Download Date:- 12 December 2011

Date:- 14 March 2012
COMPARISON OF GB AND EUROPEAN GRID CODE REQUIREMENTS
Key to Tables
Symbol
N/A
N/S
Article 4(3)
Definition
Not specified in GB Grid Code but other requirements may apply in other industry Codes such as the System Operator Transmission Owner
Code (STC) Distribution Code or Engineering Recommendations such as G59, ETR 113 and G83.
Not specified in ENTSO-E RfG Code often because not deemed to be a cross border issue but other National requirements may apply.
Where reference in the Table is given to Article 4(3) this means that any decision made by a Relevant Network Operator, or Relevant TSO and a
Relevant Network Operator or Power Generator may require agreement with the National Regulating Authority.
Notes:Table 1 compares the ENTSO-E Network Code – Requirements for Generators (RfG) with the GB Grid Code. In other words each clause of the ENTSO-E
RfG has been compared against the GB Grid Code. This table is deliberately light on detail to identify where the ENTSO-E RfG is possibly more onerous
(red text) or less onerous (green text) than the GB Grid Code.
Table 2 compares the GB Grid Code with the ENTSO-E RfG. This is a much more detailed Table comparing the exact requirements of the GB Grid Code
with the exact requirements of the ENTSO-E RfG. The reader should however be aware that in adopting this comparison there may be elements in the
ENTSO-E RfG that have not been identified as and this is where Table 1 is considered to be helpful.
Table 3 compares the GB Grid Code with the ENTSO-E RfG in respect of Offshore Power Park Modules. As the ENTSO-E RfG makes extensive reference to
the Onshore ENTSO-E RfG requirements, Table 3 compares in detail the Offshore ENTSO-E RfG with the GB Grid Code.
These Tables have been prepared in good faith with limited internal review and indicate National Grid’s interpretation of the differences between the GB
Grid Code and ENTSO-E RfG. Where there is a conflict between these Tables and the Code, the Code should be taken as the definitive text.
TABLE 1 – COMPARISION OF ENTSO-E RfG TO GB GRID CODE
ENTSO-E – RfG
GB Code
Requirements applicable to Type A Units - 400W – 1MW but equally applicable to Type A, B, C and D
Units
This comparison only applies to the GB Code and not other codes such as the Distribution Code, STC
or other documents such as G59, etc. The purpose of this table is simply to provide a comparison
between the ENTSO-E RfG and GB Code with reference to the ENTSO-E RfG.
Article 7 – General Requirements - Type A Units
Article 7 (1) (a) - Frequency range
Consistent with GB Grid Code – CC.6.1.3, CC.6.3.12 and CC.6.3.13 (CC.6.3.12 and CC.6.3.13 apply only to
Large and Medium Power Stations.
Rate of change of Frequency limits not specially covered in GB Grid Code although reference can be made in
the Bilateral Agreement as specified in CC.6.3.12 - applies only to Large and Medium Generators).
Consistent with GB Code but only for BM Units (ie Generation operating in the wholesale Electricity Market) –
BC.3.7.2.
For Embedded Small Power Stations which are not BMU’s – N/A. The BC’s will apply to BMU’s.
Article 7 (1) (b) – Rate of Change of Frequency
Article 7 (1) (c) – Limited Frequency Sensitive Mode – Over- frequency
Article 7 (1) (d) – Fitting of logic interface in order to disconnect from the Network
1
TABLE 1 – COMPARISION OF ENTSO-E RfG TO GB GRID CODE
ENTSO-E – RfG
GB Code
Article 8 – General Requirements - Type B Units
Article 8 (1) – All Type B units must meet the same requirements as Type A units
Article 8 (2) – Reduction of Active Power in steps not bigger than 20% of maximum capacity
Article 8 (3) – Reconnection requirements following a Network Disturbance
For Small Power Stations – N/A. For Large and Medium Power Stations more stringent requirements apply.
Applicable only to Power Stations for which NGET have a direct relationship – specified under the Grid Code
Balancing Codes
Not believed to conflict with the GB Grid Code.
Article 8 (4) (a) – General System Management requirements – Control schemes and settings as
agreed with the TSO, Network Operator and Power Generating Facility Owner – Isolated Network
Operation, damping, system disturbances
Article 8 (4) b) Information Exchange – Power Generating facilities shall be equipped with information
exchange facilities between the Relevant Network Operator and Power Generating Facility.
Article 9 – General Requirements - Type C Units
Article 9 (1) – All Type C units must meet the same requirements as Type A and B units except Articles
7(1)(d) and Article 8(2)(a)
Article 9(2) (a) – Active Power controllability and Control range
Article 9(2)(b) – Synthetic inertia
Not believed to conflict with the GB Grid Code. Requirements for information exchange are covered in CC.6.5
Control Telephony, CC.6.5.8 – Instructor Facilities and CC.6.5.9 – Fax machines.
Consistent with GB Grid Code – CC.6.3.6(a), CC.6.3.7 and BC3.
Not currently specified in GB Grid Code but the Frequency Response Working Group are investigating these
issues.
Not specified in GB Grid Code – ENTSO-E RfG requirement is over and above the requirement in the GB Grid
Code.
Consistent with GB Grid Code – CC.6.3.7 and CC.A.3. Note:- The ENTSO-E RfG specifies a frequency
response capacity (as a percentage of Registered Capacity of between 2 and 10%). The GB Grid Code
specifies a minimum frequency response capability of 10% of Registered Capacity.
Consistent with GB Grid Code – CC.6.3.6(a), CC.6.3.7, CC.A.3 and BC3
This is not currently specified in the GB Grid Code. There is no mandatory requirement for Demand
Disconnection from Pumped Storage Demand to control system frequency. Currently only applicable to
HVDC Converters and Pumped Storage or Demand Customers for whom NGET have a Commercial Contract.
Broadly consistent with GB Code – OC5.4.1(c) – Ancillary Services and instructions via EDL – CC.6.5.8. In
GB there is no requirement for Automatic Generation Control (AGC) which is specified under ENTSO-E RfG
Article 9(2)(g)(2). Some of the frequency response monitoring signals which are provided back to NGET are
not currently provided (eg droop and deadband).
Does not contravene GB Grid Code.
Article 9(2)(c) – Limited Frequency Sensitive Mode – Under Frequency
Article 9(2)(d) – Frequency Sensitive Mode
Article 9(2)(e) – Frequency restoration
Article 9(2)(f) – Disconnection due to under frequency – any Power Generating Facility being capable
of acting as a load except for auxiliary supply (including pumped storage) shall be capable of
disconnecting its load in case of underfrequency
Article 9(2)(g) – Real Time Monitoring of Frequency Sensitive Mode operation
Article 9(3) – Voltage Stability – automatic disconnection at specified voltages if required by the
Relevant Network Operaotor
Article 9(4)(a) – Steady State Stability at any operating point within the PQ diagram
Article 9(4)(b) – Generating Units shall be designed such that the shaft torsional stress which may be
excited by transient Active Power steps up to 50% of its maximum capacity are considered a routine
part of normal operation and shall be taken into account when specifying the shaft characteristics
Article 9(4)(c) – Auto Re-closure. Requirements specified by TSO pursuant to Article 4(3)
Article 9(5)(a) – Black Start
Consistent with GB Grid Code – CC.6.3.8
Not explicitly defined in the GB Grid Code, however such switching is considered routine and the RfG helps to
provide greater transparency
Does not contravene GB Grid Code
Consistent with GB Grid Code – CC.6.3.5
Article 9(5)(b) – Island Operation
Article 9(5)(c)(1) – Quick Re-synchronisation capability – as agreed with TSO, Relevant Network
Operator and Power Generating Facility.
Article 9(5)(c)(2) – The generating unit whose minimum re-synchronisation time after its disconnection
from an external power supply exceeds 15 minutes shall be designed for tripping to house load from
any operating point in the P Q Capability Diagram without using any switchgear position signals for
identifying house load Operation.
Article 9(5)(c)(3) – Generating Units shall be capable of continuing operation following tripping to house
load, irrespective of any auxiliary connection to the external network. The minimum operation time
shall be decided by the Relevant Network Operator pursuant to Article 4(3) in coordination with the
Consistent with GB Grid Code – CC.6.3.7(c)(i), although references to switchgear position are unclear.
Consistent with GB Grid Code
Not currently specified in GB Grid Code.
Not currently specified in GB Grid Code.
2
TABLE 1 – COMPARISION OF ENTSO-E RfG TO GB GRID CODE
ENTSO-E – RfG
GB Code
Relevant TSO.
Article 9(5)(c)(4) – All Power Generating Facility Control Systems shall remain in automatic mode
Generally most control systems would be expected to remain in automatic mode but there are occasions
where such equipment may be switched into manual mode but only with the approval of NGET.
Consistent with GB Grid Code – covered in Bilateral Agreement and Relevant Electrical Standards (RES).
Consistent with GB Grid Code (CC.6.2.2) and Bilateral Agreement
Not currently specified in GB Grid Code but not believed to be an issue
Consistent with Grid Code (CC.6.2.2.3.4 – Pole Slipping Protection) and Bilateral Agreement
Consistent with GB Grid Code (CC.6.1.5 - Quality of Supply and CC.6.6 – System Monitoring) and Bilateral
Agreement
Consistent with GB Grid Code (Planning Code). Note the GB Grid Code does not at present require
Generating Units to provide electromagnetic transient simulations but note these are at the request of the TSO
and pursuant to Article 4(3)
Consistent with GB Grid Code
Consistent with GB Grid Code BC1.A.1.1
Consistent with GB Grid Code – CC.6.3.11
Consistent with GB Grid Code – CC.6.1.5, CC.6.1.6, CC.6.1.7
Covered under CUSC and Grid Code Modification process
Article 9(6)(a) – Synchronisation
Article 9(6)(b) – Protection Schemes and Settings
Article 9(6)(c) – Priority ranking of protection and control
Article 9(6)(d) – Loss of Stability
Article 9(6)(e) – Instrumentation and monitoring – Fault Recording, Dynamic System Monitoring,
Quality of Supply
Article 9(6)(f) – Simulation Models
Article 9(6)(g) – Installation of devices for system operation and/or security
Article 9(6)(h) – Minimum and maximum limits on rates of change of Active Power
Article 9(6)(i) – Neutral earthing arrangements of step up transformers
Article 9(6)(j) – Power / Voltage Quality
Article 9(6)(k) – Modernisation / replacement of Generating Plant and Equipment
Article 10 – General Requirements - Type D Units
Article 10(1) – All Type D units must meet the same requirements as Type A, B and C units except
Articles 7(1)(d), Article 8(2)(a) and Article 9(3)(a).
Article 10(2(a) – Voltage ranges
Article 11 – Requirements for Type B Synchronous Generating Units
Article 11(2) Voltage stability – Reactive Power Capability and Excitation System requirements
Article 11(3) – Fault Ride Through
Consistent with GB Grid Code (CC.6.1.4)
Consistent with GB Grid Code (CC.6.3.2 and CC.6.3.8). For Small Power Stations N/A.
GB Grid Code requirements (CC.6.3.15) are slightly different (see Table 2 below). In summary, the
differences from the GB Code as against the ENTSO-E RfG are:i)
Voltage profile is defined at the Connection Point whereas in GB, requirement applies only to
Transmission System faults which occur at 200kV or above.
ii)
The ENTSO-E RfG stipulates a voltage range for both short duration and long duration faults. The
TSO will be able to define the voltage profile requirements within a range of up to 150ms and
optionally up to 250ms. Note in GB the fault ride through for short duration faults only applies for up
to 140ms. The minimum voltage at the Connection voltage will be in the range of between 0.3 p,u
and 0.05 p.u. The voltage duration curve (ie the time for which a Generator must withstand low
voltages in GB is longer than that stipulated in ENTSO-RfG. For longer duration faults, the voltage
duration curve in GB is more onerous than Europe. Compliance issues have been experienced in
GB which it is believed the ENTSO-E RfG will resolve. The ENTSO-E RfG implementation will give
an opportunity to resolve GB Grid Code anomalies.
iii) The TSO (pursuant to article 4(3)) is required to define pre and post fault operating conditions (the
details are covered in Table 2 below on the Generating unit.
iv) The Relevant TSO (pursuant to Article 4(3)) shall specify the Active Power Recovery
characteristics.
v)
In general there are slight differences but the ENTSO-E RfG are considered to be slightly easier
than the GB requirements.
Article 12 – Requirements for Type C Synchronous Generating Units
Article 12(1) – All Type C Synchronous Generating Units must meet the general requirements listed in
Articles 7, 8 and 9 as well as the specific type B Synchronous Generating Unit requirements listed in
Article 11, except Article 11(2)(a).
Article 12 (2) – Output Power with Falling Frequency and Active Power Regulation – specified by TSO.
Article 12 (3) – Reactive Power Capability
Consistent with GB Grid Code (CC.6.3.3 and CC.6.3.7)
ENTSO-E RfG is broadly consistent with GB Grid Code but is specified in a slightly different way as detailed in
3
TABLE 1 – COMPARISION OF ENTSO-E RfG TO GB GRID CODE
ENTSO-E – RfG
GB Code
table 2 below. The principle differences are as follows:i)
TSO to define a U/Q profile (Voltage / Reactive Power profile), Figure 6 - which is not replicated in
the GB Code.
ii)
Under the ENTSO-E RfG the maximum Q/Pmax range specified for GB is 0.95 at the HV terminals
of the Generator Transformer. This equates to a Power Factor range of approximately 0.9 Power
Factor Lead to 0.9 Power Factor lag at the HV terminals of the Generator Transformer. The
ENTSO-E RfG does not provide any distinction between lead and lag – ie the mid point. Under the
GB Grid Code the requirement is for a Power Factor of 0.85 Power Lag to 0.95 Power Factor Lead
at the Generating Unit terminals.
iii) These requirements apply at a steady state voltage of 0.1p.u. (ie 10%)
Consistent with GB Grid Code (CC.6.3.7)
Article 12 (4) – Power and Speed Control
Article 13 – Requirements for Type D Synchronous Generating Units
Article 13(1) – All Type D Synchronous Generating Units must meet the general requirements listed in
Articles 7, 8, 9 and 10 as well as the specific type B and C Synchronous Generating Unit requirements
listed in Article 11 and 12.
Article 13(2) – Excitation System Performance requirements including Power System Stabilisers
Article 13(3) – Fault Ride Through
Consistent with GB Grid Code (CC.6.3.8 and CC.A.6)
GB Grid Code requirements (CC.6.3.15) are slightly different (see Table 2 below). In summary, the
differences from the GB Code as against the ENTSO-E RfG are:i)
Voltage profile is defined at the Connection Point whereas in GB requirement applies only to
Transmission System faults which occur at 200kV or above.
ii)
The ENTSO-E RfG stipulates a voltage range for both short duration and long duration faults. The
TSO will be able to define the voltage profile requirements within a range of up to 150ms and
optionally up to 250ms at zero voltage at the Connection Point. The voltage duration curve (ie the
time for which a Generator must withstand low voltages in GB is longer than that stipulated in
Europe by 10ms (ie a move from 140ms to 150ms) for short duration faults. For longer duration
faults, the voltage duration curve in GB is more onerous than Europe. Compliance issues have
been experienced in GB which it is believed the ENTSO-E RfG will resolve.
iii) The TSO (pursuant to article 4(3)) is required to define pre and post fault operating conditions (the
details are covered in Table 2 below on the Generating unit.
