Ra
p.u.
Reference temperature for stator
TR
°C
Q.14
Stator spreading reactance per
phase
Xad
p.u.
Q.15
Positive-sequence reactance, d-axis
Xd
p.u.
Q.16
Transient reactance, d-axis
X’d
p.u.
Q.17
Subtransient reactance, d-axis
X’’d
p.u.
Xd,sat
p.u.
X”d,sat
p.u.
Q.13.1
Q.18
Q.19
Saturated positive-sequence
reactance, d-axis
Saturated subtransient positivesequence reactance, d-axis
Q.20
Positive-sequence reactance, q-axis
Xq
p.u.
Q.21
Transient reactance, q-axis
X’q
p.u.
Q.22
Subtransient reactance, q-axis
X’’q
p.u.
T’d0
s
T’’d0
s
T’q0
s
T’’q0
s
Xp
p.u.
SG1.0
p.u.
SG1.2
p.u.
Q.23
Q.24
Q.25
Q.26
Q.27
Q.28
Q.29
Transient open circuit time
constant, d-axis
Subtransient open circuit time
constant, d-axis
Transient open circuit time
constant, q-axis
Subtransient open circuit time
constant, q-axis
Potier reactance
Saturation point at 1.0 p.u.
voltage, see figure below
Saturation point at 1.2 p.u.
voltage, see figure below
Q.30
Reactance, inverse-component
X2
p.u.
Q.31
Resistance, inverse-component
R2
p.u.
Q.32
Reactance, zero-component
X0
p.u.
Q.33
Resistance, zero-component
R0
p.u.
-
-
Q.34.1
Is the generator star point earthed?
Q.34.2
If yes, ground reactance
Xe
Ohm
Q.34.3
If yes, earth resistance
Re
Ohm
Distinct poles
Round rotor
Yes
No
Generator short-circuit ratio
Kc
p.u.
(nominal)
P.u. values must be stated on the basis of nominal apparent power and nominal voltage.
Q.35.0
If there is more than one generator, more tables must be filled in.
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Documentation
U (p.u.)
I (p.u.)
SG1,0 =
U 1,2
I f 1,0 / I f 0 − U1, 0
1, 0
U 1,0
I 1,0
SG1,2 =
KC =
If0
Figure 6
If1,0
If1,2
IfK
I f 1,2 / I f 0 − U1, 2
1, 2
I f 1,0
I fK
If (p.u.)
Definition of generator saturation points SG1.0 and SG1.2 as well as short-circuit ratio on the basis of noload characteristics.
The following appendices must be enclosed:
-
B1.2.3 PQ diagram for generator
B1.2.4 No-load and short-circuit characteristic for the generator
B1.2.5 Generator datasheet
B1.1.16. Step-up transformer
No.
Description
R.1
Identification
R.2
Type
R.3
Power station owner
R.99
Comments
No.
Description
R.4
Value
Symbol
Unit
Nominal apparent power (1 p.u.)
Sn
MVA
R.5
Nominal primary voltage (1 p.u.)
Up
kV
R.6
Nominal secondary voltage
Us
kV
R.7
Coupling designation , eg Dyn11
-
-
R.8
Step switch location
-
-
dutp
%/step
phitp
degree/ste
p
R.9
R.10
Step switch, additional voltage
per step
Step switch, phase angle of
additional voltage per step
R.11
Step switch, lowest position
ntpmin
-
R.12
Step switch, highest position
ntpmax
-
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Value
Primary side
Secondary side
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Documentation
R.13
Step switch, neutral position
R.14
R.15
R.16
R.17
ntp0
-
Short-circuit voltage,
synchronous
uk
%
Copper loss
-
kW
uk0
%
ukr0
%
Short-circuit voltage, zero
system
Resistive short-circuit voltage,
zero-sequence system
R.18
No-load current
I0
%
R.19
No-load loss
P0
%
R.20
Short-circuit impedance
ez
p.u.
If there is more than one transformer, more tables must be filled in.
B1.1.17. Excitation system
No.
Description
S.1
Identification
S.2
Type
S.3
Power station owner
S.4
Does the excitation system have equipment
for the damping of power swings (PSS)
S.99
Value
Yes
No
Comments
The following appendices must be attached:
-
B1.2.6 Block diagrams and parameter values for voltage regulator, tanφ-regulator, power
system stabiliser, under-excitation limiters and over-excitation limiters
B1.1.18. Power/frequency controller
For power station units to be connected in Western Denmark (meet UCTE requirements), the
following table must be filled in for items U1-U7.
Items U.1-U.3 must be filled in for all power station units, whereas items U.4-U.9 need only
be filled in for power station units > 25 MW.
No.
U.1
U.2
U.3
U.4
Description
Dead band for critical power
frequency control
Minimum adjustable droop for
critical power frequency control
Maximum adjustable droop for
critical power frequency control
Dead band for power frequency control
in case of frequency rise
Document no. 43436-08_v5.1
Symbol
Unit
fband
mHz
δmin
%
δman
%
fband
mHz
Value
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Documentation
U.5
U.6
U.7
U.8
U.9
U.99
Dead band for power frequency control
in case of frequency drop
Regulation band for power frequency
control in case of frequency rise
Regulation band for power frequency
control in case of frequency drop
Load change for power frequency
control in case of frequency rise
Load change for power frequency
control in case of frequency drop
fband
mHz
fband
mHz
fband
mHz
∆P
MW
∆P
MW
Comments
For power station units to be connected in Eastern Denmark (meet Nordel requirements), the
following table must be filled for items U.10-U.15.
Items U.10-U.14 must be filled in all power station units, whereas items U.15-U.18 need only
be filled in for power station units >25 MW.
No.
U.10
U.11
U.12
Description
Dead band for frequency-controlled disturbance
reserves in case of frequence drop
Regulation band for frequency-controlled
disturbance reserves in case of frequence drop
Load change for frequency-controlled
disturbance reserves in case of frequence drop
Symbol
Unit
fband
mHz
fband
mHz
∆P
MV
U.13
Dead band in case of frequency rise
fband
mHz
U.14
Selection of droop in case of frequency rise
δmin
%
fband
mHz
fband
mHz
∆P
MW
∆P
MW
U.15
U.16
U.17
U.18
U.99
Dead band for frequency-controlled spinning
reserves in case of frequency rise
Dead band for frequency-controlled spinning
reserves in case of frequency rise
Load change for frequency-controlled spinning
reserves in case of frequency rise
Load change for frequency-controlled spinning
reserves in case of frequency drop
Value
Comments
The following appendices must be attached:
-
B1.2.7 Block diagrams and parameter values for the power/frequency controller
B1.1.19. Operating system
No.
Description
T.1
Nominal mechanical shaft power
for operating system
T.99
Symbol
Unit
Pmech,n
MW
Value
Comments
The following appendices must be attached:
-
B1.2.8 Block diagrams and parameter values for operating system
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Documentation
B1.1.20. Relay protection
Overvoltage relay (mandatory):
No.
Description
V 1.0
Identification
Type
V.1.1
Is there an overvoltage relay
(U>> and U>)?
V.1.2
V.1.3
V.1.4
V.1.5
V.1.9
If yes, setting 1 of overvoltage
relay (voltage)
If yes, setting 1 of overvoltage
relay (protection operating time)
If yes, setting 2 of overvoltage
relay (voltage)
If yes, setting 2 of overvoltage
relay (protection operating time)
Recommended
value
Current
value
Symbol
Unit
-
-
U>
kV
UTYP x 1.06
T>
s
30 - 60
U>>
kV
UTYP x 1.10
T>>
ms
< 50
Symbol
Unit
Recommended
value
-
-
U<
kV
UTYP x 0.90
T<
s
2 - 10
Symbol
Unit
Recommended
value
-
-
U1<
kV
To be calculated
T1<
ms
≤ 50
Yes
No
Comments
Undervoltage relay (mandatory):
No.
Description
V 2.0
Identification
Type
V.2.1
Is there an undervoltage relay
(U<)?
V.2.2
V.2.3
V.2.9
If yes, setting of undervoltage
relay (voltage)
If yes, setting of undervoltage
relay (protection operating time)
Current
value
Yes
No
Comments
Positive-sequence undervoltage relay (mandatory):
No.
V 3.0
V.3.1
V.3.2
V.3.3
V.3.9
Description
Identification
Type
Is there an positive-sequence
undervoltage relay (U1<)?
If yes, setting of positivesequence undervoltage relay
(voltage)
If yes, setting of positivesequence undervoltage relay
(protection operating time)
Current
value
Yes
No
Comments
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Documentation
10 kV zero-sequence voltage relay (supplementary):
No.
V 4.0
V.4.1
V.4.2
V.4.3
V.4.9
Description
Identification
Type
Is there a zero-sequence voltage
relay (U0)?
If yes, setting of zero-sequence
voltage relay (voltage)
If yes, setting of zero-sequence
voltage relay (protection
operating time)
Recommended
value
Symbol
Unit
-
-
U0
kV
20%
T0
s
60
Symbol
Unit
Recommended
value
-
-
f>
Hz
53.0
T>
ms
300
Current
value
Yes
No
Comments
Overfrequency relay (mandatory):
No.
V 5.0
V.5.1
V.5.2
V.5.3
V.5.9
Description
Identification
Type
Is there an overfrequency relay
(f>)?
If yes, setting of overfrequency
relay (frequency)
If yes, setting of overfrequency
relay (protection operating time)
Current
value
Yes
No
Comments
Underfrequency relay (mandatory stage 1/Supplementary stage 2):
No.
V 6.0
V.6.1
V.6.2
V.6.3
V.6.4
V.6.5
V.6.9
Description
Identification
Type
Is there an underfrequency relay
(f<)?
If yes, setting 1 of
underfrequency relay (frequency)
If yes, setting 1 of frequency
relay (protection operating time)
If yes, setting 2 of
underfrequency relay (frequency)
If yes, setting 2 of
underfrequency relay (protection
operating time)
Recommended
value
Symbol
Unit
-
-
f<1
Hz
47.0
T<1
ms
300
f<2
Hz
≤ 47.5
T<2
s
≥ 10
Current
value
Yes
No
Comments
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Documentation
Frequency gradient relay (supplementary):
No.
V 7.0
V.7.1
V.7.2
V.7.3
V.7.4
V.7.5
V.7.9
Description
Identification
Type
Is there a frequency gradient relay
(df/dt)?
If yes, setting 1 of frequency gradient
relay
If yes, setting 1 of frequency gradient
relay (protection operating time)
If yes, setting 2 of frequency gradient
relay
If yes, setting 2 of frequency gradient
relay (protection operating time)
Recommended
value
Symbol
Unit
-
-
(df/dt)1
Hz/s
≥ +2.5
T1
ms
80 - 100
(df/dt)2
Hz/s
≤ -2.5
T2
ms
80 - 100
Symbol
Unit
Recommended
value
-
-
U0>
kV
10 - 15%
T0>
s
1-5
Current
value
Yes
No
Comments
Earth fault when grid is isolated (supplementary):
No.
Description
V 8.0
Identification
Type
V.8.1
Is earth fault protection in place (U0>)?
V.8.2
V.8.3
V.8.9
If yes, setting of overfrequency relay
(frequency)
If yes, setting of overfrequency relay
(protection operating time)
Current
value
Yes
No
Comments
Overcurrent relay (short-circuit stage 1 mandatory/the rest is supplementary):
No.
V 9.0
V.9.1
V.9.2
V.9.3
V.9.4
V.9.5
V.9.6
V.9.7
V.9.8
V.9.9
Description
Identification
Type
Is there an overcurrent relay (I> and
I>>)?
If yes, setting 1 of overcurrent relay
(current)
If yes, setting 1 of overcurrent relay
(protection operating time)
If yes, setting 2 of overcurrent relay
(current)
If yes, setting 2 of overcurrent relay
(protection operating time)
If yes, setting 3 of overcurrent relay
(current)
If yes, setting 3 of overcurrent relay
(protection operating time)
Relay characteristic (eg in accordance
with IEC 60255)
Recommended
value
Symbol
Unit
-
-
I>
A
≥ 1.2 x IN
T>
ms
800
I>>1
A
T>>1
ms
t>>(1) ≤ 50
I>>2
A
≥ 0.8 x I>>1
T>>2
ms
t>>(2) ≥ 200
Yes
No
≥
UN / 3
"
X d + X k,G
Comments
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Current
value
Documentation
Inverse current relay (supplementary):
No.
V 10.0
V.10.1
V.10.2
V.10.3
V.10.9
Description
Identification
Type
Is there an inverse current
protection relay (I2>)?
If yes, setting of inverse current
protection relay (current)
If yes, setting of inverse current
relay (protection operating time)
Recommended
value
Symbol
Unit
-
-
I2>
A
5 - 20%
T2>
s
3 - 10
Symbol
Unit
Recommended
value
-
-
-
A
-
ms
Current
value
Yes
No
Comments
Excitation current relay (supplementary):
No.
V 11.0
V.11.1
V.11.2
V.11.3
V.11.9
Description
Identification
Type
Is there an excitation current
relay?
If yes, setting of excitation
(current)
If yes, setting of excitation
(protection operating time)
Current
value
Yes
No
Comments
Stator differential protection relay (supplementary):
No.
V 12.0
V.12.1
V.12.2
V.12.3
V.12.9
Description
Identification
Type
Is there a stator differential
protection relay?
If yes, setting of stator
differential (current)
If yes, setting of stator
differential (protection operating
time)
Recommended
value
Symbol
Unit
-
-
-
A
2 - 20% of IN
-
ms
< 50
Current
value
Yes
No
Comments
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Documentation
Overspeed relay (supplementary):
No.
Description
V 13.0
Identification
Type
V.13.1
Is there an overspeed relay?
V.13.2
If yes, setting of overspeed relay
(percentage of overspeed)
V.13.9
Comments
Recommended
value
Symbol
Unit
-
-
n>
%
approx. 10
Symbol
Unit
Recommended
value
-
-
U2>
V
I2 x X2
T2>
s
3 - 10
Symbol
Unit
Recommended
value
-
-
Current
value
Yes
No
Inverse voltage relay (supplementary):
No.