In general there are slight differences but the ENTSO-E RfG are considered to be slightly easier than the GB
requirements.
Article 14 – Requirements for Type A Power Park Modules
Article 14 (1) – All Type A Power Park Modules must meet the same General requirements as Type A
units.
Article 14(1)(a) – Reactive Power requirements at the Connection Point defined by DSO
Article 15 – Requirements for Type B Power Park Modules
Article 15(1) – All Type B Power Park Modules must meet the general requirements listed in Articles
7, and 8 as well as the specific requirements for Type A Power Park Modules listed in Article 14.
Article 15(2)(a) and (b) – Reactive current injection at the Connection Point for balanced and
unbalanced faults.
For Small Power Stations – N/A.
The GB Grid Code is not detailed on this issue other than under CC.6.3.15 (fault ride through). The GB Grid
Code states (within clause CC.6.3.15) that a Generating Unit or Power Park Module should inject maximum
reactive current without exceeding the Transient Rating of the Generating Unit or Power Park Module. The
ENTSO-E RfG is very different on these requirements. By specifying a minimum reactive power requirement
there may be a technical constraints on the delivery of active power during the disturbance. The RfG has been
drafted with a view to a national choice of priority between real and reactive power exchange. Further detailed
scrutiny may be needed in order to ensure that intent of retaining the GB priority for real current can be
retained without overstressing the equipment.
GB Grid Code requirements (CC.6.3.15) are slightly different (see Table 2 below). In summary, the
differences from the GB Code as against the ENTSO-E RfG are:i)
Voltage profile is defined at the Connection Point whereas in GB the requirement applies only
Article 15(3) – Fault Ride Through
4
TABLE 1 – COMPARISION OF ENTSO-E RfG TO GB GRID CODE
ENTSO-E – RfG
GB Code
to Transmission System faults which occur at 200kV or above.
The ENTSO-E RfG stipulates a voltage range for both short duration and long duration faults.
The TSO will be able to define the voltage profile requirements within a range of up to 400ms.
The minimum voltage at the Connection voltage will be in the range of between 0.15 p,u and
0.05 p.u. The TSO (pursuant to article 4(3)) is required to define pre and post fault operating
conditions (the details are covered in Table 2 below on the Generating unit.
iii)
The Relevant TSO (pursuant to Article 4(3)) shall specify the Active Power Recovery
characteristics upon recovery of the voltage to 85%.
In general the ENTSO-E RfG and GB Code are broadly similar but it is noted that the ENTSO-E RfG has a
slightly longer Voltage Duration profile than the current GB Code.
ii)
Article 16 – Requirements for Type C Power Park Modules
Article 16(1) – All Type C Power Park Modules must meet the general requirements listed in Articles
7, 8 and 9 as well as the specific requirements for Type B Power Park Modules (except Type A Power
Park Modules).
Article 16(2) – Synthetic Inertia – specified by TSO pursuant to Article 4(3)
Not currently specified in GB Grid Code but the Frequency Response Working Group are investigating these
issues.
ENTSO-E RfG is fully consistent with the GB Grid Code (CC.6.3.2(c)) but is specified in a slightly different way
as detailed in table 2 below. The principle differences are as follows:iv) TSO to define a U/Q profile (Voltage / Reactive Power profile), Figure 10 - which is not replicated in
the GB Code.
v)
Under the ENTSO-E RfG the maximum Q/Pmax range specified for GB is 0.66 at the Connection
Point. This equates to a Power Factor range of 0.95 Power Factor Lead to 0.95 Power Factor
lag)(ie the same as the GB Code). The ENTSO-E RfG does not provide any distinction between
lead and lag but simply provides a range.
These requirements apply at a steady state voltage range of 0.1 p.u (ie 10%)
Consistent with GB Grid Code (CC.6.3.2(c)). In the GB the requirement of Figure 1 of CC.6.3.2(c)) does have
a reduction in reactive capability when operating in the leading mode of operation (below 50%) MW output
and the reactive capability requirement is further reduced when the plant is operating below 20% of
Registered Capacity. The ENTSO-E RfG does not capture this current GB requirement.
Consistent with GB Grid Code (CC.6.3.15) but not explicitly specified.
Consistent with GB Grid Code (CC.6.3.8 and CC.A.7)
Article 16(3) (b) – Reactive Power capability at maximum capacity
Article 16(3) (c) – Reactive Power capability below maximum capacity
Article 16(3)(d) – Priority of Reactive Power or Active Power specified by TSO pursuant to Article 4(3)
Article 16(3)(e) – Reactive Power Control Modes – ie Voltage Control, Reactive Power Control or
Power Factor Control
Article 17 – Requirements for Type D Power Park Modules
Article 17(1) – All Type D Power Park Modules must meet the general requirements listed in Articles
7, 8, 9 and 10 as well as the specific requirements for Type C Power Park Modules (except for Type A
Power Park Modules).
Article 17 (1)(a) – Fault Ride Through Capability
GB Grid Code requirements (CC.6.3.15) are slightly different (see Table 2 below). In summary, the
differences from the GB Code as against the ENTSO-E RfG are:i)
Voltage profile is defined at the Connection Point whereas in GB the requirement applies only to
Transmission System faults which occur at 200kV or above.
ii)
The ENTSO-E RfG stipulates a voltage range for both short duration and long duration faults. The
minimum voltage at the Connection voltage will be 0 p.u for between 150ms and 250ms. The time
for which a Generator must withstand low voltages as stipuated in ENTSO-E RfG is longer than
that stipulated in GB by 10ms (ie a move from 140ms to 150ms) for short duration faults. The TSO
(pursuant to article 4(3)) is required to define pre and post fault operating conditions (the details
are covered in Table 2 below on the Generating Unit.
iii)
The Active Power Recovery characteristics are specified in Article 15 (Type B Power Park
Modules).
In general the ENTSO-E RfG and GB Code are broadly similar but it is noted that the ENTSO-E RfG has a
5
TABLE 1 – COMPARISION OF ENTSO-E RfG TO GB GRID CODE
ENTSO-E – RfG
GB Code
slightly longer Voltage Duration profile than the current GB Code.
Table 3 of this document details the GB and ENTSO-E RfG differences between Offshore Power Park
Modules. This comparison has been completed on the basis of comparing the ENTSO-E RfG with the GB
Code such that no elements of the ENTSO-E RfG have been omitted. The reader is therefore referred to
Table 3 of this document to compare the differences between the Offshore GB Code and Offshore ENTSO-E
RfG.
The GB Grid Code does not currently specify a compliance requirement. At the present time the compliance
requirements are currently specified in two guidance notes (Guidance Notes for Synchronous Generators,
Issue 11, September 2008 and Guidance Notes for Power Park Developers, Issue 2, September 2008). A
Consultation has been held on the proposed Compliance Requirements for inclusion in the Grid Code which is
currently with Ofgem (the Regulator) for final approval.
Requirements for Offshore Power Park Modules – Articles 18 - 23
Operational Notification Procedure – Article 24 - 51
6
(Comparison based on GB Grid Code Issue 4 Revision 9 only and ENSTO - E RFG Internal Version dated 24 January 2012)
(Note – Does not include other Industry Codes)
Requirement
Plant Type
Large
Frequency Range
(GB CC.6.1.3
ENTSO-E – Article
7- 1(a) Table 2
Synchronous and
Asynchronous
Voltage Operating
Range
(GB CC.6.1.4)
(ENTSO-E – Article
9 – 3a) and Article
10 – 2 a) – 1 Tables
5.1 and 5.2)
Synchronous and
Asynchronous
Power Quality
Harmonic Content
(GB CC.6.1.5(a)
ENTSO-E – Article
9 – 6 j1),2)
Synchronous and
Asynchronous
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
51.5 – 52 Hz for 15
minutes
51 – 51.5 Hz for 90
minutes
49.0 – 51 Hz
Continuous
47.5 – 49 Hz 90
minutes
47 – 47.5 Hz 20
seconds
50 – 100MW
N/A (SPT / SHETL)
At 400 kV 5%
(although voltages
between +5% and
+10% will not last
longer than 15
minutes)
At 275 kV  10%
At 132 kV  10%
Below 132 kV  6%
The harmonic
distortion from all
sources under both
Planned Outage
and fault conditions
shall comply with
the requirements of
the Tables of
Appendix A of
Engineering
Recommendation
G5/4. The
Electromagnetic
Compatibility levels
will be specified by
NGET in the
1 – 10 MW
400W – 1 MW
As per Type A
As per Type A
Between 300 kV
and 400kV
0.9 p.u – 1.05 p.u
and between 1.05
p.u and 1.1p.u for
15 minutes
Between 110kV and
300kV
0.9 – 1.10 p.u
As defined by the
Relevant Network
Operator as defined
in Article 9 – 3a)
pursuant to Article
4(3).
N/S
51.5Hz – 52.0 Hz
for 15 minutes
51 Hz – 51.5 Hz for
90 minutes
49 Hz – 51 Hz
Unlimited
48.5 – 49 Hz –
defined by TSO but
pursuant to Article
4(3)
47.5 – 48.5Hz for 90
minutes
47 – 47.5 Hz for 20
seconds
N/S
As per Type C
Specified by the
Relevant Network
Operator which
shall be consistent
with National and
International
technical rules.
N/S
N/S
> 30MW or
connected at 110kV
or above
As per Type A
As per Large
N/A unless directly
connected
For directly
Connected Power
Stations – as per
Large.
N/A
As per Large
N/A for Embedded
Power Stations –
specified by DNO.
7
A
30 – 10 MW
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A unless directly
connected
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Bilateral Agreement
Power Quality
Phase Unbalance
(GB CC.6.1.5(b))
ENTSO-E – Article
9 – 6 j 1), 2)
Power Quality
Phase Unbalance
during infrequent
short duration peaks
(GB CC.6.1.6)
ENTSO-E – Article
9 – 6j 1), 2)
Synchronous and
Asynchronous
Synchronous and
Asynchronous
N/A for Embedded
Power Stations
(Specified by DNO)
For Directly
Connected Users Under Planned
Outage Conditions
the maximum
Phase Voltage
Unbalance should in
England and Wales
should remain
below 1% and in
Scotland below 2%
unless abnormal
conditions prevail.
N/A for Embedded
Power Stations –
specified by DNO
For Directly
Connected Users Under Planned
Outage Conditions
stated in
CC.6.1.5(b)
infrequent short
duration peaks with
a maximum value of
2% are permitted for
phase (voltage)
unbalance subject
to the prior
agreement of NGET
under the Bilateral
Agreement.
A
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
400W – 1 MW
For directly
Connected Power
Stations – as per
Large.
N/A
As per Type C
Specified by the
Relevant Network
Operator which
shall be consistent
with National and
International
technical rules.
N/S
N?S
N/A
As per Type C
Specified by the
Relevant Network
Operator which
shall be consistent
with National and
International
technical rules.
N/S
N/S
N/A for Embedded
Power Stations –
specified by DNO
For directly
Connected Power
Stations – as per
Large.
N/S for Embedded
Power Stations –
specified by DNO
N/Ae for Embedded
Power Stations –
specified by DNO
8
Requirement
Plant Type
Large
Voltage Fluctuations
(GB CC.6.1.7(a)
and (b)
ENTSO-E – Article
9 – 6 j 1), 2)
Synchronous and
Asynchronous
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
For Directly
Connected Users –
Voltage fluctuations
at a Point of
Common Coupling
with a fluctuating
load directly
connected to the
Onshore
Transmission
System shall not
exceed (a) in
England and Wales,
1% of the voltage
level for step
changes which
occur repetitively.
Any large voltage
excursions other
than step changes
may be allowed up
to a level of 3%
provided that this
does not constitute
a risk to the
Transmission
System. In
Scotland the limits
for voltage level
step changes are
defined in P28
50 – 100MW
N/A (SPT / SHETL)
For directly
Connected Power
Stations – as per
Large.
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A
N/A for Embedded
Power Stations –
specified by DNO
For voltages above
132 kV the Flicker
Severity (short term)
of 0.8 Unit and a
Flicker Severity
(Long Term) of 0.6
Unit for voltages of
132 kV and below,
Flicker Severity
*(Short Term) of 1.0
Unit and a Flicker
Severity (Long
Term) of 0.8 Unit,
as set out in
9
> 30MW or
connected at 110kV
or above
As per Type C
A
30 – 10 MW
1 – 10 MW
400W – 1 MW
Specified by the
Relevant Network
Operator which
shall be consistent
with National and
International
technical rules.
N/S
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
A
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
400W – 1 MW
Applicable only for
Direct Connections
Applicable only for
Direct Connections
Applicable only for
Direct Connections
As per Type C
N/S
N/S
The Protection
Operating Times will
be specified by
NGET in the
Bilateral Agreement
but shall not be
faster than:-
N/A for Embedded
Connections
specified by DNO
N/A for Embedded
Connections
specified by DNO
The probability that
the fault clearance
time stated in
accordance with the
Bilateral Agreement
will be exceeded by
any given fault must
be less than 2%.
The Relevant
Network Operator
shall define the
Settings necessary
to protect the
Network taking into
account the
characteristics of
the Power
Generating Facility.
The Power
Generating
Facilities and
Network Settings
relevant to the
Power Generating
Facility shall be coordinated and
agreed between the
Network Operator
and Generator as
defined in Article 9 6
b) pursuant to
Article 4(3).
N/A for Embedded
Connections
Electrical protection
of the Generating
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Engineering
Recommendation
P28 as current at
the Transfer Date.
N/S for Embedded
Power Stations –
specified by DNO.
Protection Fault Clearance
Times
(CC.6.2.2.2.2(a)
Article 9 – 6 b)
and Article 9 – 6b) –
2).
Synchronous and
Asynchronous
At 400kV:- 80ms
At 275kV:- 100ms
At 132kV and
below:- 120ms
10
Requirement
Plant Type
Large
Back Up Protection
Requirements
GB CC.6.2.2.2.2(b)
ENTSO-E Article 9
– 6b)
Synchronous and
Asynchronous
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
specified by DNO
50 – 100MW
N/A (SPT / SHETL)
Applicable only to
directly connected
Generators
Applicable only for
Direct Connections
Applicable only for
Direct Connections
N/A for Embedded
Connections
specified by DNO
N/A for Embedded
Connections –
specified by DNO
In the event that
clearance times
defined under
CC.6.2.2.2.2(a) are
not met, Generators
are required to
provide Back-up
Protection. NGET
will also provide
back-up Protection.
The two back-up
protections will be
co-ordinated to
provide
discrimination.
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
On a Generating
Unit or Power Park
Module where only
One Main protection
is provided the back
up protection
provided by the
Generator is
required to operate
within 300ms.
Where two main
protections are
provided or for
directly connected
11
> 30MW or
connected at 110kV
or above
As per Type C
30 – 10 MW
Unit shall take
precedence over
operational controls
taking into account
system security,
health and safety of
staff and the public
and mitigation of the
damage to the
Generating Unit in
accordance with
Article 9 – 6 b),2).
the Relevant
Network Operator
shall define the
Settings necessary
to protect the
Network taking into
account the
characteristics of
the Power
Generating Facility
as per Article 9 –
6b) pursuant to the
requirements of
Article 4(3)..