V 14.0
V.14.1
V.14.2
V.14.3
V.14.9
Description
Identification
Type
Is there an inverse voltage relay
(U2>)?
If yes, setting of the inverse
voltage
If yes, setting of the inverse
voltage (protection operating
time)
Current
value
Yes
No
Comments
Reverse power protection relay (supplementary):
No.
V 15.0
V.15.1
Description
Identification
Type
Is there a reverse power
protection relay?
Current
value
Yes
No
V.15.2
If yes, setting of reverse power
Pretur
W
1 - 2%
V.15.3
If yes, setting of reverse power
(protection operating time)
Tretur
s
3 - 30
V.15.9
Comments
Other relays (supplementary):
No.
V.16.0
V.16.1
V.16.9
Description
Value
Identification
Type
Description of other relays, incl.
settings
Comments
Document no. 43436-08_v5.1
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Documentation
B1.2.
Supplementary appendices
B1.2.1.
Power station unit process diagram
This Appendix includes the power station unit process diagram and any comments.
B1.2.2. Single-line representation with indication of settlement metering
and operational supervisor limit
This Appendix includes a figure with a single-line representation of the power station unit’s
connecting point(s) with indication of the point of common coupling, measuring points,
including settlement metering, limits of owner and operational supervisor limits/limits of
liability.
B1.2.3.
PQ diagram for generator
This Appendix includes a PQ diagram of the power station unit's generators.
In the diagram, the nominal voltage and nominal generator frequency are shown. An
example of the PQ diagram (capability diagram) can be seen in EN60034-3-3, Figure 2.
B1.2.4.
No-load and short-circuit characteristic for the generator
In this Appendix, the no-load and short-circuit characteristic for the power station unit's
generator(s) are included.
B1.2.5.
Generator datasheet
This Appendix includes the datasheet(s) for the power station unit's generator(s).
B1.2.6. Block diagrams and parameter values for voltage regulator,
tanφ-regulator, power system stabiliser, under-excitation limiters and
over-excitation limiters
Voltage regulator
This section includes block diagrams and parameter values for voltage regulator and tanφ
regulator with regard to representation in a software program for dynamic modelling.
The block diagram must be illustrated by symbolic notation, and incoming parameter values
must be stated in a table. The model must use nomenclature (symbols, units, etc.) to the
extent outlined in the references below.
If several modes of operation cause various block diagrams and time constants etc. the block
diagrams must be enclosed for each mode of operation.
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Documentation
References:
-
"IEEE Recommended Practice for Excitation System Models for Power System Stability
Studies", IEEE Std. 421.5-2005, 2005.
"Computer Models for Representation of Digital-Based Excitation Systems", IEEE
Transactions on Energy Conversion, Vol. 11, No. 3, September 1996.
Crenshaw, M.L. et al., "Excitation System Models for Power System Stability Studies",
IEEE Transactions on Power Apparatus and Systems, PAS-100 (2), 1981, p. 494-509.
Power system stabiliser (PSS)
This section includes a block diagram and parameter values for power system stabilisers with
regard to representation in a software program for dynamic modelling. The model must
describe the voltage regulator as well as possible.
The block diagram must be illustrated by symbolic notation, and incoming parameter values
must be stated in a table. The model must use nomenclature (symbols, units, etc.) to the
extent outlined in the references below.
References:
-
"IEEE Recommended Practice for Excitation System Models for Power System Stability
Studies", IEEE Std. 421.5-2005, 2005.
"Computer Models for Representation of Digital-Based Excitation Systems", IEEE
Transactions on Energy Conversion, Vol. 11, No. 3, September 1996.
Crenshaw, M.L. et al., "Excitation System Models for Power System Stability Studies",
IEEE Transactions on Power Apparatus and Systems, PAS-100 (2), 1981, p. 494-509.
Under-excitation limiters and over-excitation limiters
This section includes a block diagram and parameter values for under-excitation limiters and
over-excitation limiters with regard to representation in a software program for dynamic
modelling.
The block diagram must be illustrated by symbolic notation, and incoming parameter values
must be stated in a table. The model must use nomenclature (symbols, units, etc.) to the
extent outlined in the references below.
References:
-
"IEEE Recommended Practice for Excitation System Models for Power System Stability
Studies", IEEE Std. 421.5-2005, 2005.
"Computer Models for Representation of Digital-Based Excitation Systems", IEEE
Transactions on Energy Conversion, Vol. 11, No. 3, September 1996.
Crenshaw, M.L. et al., "Excitation System Models for Power System Stability Studies",
IEEE Transactions on Power Apparatus and Systems, PAS-100 (2), 1981, p. 494-509.
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Documentation
B1.2.7. Block diagrams and parameter values for power/frequency
controller
This section includes block diagrams and parameter values for the power/frequency
controller with regard to representation in a software program for dynamic modelling.
The block diagram must be illustrated by symbolic notation, and incoming parameter values
must be stated in a table. The model must use nomenclature (symbols, units, etc.) to the
extent outlined in the references below.
If several modes of operation cause various block diagrams and time constants etc. block
diagrams must be enclosed for each mode of operation.
References:
-
"Dynamic Models for Fossil Fuelled Steam Units in Power System Studies", IEEE
Transactions on Power Systems, VOL. 6, No. 2, May 1991, p. 753-61.
"Dynamic Models for Steam and Hydro Turbines in Power System Studies", IEEE
Transactions on Power Apparatus and Systems, PAS-92 (6), 1973, p. 1904-15.
B1.2.8.
Block diagrams and parameter values for operating system
This section includes block diagrams and parameter values for the operating system with
regard to representation in a software program for dynamic modelling. The model must
describe the operating system as well as possible.
The block diagram must be illustrated by symbolic notation, and incoming parameter values
must be stated in a table. The model must use nomenclature (symbols, units, etc.) to the
extent outlined in the references below.
If several modes of operation cause various block diagrams and time constants etc. block
diagrams must be enclosed for each mode of operation.
References:
- "Dynamic Models for
Transactions on Power
- "Dynamic Models for
Transactions on Power
Document no. 43436-08_v5.1
Steam and Hydro Turbines in Power System Studies", IEEE
Apparatus and Systems, PAS-92 (6), 1973, p. 1904-15.
Fossil Fuelled Steam Units in Power System Studies", IEEE
Systems, Vol. 6, No. 2, May 1991, p. 753-61.
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Appendix 2: Required relay protection at plants with synchronous generator
Appendix 2: Required relay protection at plants with
synchronous generator
Out of consideration for the grid, the following relay protection functions must be
established with the settings stated:
Relay type
Symbol
Setting
Operating
time
Desired purpose of protection
To safeguard against the
maintaining of electric arc in
connection with grid faults,
asynchronous connection to grid
by reclosing following grid faults
and loss of synchronism
Note
Undervoltage
(synchronous
component)
U1<
approx. 70%
≤ 50 ms
Overvoltage
(3-phase)
U>>
U>
230 V+10%
230 V+6%
< 50 ms
30-60 s
Undervoltage
(3-phase)
U<
230 V-10 %
2-10 s
Overfrequency
f>
53.0 Hz
300 ms
-
Underfrequency
f<
47.0 Hz
300 ms
-
Overcurrent(1) or
I>>(1)
0.4 kV
fuse
-
≥
UN / 3
"
X d + X k,G
≥ IN
2, 3
To protect consumers against
unacceptable impacts
t>>(1)≤ 50 ms
If the reserve protection trips;
opening during internal fauls and
lost synchronism
DIN type
gL or gI
Alternative to the overcurrent
protection mentioned above
Protection operating time is the time in which the trip condition constantly must
be met before the relay can send out a trip signal. It is thus not a question of the
trip signal being subjected to a simple time lag.
Note 1:
Note 2:
Note 3:
Note 4:
The setting depends on the local generator and grid data;
70% is only a typical value. The actual setting is determined by the
electric power utility.
The values apply to the 0.4 kV grid. The actual setting for the 10-20
kV grid must be calculated on the basis of the ratio of
transformation for voltage transformers at the production plant and
for step-up transformers in the vicinity of the plant.
Phase-to-ground voltages must be measured for plants connected to
the 0.4 kV supply grid. For plants connected to the 10 kV grid,
phase-to-phase voltages must be measured.
UN and Xd" are the rated generator voltage (phase-to-phase value in
V) and the subtransient reactance (phase value in Ω). Xk,G is the
grid’s short-circuit impedance on the generator terminals in Ω per
phase. IN is the rated generator current.
Relay settings deviating from the stated settings can only be used if they have
been approved by the electric power utility.
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2, 3
4
-
Appendix 3: Supplementary relay protection at plants with synchronous generator
Appendix 3: Supplementary relay protection at plants
with synchronous generator
As supplementary protection to ensure the generation during grid faults the
following relay protection with the stated settings may be established:
Operating
Relay type
Symbol
Setting
Stator differential
protection
-
2-20% of IN
< 50 ms
Opening at inner generator faults
-
Change of
frequency
df/dt
≥ +2.5 Hz/s
≤ -2.5 Hz/s
80-100 ms
Protection against asynchkronous
grid connection
1, 2
I>
≥ 1.2 * IN
t>≥ 0.8 s
I>>(1)
U / 3
≥ "N
X d + X k,G
t>>(1)≤ 50 ms
I>>(2)
≥ 0.8 x I>>(1)
t>>(2)≥ 200 ms
Overspeed
n>
approx. 10%
-
Reverse power
-
1-2%
Excitation
monitoring
-
Overcurent
10 kV
zero-sequence
voltage
Underfrequence
II
Negative
sequence voltage
Negative
sequence current
Earth fault
time
Desired protection purpose
Overload and
reserve protection
3
If reserve protection has 2 steps
-
Mechanical protection
-
3-30 s
Protection of generator driving
power
-
20% reactive reverse
power
300 ms
Protection against underexcitation operation
-
U0
20%
60 s
f<
≤ 47.5 Hz
≥ 10 s
U2>
I2 * X2
3-10 s
I2>
5-20%
3-10 s
Uo>
10-15%
1-5 s
Protection of generator when
searching for earth faults
(Peterson coil)
Rotary transformer protection, if
any
Note 2:
Note 3:
Protection of generator windings
in isolated grid (IT grid).
-
It is recommended to add a df/dt-relay. The relay function principle
must comply with the requirements in DEFU’s technical report
TR293. The electric power utility may require a less sensitive setting
(max ± 3.5 Hz/s).
The phase-to-ground voltage must be measured at plants connected
to the 0.4 kV supply grid. For plants connected to the 10 kV grid,
the phase-to-phase voltage must be measured.
UN and Xd" are the rated generator voltage (outer value in V), and
the subtransient reactance (phase value in Ω). Xk,G is the grid’s
IN is the rated current of the generator.
The indicative negative-sequence setting in p.u. can be converted
into an equivalent inverse voltage setting by multiplying the inverse
generator impedance in p.u. If X2 is not known it can be
approximated by (Xq"+Xd")/2. To avoid false tripping, the relay
measuring accuracy must be taken into account.
Relay settings deviating from the stated settings can only be used if they have
been approved by the electric power utility.
Document no. 43436-08_v5.1
4
short-circuit impedance on the generator terminals in Ω per phase.
Note 4:
-
Protection of generator during
open phase
Protection operating time is the time in which the trip condition constantly must
be met before the relay can send out a trip signal. It is not a question of the trip
signal being subjected to a simple time lag.
Note 1:
Note
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Appendix 4: Comments (not part of the regulation)
Appendix 4: Comments (not part of the regulation)
Re 1.1.5 Normal operating condition
The setting of the normal operating condition is important when it comes to
setting, for example, maximum power and control ability as the provisions
stipulate requirements for power station unit operating precisely in normal
operating condition.
Examples of power station units where there may be doubt about the normal
operating condition and where the TSO must make decisions include plants
operated with and without district heat outlet (back-pressure operation and
condensing operation).
Re 1.2 Power
Nominal maximum power is related to specific external operating conditions and
will lie between lowest maximum power and highest maximum power. Both are
related to extreme external operating conditions.
The current maximum power will fluctuate between lowest maximum power and
highest maximum power depending on the current external operating conditions.
For power station units that do not depend on external operating conditions, all
sizes will converge.
Maximum power range
Lowest maximum power
(Unfavourable external
operating conditions)
Figure 7
Nominal maximum power Highest maximum power
(Nominal external
(Favourable external
operating conditions)
operating conditions)
Real power
[P]
Relation between lowest, highest and nominal maximum power.
Minimum power replaces the previously used term 'technical minimum'.
It should be noted that the definition of effective power deviates from the
definition of net generation in ”Nettoproduktion og bruttoforbrug på
elproducerende anlæg” (Net production and gross consumption in power
generating plants) and market regulation D1 in Appendix 1.
Re 1.7 Short-circuit ratio
The short-circuit ratio corresponds more or less to the reciprocal value of the
generator’s synchronous impedance when measured in p.u. In case of a low shortcircuit ratio, major changes in the excitation current are required to maintain a
stable stator voltage for a given change in the load.
A high short-circuit ratio for the generators connected to the grid typically
improves the transient stability of the system.
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Appendix 4: Comments (not part of the regulation)
Re 1.8 Power station unit
A power station unit is equivalent to an energy unit used for grid connection
agreements used by the electric power utilities. In legislation, this is also called a
power generating plant.
Re 1.17 Secondary control
It should be noted that the control can be ordered automatically by a grid
controller or by manual order.
Re 1.22 Thermal power station unit
Gas engine plants, gas turbine plants, and steam turbine plants are examples of
thermal power station units.
Re 1.23 Connecting point
Figure 8 below shows an example with the purpose of clarifying various terms.
Connecting point
10 kV
Connecting point/
common point of coupling
10 kV
Public electricity supply grid
Limits of owner
Power station unit
10 / 0. kV
10 / 0.69 kV
0.4 kV
0.69 kV
G
~
0.4 kV
0.4 kV
Excitation/
auxiliary equipment
Auxiliary supply
Figure 8
Drawing of connecting point, point of common coupling and limits of owner in relation to the
power station unit.