A
1 – 10 MW
400W – 1 MW
N/S
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Generators and
Power Park
Modules connected
at or below 132kV
the back up
clearance time shall
operate to give a
fault clearance time
of no slower than
800ms in England
and Wales and
300ms in Scotland
Generators and
Power Park
Modules shall also
be required to
withstand, without
tripping, the loading
incurred by
clearance of
breaker fail
protection or back
up protection
Circuit Breaker Fail
Protection
CC.6.2.2.2.2(c)(d)
ENTSO-E – Article
9 – 6b).
Synchronous and
Asynchronous
N/A for Embedded
Connections
specified by DNO
The Generator is
required to provide
circuit breaker fail
protection for direct
connections at 400
or 274kV and for
direct connections
in Scotland at 132
kV. In the event of
a protection system
failure circuit
breaker fail is
required to initiate
tripping so as to
interrupt fault
current within the
next 200ms. The
target performance
for the System Fault
A
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
400W – 1 MW
Applicable only for
Direct Connections
Applicable only for
Direct Connections
As per Type C
N/S
N/S
N/A for Embedded
Connections–
specified by DNO
N/Afor Embedded
Connections –
specified by DNO
The Relevant
Network Operator
shall define the
Settings necessary
to protect the
Network taking into
account the
characteristics of
the Power
Generating Facility
as per Article 9 –
6b) but pursuant to
the requirements of
Article 4(3).
12
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Dependability index
shall be not less
than 99%.
Protection
Equipment to be
provided
GB CC.6.2.2.3
ENTSO-E Article 9
– 6 b) – 3), Article 9
– 6 b) c) and d)
Synchronous and
Asynchronous
N/A for Embedded
Connections
specified by DNO
For direct
connections the
following mandatory
requirements are
necessary
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
As per Large for
Directly connected
and Embedded
Plant
As per Large for
Directly Connected
and Embedded
Plant
As per type C
Agreed between the
Network Operator
and Power
Generating Facility
pursuant to Article
4(3). The protection
systems can include
the following
requirements
Loss of Excitation
protection
No busbar, mesh
corner circuit
breaker fail
protection
equipment or AC or
DC wiring may be
worked upon in the
absence of a
representative from
NGET
External and
internal short circuit
Asymmetric load
(Negative Phase
sequence)
Stator and rotor
overload
Over/under
excitation
Over / under
undervoltage at the
connection point
Over / under voltage
at the alternator
terminals
Inter-area
oscillations
Robustness against
power swings (for
example angle and
voltage stability
Over and
underfrequency
Asynchronous
operation (pole slip)
Protection against
inadmissible shaft
torsions (for
example
In addition, the
following
requirements shall
apply as specified
by NGET in the
Bilateral Agreement
Protection of
Interconnecting
Connections
Circuit Breaker Fail
Pole Slipping
Protection
(Synchronous Plant
only)
Signals for Tariff
Metering
and the coordination of relay
settings
across the
13
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Connection Point.
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
subsynchronous
resonance
Generating Unit line
protection
Unit transformer
protection
Backup schemes
against protection
and switchgear
malfunction
Overfluxing
Inverse power
Rate of change of
frequency
Neutral voltage
displacement as per
Article 9 – 6 b) 3).
For Embedded
Generators the
requirements will be
specified by the
DNO at the
connection point
other than
requirements for
Pole Slipping
protection and Tariff
Metering Signals
In addition with
regard to priority
ranking of protection
and control the
Power generating
facility shall
organise their
protections and
control devices in
compliance with the
following priority
ranking organised in
decreasing order of
importance
Network System
and Generating Unit
Protections
Synthetic Inertia (if
applicable)
Frequency Control
(Active Power
adjustment)
Power Restriction
and Power gradient
constraints as per
Article 9 – 6 c).
14
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Short Circuit Ratio
GB CC.6.3.2(a)
(ENTSO-E – Article
34 – 3.
Reactive Capability
(GB - CC.6.3.2)
(ENTSO-E
Synchronous –
Article 11 – 2a),
Article 12 – 3(a) and
(b)
Asynchronous
Article 14-1a),
Article 16 – 3(b) and
(c)
Synchronous
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
In the event of loss
of stability of a
single generating
unit it shall
automatically
disconnect in order
to support system
security and prevent
damage to the
Generating Unit as
per Article 9 – 6 – d)
pursuant to the
requirements of
Article 4(3).
As per type B
A
1 – 10 MW
400W – 1 MW
No less than 0.5
unless a lower value
is specified by the
TSO pursuant to the
requirements of
Article 4(3).
N/S
For plant of
1600MVA or greater
no less than 0.4.
For Plant less than
1600MVA no less
than 0.5
No less than 0.5
N/A
Asynchronous
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Not applicable
Synchronous
0.85 PF Lead to
0.95 Lag at Rated
MW Output at
Generator Unit
Terminals
As per Large
N/S
As per Type C
0.95 PF Lead to
0.95 PF Lag at
Rated MW output.
Capability to meet
requirements of Fig
1 of Connection
Conditions. In
Scotland the
reactive capability of
As per Large
N/A
As per Type C
Specified by the
Relevant Network
Operator at the high
voltage terminals of
the step up
transformer at the
Connection Point or
at the alternator
terminals if no
transformer exists
as per Article 11 –
2a) pursuant to the
requirements of
Article 4(3).
As per Type A
N/S
Asynchronous
Voltage – Q/Pmax
range (at 1p.u
voltage) at the
Connection Point (ie
the HV side of the
Generator
Transformer.
Equates to approx
0.92 PF lead to
0.876 PF lag at
Rated MW Output
as specified by the
TSO pursuant to
Article 4(3).
Voltage – Q/Pmax
range (at 1p.u
voltage) at the
Connection Point.
Equates to approx
0.97 PF lead to 0.92
PF lag at Rated MW
Output as specified
by the TSO. At
15
As per Type B
30 – 10 MW
Specified by the
Relevant DSO in
accordance with
Article 14 – 1a) but
must be pursuant to
Article 4(3).
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
0.95 Power Factor
Lead to Power
Factor Lag applies
at the HV Side of
the Connecting
Transformer at
132kV, 275kV or
400kV.
50 – 100MW
N/A (SPT / SHETL)
Synchronous
Power Output not to
fall more than prorata with frequency
as per Figure 2 of
Connection
Conditions
As per Large
N/A
As per Type C
Asynchronous
As per Synchronous
As per Large
N/A
N/S
Voltage Changes in
the normal
operating Range
(GB – CC.6.3.4
(Synchronous
ENTSO-E – Article
11 – 2), Article 12 –
3(a) and (b))
Synchronous
Reactive Power
output under steady
state conditions
should be within the
voltage range of
5% at 400kV,
275kV and 132 kV
and lower voltages
As per Large
N/A
As per Type C
Voltage Changes in
the normal
operating Range
(GB – CC.6.3.4
(Asynchronous
Asynchronous
As per Synchronous
but in addition
requirements for
voltage and reactive
power requirements
As per Large
N/Ae
As per Type C
Output Power with
Falling Frequency
(GB - CC.6.3.3)
(ENTSO-E
Synchronous –
Article 12 – 2(a) and
(b)
Asynchronous
(Not Specified)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
16
> 30MW or
connected at 110kV
or above
30 – 10 MW
lower Active Power
outputs the Power
Park Module must
operate as specified
by the TSO and
remain consistent to
the Q/Pmax range
anywhere in the
operating diagram
of Figure 11
pursuant to Article
4(3)
Specified by TSO
pursuant to Article
4(3) but within the
boundaries of
Below 49Hz –
maximum reduction
rate of 2% of
maximum capability
per 1Hz frequency
drop below 49 Hz
Below 49.5 Hz up to
a maximum
reduction rate of
10% of maximum
capacity per 1Hz
frequency drop
below 49.5 Hz.
N/S
Generating Unit is
required to meet a
Voltage – Q/PMax
curve as specified
by the TSO
pursuant to Article
4(3) at both full load
(Article 12 -3(a) (1)
– (2) and Article 12 3(b) at lower loads.
Power Park Module
is required to meet
a Voltage – Q/PMax
curve as specified
by the TSO
A
1 – 10 MW
400W – 1 MW
N/S
N/S
N/S
N/S
DSO to define
requirement as per
Article 11- 2)
pursuant to Article
4(3).
N/S
As per Type B.
DSO to define
requirement as per
Article 14 -1(a)
pursuant to Article
4(3).
Requirement
Plant Type
Large
ENTSO-E – Article
14 – 1(a), Article 16
- 3(b) and Article 16
– 3(c)
(Asynchronous –
Black Start
(GB CC.6.3.5)
ENTSO-E – Article
9 – 5(a)
Contribution to
Frequency Control
by continuous
Modulation of Active
Power
(GB – CC.6.3.6(a)
ENTSO-E – Article
9 – 2(a)
Contribution to
Voltage Control by
continuous
Modulation of
Reactive Power
(GB – CC.6.3.6(b)
ENTSO-E Article 11
– 2(a) and (b) and
Article 12 - 3
Requirement for
Power Station to be
fitted with a
Proportional Turbine
Speed Governor
GB – CC.6.3.7(a)
ENTSO-E - Article 9
– 2(a) and Article 12
– 4(a)
Requirement for
Frequency
Controller or
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
if Embedded and
connected at 33kV
and below are also
specified
50 – 100MW
N/A (SPT / SHETL)
Synchronous and
Asynchronous
Specified by NGET
in the Bilateral
Agreement
As per Large
Not applicable
As per Type C
Synchronous
Required
As per Large
Not applicable
As per Type C
pursuant to Article
4(3) at both full load
(Article 16 -3(b) and
Article 16 - 3(c) at
lower loads.
Not a mandatory
requirement but
specified by the
TSO pursuant to
Article 4(3)
depending upon
System Security in
a Synchronous
area.
Required
Asynchronous
Required unless the
Power Park Module
is in Scotland and
has a Registered
Capacity of less
than 50MW.
As per Large
N/A
As per Synchronous
Synchronous and
Asynchronous
Required
As per Large
N/A
Synchronous
Required
Required
Asynchronous
Required except in
relation to Power
Park Modules in
Scotland which
have a Registered
Capacity of less
than 50MW
Required except in
relation to Power
Park Modules in
Synchronous and
Asynchronous
400W – 1 MW
N/S
N/S
N/S
N/S
As per Synchronous
N/S
N/S
As per Type C
Required as per
Article 12 – 3
pursuant to Article
4(3).
Required as
specified by the
Relevant DSO in
accordance with
Article 11 – 2(a) and
(b) and pursuant to
Article 4(3)
N/S
N/A
As per Type C
N/S
N/S
Required
N/A
As per Type C
Required as per
Article 9 – 2(a)
pursuant to Article
4(3) and Article 12
– 4(a)
Required as per
Article 9 – 2(a)
N/S
N/S
Required
N/A
As per Type C
Required as
specified in Article 9
– 2(e) pursuant to
N/S
N/S
17
> 30MW or
connected at 110kV
or above
30 – 10 MW
A
1 – 10 MW
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
Requirement
Plant Type
Large
Governor to be
designed and
operated to an
appropriate
standard /
specification
(GB CC.6.3.7(a)(i),(ii)
ENTSO-E – Article
9 – 2(e).
Requirement for the
Frequency
Controller or
Turbine speed
Governor to Control
the Generating Unit
or Power Park
Module Active
Power with stability
over the entire
operating range
(GB CC.6.3.7 (b)
ENTSO-E - Article 8
– 2 and Article 9 –
2
Ability of a
Generating Unit
Frequency
Controller or
Governor to control
system frequency
below 52Hz unless
this causes the
Generating Unit or
Power Park Module
to operate below its
designed minimum
operating level.
(GB CC.6.3.7(c)(i))
(ENTSO-E – Article
9 – 5(b)
Governor Droop or
Frequency Control
Droop
(GB CC.6.3.7 (c)(ii))
ENTSO-E Article 7
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Scotland which
have a Registered
Capacity of less
than 50MW
50 – 100MW
N/A (SPT / SHETL)
Synchronous and
Asynchronous
Required
(Not applicable to
Power Park
Modules in Scotland
which have a
Registered Capacity
of less than 50MW)
Required
N/A
As per Type C
Synchronous and
Asynchronous
Required
(Not applicable to
Power Park
Modules in Scotland
which have a
Registered Capacity
of less than 50MW)
Required
N/A
Synchronous and
Asynchronous
Droop Setting to be
between 3 and 5%
(Not applicable to
Power Park
Modules in Scotland
Droop Setting to be
between 3 and 5%
N/A
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
30 – 10 MW
A
1 – 10 MW
400W – 1 MW
Required as per
Article 9 –
2 pursuant to
Article 4(3)
Required for
reducing power
output in steps no
more than 20% of
maximum capacity
as specified in
Article 8 – 2
pursuant to Article
4(3).
N/S
As per Type C
Required as
specified by
Relevant Network
Operator and TSO
in accordance with
Article 9 – 5(b)
pursuant to Article
4(3).
N/S
N/S
As per Type C
For Plant in
Frequency Sensitive
Mode
Droop specified by
the TSO but must
As per Type A
Not specified for
Plant in Frequency
Sensitive Mode.
For Plant operating
in Limited
> 30MW or
connected at 110kV
or above
Article 4(3)
18
Requirement
Plant Type
Large
– 1(c)(2) and Article
9 –2) d) - 1 – Table
3.
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
which have a
Registered Capacity
of less than 50MW)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
A
1 – 10 MW
400W – 1 MW
be between 2 and
20% as detailed in
Article 9 – 2d) –1) Table 3
Frequency Control
/Governor
Deadband Settings
(GB CC.6.3.7(c)(iii))
ENTSO-E - Article
9 – 2)d) - 1 – Table
3
Synchronous and
Asynchronous
Deadband to be
0.03Hz or 
0.015Hz
(Not applicable to
Power Park
Modules in Scotland
which have a
Registered Capacity
of less than 50MW)
Deadband to be
0.03Hz or 
0.015Hz
N/A
As per Type C
For Plant in
Frequency Sensitive
Mode
Deadband specified
by the TSO but
must be between 0
– 0.5 Hz as detailed
in Article 9 – 2)d) –
1 - Table 3
N/S
Frequency Sensitive
Mode Droop is
defined by the TSO
but must be
between the range
of 2 and 12% as per
Article 7 – 1(c)(2)
No/S
Target Frequency
Settings
GB CC.6.3.7 (d)
ENTSO-E Article 9
– 2) d) - 8)
Synchronous and
Asynchronous
Unit Load Controller
or Power Park
Module Load
Controller to a
Target Frequency
either continuously
or in a maximum of
0.05Hz steps over
at least the range of
50  0.1Hz
N/A
As per Type C
Defined by the TSO
with the target
frequency range set
between 49.9 and
50.1 Hz as defined
in Article 9 – 2) d) 8)
N/S
N/S
Frequency
Performance
Requirements for
Plant operating in
Frequency Sensitive
Mode
(GB CC.6.3.7(e)
and Appendix 3 of
the GB Connection
Conditions
(ENTSO-E Article 9
- 2 d))
Synchronous and
Asynchronous
Unit Load Controller
or Power Park
Module Load
Controller to a
Target Frequency
either continuously
or in a maximum of
0.05Hz steps over
at least the range of
50  0.1Hz
(Not applicable to
Power Park
Modules in Scotland
which have a
Registered Capacity
of less than 50MW)
Generating Units
and Power Park
Modules must be
capable of providing
at least 10% of their
Registered Capacity
(when subject to a 
0.5Hz change or
greater (and
proportionally for
lower frequency
changes)) as
Primary, Secondary
Generating Units
and Power Park
Modules must be
capable of providing
at least 10% of their
Registered Capacity
(when subject to a 
-0.5Hz change or
greater(and
proportionally for
lower frequency
changes)) as
Primary, Secondary
N/A
As per Type C
Parameters for
frequency response
performance
specified by TSO in
accordance with
Article 9 – 2) d)– but
in general these are
similar to that
required by the GB
Grid Code. The
TSO must define
the parameters for
minimum frequency
N/S
N/S
19
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
and High Frequency
Response as
defined in Figures
CC.A.3.1, CC.A.3.2
and CC.A.3.3
Note – Primary
Response – defined
as additional
release of Active
Power gradually
increasing over the
period 0 – 10
seconds and
sustained for a
further 20 seconds,
Secondary
Response – Active
Power gradually
released over the
period 0 – 30
seconds and
sustained for a
further 30 minutes
and High Frequency
Response is the
reduction in Active
Power to a
frequency rise
which must be
achievable within 10
seconds and
sustainable
thereafter.
Synchronous
Generating Unit
Excitation System
Requirements
GB CC.6.3.8(a)(i)
ENTSO-E Article 11
Synchronous
(Not applicable to
Asynchronous
Plant)
(Not applicable to
Power Park
Modules in Scotland
which have a
Registered Capacity
of less than 50MW)
Required to have a
continuously acting
automatic excitation
control system to
provide constant
terminal voltage of
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
and High Frequency
Response as
defined in Figures
CC.A.3.1, CC.A.3.2
and CC.A.3.3
Note – Primary
Response – defined
as additional
release of Active
Power gradually
increasing over the
period 0 – 10
seconds and
sustained for a
further 20 seconds,
Secondary
Response – Active
Power gradually
released over the
period 0 – 30
seconds and
sustained for a
further 30 minutes
and High Frequency
Response is the
reduction in Active
Power to a
frequency rise
which must be
achievable within 10
seconds and
sustainable
thereafter.
As per Large
30 – 10 MW
A
1 – 10 MW
400W – 1 MW
Required to have a
permanent
automatic excitation
control system in
order to provide
constant alternator
N/S
response capability
as a percentage of
Registered Capacity
(Pmax) which is
between 2 – 10%,
the Initial delay time
shall be less than 2
seconds (which is
not covered in the
GB Code) and full
delivery of Active
Power shall be
achieved as
specified by the
TSO but shall be
less than 30
seconds.
Generating Units to
be capable of
providing full Active
Power Frequency
Response (to be
specified) for a
period of between
15 minutes and 30
minutes and
Generators must
operate between
their maximum and
minimum headroom
See Article 9 –
2d)6).
N/A
20
As per Type B
As per Type B
Requirement
Plant Type
Large
– 2(b)
Synchronous
Generating Unit
Excitation System
Performance
Requirements
GB CC.6.3.8(a)(ii)
and Appendix 6 of
the Connection
Conditions
(ENTSO-E Article
11-2(b), Article 12 –
3(a)(5) and
Article 13 – 2) b) (c),
(d), (e), (f), (g) and
(h)
Synchronous
(Not applicable to
Asynchronous
Plant)
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
the Synchronous
Generating Unit
without instability
over the entire
operating range
50 – 100MW
N/A (SPT / SHETL)
Either specified in
the Bilateral
Agreement if
historical plant or
detailed in Appendix
6 of the Connection
Conditions if the
Connection date is
after 1 January
2009. In general
the following high
level requirements
apply,
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A
i) The Excitation
System shall
comprise of an
Excitation Source,
Power System
Stabiliser and
Automatic Voltage
Regulator
ii) Steady State
Voltage Control to
limit the change in
terminal voltage
from no load to full
load
iii) Transient
Voltage Control
Performance when
on open circuit with
performance
requirements to
achieve 100%
voltage being
achieved within
less than 0.6
seconds and the
> 30MW or
connected at 110kV
or above
In addition to the
requirements of
Type B and Type C
(as appropriate) the
following
requirements apply
as
specified in Article
13 – 2) b), (c), (d),
(e), (f), (g) and (h).
In general the
following high level
requirements apply
which shall be
pursuant to Article
4(3).
i) Steady State
Voltage Control to
limit the change in
terminal voltage
from no load to full
load the parameters
being defined by the
Relevant Network
Operator
ii) Transient Voltage
Control
Performance when
on open circuit with
performance
requirements for the
time to achieve
100% voltage and
the time to settle
within 5% of the
voltage change
being specified by
the Relevant
21
30 – 10 MW
None other than in
respect of the
requirements of
Type B. The
Relevant Network
Operator will specify
what additional
facilities are
installed on the
Synchronous Power
Generating Facility
in order to carry out
voltage and
Reactive Power
control within its
area as detailed in
Article 12 – 3(a)(5)
pursuant to Article
4(3).
A
1 – 10 MW
400W – 1 MW
terminal voltage
without instability
over the entire
operating range of
the synchronous
Generating Unit as
per Article 11 – 2(b).
Not specified other
than in respect of
the requirement to
have a automatic
excitation control
system as detailed
in Article 11-2(b) as
noted above
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
time to settle within
5% of the voltage
change achieved
within 3 seconds.
iv) Performance
requirements for the
Exciter rise Time
will be specified by
the TSO but shall
generally be
between 50ms and
300ms.
v) Requirements for
Excitation System
on load Positive
Ceiling Voltage will
be specified by
NGET but will
generally be
between 2 p.u and 4
p.u or Rated field
voltage
vi) Requirements for
a negative ceiling
voltage of 80% of
the positive ceiling
voltage if a static
exciter is employed
vii) Maintenance of
free firing when the
Generator terminals
are exposed to a
drop of between 20
– 30% of rated
terminal voltage
viii) The Excitation
System (if static)
should obtain a
positive on load
ceiling voltage of
not less than 80%
upon recovery of
the Generating Unit
following fault
clearance.
ix) The overall
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
22
> 30MW or
connected at 110kV
or above
Network Operator.
iii) Requirements
for Excitation
System on load
Positive Ceiling
Voltage will be
specified by the
Relevant Network
Operator
iv) Requirements for
a negative ceiling
voltage if a static
exciter is employed
will be specified by
the Relevant
Network Operator
v) Maintenance of
free firing when the
Generator terminals
are exposed to a
drop of 25% of rated
terminal voltage
vi) The Excitation
System (if static)
should obtain a
positive on load
ceiling voltage of
not less than 80%
upon recovery of
the Generating Unit
following fault
clearance.
vii) The overall
Excitation Control
System shall limit
the bandwidth of the
output signal so as
not to cause
torsional oscillations
on other plant
connected to the
network. The
Bandwidth shall be
limited to 3Hz
unless otherwise
specified by the
30 – 10 MW
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
Power Park Module
Voltage Control
Requirements
GB – CC.6.3.8(a)(iii)
Article 14 -1(a) and
Article 16 –3) (e)
Asynchronous
(Not applicable to
Synchronous Plant)
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Excitation Control
System shall limit
the bandwidth of the
output signal so as
not to cause
torsional oscillations
on other plant
connected to the
network.
x) The Excitation
System shall be
equipped with an
Under Excitation
Limiter
xi) The Excitation
System shall be
equipped with an
Over Excitation
Limiter.
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
Each Power Park
Module is required
to have a
continuously acting
automatic control
system to control
the voltage at the
Connection Point
without instability
over the entire
operating range of
the Power Park
Module. Any Plant
or Apparatus used
in the provisions of
such voltage control
may be located at
the Power Park Unit
Terminals, an
intermediate bus
bar of the
Connection Point
As per Large
N/A
23
> 30MW or
connected at 110kV
or above
TSO.
viii) The Excitation
System shall be
equipped with an
Under Excitation
Limiter
ix) The Excitation
System shall be
equipped with an
Over Excitation
Limiter
x) Co-ordination is
required between
the Stator Current
Limiter and
Overexcitation
Limiter
xi) The Excitation
System shall
include a Power
System Stabiliser if
specified by the
Relevant TSO.
As per Type C
A
30 – 10 MW
1 – 10 MW
400W – 1 MW
The Power Park
Module shall be
capable of providing
Reactive Power
automatically by
operation in either
Voltage Control
mode, Reactive
Power Control
Mode or Power
Factor Control
Mode or by a
combination of two
of these as defined
in Article 16 –3) (e).
As per type A
Power Park
Modules are only
required to have a
Reactive Power
Capability at the
high voltage
terminals of the step
up transformer to
the voltage level of
the Connection
Point or at the
alternator terminals,
if no step up
transformer exists
as defined by the
Relevant DSO as
defined in Article 14
-1(a) pursuant to
Article 4(3).
Requirement
Plant Type
Large
Power Park Module
Voltage Control
Performance
Requirements
GB –
CC.6.3.8(a)(iv) and
Appendix 7 of the
Connection
Conditions
(ENTSO-E Article
14 -1(a) and Article
16 – 3) (e) and (f)
Asynchronous
(Not applicable to
Synchronous Plant)
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Either specified in
the Bilateral
Agreement if
historical plant or
detailed in Appendix
7 of the Connection
Conditions if the
Connection date is
after 1 January
2009. In general
the following high
level requirements
apply:-
50 – 100MW
N/A (SPT / SHETL)
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A
i) Continuous
steady state voltage
control is required at
the Connection
Point with a setpoint
voltage and slope
characteristic as
shown in Figure
CC.A.7.2.2(a)
ii) The control
system shall be
capable of operating
to a setpoint voltage
of between 95%
and 105% with a
resolution of 0.25%.
iii) The initial
setpoint voltage will
be 100% but NGET
may specify and
alternative setpoint
voltage within the
range of 95% to
105%.
iv) The setpoint
voltage should be
adjustable between
95% and 105% to a
tolerance of 0.25%
(ie 95%, 95.25%,
95.5%...)
v) The Slope setting
> 30MW or
connected at 110kV
or above
As per Type C
1 – 10 MW
400W – 1 MW
In addition to the
requirements of
Type A (as
appropriate) the
following
requirements apply
as
specified in Article
16 – 3) (e) and (f).
In general the
following high level
requirements
apply:-
As per Type A
Power Park
Modules are only
required to have a
Reactive Power
Capability as
defined by the
Relevant DSO as
defined in Article 14
-1(a) and pursuant
to Article 4(3).
i) The Power Park
Module shall be
capable of
contributing to
voltage control at
the Connection
Point by provision of
Reactive Power
exchange with the
System with a
setpoint voltage
covering at least
0.95 to 1.05 p.u in
steps no greater
than 0.01p.u with a
Slope with a range
of at least 2-7% in
steps no greater
than 0.5%. The
Reactive Power
output shall be zero
when the Grid
voltage value at the
Connection Point
equals the voltage
setpoint. The
setpoint may be
operated with or
without a deadband
selectable in a
range from 0 to
+10% of nominal
24
A
30 – 10 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
should also be
adjustable with a
range of between 2
and 7% with a
resolution of 0.5%
(ie slope settings of
2, 2.5, 3.5 %... may
be specified.
vi) The Voltage
control System
should have a
steady state
operating range
over a range of
setpoint voltages
(95% - 105%) and
slopes 2-7% as
detailed in Figures
CC.A.7.2.2b and
CC.a.7.2.2c (in the
case of 33kV
Connections or
below) of Appendix
7 of the Connection
Conditions.
vii) If the operating
point of the Power
Park Module
deviate so that it is
no longer on the
operating
characteristic
defined by the
setpoint voltage and
slope the control
system shall act
progressively to
return the value to a
point on the
required
characteristic within
5 seconds
viii) The automatic
control system
should also be able
to respond to
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
network voltage in
steps no greater
than 0.5%.
ii) Following a step
change in voltage
90% of the change
in Reactive Power
shall be achieved
within 1 second and
settle at the value
defined by the
operating slope
within 5 seconds
with a steady state
reactive tolerance
no greater than 5%.
iii) For Reactive
Power Control
Mode the Power
Park Module shall
be capable of
setting the Reactive
Power target
anywhere in the
Reactive Power
Range and with
setting steps no
greater than 5MVAr
or 5% (whichever is
smaller) of full
Reactive Power,
controlling the
Reactive Power at
the Connection
Point to an accuracy
within 5MVAr or
5% whichever is
smaller of the full
reactive Power.
iv) For Power Factor
Control, Power
Factor Control shall
be capable of being
controlled at the
Connection Point as
defined by the
25
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
transient events.
ix) For an onload
step change in
Connection Point
Voltage the reactive
power output
response shall
commence within
0.2 seconds of the
application of the
step 90% of the full
delivery of reactive
power shall be
achieved within 1
seocnd.
x) Under transient
conditions the
Settling time shall
be no greater than 2
seconds from the
application of the
step change in
voltage and the peal
to peak magnitude
of any oscillations
shall be less than
5% of the change in
steady state
Reactive Power
within this time
frame.
xi) The Requirement
for a Power System
Stabiliser will be
specified in the
Bilateral Agreement
x) The overall
voltage control
system shall
respond to minor
variations, steps,
gradual changes or
major variations
xi) The overall
voltage control
system shall have a
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
Relevant DSO with
Target Power
Factor steps of no
greater than
0.01.The Relevant
Network Operator
will specify the
tolerance expressed
in MVAr of % within
a period of time
following a sudden
change of Active
Power or step
change in voltage at
the Connection
Point pursuant to
Article 4(3).
v) The Control
Mode, parameter
settings and
operating point for
steady state
Reactive Power
exchange at the
Connection Point
shall be determined
by the Relevant
Network Operator in
co-ordination with
the Relevant TSO
pursuant to Article
4(3).
vi) The Relevant
Network Operator
on co-ordination
with the Relevant
TSO will determine
which reactive
power control mode
(ie Voltage Control,
Reactive Power
Control or Power
Factor Control
mode) shall apply.
vii) The Relevant
TSO will determine
26
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
Other Reactive
Power Control
Modes
Grid Code
CC.6.3.8(a)(v)
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
limited bandwidth
output of between 0
– 5 Hz.
50 – 100MW
N/A (SPT / SHETL)
Synchronous
Reactive Power and
Power Factor
Control Modes
(excluding VAR
limiters) are not
required unless
specified by NGET
in the Bilateral
Agreement
As per Large
N/A
As per Type B and
C
Asynchronous
Reactive Power and
Power Factor
Control Modes
(excluding VAR
limiters) are not
required unless
specified by NGET
in the Bilateral
Agreement
As per Large
N/A
As per Type C
ENTSO-E –
Synchronous Article
11 – 2(b) Article 12
–3(a)
(5)Asynchronous
Article 14 -1(a)
Article 16 – 3(e)(6).
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
27
> 30MW or
connected at 110kV
or above
30 – 10 MW
if the Power Park
Module is to be
fitted with a Power
Oscillation Damping
facility (Power
System Stabiliser)
pursuant to Article
4(3).