Re 2.3 Complaints
Pursuant to the Danish Public Administration Act, the TSO is obliged to hear all
parties in a case before making a decision. A complaint about a electric power
utility will always oblige the TSO to ask the electric power utility to comment on
the complaint.
Re 3.2 Existing plants
A substantial change is the replacement of an essential plant component that
changes the properties of the power station units seen in the eyes of the public
electricity supply grid.
Examples of replacements include:
-
Replacement of voltage regulators or regulators belonging to the generator's
prime mover is considered essential.
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Appendix 4: Comments (not part of the regulation)
-
Replacement of the generator itself or its prime mover is also considered
essential, even if the original units are replaced by new units with the same
output.
Re 4.1 Maximum power
The provisions mean that there are no requirements as to production from a
power station unit with district heat outlet as the only source of cooling (purely
back-pressure plant) if the power station unit cannot dispose of heat due to low
district heating consumption and filled heat accumulator tanks.
The provisions mean that a power station unit whose normal operating condition
and thus maximum power is defined as being without heat production can reduce
the effective power when producing heat. As such, the provisions ensure that a Cv
value different from zero is allowed.
The nominal external operating conditions stated for gas turbines correspond to
the ISO’s reference conditions.
Other external operating conditions may include return flow temperature of district
heating water.
Re 4.2 Overload capacity
The establishing of overload capacity by using the natural reserves of the plant for
example can enable the power station unit to supply regulating services. That is
why it is recommended to establish overload capacity wherever possible taking
into account the financial consequences.
The provision implies that a power station unit must not sell regulating services
etc. that exceed the sum of the maximum power and overload capacity stated,
see section 16.2.
Re 4.3 Minimum power
The requirement of coal dust-fired units to the effect that minimum power
constituting 35% of maximum power is equivalent to dividing coal-mill capacity at
maximum generation on three coal mills, assuming that one coal mill functions
satisfactorily at 50% firing, and that minimum two coal mills are always required
to be in operation in order to ensure continuous operation.
Re 4.4 Part load
There are no requirements for a power station unit’s efficiency when operating at
part load. However, it is recommended that a power station unit be designed for
as high efficiency as possible at part load, taking account of the financial
consequences involved with a view to enabling the power station unit to supply
regulating services.
Re 5 Tolerances towards frequency and voltage deviations
It should be noted that the provisions apply to the entire power station unit.
Consequently, the auxiliary supply facilities must be dimensioned to withstand
conditions specified without disconnecting.
Re 5.1 Full-load voltage/frequency range
The voltage and frequency limits stated solely define the limits within which the
power station unit must be able to supply maximum power and reduced maximum
power and thus do not define the quality parameters which the electric power
utility must aim at maintaining in the point of common coupling. The voltage
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Appendix 4: Comments (not part of the regulation)
quality which the electric power utility aims at achieving in the point of common
coupling can typically be seen from the electric power utility's agreement on the
operational use of the grid.
Typical operating voltage is selected on the basis of normal practice used by the
grid companies. It should be noted that the company is not obliged to maintain
the typical operating voltage UTYP stated at the time of establishment, see Table
3.
If UTYP is changed, and the power station unit no longer complies with the
minimum requirements defined in this regulation, the owner of the power station
unit must either request the TSO to issue an exemption or make the
arrangements necessary to ensure that the power station unit complies with this
regulation.
The voltage in the auxiliary supply facilities can be maintained at 400 V ±10%, and
standard components can thus be used without installing an automatic step switch
in the auxiliary supply transformer. At voltages below ULF, which normally only
occur briefly, power reduction is allowed.
Upper and lower voltages (UH and UL) in Table 2 and Table 3 have been set at
±10% in pursuance of EN50160 and EN60038, Table III, Note 2. For voltages of
132 kV and higher the upper voltage limit is higher than the recommendations in
EN 60038 due to brief high voltages in the event of black start. Brief periods are
not longer than 30 minutes. In the last 20 years there has been two black starts.
The electric power utility is authorised to decide to which voltage level a power
station unit is to be connected. It is therefore recommended to contact the electric
power utilities at an early stage in the project in order to determine the voltage
level and the normal operating voltage in the connecting point.
The start engines and auxiliary facilities of the power station units must be
dimensioned for start and continuous operation within the same voltage range
unless tap changers have been installed.
Where plants with asynchronous generators are concerned, the power station
owner and the electric power utility may agree that a part of the reactive
production necessary will be supplied by capacitor banks in the grid.
Re 5.2.4 Extra high voltages
An extra high voltage limit corresponds to the highest voltage for equipment, see
EN60038, Table III. For the voltage levels 10 kV, 15 kV and 20 kV Zone B in
EN60034-1, Figure 11, is used.
Re 5.2.5 Voltage ramp rate
The stated provision relating to the voltage ramp rate can apply to the design of a
potential step switch for the power station unit's auxiliary supply transformer.
Re 5.2.6 Transient voltages
Switchings with circuit breakers based on vacuum technology may cause transient
voltages in the connecting point of the power station unit. The necessary
information should therefore be obtained from the electric power utility at a very
early stage in the project so that any need for installing overvoltage conductors in
connection with the generator circuit breaker and the machine transformer at the
power station unit can be assessed.
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Appendix 4: Comments (not part of the regulation)
Re 5.3 Frequency deviations
To comply with the frequency requirements it is recommended that the design
incorporate thermal over-dimensioning of the generator (stator and rotor),
constructed for class F insulation, but operated pursuant to class B insulation
during normal operation.
Frequencies below 49.0 Hz and above 50.5 Hz are only expected to occur a few
times a year at the most. Normally, the frequency is kept within the 50±0.1 Hz
range.
Re 5.2.4 Extra high frequencies
Normally, frequencies above 51 Hz only occur during control sequences, for
example in connection with the transition to isolated island operation.
Re 5.3.4 Transient frequencies
There is a possibility of reverse power to the generator (engine operation) at large
positive frequency gradients. The generator may be equipped with a reverse
power protection relay as a turbine may be damaged during engine operation.
There may be a potential conflict between the protection and the requirement of
being connected at the frequency gradients stated. In practice, however, conflicts
rarely occur. Reverse power occurs when:
Pmek <
2 ⋅ H ⋅ Sn
fn
⎛ df ⎞
⋅⎜ ⎟
⎝ dt ⎠
where
Pmek
: Supplied mechanical power (shaft power)
H
: Stored-energy constant
Sn
: Rated generator power
fn
: Nominal frequency (50 Hz)
If the stored-energy constant, H, is 3 s, and the frequency gradient, df/dt, is 2.5
Hz/s, it results in:
Pmek < 0,3 ⋅ S n
The mechanical power supplied must thus be below approx. 30% of the maximum
power before reverse power occurs. This is less than the minimum power of the
majority of the power station units.
Please note that this only comprises frequency gradients, not frequency jumps.
Re 6 Tolerance towards grid faults
The provisions imply that a power station unit must be constructed in such a way
that the power station unit can remain connected at the voltage disturbances
stated. This must take place whether or not a relay protection has been specified,
and in practice this means that the power station unit is disconnected at
disturbances smaller than the ones indicated in section 6.