None other than in
respect of the
requirements of
Type B. The
Relevant Network
Operator will specify
what additional
facilities are
installed on the
Synchronous Power
Generating Facility
in order to carry out
voltage and
Reactive Power
control within its
area as detailed in
Article 12 –3(a) (5)
pursuant to Article
4(3).
The Relevant
Network Operator
on co-ordination
with the Relevant
TSO will determine
which reactive
power control mode
(ie Voltage Control,
Reactive Power
Control or Power
Factor Control
mode) shall apply in
accordance with
Article 16 – 3)(e)
(6).
A
1 – 10 MW
400W – 1 MW
Required to have a
permanent
automatic excitation
control system in
order to provide
constant alternator
terminal voltage
without instability
over the entire
operating range of
the synchronous
Generating Unit as
per Article 11 – 2(b).
N/S
As per Type A
Power Park
Modules are only
required to have a
Reactive Power
Capability to provide
Reactive Power at
the high voltage
terminals of the step
up transformer to
the voltage level of
the Connection
Point or at the
alternator terminals
if no step up
transformer exists
as defined by the
Relevant DSO as
defined in Article 14
-1(a) pursuant to
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
A
400W – 1 MW
Article 4(3).
Steady State Load
Inaccuracies
GB CC.6.3.9
ENTSO-E Article 9
– 2(a)(2)
Synchronous and
Asynchronous
Negative Phase
Sequence Loadings
GB CC.6.3.10
ENTSO-E Article 11
– 3(a)(5) and Article
13 – 3(a)(5)
Synchronous only
(Asynchronous
captured under
CC.6.3.15 Fault
Ride Through
requirements)
Neutral Earthing
(GB CC.6.3.11
ENTSO-E Article 9
– 6(i)
Synchronous and
Asynchronous
Frequency Sensitive
Relays
(GB - CC.6.3.12
ENTSO-E Article 7
– (1)(a) and Article
1 – (b)
Synchronous and
Asynchronous
The standard
deviation of load
error at steady state
load over a 30
minute period must
not exceed 2.5% of
a Genset’s
Registered
Capacity.
Each Synchronous
Generating Unit is
required to
withstand without
tripping the negative
phase loading
incurred by
clearance of a close
up phase to phase
fault by system back
up protection on the
Transmission
System.
At nominal system
voltages of 132kV
and above the
higher voltage
windings of a
transformer of a
Generating Unit or
Power Park Module
must be star
connected with the
star point suitable
for connection to
Earth
As specified in
CC.6.1.3 the
System Frequency
could rise to 52Hz
or fall to 47Hz.
Each Generating
Unit must continue
to operate within
this frequency range
As per Large
N/A
As per Type C
Specified by
Relevant Network
Operator under
Article 9 – 2(a)(2)
pursuant to Article
4(3).
N/S
N/S
As per Large
N/A
Specified by the
Relevant Network
Operator in
accordance with
Article 13 – 3(a)(5)
As per Type B
Specified by the
Relevant Network
Operator in
accordance with
Article 11 – 3(a)(5)
and pursuant to
Article 4(3)
N/S
As per Large
N/A
As per Type C
Specified by the
Relevant Network
Operator as per
Article 9 – 6 (i)
N/S
N/S
As per Large
N/A
As per Type A
As per Type A
As per Type A
Tripping within the
frequency and time
ranges as specified
in Table 2 of Article
7 – (1)(a) (which is
broadly similar to
the GB Frequency /
time requirements)
to be is prohibited
28
Requirement
Plant Type
Large
Plant operation /
protection outside
the defined
frequency / time
operating ranges
(GB CC.6.3.13
ENTSO-E Article 71(a)(2) and (3).
Synchronous and
Asynchronous
Fast Start Capability
GB CC.6.3.14
(ENTSO-E Article 9
– 5(c))
Synchronous and
Asynchronous
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
for at least the time
periods defined in
CC.6.1.3 unless
NGET has agreed
within the Bilateral
Agreement to any
Frequency level
relays or rate of
change of frequency
relays which will trip
the Generating Unit
or Power Park
Module
50 – 100MW
N/A (SPT / SHETL)
Generating Units
and Power Park
Modules will be will
be responsible for
protecting their plant
outside the range
52 – 47 Hz. Should
such excursions
arise it is up to the
Generating Unit to
disconnect their
plant for the
reasons of safety of
plant and
apparatus.
NGET may specify
in the Bilateral
Agreement the
requirement for a
Genset to have a
Fast Start
Capability. Such
Gensets may be
used for Operating
Reserve and be
initiated by
Frequency level
relays in the range
49 – 50Hz
As per Large
N/A
As per Type A
As per Type A
As per Type A
N/A unless specified
by NGET
N/A
As per Type C
Quick resynchronisation
capability is
required in the case
of disconnection as
agreed between the
Network Operator
and Generator as
per Article 9 – 5(c)
pursuant to Article
4(3)
N/S
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
A
400W – 1 MW
unless otherwise
agreed by the
Relevant TSO
pursuant to Article
4(3)
29
A Generating Unit
shall not disconnect
from the Network
due to rates of
change of
Frequency up to
2Hz/s other than by
loss of mains
protection as
specified in Article 7
– 1(b).
A Generating Unit
shall be capable of
automatic
disconnection at
specified
frequencies if
required by the
Relevant Network
Operator or as
specified in the
National Grid Code
in accordance with
Article 7 – 1(a)(2)
and (3) pursuant to
Article 4(3).
N/S
Requirement
Plant Type
Large
Fault Ride Through
for short term faults
up to 140ms.
(CC.6.3.15(a) and
Appendix 4A of the
Connection
Conditions
ENTSO-E Article
11-3(a)(b))
Article 13-3(a))
Synchronous
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
In GB the Fault Ride
Through
Requirements for
Synchronous and
Asynchronous Plant
are broadly the
same. For faults up
to 140ms in duration
the following high
level requirements
apply:
50 – 100MW
N/A (SPT / SHETL)
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A
i) Each Generating
Unit and Power
Park Module shall
remain transiently
stable and
connected to the
System for any
close up solid
balanced or
unbalanced fault
operating at
Supergrid Voltage
(ie above 200kV) for
a total fault
clearance time of up
to 140ms. A solid
three phase fault or
unbalanced earth
fault may result in
zero voltage on the
faulted phase at the
point of the fault.
ii) Each Generating
Unit or Power Park
Module shall be
designed such that
upon clearance of
the fault on the
Transmission
System and within
0.5 seconds of the
restoration of the
voltage at the
Connection Point to
30
> 30MW or
connected at 110kV
or above
Under ENSTO-E
The Fault Ride
Through
requirements are
segregated between
Synchronous and
Asynchronous Plant
unlike GB. A
voltage Time profile
is also specified
over the whole time
frame unlike GB
which specifies the
requirement for the
period between 0 –
140ms and for
voltage dips after
140ms.
A
30 – 10 MW
1 – 10 MW
400W – 1 MW
As per Type B
Under ENSTO-E
The Fault Ride
Through
requirements are
segregated between
Synchronous and
Asynchronous Plant
unlike GB. A
voltage Time profile
is also specified
over the whole time
frame unlike GB
which specifies the
requirement for the
period between 0 –
140ms and for
voltage dips after
140ms.
N/S
Under the ENTSOE Code
Synchronous
Generators are
required (as per
Article 13-3(a)
(pursuant to Article
4(3)) to:-
Under the ENTSOE Code
Synchronous
Generators are
required (as per
Article 11-3(a)(b)
(pursuant to Article
4(3)) to:-
i) The TSO
(pursuant to Article
4(3)) will define a
voltage against time
profile at the
Connection Point
(within the
boundaries defined
by Figure 7 minimum voltage at
the connection point
being 0 p.u for
150ms up to
250ms) under which
the Synchronous
Generating Unit
shall stay connected
and stable after the
i) The TSO
(pursuant to Article
4(3) will define a
voltage against time
profile at the
Connection Point
(within the
boundaries defined
by Figure 5 –
minimum voltage at
the connection point
being defined by the
TSO but could
range between 0.3
p.u and 0.05 p.u for
between 150ms and
250ms) under which
the Synchronous
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
the minimum levels
defined in CC.6.1.4,
90% of the pre fault
Active Power
generated by the
Generating Unit or
Power Park Module
shall be restored
and supplied to the
System.
iii) In addition during
the period of the
fault when the
voltage is outside of
nominal limits each
Generating Unit or
Power Park Module
shall generate
maximum reactive
current without
exceeding the
transient rating of
the Generating Unit
or Power Park
Module
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
31
> 30MW or
connected at 110kV
or above
power system has
been disturbed by
secured faults on
the network
(balanced and
unbalanced faults)
unless the
protection scheme
requires the
disconnection of the
Generating Unit
from the Network.
ii) The voltage
against time profile
shall be expressed
as the lower limit of
the lowest phase
voltage (in the case
of asymmetrical
faults the lowest
phase voltage shall
be used irrespective
of the voltage drop
on the other two
phases) as a
function of time both
during and after the
fault.
iii) Each TSO
(pursuant to Article
4(3))will define the
pre-fault and post
fault conditions for
fault ride through in
terms of the pre
fault minimum short
circuit capacity at
the Connection
Point, the conditions
for pre fault active
and Reactive Power
operating point of
the Generating Unit
at the Connection
Point and Voltage at
the Connection
30 – 10 MW
1 – 10 MW
Generating Unit
shall stay connected
and stable after the
power system has
been disturbed by
secured faults
(balanced and
unbalanced faults)
on the network
unless the
protection scheme
requires the
disconnection of the
Generating Unit
from the Network
ii) The voltage
against time profile
shall be expressed
as the lower limit of
the lowest phase
voltage (in the case
of asymmetrical
faults the lowest
phase voltage shall
be used irrespective
of the voltage drop
on the other two
phases) as a
function of time both
during and after the
fault.
iii) Each TSO
(pursuant to Article
4(3)) will define the
pre-fault and post
fault conditions for
fault ride through in
terms of the pre
fault minimum short
circuit capacity at
the Connection
Point, the conditions
for pre fault active
and Reactive Power
operating point of
the Generating Unit
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
32
> 30MW or
connected at 110kV
or above
Point and conditions
for the calculation of
the post fault
minimum short
circuit capacity at
the Connection
Point
iv) Each Network
Operator(pursuant
to Article 4(3) shall
define the pre and
post fault
parameters for fault
ride through
capability as an
outcome of the
calculations at the
Connection Point
regarding the prefault minimum short
circuit capacity at
each Connection
Point expressed in
MVA, the pre fault
operating point of
the generating unit
expressed in Active
Power output and
Reactive Power
Output at the
Connection Point
and voltage at the
Connection Point,
the Post fault
minimum short
circuit capacity at
each Connection
Point expressed in
MVA.
iv) The
Undervoltage
protection on the
Generating Unit
should be set to the
widest possible
range by
30 – 10 MW
1 – 10 MW
at the Connection
Point and Voltage at
the Connection
Point and conditions
for the calculation of
the post fault
minimum short
circuit capacity at
the Connection
Point
iv) Each Network
Operator (pursuant
to Article 4(3) shall
define the pre and
post fault
parameters for fault
ride through
capability as an
outcome of the
calculations at the
Connection Point
regarding the prefault minimum short
circuit capacity at
each Connection
Point expressed in
MVA, the pre fault
operating point of
the generating unit
expressed in Active
Power output and
Reactive Power
Output at the
Connection Point
and voltage at the
Connection Point,
the Post fault
minimum short
circuit capacity at
each Connection
Point expressed in
MVA.
iv) The
Undervoltage
protection on the
Generating Unit (as
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Fault Ride Through
for short term faults
up to 140ms.
(CC.6.3.15(a) and
Appendix 4A of the
Connection
Conditions
ENTSO-E Article 15
– 3(a) (b) and
Article 17-1(a)
Asynchronous
As per GB
Synchronous Fault
Ride Through
requirements for
short term faults up
to 140ms
50 – 100MW
N/A (SPT / SHETL)
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A
> 30MW or
connected at 110kV
or above
theGenerator
30 – 10 MW
Under the ENTSOE RfG a substantial
section on Reactive
Current injection
has been included
(Article 15 - 2 .
These requirements
are captured below,.
As per Type B
Under the ENTSOE RfG Power Park
Modules are
required(as per
Article 171(a)(pursuant to
Article 4(3)) to:i) The TSO
(pursuant to Article
4(3)) will define a
voltage against time
33
1 – 10 MW
A
400W – 1 MW
set by the
Generator) should
be set to the widest
possible range
v) The Relevant
TSO (pursuant to
Article 4(3)) will
specify the
requirements for
90% of the Active
Power to be
restored on fault
clearance measured
from the time the
voltage has
recovered above
85% of the pre-fault
nominal voltage
value. The
maximum recovery
period shall be
greater than 0.5
seconds and less
than 15 seconds.
Under the ENTSOE RfG a substantial
section on Reactive
Current injection
has been included
(Article 15 - 2 .
These requirements
are captured below,
.
Under the ENTSOE RfG Power Park
Modules are
required(as per
Article 15-3(a) and
(b) (pursuant to
Article 4(3)) to:i) The TSO
(pursuant to Article
4(3)) will define a
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
34
> 30MW or
connected at 110kV
or above
profile at the
Connection Point
(within the
boundaries defined
by Figure 12 –
minimum voltage at
the connection point
being between 0 p.u
voltage for between
150ms up to
250ms) under which
the Power Park
Module shall stay
connected and
stable after the
power system has
been disturbed by
secured faults
(balanced and
unbalanced faults)
on the network
unless the
protection scheme
requires the
disconnection of the
Power Park Module
from the Network.
ii) The voltage
against time profile
shall be expressed
as the lower limit of
the lowest phase
voltage (in the case
of asymmetrical
faults the lowest
phase voltage shall
be used irrespective
of the voltage drop
on the other two
phases) as a
function of time both
during and after the
fault.
iii) Each
TSO(pursuant to
Article 4(3)) will
30 – 10 MW
1 – 10 MW
voltage against time
profile at the
Connection Point
(within the
boundaries defined
by Figure 9 –
minimum voltage at
the connection point
being between 0.15
p.u - 0.05 p.u for up
to 400ms) under
which the Power
Park Module shall
stay connected and
stable after the
power system has
been disturbed by
secured faults
(balanced and
unbalanced faults)
on the network
unless the
protection scheme
requires the
disconnection of the
Power Park Module
from the Network.
ii) The voltage
against time profile
shall be expressed
as the lower limit of
the lowest phase
voltage (in the case
of asymmetrical
faults the lowest
phase voltage shall
be used irrespective
of the voltage drop
on the other two
phases) as a
function of time both
during and after the
fault.
iii) Each TSO
(pursuant to Article
4(3)) will define the
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
35
> 30MW or
connected at 110kV
or above
define the pre-fault
and post fault
conditions for fault
ride through in
terms of the pre
fault minimum short
circuit capacity at
the Connection
Point, the conditions
for pre fault active
and Reactive Power
operating point of
the Power Park
Module at the
Connection Point
and Voltage at the
Connection Point
and conditions for
the calculation of
the post fault
minimum short
circuit capacity at
the Connection
Point
iv) Each Network
Operator (pursuant
to Article 4(3)) shall
define the pre and
post fault
parameters for fault
ride through as an
outcome of the
calculations at the
Connection Point
regarding the prefault minimum short
circuit capacity at
each Connection
Point expressed in
MVA, the pre fault
operating point of
the Power Park
Module expressed
in Active Power
output and Reactive
Power Output at the
30 – 10 MW
1 – 10 MW
pre-fault and post
fault conditions for
fault ride through in
terms of the pre
fault minimum short
circuit capacity at
the Connection
Point, the conditions
for pre fault active
and Reactive Power
operating point of
the Power Park
Module at the
Connection Point
and Voltage at the
Connection Point
and conditions for
the calculation of
the post fault
minimum short
circuit capacity at
the Connection
Point
iv) Each Network
Operator (pursuant
to Article 4(3)) shall
define the pre and
post fault
parameters for fault
ride through as an
outcome of the
calculations at the
Connection Point
regarding the prefault minimum short
circuit capacity at
each Connection
Point expressed in
MVA, the pre fault
operating point of
the Power Park
Module expressed
in Active Power
output and Reactive
Power Output at the
Connection Point
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Fault Ride Through
for long term faults
greater than 140ms.
(CC.6.3.15(b) and
Appendix 4A of the
Connection
Conditions
ENTSO-E Article
11-3I(a)(b), Article
Synchronous and
Asynchronous
50 – 100MW
N/A (SPT / SHETL)
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
N/A
In addition to the
fault ride through
requirements for
short duration faults
(CC.6.3.15(a) each
Generating Unit and
Power Park Module
is required to:-
36
> 30MW or
connected at 110kV
or above
Connection Point
and voltage at the
Connection Point,
the Post fault
minimum short
circuit capacity at
each Connection
Point expressed in
MVA.
iv) The
Undervoltage
protection on the
Power Park Module
should be set to the
widest possible
range by the
Generator.
30 – 10 MW
Under the ENTSOE RfG no distinction
is made between
short and long
duration faults see
Article 11 – 3(a)(b),
Article 13-3(a)
Article 17-1(a) and
Article 15-3(a) (b).
As per Type B
1 – 10 MW
A
400W – 1 MW
and voltage at the
Connection Point,
the Post fault
minimum short
circuit capacity at
each Connection
Point expressed in
MVA.
iv) The
Undervoltage
protection on the
Power Park Module
should be set to the
widest possible
range by the
Generator.
v) The Relevant
TSO (pursuant to
Article 4(3)) will
specify the
requirements for
90% of the Active
Power to be
restored on fault
clearance measured
from the time the
voltage has
recovered above
85% of the pre-fault
nominal voltage
value. The
maximum recovery
period shall be
greater than 0.5
seconds and less
than 10 seconds.
Under the ENTSOE RfG no distinction
is made between
short and long
duration faults See
Article 11-3(a)(b)
and Article 15-3(a)
(b). The Reactive
injection during
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
13-3(a), Article 15 –
3(a) (b) and Article
17-1(a)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
i) Remain
transiently stable
and connected to
the System without
tripping for any
Balanced Supergrid
Voltage dips
anywhere on or
above the heavy
black line of Figure
5 defined under
CC.6.3.15(b).
ii) Provide Active
Power output at
least in proportion to
the retained
balanced voltage at
the Connection
Point allowing for a
reduction in the
power output of a
Power Park Module
where the primary
energy source has
reduced
iii) Generate
maximum reactive
current without
exceeding the
transient rating of
the Generating Unit
or Power Park
Module during the
period of the voltage
dip
iv) Restore Active
Power output to at
least 90% of its pre
fault output (unless
there has been a
reduction in the
37
> 30MW or
connected at 110kV
or above
The Reactive
injection during
system faults and
disturbances for
Power Park
Modules is covered
under Article 15 -2.
30 – 10 MW
1 – 10 MW
system faults and
disturbances for
Power Park
Modules is covered
under Article 15 -2.
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
primary energy
source to the Power
Park Module) within
1 second of
restoration of the
voltage at the
Connection Point.
Fault Ride Through
– Other
Requirements
Operation under
high wind speed or
emergency
shutdown conditions
(GB CC.6.3.15.3(i)
ENTSO-E – Article
17-1(a) or Article
15-(3)
Asynchronous
Fault Ride Through
– Other
Requirements
Negative Phase
sequence loading
CC.6.3.15.3(ii)
ENTSO-E – Article
17-1(a) or Article
15-3).
Asynchronous
Reactive Current
Injection during
System faults and
Disturbances
Synchronous
A
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
400W – 1 MW
As per Large
N/A
Not explicitly
specified but could
be within the
framework of Article
17-1(a) by being
specified by the
Relevant TSO
pursuant to Article
4(3).
As per Type C
Not explicitly
specified but could
be within the
framework of Article
15-(3) by being
specified by the
Relevant TSO
pursuant to Article
4(3).
N/S
As per Large
N/A
Specified by the
Relevant Network
Operator (pursuant
to Article 4(3)) in
accordance with
Article 17 – 1(a)
As per Type C
Specified by the
Relevant Network
Operator (pursuant
to Article 4(3)) in
accordance with
Article 15 – 3.
N/S
As per Large
N/A
N/S
N/S
N/S
N/S
For Power Park
Modules comprising
of wind turbine
generating units the
fault ride through
requirements do not
apply when the wind
farm is operating at
less than 5% of
Rated MW output or
when 50 % or more
of the wind turbines
have been shut
down due to
emergency shut
down sequence.
Each Power Park
Module must be
able to withstand
without tripping the
negative phase
sequence loading
incurred by
clearance of a close
up phase to phase
fault by System
Back up Protection
on the Transmission
System operating at
Supergrid Voltage.
Maximum Reactive
Current to be
injected during the
38
Requirement
Plant Type
Large
CC.6.3.15
Article 15-2
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
period of the fault
without exceeding
the Transient Rating
of the Generating
Unit as specified in
CC.6.3.15.
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
As per Large
N/A
Maximum Reactive
Current to be
injected during the
period of the fault
without exceeding
the Transient Rating
of the Generating
Unit as specified in
CC.6.3.15.
> 30MW or
connected at 110kV
or above
30 – 10 MW
400W – 1 MW
Under the ENSO-E
Code a specific new
section has been
included for Power
Park Modules
relating to reactive
current injection
during system
faults. These are
specified under
Article 15 – 2. The
requirements
include:-
N/S
For a symmetrical
three phase fault a
Type B Power Park
Module is required
to
i) Inject fast acting
reactive current into
the network at the
Connection Point at
no less than the red
line shown in Figure
8 of Article 152(a)(1).
ii) As a minimum the
reactive current
supplied at the
Power Park Module
terminals shall
contribute at least
2% of the rated
current per percent
of voltage deviation.
iii) The Power Park
Module shall be
capable of feeding
39
A
1 – 10 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
the required
reactive current no
later than 40ms
after fault inception
allowing the voltage
to be measured at
each Power Park
Units terminals.
iv) The relevant
Network Operator
(pursuant to Article
4(3)) shall define in
co-ordination with
relevant TSO the
parameter settings
for the fast acting
reactive current
injection.
v) If required the
reactive current
supply during the
fault duration shall
not be less than
1p.u of the short
term dynamic rating
of the equipment
(>=1.0p.u) between
50% and 40%
retained voltage
(respectively in the
case of a voltage
drop between 50%
and 60%) at the
Connection Point.
Below 40% retained
voltage reactive
current shall be
supplied as far as
technically feasible.
vi) In the case of
unbalanced faults
the Relevant
Network Operator in
co-ordination with
the Relevant TSO
will specify the
40
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Operational
Intertripping
(GB CC.6.3.17)
ENTSO-E – Article
7 – 1(d)
Synchronous and
Asynchronous
50 – 100MW
N/A (SPT / SHETL)
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
Not applicable
Specified by NGET
in the Bilateral
Agreement
depending upon
whether this is
required for thermal,
voltage or stability
reasons.
41
> 30MW or
connected at 110kV
or above
As per Type A
30 – 10 MW
1 – 10 MW
As per Type A
Reactive Current
injection
requirements
pursuant to Article
4(3)
vii) If a Power Park
Module fails to
provide the reactive
support necessary
then if required by
the Relevant TSO
the Power Park
Module causing the
Network
Disturbance shall be
disconnected from
the Network after
0.5 seconds if the
positive phase
sequence voltage at
the connection point
falls and remains at
a value of 85% or
below the reference
voltage (based on
the highest phase
voltage) and a
resetting ratio of
0.98 and at the
same time the
direction of the
Reactive Power at
the connection point
is reversed (ie into
the Power Park
Module).
As per Type A
A
400W – 1 MW
Defined by Relevant
Network Operator
As per Article 7 –
1d) pursuant to
Article 4(3).
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Control Telephony
and System
Telephony
GB CC.6.5.2
ENTSO-E Article 8 4(b), Article 9 – 2(a)
and Article 9 – 5(2).
Synchronous and
Asynchronous
Control Telephony
is a dedicated
telephony service
with a high level of
redundancy and
resilience and
System Telephony
is based on the
standard Public
Telephone Provider
(BT)
Control Telephony
is required for all
Large Power
Stations. If NGET
consider Control
telephony is not
practicable then
NGET will specify
the use of System
Telephony in the
Bilateral Agreement
Operational
Metering
(GB CC.6.5.6 and
CC.6.4.4
ENTSO-E Article 8
– 4(b).
Synchronous and
Asynchronous
Instructor Facilities
including Fax
Machines
CC.6.5.7, CC.6.5.8
and CC.6.5.9
Synchronous and
Asynchronous
Generator to
provide signals
required by NGET
in accordance with
the terms of the
Bilateral Agreement
and NGET will then
provide the
communications
routes to access the
signals at the
Transmission
Interface Point as
specified in the
Bilateral Agreement
All BM Participants
must have
appropriate
electronic data
50 – 100MW
N/A (SPT / SHETL)
A
1 – 10 MW
400W – 1 MW
Control telephony is
not specifically
defined but is
required in the
context of
instructions and
communications
facilities (Article 8 –
4(b)) and in respect
of frequency
stability and Black
Start as defined in
Article 9 – 2(a) and
Article 9 – 5(2)
pursuant to Article
4(3).
N/S
N/S
Only required for
directly connected
Medium Power
Stations.
For those Medium
Power Stations
which are
Embedded and SVA
registered there is
no requirement for
Control or System
Telephony
For those Small
Power Stations
which are
Embedded and SVA
registered there is
no requirement for
Control or System
Telephony
For those Medium
Power Stations
which are CVA
Registered and BM
Participants there is
a requirement for
Control or System
Telephony
For those Small
Power Stations
which are CVA
Registered and BM
Participants there is
a requirement for
Control or System
Telephony
As specified by
NGET in
accordance with
CC.6.5.6 and
CC.6.4.4
N/A
As per Type B
As per Type B
Specified by the
Relevant Network
Operator and
Relevant TSO in
accordance with
Article 8 – 4(b)
N/S
As per Large- Note
the reference to BM
Participants which
has implications as
to whether the plant
N/A
As per type C
Instructor Facilities
are not specifically
defined but
equivalent facilities
are required under
N/S
N/S
42
> 30MW or
connected at 110kV
or above
30 – 10 MW
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
Only required for
directly connected
Small Power
Stations.
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
communication
facilities to permit
the submission of
data as required by
the Grid Code
(EDT). In addition
any Party that
provides all Type 1
Ancillary Services
and is a BM
Participant shall be
required to
automatic logging
facilities if they have
a completion date
after 1 January
2013.
ENTSO-E Article 84(b), Article 9 – 2(a)
and Article 9 – 5(2)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
A
1 – 10 MW
400W – 1 MW
N/S
N/S
Article 8 – 4(b)) and
in the context of
instructions and
communications
facilities in respect
of frequency
stability and Black
Start are required
as defined in Article
9 – 2(a) and Article
9 – 5(2).
is SVA or CVA
registered.
Each Generator is
required to install a
Fax Machine
Dynamic System
Monitoring, Quality
of Supply
Monitoring and
Ancillary Services
Monitoring
GB CC.6.5.6,
CC.6.1.6 and OC
5.4.1 (c)
ENTSO-E Article 9
– 6) (e), Article 9 –
(6)(j) and Article 9 –
2(g).
Synchronous and
Asynchronous
The requirements
for Dynamic System
Monitoring are
specified by NGET
in the Bilateral
Agreement
As per Large – Note
however some of
these requirements
vary depending on
whether the Plant is
SVA or CVA
Registered.
Not specified
Note requirements
for Ancillary
Services Monitoring
and Quality of
Supply Monitoring
are also defined by
NGET in the
Bilateral Agreement
43
As per Type C
For Dynamic
System monitoring,
Fault Recording and
Quality of Supply
Monitoring the
requirements are
defined Article 9 –
6)(e) and Article 96)(j). The signals
required shall
include Voltage,
Active Power,
Reactive Power,
Frequency and
Harmonics. The
Relevant Network
Operator (pursuant
to Article 4(3)) shall
have the right to
add other quality of
supply parameters
provided reasonable
notice is given. The
settings, triggering
parameters,
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
interfacing
arrangements and
data submission of
the monitoring / fault
recording
equipment shall be
agreed with the
Relevant Network
Operator and TSO
pursuant to Article
4(3)).
For Frequency
Response
monitoring (Ie
Ancillary Services
Modelling in GB
terms) the
requirements are
defined under
Article 9 – 2)(g) The
Network Operator
and TSO can
request the
following signals
Status signal of
frequency sensitive
mode
Scheduled Active
Power output
Actual value of
Active Power output
Actual set point
value fro frequency
response
Droop and
deadband
and for Power Park
Modules available
power reflecting
maximum
unrestricted power
taking into account
variable source of
primary power – ie
44
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
A
1 – 10 MW
400W – 1 MW
wind or solar.
Safety Related
Conditions
CC.7
Synchronous and
Asynchronous
Ancillary Services
CC.8
Synchronous and
Asynchronous
As per Large
As per Large
N/S
N/S
N/S
N/S
As per Large except
in the case of
Licence Exempt
Embedded Medium
Power Stations
where they are not
applicable
N/A
Specified through
the obligations on
Type D Units
(including the
specific
requirements for
Synchronous
Generating Units
and Power Park
Modules
Specified through
the obligations on
Type C Units
(including the
specific
requirements for
Synchronous
Generating Units
and Power Park
Modules
Specified through
the obligations on
Type B Units
(including the
specific
requirements for
Synchronous
Generating Units
and Power Park
Modules
Specified through
the obligations on
Type A Units
(including the
specific
requirements for
Synchronous
Generating Units
and Power Park
Modules
Captured under
CC.7 and applies to
directly Connected
Plant
Defines the
Mandatory Ancillary
Services (Part I)
and (Part II) that
Generators are
required to provide.
For Part 1 Ancillary
Services
(Frequency
response – in
general required
from Large Power
Stations except
those which are less
than 50MW and
comprise Power
Park Modules and
Reactive Capability
required from Large
and Medium Power
Stations.
In terms of Part II
Ancillary Services
such as Frequency
Control, Black Start
and Operational
intertripping these
are defined by
NGET in the
Bilateral Agreement.
Commercial
Ancillary Services
are those over and
45
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
above the minimum
requirements which
are agreed by
NGET and the User
and dealt with under
the terms of the
Ancillary Services
Agreement
Performance when
operating in
Frequency Sensitive
Mode for Over
Frequencies
(BC.3.7.1
Performance when
operating in Limited
Frequency Sensitive
Mode for Over
frequencies
(BC.3.7.2 and
Article 7 - 1(c).