It should be noted that the provisions apply to the entire power station unit.
Consequently, the auxiliary supply facilities must be dimensioned to withstand the
specified conditions without disconnecting, for which reason they must feature
secured supply of the control voltages necessary for operation.
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Appendix 4: Comments (not part of the regulation)
The equipment includes a C&I system (control and instrumentation), oil pumps,
contactors etc., ll of which are examples of critical plant parts that must be taken
into account when dimensioning the auxiliary supply facilities to prevent the unit
from breaking down when the grid is short-circuited. Simultaneous voltage sags in
all three phases are of importance to engines, while voltage sags in one phase has
a special impact on the C&I system and latched contactors.
Auxiliary supply facilities and generators must be connected so that the auxiliary
facilities can withstand the specified voltage variations in the connecting point.
Where the typical connection of generator and auxiliary supply facilities is
concerned, reference is made to DEFU technical report no. 303, “Relæbeskyttelse
af kraftværkers egenforsyningsanlæg” (Relay protection of power stations'
auxiliary supply facilities), July 1992, and DEFU committee report no. 88,
”Nettilslutning af decentrale produktionsanlæg” (Grid connection of local
production units), March 1991.
Re 6.1 Connecting points above 100 kV
This regulation deals with faults occurring close to the power station unit (where
the contribution of the unit to the short-circuit current is significant).
In such case, a power station unit must be able to handle the following fault
profiles:
-
for three-phase short-circuit in the connecting point with subsequent
transient state of the voltage as shown in Figure 2;
for one- and two-phase short-circuits in the connecting point with subsequent
transient state of the voltage where resynchronisation may occur on the fault
as shown in Figure 3.
This means that the power station unit must be able to handle all faults that are
disconnected by the primary protection in the electricity supply grid.
As part of the compliance with this regulation, the auxiliary supply system must be
able to tolerate the voltage sag that occurs during the connection of the auxiliary
supply system due to the voltage disturbance specified in section 6.1.
This regulation deals with faults that occur far away from the power station unit
(where the unit’s contribution to the short-circuit current is small). In this
situation, a power station unit must be able to supply short-circuit current in the
time it takes at the most to disconnect a fault by means of reserve protection plus
the voltage transient time, in total up to five seconds. This means that the power
station unit must be able to handle all faults far away from the generator even
though they are not disconnected by the grid’s primary protection.
As part of the compliance with the provision, the auxiliary supply facility must be
able to tolerate the voltage sag caused by the fault. The maximum voltage sage in
the auxiliary supply system can be calculated on the basis of the impedances of
generator, engine transformer and grid as well as the connection of the auxiliary
supply. The grid’s impedance is given as the impedance between generator and
fault, which precisely results in the fault occurring far away from the generator corresponding to the fact that the initial short-circuit current’s AC contribution
from the generator (Ik”) is precisely 1.8 times the rated generator current.
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Appendix 4: Comments (not part of the regulation)
The extent of the voltage sag in the auxiliary supply depends on the generator’s
capability of maintaining the voltage. The voltage sag in the auxiliary supply can
be minimised by the suitable capabilities of the generator.
Re 6.2 Connection points up to 100 kV
The stated voltage profile of power station units connected to the distribution grid
(<100 kV) must ensure that one- and two-phase faults in the transmission grid do
not result in the disconnection of the power station unit. One-phase earth faults,
two-phase short-circuits, two-phase short-circuits with earthing wire or one-phase
breaking of the phase in the transmission grid can lead to voltage sags near a
power station unit of the specified size connected to the distribution grid.
The extent and duration of voltage sags that a power station unit connected up to
100 kV must be capable of tolerating are illustrated in Figure 4. It applies to
voltage sags with a duration of between one and five seconds that the relationship
between the extent and duration of the voltage sag is represented by: ΔU⋅t =
constant where ΔU = Un-U. The constant varies with one-phase and three-phase
voltage sags.
Note that the figure does not show the time voltage gradient for a fault but rather
the period of time in which a power station unit is able to withstand a given
voltage , eg 50% voltage in one phase for two seconds and 75% voltage in three
phases for two seconds.
Re 7 Island operation
A power station unit’s possibility of going into island operation requires, among
other things, precise dimensioning of all the related necessary electrical and
mechanical systems.
Re 7.1.1 House-load operation
The transition to house-load operation can be triggered by a grid fault, eg
overfrequency, underfrequency or voltage deviations of such a nature that the
power station unit must be protected from it. The purpose of house-load operation
is to ensure that the power station unit is available after the fault has been
rectified.
At small power station units with short starting times, house-load operation is thus
of little consequence. The impact of house-load operation on the system is
estimated as being modest relative to the costs of ensuring such a form of
operation.
Re 7.1.2 Isolated island operation
Isolated island operation may be necessary in connection with major faults in the
high-voltage grid (also at voltage levels higher than the connection voltage).
Due to the risk of asynchronous reconnection/reclosure and out of consideration
for the synchronism in the grid after a fault, isolated island operation without
special permission should be avoided.
This also comprises operational and personal safety when working on the public
electricity supply grid.
Re 8 Start and synchronisation
Power station units with starting times of less than 15 minutes are especially
valuable as they can be activated before any thermal overload of power lines.
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Appendix 4: Comments (not part of the regulation)
It is necessary to have the possibility of black start from a few units in the system
for the purpose of re-establishing supply after a total system breakdown. The
ensuring of such facilities is assumed to be handled by the TSO by other means,
eg via tendering or negotiations.
Re 8.2 Starting times
A gas turbine of the industrial type has been developed specifically for industrial
applications. A gas turbine of the jet type is based on gas turbines developed for
airplanes. Gas turbines of the jet type differ from the industrial type in that they
are typically lighter and have higher pressure conditions. Furthermore, gas
turbines of the jet type are constructed for a smaller output than gas turbines of
the industrial type.
Re 8.3 Synchronisation
DEFU committee report 88 sets requirements as to the relationship between the
magnitude of the cut-in current and the rated current depending on the grid’s
short-circuit capacity and the rated generator power for power station units
connected to 0.4 kV and 10-20 kV.
The provision ensures that the inrush current, including the excitation current
when the engine transformer is being connected, does not cause unacceptable
voltage disturbances.
Re 9 Active power production and frequency control
Denmark is subordinated to the Nordel requirements for Eastern Denmark and for
UCTE requirements for Western Denmark. Figures 9 and 10 show the individual
mode of controls.
As can be seen from Figures 9 and 10, only critical power frequency control is
regular droop control. The other modes of control are based on a mode of droop
for determining the required power response, but the power response must be
supplied time-based. The purpose of the time-based controls is solely to stabilise
the frequency within a defined frequency range. By means of manual reserves the
frequency is subsequently set to the reference frequency (in Western Denmark
also automatic LFC control on the interconnections to Germany).
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Appendix 4: Comments (not part of the regulation)
Nordel - Frequency control
FDR
FNR
-500
-200
-100
mHz
100
REFERENCE FREQUENCY
FDR = FREQUENCY CONTROLLED DISTURBANCE RESERVE
FNR = FREQUENCY CONTROLLED NORMAL OPERATION RESERVE
Power response – Frequency controlled normal operation reserve
Power response as a function
of frequency deviation (MW)
100%
Time (sec.)
150
- 100%
Power response – Frequency controlled disturbance reserve
Power response as a function
of frequency deviation (MW)
100%
50%
Time (sec)
5
Figure 9
30
Outline of Nordel requirements for power generation and frequency control.
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Appendix 4: Comments (not part of the regulation)
UCTE - Frequency control
KFR
KFR
PRIMARY CONTROL
PRIMARY CONTROL
mHz
-200
-20 20
KFR = CRITICAL POWER
FREQUENCY SUPPORT
200
REFERENCE FREQUENCY
Primary control
Power response as a
function of the frequency
deviation (MW)
100%
50%
Time (sec.)
15
30
- 50%
- 100%
Critical power frequency control
Max load
6%
mHz
200
-200
6%
Min. load
REFERENCE FREQUENCY
Figure 10 Outline of UCTE requirement for power generation and frequency control.
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Appendix 4: Comments (not part of the regulation)
Re 9.1 General requirements of the regulating capability of the power
station unit
The maximum (design) power response of a power station unit occurs at a dead
band of ±0 mHz and at the smallest droop.
It must be possible to set the dead band of the power/frequency controller within
the ±0 mHz to ±200 mHz range. In other words, the dead band lies symmetrically
about the reference frequency, and the total width must be set between 0 mHz
and 400 mHz, see Figure 9.
Power
change
Droop
Fre que ncy
deviation
0 mHz 2 0 0 mHz
De ad band
0 mHz 2 0 0 mHz
Figure 11 Drawing of power/frequency controller dead band setting.
Re 10 System stability
With the technology of today, power station units with nominal maximum power of
1.5 MW or above are based on synchronous generators. The formulation of several
provisions in this regulation is based on that assumption.
If new generator technologies are developed, including for example power
electronics, it is conceivable that it would be desirable to base power station units
on such technologies. Should such a desire/need arise it will be necessary to
revise this regulation and/or grant an exemption.
Re 10.1 Generator
The short-circuit ratio is the reciprocal of the saturated synchronous reactance in
p.u. The requirement as to a short-circuit ratio of at least 0.45 complies with
EN60034-3 for units smaller than 200 MVA.
It is the saturated value of the transient reactance that is to be used. This will
ensure compliance with Nordel’s recommendations.
Re 11.1 Power factor
Please note that with this regulation there are requirements as to the reactive
power production between the lower voltage limit, ULF, of the full-load range and
the lower voltage limit, UL, according to section 5.2.1 and between the upper
voltage limit, UHF, of the full-load range and the upper voltage limit, UH, according
to section 5.2.3.
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Appendix 4: Comments (not part of the regulation)
Re 11.4 Excitation system during grid faults
The provisions as to ceiling voltage and voltage response time replace previous
provisions as to nominal exciter response ratio.
The ceiling voltage indicates the capacity of the excitation system to force the
excitation current up. A high ceiling voltage has a tendency to improve the
transient stability.
The voltage response time corresponds to the excitation system having a so-called
‘high initial response’ in accordance with the IEEE std. 421.2-1990.
A suitable negative-sequence characteristic and not constant-time characteristic
must be used to limit the current in stator and rotor in order to protect the
excitation system.
Re 12.1 General
Faults and incidents in the grid include:
-
Short-circuit and earthing currents
Recurring voltages in connection with the disconnection of grid short-circuiting
and earthing
Increased voltage on fault-free phases in case of one-phase earth faults in
isolated grids and grids equipped with Peterson coil protection
Phase disconnection
Asynchronous connections.
In case of grid interruptions where the local power station unit is in isolated island
operation there is a high risk of connection in phase opposition, for which reason
power station units connected to 50 kV and 60 KV or lower voltages are switched
off during unintentional isolated island operation.
Short-circuits in the grid leading to isolated island operation are expected to be
detected by the synchronous voltage relays.
Isolated island operation due to erroneous manoeuvring, faults in the remote
control system, Buchholz tripping of transformer, etc. can often be detected by a
df/dt relay.
Complete protection against serious impacts on the power station unit cannot be
achieved despite the recommended relays, as the asynchronous connection of grid
and generator may occur in connection with grid modifications, unknown faults
and defects in the relay protection.
Therefore is recommended that during the planning of a power station unit it is
examined and evaluated whether the power station unit should be dimensioned to
be so robust that it can withstand asynchronous connection when comparing the
additional costs in this connection with the reduced risk of damage to the power
station unit.
In case of short-circuiting in the grid where auto-reclosure is used and where the
local power station unit switches to isolated island operation in the dead time, the
protection mentioned in section 12 hereof must have detected the fault and
disconnected the power station unit before the auto-reclosure.
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Appendix 4: Comments (not part of the regulation)
Reclosure procedures (single-pole or triple-pole reclosure) in the grid can be as
follows, but it is recommended to obtain reclosure data from the electric power
utility:
Reclosure procedures for Jutland and Funen:
-
10 kV and 60 kV using triple-pole reclosure
150 kV and 400 kV using one and triple-pole reclosure
Normally, the dead times indicated below are used:
-
"fast", triple-pole reclosure
"fast", single-pole reclosure
"slow", triple-pole reclosure
270-500 ms.
1.0-1.2 s.
20-30 s.
If auto-reclosure fails, manual reclosure is normally performed, typically after 510 minutes.
Reclosure procedure for Zealand and the islands:
-
10 kV and 132 kV grids use triple-pole reclosure
30 kV does not use reclosure
50 kV does not use reclosure
400 kV does not use single-pole reclosure
In the 132 kV and the 400 kV grids only one-phase faults are reclosed.
Normally, the dead times indicated below are used:
-
"fast", triple-pole reclosure, 10 kV
"slow", single-pole reclosure, 132 kV
"slow", single-pole reclosure, 400 kV
300 ms.
100-300 ms.
800 ms.
If automatic reclosure fails, manual reclosure is normally performed, typically after
5-10 minutes.
Re 12.2 Protection against external faults
The instructions in the DEFU report TR293, 2. version, attempts to ensure that a
power station unit cannot be connected asynchronously to the grid (is
synchronised in phase opposition to the grid typically in connection with reclosure
in the grid after faults).
Complete protection against asynchronous connection cannot be obtained,
however, as situations where there is a risk that asynchronous connection may
occur, for example in connection with grid modifications, unknown faults and
defects in the relay protection. Consequently, it is recommended to examine
whether a power station unit can be reasonably dimensioned to be so robust that
it can withstand asynchronous connection to the grid without damaging the plant.
It is no longer allowed to use vector leap relay as supplementary protection as the
function is often faulty.
Re 13 Metering, communication and data exchange
The metering regulations are available at www.energinet.dk.
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Appendix 4: Comments (not part of the regulation)
Re 13.3 Data exchange
IEC 61850-7-420 defines the relevant data points (logical nodes and classes) of
the standard for local production units.