Synchronous and
Asynchronous
Synchronous and
Asynchronous
Requires all Large
Generating units
that are obliged to
meet the
requirements of the
Balancing Codes to
automatically deload at a rate of at
least 2 percent of
output per 0.1 Hz
deviation of System
Frequencies above
50.5 Hz.
Requires all Large
Generating units
that are obliged to
meet the
requirements of the
Balancing Codes to
automatically deload at a rate of at
least 2 percent of
output per 0.1 Hz
deviation of System
Frequencies above
50.4 Hz.
A
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
1 – 10 MW
400W – 1 MW
Required only if the
Medium Power
Station is required
to meet the
requirements of the
Balancing Codes
N/A
As per Type C
The Generating Unit
shall be capable of
providing Active
Power Frequency
Response with
respect to Figure 3
of Article 9 – 2(d).
N/S
N/S
As per Type A
Each Generating
Unit shall be
capable of
activating Active
Power Frequency
Response at
according to Figure
1 defined in Article 7
– 1(c). The
Generating unit
shall in Limited
frequency Sensitive
Mode
overfrequency be
capable of
activating Active
Power Frequency
Response at a
The Frequency
Performance
requirements when
the Plant is
operating in
Frequency Sensitive
Mode for under
frequencies are
detailed in Article 9
– 2 (d) as defined
above.
Required if the
Medium Power
Station is only
required to meet the
requirements of the
Balancing Codes
Not applicable
46
As per Type A
As per Type A
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Performance when
operating in Limited
Frequency Sensitive
Mode for under
frequencies
ENTSO-E Article 9
– 2)(c)
Synchronous and
Asynchronous
50 – 100MW
N/A (SPT / SHETL)
Not required
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
Not required
Not required
47
> 30MW or
connected at 110kV
or above
As per Type C
30 – 10 MW
Each Generating
Unit shall be
capable of providing
Active Power
Frequency Sensitive
Mode – Under
Frequency (LFSMU) in accordance
with Figure 2 as
defined in Article 9 –
2)(c)(1). The
Generating Unit
shall in the LFSM-U
A
1 – 10 MW
400W – 1 MW
N/S
frequency threshold
between and
including 50.2Hz
and 50.5Hz with a
droop in a range of
2 – 12 %. The
actual Frequency
threshold and droop
settings shall be
determined by the
Relevant TSO. The
Active Power
Frequency
Response shall be
activated as fast as
technically feasible
with an initial delay
that shall be as
short as possible
and reasonably
justified if greater
than 2 seconds.
Stable operation of
the Generating Unit
during LFSM-O
shall be ensured.
Any contradiction
between LFSM-O
speed Control and
Power Control
during LFSM-O
operation shall be
avoided.
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
mode be capable of
activating Active
Power Frequency
Response at a
frequency threshold
between 49.8Hz
and 49.5 Hz with a
droop in a range of
2 – 12% by
providing a power
increase up to its
maximum capacity
taking account of
limitations for some
generation
technologies from
operation near
maximum capacity
at low frequencies.
The Active Power
Frequency
Response shall be
as fast as
technically feasible
with an initial delay
that shall be as
short as possible
and reasonably
justified if greater
than 2 seconds.
Stable operation of
the Generating Unit
during LFSM – U
operation shall be
ensured. Any
contraction between
power and speed
control during
Limited Frequency
Sensitive Mode
(underfrequency)
shall be prohibited.
When in LFSM-U
operation the
Generating Unit will
also simultaneously
48
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Compliance
ENTSO-E – Articles
24 - 51
Synchronous
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
A
30 – 10 MW
1 – 10 MW
400W – 1 MW
Covered under
Articles 24 – 51 as
applicable
Covered under
Articles 24 – 51 as
applicable
As per Large
N/A
Covered under
Articles 24 – 51 as
applicable
be in LFSM-O
Mode.
Covered under
Articles 24 – 51 as
applicable
As per Large
N/A
Covered under
Articles 24 – 51 as
applicable
Covered under
Articles 24 – 51 as
applicable
Covered under
Articles 24 – 51 as
applicable
Covered under
Articles 24 – 51 as
applicable
As per Large
As per Large
As per Type C
Each Network
Operator in
coordination with
the relevant TSO
(pursuant to Article
4(3) shall have the
right to require
simulation models
N/S
N/S
Work is currently
underway to include
Compliance issues
in the Grid Code. At
the present time the
requirements are
defined in Guidance
notes for
Synchronous
Generators, issue
11 which is
available from
NGET’s website.
Re testing is
captured under OC
5
Compliance
ENTSO-E – Articles
24 - 51
Asynchronous
Work is currently
underway to include
Compliance issues
in the Grid Code. At
the present time the
requirements are
defined in Guidance
notes for Power
Park Developers,
issue 2 which is
available from
NGET’s website.
Re testing is
captured under OC
5
Data / Models
GB Planning Code
Article 9 – 6(f).
Synchronous and
Asynchronous
Detailed Modelling
Data is required
under different time
phases under the
Grid Code Planning
Code depending
49
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
upon the type of
plant and whether
or not it is a Large
Medium or Small
Generator. There is
no requirement for
model data to be
submitted under the
Connection
Conditions
50 – 100MW
N/A (SPT / SHETL)
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
> 30MW or
connected at 110kV
or above
30 – 10 MW
that shall reflect the
behaviour of the
Generating Unit in
both steady state
and dynamic
simulations and
where appropriate
and justified
electromagnetic
transient
simulations. The
requirement for
simulation models
shall include the
format in which they
shall be provided
and the
documentation of
structure and block
diagrams for the
purpose of
verification of the
requirements of this
Network Code and
for the use in all
studies for
continuous
evaluation in system
planning and
operation.
For the purpose of
dynamic simulations
the model provided
shall contain the
following submodels
Alternator and prime
mover
Speed and power
control
Voltage control
including PSS and
excitation system
and limiters
50
1 – 10 MW
A
400W – 1 MW
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Synchronisation
In GB covered
under the site
specific Bilateral
Agreement under
Appendix F3 and
Relevant Electrical
Standards).
(ENTSO-E – Article
9 – 6(a))
Synchronous and
Asynchronous
50 – 100MW
N/A (SPT / SHETL)
As per Large
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
As per Large
For directly
connected plant
specified in the site
specific Bilateral
Agreement and
referenced in the
Relevant Electrical
Standards
N/A for Embedded
Plant
51
> 30MW or
connected at 110kV
or above
As per Type C
30 – 10 MW
Generating Unit
protection models
as agreed with the
relevant Network
Operator and Power
Generating Facility
(pursuant to Article
4(3))
Converter Models
for Power Park
Modules
The Relevant
Network Operator or
Relevant TSO
(pursuant to Article
4(3)) shall have the
right to require
Generating Unit
recordings in order
to compare the
response of the
model with these
recordings.
Generating Unit
synchronisation
shall be performed
by the Power
Generating facility
owner equipped
with the necessary
synchronisation
facilities. The
Generating Unit
shall be equipped
with the necessary
synchronisation
facilities.
Synchronisation of
Generating Units
shall be possible for
frequencies within
the ranges specified
in Table 2. The
Network Operator
and the Power
Generating Facility
A
1 – 10 MW
400W – 1 MW
N/S
N/S
Requirement
Plant Type
Large
TABLE 2 – GB Grid Code Comparison to ENTSO-E RfG
GB Power Station Type
ENTSO-E RfG– Generating Unit Type
Medium
Small
D
C
B
> 100 MW (E&W)
> 30 MW (SPT)
> 10 MW (SHETL)
Auto Reclosure
GB – Not specified
ENTSO-E Article 9
– 4(c)
Synchronous and
Asynchronous
50 – 100MW
N/A (SPT / SHETL)
Not specified
< 50MW
< 30MW (SPT)
< 10 MW (SHETL)
Not specified
Not specified
52
> 30MW or
connected at 110kV
or above
As per Type C
30 – 10 MW
Owner shall agree
on the settings of
synchronisation
devices to be
concluded prior to
operation of the
Generating Unit.
This agreement
shall cover the
following matters:
voltage, frequency,
phase angle range,
phase sequence,
deviation of voltage
and frequency as
specified in Article 9
– 6(a) pursuant to
Article 4(3).
Relevant Network
Operators have the
right (Pursuant to
Article 4(3)) to
request single
phase autoreclosure on
Generating Unit
supply lines (radial
connection of one or
more Generating
Units to the public
network) and single
phase or three
phase auto
reclosures on
meshed Network
lines to be withstood
by Generating Units
without tripping. If
the first autoreclosure attempt is
not successful, a
subsequent attempt
will be delayed by at
least 3 seconds.
1 – 10 MW
A
400W – 1 MW
COMPARISION OF OFFSHORE REQUIREMENTS
(Comparison based on GB Grid Code Issue 4 Revision 9 only and ENSTO - E RFG Internal Version dated 24 January 2012)
(Note – Does not include other Industry Codes such as the STC)
Key to Table
Symbol
N/A
N/S
Article 4(3)
Offshore
Power Park
Modules
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
Definition
Not specified in GB Grid Code but other requirements may apply in other industry Codes such as the System Operator Transmission
Owner Code (STC) Distribution Code or Engineering Recommendations such as G59, ETR 113 and G83.
Not specified in ENTSO-E RfG Code often because not deemed to be a cross border issue but other National requirements may apply.
Where reference in the Table is given to Article 4(3) this means that any decision made by a Relevant Network Operator, or Relevant TSO
and a Relevant Network Operator or Power Generator may require agreement with the National Regulating Authority.
NOTE:- The same grading thresholds applies to Offshore Power Park Modules as Onshore Generating Units and Onshore Power Park
Modules. To simplify the Offshore Table and reduce complexity the Type has been explicitly defined. Offshore Power Park Modules are
required to meet those requirements applicable to Offshore Power Park Modules but the following should be noted:Type A Offshore Power Park Module:- 400W – 1MW
Type B Offshore Power Park Module:- 1MW – 10MW
Type C Offshore Power Park Module:- 10MW – 30MW
Type D Offshore Power Park Module:- 30 MW or Greater or Connected at 110kV or more
Type D units are required to meet the full requirements of Type A, B and C Units, Type C units are required to meet the requirements of
Type A and B and Type B units are required to meet the requirements of Type A except where the following Exclusions noted below apply.
Exculsions
Type C Offshore Power Park Modules are required to meet the requirements applicable to Type A and B Units defined in Articles 7 and 8
except for Article 7(1)(d)(facilitation of a logic interface signal to permit disconnection from the network or additional facilities pursuant to
Article 4(3)), Article 8(2)(a) (Capability to reduce Active Power in steps not bigger than 20% of Maximum Capacity through an interface and
the requirements applicable to Type A Onshore Power Park Modules). For Type C Units, more stringent requirements are specified.
Type D Units are required to meet the requirements of types A, B and C Units defined in Articles 7, 8 and 9 except Article 7(1)(d) (facilitation
of a logic interface signal to permit disconnection from the network or additional facilities pursuant to Article 4(3)), Article 8(2)(a) (Capability
to reduce Active Power in steps not bigger than 20% of Maximum Capacity through an interface), Article 9(3)(a) (Generating Units to be
capable of automatic disconnection at specified voltages if required by the Network Operator with the settings pursuant to Article 4(3)) and
the requirements applicable to Type A Onshore Power Park Modules.
53
Requirement
Large
Definitions and
Scope
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
Any Generating Plant which is connected to an
Offshore Transmission System at an Offshore
Grid Entry Point is required to satisfy the
Offshore Grid Code requirements. In general
the Offshore Grid Code requirements are the
same as the Onshore Grid Code requirements
unless otherwise stated in this table below.
An Offshore Transmission System is one
which is owned under Licence by an appointed
Offshore
Transmission
Licensee
and
comprises high voltage electric lines or cables
of 132 kV or above between an Offshore
Platform and the Shore. The Offshore
Transmission System is classified as part of
the National Electricity Transmission System
being Controlled by National Grid as System
Operator but the actual Offshore Transmission
Network is owned and maintained by an
appointed Offshore Transmission Licensee.
< 10MW
As per Large except, the connection requirements
as detailed under CC.6.3 of the GB Grid Code
connection
conditions
such
as
reactive
capability(CC.6.3.2), output power with falling
frequency (CC.6.3.3), active power output and
voltage range(CC.6.3.4), black start (CC.6.3.5),
frequency control (CC.6.3.6, CC.6.3.7), voltage
control (CC.6.3.6, CC.6.3.8), steady state load
inaccuracies (CC.6.3.9), negative phase sequence
loadings (CC.3.10), neutral earthing (CC.6.3.11),
frequency
sensitive
relays
(CC.6.3.12
–
CC.6.3.13), fast start (CC.6.3.14) and fault ride
through (CC.6.3.15) are not required.
The ENTSO-E RfG applies only to Offshore Power Park Modules only.
A Power Park Module located Offshore which does not have an Offshore
Connection Point shall be considered as an Onshore Power Park Module and
shall thus be compliant with the requirements defined above for Onshore Power
Park Modules.
The Offshore Connection Point of an Offshore Power Park Module shall be
defined pursuant to Article 4(3).
An Offshore Power Park Module may comprise of one or more Generating Units.
All associated auxiliary system and secondary equipments shall be considered as
parts of the Offshore Power Park Module.
Under the ENTSO-E RfG the Offshore Power Park Modules are categorised in
accordance with the following Offshore Grid Connection System Configurations.
1) Configuration 1 – AC connection to single onshore point - One or more
Offshore Power Park Modules are interconnected offshore to form an
Offshore AC System. The Offshore AC System is connected to the Onshore
System with one or more AC connection(s) to the same Onshore Grid
Interconnection Point.
The Offshore Generator will be required to
satisfy technical connection requirements
under the Grid Code where as the Offshore
Transmission Licensee will be required to
satisfy connection requirements under the
System Operator Transmission Owner Code
(STC).
2) Configuration 2 - Meshed AC connection - A number of Offshore Power Park
Modules are interconnected offshore to form an Offshore AC System. The
Offshore AC System is connected to the Onshore System at two or more
Onshore Grid Interconnection Point locations.
3) Configuration 3 - DC connection to single onshore point with AC collection One or more Offshore Power Park Modules are interconnected offshore to
form an Offshore AC System. The Offshore AC System is connected to the
Onshore System with one or more DC connections at one Onshore Grid
Interconnection Point location.
The point of connection between an Offshore
Generator
and
Offshore
Transmission
Licensee is defined as the Offshore Grid Entry
Point whereas the point of Connection
between an Offshore Transmission Licensee
and Onshore Transmission Licensee is
defined as the Interface Point.
When the Offshore Transmission Grid Code
was prepared in 2008/2009, it generally
assumed the Offshore Transmission System to
comprise of radial HVAC or HVDC
connections of 132kV or above. There have
been some applications in the last few years
where there has been interconnection between
Offshore Platforms and Offshore Transmission
Interface Points.
However, as Offshore
Transmission Systems start to evolve and
54
4)
Configuration 4 - Meshed Hybrid AC and DC connections with AC collection A number of Offshore Power Park Modules are interconnected offshore to
form an Offshore AC System. The Offshore AC System is connected to the
Onshore System with AC and DC connections at two or more Onshore Grid
Interconnection Point locations.