Re 14 Power station unit structure
Earthing method:
0.4 kV grid:
10 kV, 15 kV and 20 kV grid (with overhead lines):
10 kV, 15 kV and 20 kV grid (only cable grid):
Directly earthed
With Peterson coil
protection
Insulated or with
Peterson coil protection
Operation with one-phase earth faults may occur for longer periods of time in
grids protected with Peterson coil.
The earthing of the generator star point cannot change the earthing condition of
the grid.
Re 16 Verification and documentation
Templates for Appendix 1 are available at www.energinet.dk.
Re B1.2.6 Block diagrams and parameter values for voltage regulator,
tanφ regulator, power system stabiliser, under-excitation limiters and
over-excitation limiters
Block diagrams must be stated in the Laplace-domain so that they can be used in
connection with dynamic simulations of the power station unit and the public
electricity supply grid. In case of doubt about the models’ degree of detail, etc., it
is recommended that this be agreed with the TSO beforehand.
Figure 12 below shows a simple example of the block model’s desired layout and
degree of detail.
Figure 12 Example of a simple excitation system.
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Appendix 4: Comments (not part of the regulation)
Figure 13 below shows a simple example of the block model’s desired layout and
degree of detail.
Figure 13 Block diagram for an excitation system.
Example of block diagram covering generator terminal voltage
Figure 14 Example of degree of detail for block diagram for transducer for measuring generator terminal
voltage for the excitation system in Figure 13.
Example of block diagram covering the rectifier’s regulation equation
Figure 15 Block diagram for the rectifier’s regulation equation (FEX = ƒ[IN]) for the excitation system in
Figure 13.
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Appendix 4: Comments (not part of the regulation)
Re B1.2.7 Block diagram and parameter values for the power/frequency
controller
Block diagrams must be stated in the Laplace-domain so that they can be used in
connection with dynamic simulations of the power station unit and the public
electricity supply grid. In case of doubt about the models’ degree of detail, etc., it
is recommended that this be agreed with the TSO beforehand.
Figure 16 below shows a simple example of the block diagram’s desired layout
and degree of detail.
Figure 16 Example of block diagram for speed regulator.
Re B1.2.8 Block diagrams and parameter values for operating system
Block diagrams must be stated in the Laplace-domain so that they can be used in
connection with dynamic simulations of the power station unit and the public
electricity supply grid. In case of doubt about the models’ degree of detail, etc., it
is recommended that this be agreed with the TSO beforehand.
Figure 17 below shows a simple example of the block diagram’s desired layout
and degree of detail.
Figure 17 Example of block diagram for steam turbine.
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Appendix 5: Previous provisions (not part of the regulation)
Appendix 5: Previous provisions (not part of the
regulation)
Below follows an overview of the previous provisions and recommendations
applying to thermal power station units. The previous provisions and
recommendations will comprise existing plants established prior to this regulation
coming into force.
For power station units above 25-50 MW in the West Danish area (Jutland and
Funen):
- 1977-1987:
- 1987-1995:
- 1995-2004:
"Kraftværkspecifikationer for effektudbygning i 1980'erne",
(Power station specifications for capacity expansion in the 1980s)
memorandum ARN-77/179, Elsam, 1977.
"Kraftværksspecifikationer for nyanlæg større end 25 MW”,
(Power station specifications for new facilities above 25 MW)
memorandum S87-56g, Elsam, 1987.
"Kraftværksspecifikationer for produktionsanlæg > 50 MW",
(Power station specifications for production units >50 MW)
memorandum SP92-230j, Elsam, 1995.
For power station units below 25-50 MW in the West Danish area (Jutland and
Funen):
- 1977-1991:
- 1991-1995:
- 1995-2004:
"Kraftværkspecifikationer for effektudbygning i 1980'erne",
(Power station specifications for capacity expansion in the 1980s)
memorandum ARN-77/179, Elsam, 1977.
"Kraftværksspecifikationer for decentrale kraftvarmeanlæg op til
50 MW”, (Power station specifications for local CHP plants up to
50 MW), memorandum EP91/172, Elsamprojekt, 1991.
"Kraftværksspecifikationer for produktionsanlæg mellem 2 og
50 MW", (Power station specifications for production units
between 2 and 50 MW), memorandum SP92-017a, Elsam, 1995.
For power station units above 100-200 MW in the East Danish area (Zealand and
islands):
- 1975-1982:
- 1982-1995:
- 1995-2004:
"Drifttekniske specifikationer för värmekraft", (Operational
performance specifications for CHP), Nordel, July 1975.
"Drifttekniske specifikationer för värmekraft, Revision nr. 1",
(Operational performance specifications for CHP, Revision no.
1), Nordel, June 1982.
"Operational Performance Specifications for Thermal Power
Units larger than 100 MW", Nordel, 1995.
For power station units below 100-200 MW in the East Danish area (Zealand and
islands):
- 1990-1995:
- 1995-2004:
"Driftstekniske specifikationer for mindre varmekraft anlæg,
Tillæg nr. 1", (Operational performance specifications for smallscale CHP plants, amendment no. 1), Nordel, August 1990.
"Operational Performance Specifications for small Thermal
Power Units, Amendment no. 1", Nordel, 1995.
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Appendix 6: Reference list (not part of the regulation)
Appendix 6: Reference list (not part of the regulation)
In the regulation, reference is made to the following documents:
1. Nordel, "Operational Performance Specifications for Thermal Power Units
larger than 100 MW", 1995.
2. Nordel, "Operational Performance Specifications for small Thermal Power
Units, Amendment no. 1", 1995.
3. Elsam, "Kraftværksspecifikationer for produktionsanlæg >50 MW",
memorandum SP92-230j, 1995.
4. Elsam, "Kraftværksspecifikationer for produktionsanlæg mellem 2 og 50 MW",
memorandum SP92-017a, 1995.
5. DEFU committee report 88, "Nettilslutning af decentrale produktionsanlæg",
March 1991.
6. DEFU technical report 293, "Relæbeskyttelse ved decentrale produktionsanlæg
med synkrongeneratorer", version 2, June 1995.
7. EN60034-16-1 "Rotating electrical machines – Part 16: Excitation systems for
synchronous machines – Chapter 1: Definitions", 1995.
8. IEC technical report IEC60034-16-3 "Rotating electrical machines – Part 16:
Excitation systems for synchronous machines – Section 3: Dynamic
performance", 1996.
9. IEEE Std. 421.5-1992 "IEEE Recommended Practice for Excitation System
Models for Power System Stability Studies", 1992.
10. IEEE Std. 421.2–1990 "IEEE Guide for identification, Testing and Evaluation of
the Dynamic Performance of Excitation Control Systems", 1990
11. DEFU technical report 303, "Relæbeskyttelse af kraftværkers egenforsyningsanlæg", July 1992.
12. EN50160, "Voltage characteristics of electricity supplied by public distribution
systems", Draft, May 2005
13. EN60034-1, "Rotating electrical machines – Part 1: Rating and performance",
2004
14. EN60034-3, "Rotating electrical machines, part 3: Specific requirements for
turbine-type synchronous machines", 1995,
15. EN60038, "IEC Standard voltages", 1983
16. EN60076-1, "Power transformers, part 1: General", 1997
17. IEC 61850-7-420, "DER Logical Nodes"
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