5)
Configuration 5 - Meshed Multiterminal DC connection with AC Collection - A
number of Offshore Power Park Modules are interconnected offshore to form
an Offshore AC System. The Offshore AC System is connected to the
Onshore System with multiple DC connections at two or more Onshore Grid
Interconnection Point locations. The DC connections may be combined in a
multi-terminal system and may also have a connection to an offshore system
of another country.
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
become increasingly integrated, there will be
an increasing requirement to update and
amend the Offshore Grid Code and STC
requirements
< 10MW
6)
The Offshore Grid Code requirements will
apply to all types of plant which connect to an
Offshore Grid Entry Point irrespective of
whether
they
are
Synchronous
or
Asynchronous. The requirements applicable
to asynchronous plant not only apply to wind
generation but other technologies such as
wave and tidal generation.
Configuration 6 - Meshed DC connection with DC Collection - An
Offshore Power Park Module consisting of DC Generating Units and
DC collection network. The Offshore Power Park Module connected by
DC to an Offshore DC System. The Offshore DC connection is
connected to the Onshore system with one or more DC link(s).
NOTE:- A further Connection Procedures Code (ie detailing the Connection
Process) is planned at a later stage. The Florence forum has decided that the
Connection Procedures Code is of lower priority and will be implemented post
2015.
The connection process under the Offshore
Transmission regime can progress in two
ways.
1) The Enduring process in which an
Offshore Generator will apply to the
System Operator (National Grid) for a
connection.
National Grid will then
prepare an indicative offer to the
generator based on a number of
assumptions including the Interface Point
and Onshore Network reinforcements. A
Tender process will then take place which
seeks to encourage a number of potential
Offshore Transmission Licensee’s (OFTO)
to design an Offshore Transmission
System. The Regulator (Ofgem), will then
select the preferred OFTO based on their
ability to design, build and construct an
Offshore
Transmission Network
to
appropriate standards and provide value
for money. The OFTO is then appointed,
agreements between the OFTO and
National Grid are prepared and the initial
connection offer to the Offshore Generator
is revised based on the requirements of
the OFTO and the design of the Offshore
Transmission network. Construction can
then commence but it should be noted
that a draw back of this option is the
potential delays to the Offshore Generator
whilst the Offshore Transmission Tender
process is proceeding.
55
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
2) An alternative to this process is the
Generator Build option.
Under this
arrangement the Offshore Generator will
design
and
build
the
Offshore
Transmission System as well as the
Offshore Generation. Once the Offshore
Transmission
System
has
been
constructed the Offshore Transmission
element will be sold to an appointed
Offshore Transmission License.
The
advantage to the Offshore Generator over
the above option is that there is no delay
to the Offshore Generator whilst Tender
process is taking place.
< 10MW
Where a Generator is not connected to an
Offshore Transmission Network (ie the
Offshore Transmission Network contains
undersea cables or overhead lines of no
greater than 132 kV) then the Offshore
network is considered to comprise solely of
Generator assets and the Generator is treated
in the same way as an Onshore Power Park
Module.
Frequency Stability
GB CC.6.1.3,
CC.6.3.6(a),
CC.6.3.7, CC.6.3.9,
CC.6.3.12,
CC.6.3.13, BC.3.7.1
and BC.3.7.2
(ENTSO-E – Article
19
The requirements for Offshore Power Park
Modules are the same as Onshore Power Park
Modules in respect of frequency range
(CC.6.1.3), Frequency Control (both in
Frequency Sensitive and Limited Frequency
Sensitive
Mode)
(CC.6.3.6(a)/CC.6.3.7,
Steady State load inaccuracies (CC.6.3.9)
frequency sensitive relays (CC.6.3.12 and
CC.6.3.13) and frequency performance under
high frequencies when operating above
50.5Hz (Frequency Sensitive Mode BC.3.7.1)
and when operating above 50.4Hz (Limited
Frequency Sensitive Mode BC.3.7.2)
Not applicable
Frequency Stability
Type B Offshore Power Park Modules
The frequency stability requirements defined in Article 8(2)(a) (Reduction of
Active Power in steps not greater than 20%) shall apply to any Offshore Power
Park Module irrespective of its configuration.
Type C and D Offshore Power Park Modules
In addition to the requirements of Type B Offshore Power Park Modules, Type C
and D Offshore Power Park Modules are also required to satisfy the Frequency
stability requirements defined in Article 9(2) (a) (Active Power Set Point control /
Steady State Load inaccuracies) Article 9(2)(b), (Synthetic Inertia), Article 9(2)(e)
(frequency restoration), Article 9(2)(g) (real time frequency monitoring)
irrespective of the Offshore Power Park Module configuration.
Frequency Ranges
Type A, B, C and D Offshore Power Park Modules
The Frequency ranges as defined in Article 7(1) (a) (as per onshore) shall apply
to Offshore Power Park Modules of Configurations 1, 2 and 4. For Configuration
3 and 5 in anticipation to temporarily extreme system disturbances, such as
transient oscillations or HVDC Controller failures, wider frequency ranges may
apply in the range 46.5Hz to 53Hz for at most 10 seconds. The precise frequency
ranges are to be decided by the TSO pursuant to Article 4(3).
56
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
< 10MW
Rate of Change of Frequency
Type A, B, C and D Offshore Power Park Modules
The rate of change of frequency withstand capability requirement as defined in
Article 7(1) (b) (of 2Hz/s) shall apply to Offshore Power Park Modules of
configurations 1,2,3,4 and 5.
Frequency Stability
Type A and B Offshore Power Park Modules
The Frequency stability requirements as defined in Article 7(1)(c) (operation to
high frequencies in Limited Frequency Sensitive Mode) shall apply to any
Offshore Power Park Module irrespective of its configuration. Nevertheless, for
configurations 3, 5, and 6 offshore frequency or alternatively onshore frequency
signals shall be used as reference.
Type C and D Offshore Power Park Modules
In addition to the requirements of Type B Offshore Power Park Modules, Type C
and D Offshore Power Park Modules are also required to satisfy the Frequency
stability requirements as defined in Article 9(2)(c) (operation to low frequencies in
Limited Frequency Sensitive Mode), Article 9(2)(d) (Response to frequency
changes in Frequency Sensitive Mode) and Article 16(2)(a) (synthetic inertia).
These requirements shall apply to any Offshore Power Park Module irrespective
of its configuration. Nevertheless, for configurations 3, 5, and 6 offshore
frequency or alternatively onshore frequency signals shall be used as reference.
Voltage Stability
Requirements
Voltage Range
GB CC.6.1.4,
CC.6.3.15,
CC.6.3.2(e)
CC.6.3.8 (b)
(ENTSO-E – Article
20)
Voltage Range (CC.6.1.4) - Large Offshore
Generators are required to satisfy the same
voltage range requirements as Large Onshore
Generators as defined in CC.6.1.4 (ie at 400kV
 5% with operation unless abnormal
conditions prevail. The minimum voltage is 10% and the maximum is +10% but voltages
of +5 to +10% will not last longer than 15
minutes. For voltages of 275kV and 132kV the
system voltage variation shall be  10%.
Not applicable
Voltage Stability Requirements (Article 20)
Voltage Range (Article 20(1))
All Offshore Power Park Modules – Irrespective of Type
The Voltage ranges defined in Table 8 apply to all Offshore Power Park Modules
of configurations 1, 2, 3, 4 and 5 within the time periods specified by Table 8 of
Article 20(1). For configuration 6, the voltage range shall be defined individually.
In GB (for voltages of 110kV and upwards) the ranges defined are 0.9 – 1.05 p.u
continuous operation required and 1.05 – 1.10 operation is required for 15
minutes. (NOTE – Reference to Table 5.2 (which is applicable to voltages in the
range of 110kV to 300KV) appears to be missing ).
Reactive Power Injection (CC.6.3.15) – The
requirements for reactive Power injection for
an Offshore Power Park Module are defined in
the Fault Ride Through requirements defined
under CC.6.3.15.1 or CC.6.3.15.2.
In
summary the Offshore Power Park Module is
required to generate maximum reactive current
without exceeding the transient rating of the
Offshore Generating Unit or Offshore Power
Park Module.
Voltage Stability Requirements (Article 20(2))
Type B Offshore Power Park Modules
The voltage stability requirements defined in Article 15(2) (a) and (b) (Reactive
Current Injection) shall apply to Offshore Power Park Modules of configurations 1,
2, 3, 4 and 5
Type C and D Offshore Power Park Modules
In addition to the requirements of Type B Offshore Power Park Modules, Type C
and D Offshore Power Park Modules are required to meet Article 16 (3) (c)
(Reactive Power below maximum capacity) and Article 16(3)(d) (the priority of
Active Power over Reactive Power)
Reactive Capability (CC.6.3.2(e)) – Offshore
Generators have the option of one of the
57
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
following requirements.
i)
< 10MW
Reactive Capability (Article 20(3))
Type C and D Offshore Power Park Modules
The Reactive Power Capability at maximum Active Power as defined in Article
16(3) (b) (Reactive Power Capability (P/Q Profile at maximum capacity) shall
apply to Offshore Power Park Modules of configurations 1, 2, 3, 4 and 5 except
for Table 7 of Article 16(3)(b) which shall be replaced by Table 9 of Article 20(3).
Under the ENTSO-E RfG within Great Britain the Q/PMax range for Configurations
1 and 6 shall be 0 (equivalent to Unity Power Factor at 1.0 p.u voltage) and for
Configurations 2,3,4 within Great Britain the Q/PMax range shall be 0.33
(equivalent to a Power Factor Range of 0.95 or 0.975 lead to 0.975 lag) at 1.0
p.u voltage. (NOTE:- Figure 11 should be read in the context of Table 9 instead of
Table 7)).
Maintenance of zero transfer of Reactive
Power at all Active Power output levels (ie
unity power factor) at the Offshore Grid
Entry Point where the Offshore Grid Entry
Point is at the LV side of the Offshore
Platform. The steady state tolerance on
Reactive Power Transfer to and from an
Offshore Transmission System expressed
in MVAr shall be no greater than 5% of
the Rated MW (CC.6.2.3(e)(i))
Reactive Power Control Modes (Article 20 (4))
Type C and D Offshore Power Park Modules
The Reactive Power Control Modes as defined in Article 16(3) (e) (ie Power
Factor Control, Reactive Power Control or Voltage Control) shall apply to
Offshore Power Park Modules of Configurations 1, 2, 3, 4 and 5. For
Configuration 6 only the Voltage Control option shall apply.
ii) Maintain a transfer of Reactive Power at
the Offshore Grid Entry Point at a value
specified in the Bilateral Agreement that is
equivalent to zero transfer (ie unity Power
Factor) at the LV Side of the Offshore
Platform. The steady state tolerance on
Reactive Power to and from an Offshore
Transmission System expressed in MVAr
shall be no greater than 5% of the rated
MW. In other words this requirement is
the same as i) above except allowing for
the fact that the Offshore Grid Entry Point
may not be at the LV Side of the Offshore
Platform (CC.6.3.2(e)(ii))
iii) The Reactive Power Capability (including
any tolerance) will be specified in the
Bilateral Agreement providing agreement
has been reached between the Generator,
Offshore Transmission Licensee and
NGET (CC.6.3.2(e)(iii)).
iv) For Offshore Synchronous Generators,
the Short Circuit Ration should be not less
than 0.5.
Voltage
Control
(CC.6.3.8(b))
–
A
continuously acting control system is required
to provide control of reactive power (as
detailed in CC.6.3.2(e)(i)(ii)) at the Offshore
Grid Entry Point without instability over the
entire operating range. The performance
requirements of this automatic control system
will be specified in the Bilateral Agreement.
58
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
Where an alternative reactive capability has
been specified in the Bilateral Agreement in
accordance with CC.6.3.2(e)(iii) the Offshore
Generator will be required to control voltage
and / or reactive power without instability over
the entire operating range. The performance
requirements of the control system will be
specified in the Bilateral Agreement.
Robustness of
Generating Units
applicable to
Offshore Power
Park Modules
(GB CC.6.3.7(b),
CC.6.3.8(b),
CC.6.3.15 and
ENTSO-E Article
21(4)
In addition the requirements for excitation
control facilities including Power System
Stabilisers where in NGET’s view these are
necessary for system reasons they will be
specified in the Bilateral Agreement.
In Great Britain the same requirements for
Onshore Generators applies to Offshore
Generator unless otherwise specified.
< 10MW
Not applicable
Steady State Stability – captured under
Governor / Frequency Control Stability
covered under CC.6.3.7(b), Voltage / Reactive
Power Controllers covered under CC.6.3.8(b)
and Stability during faults is covered under the
fault ride through requirements defined under
CC.6.3.15.
Steady State Stability (Article 21(1)
Type C and D Offshore Power Park Modules
The requirements defined in Article 9(4)(a) (maintenance of steady state stability
for any point within the PQ diagram in the case of power oscillations and
prohibition of tripping or power reduction) shall apply to Offshore Power Park
Modules of configurations 1, 2, 4 and 6.
Torsional Stress (Article 21(2))
Type C and D Offshore Power Park Modules
The requirements defined in Article 9(4)(b) (ability of Generating units to be
designed in a way that shaft torsional stress which may be excited by transient
Active Power steps up to 50% of its maximum capacity are considered a routine
part of normal operation and shall be taken into account when specifying the shaft
characteristics) withstand torsional stress and the ability of generating units to
withstand auto re-closure (including fast single phase auto re-closure) shall apply
to Offshore Power Park Modules of configurations 1, 2 and 4.
Torsional Stress – Not explicitly defined. The
requirements for subsynchronous resonance
are however applicable to HVDC Converters.
Power Oscillation Damping Control – Captured
under Voltage / Reactive Power Control under
CC.6.3.8(b) with the specific requirement for
power oscillation damping being specified in
the Bilateral Agreement.
Power Oscillation Damping Control (Article 21(3))
Type C and D Offshore Power Park Modules
The requirements as defined in Article 16(3)(f) (requirements for power
oscillations damping control as specified by the TSO pursuant to Article 4(3)) shall
apply to Offshore Power Park Modules of configurations 1, 2, 4 and 5.
Fault Ride Through – Offshore Power Park
Modules are required to have a fault ride
through capability and have the option of
satisfying one of two options.
Fault Ride Through Capability (Article 21(4))
Type D Offshore Power Park Modules
The fault ride through requirements of Power Park Modules as defined as in
Article 17(1)(a) (Fault Ride Through for Type D Power Park Modules) shall apply
to any Offshore Power Park Module, irrespective of its configuration. (Note – This
reference (Article 17(1)(a)) may require review as it only applies to Type D
Offshore Power Park Modules)
Option 1 – is the same requirement as
required from Onshore Power Park Modules
with compliance being measured at the
Interface Point as defined under CC.6.3.15.1
as outlined above.
Option 2 - Fault Ride Through requirements
59
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
are defined at the LV side if the Offshore
Platform.
< 10MW
Faults up to 140ms in duration:For faults up to 140ms in duration each
offshore Generating Unit or Power Park
Module is required to remain transiently stable
and connected to the System without tripping
for any balanced or unbalanced voltage dips
on the LV Side of the Offshore Platform whose
voltage profile is anywhere on or above the
heavy black line shown in Figure 6. Under
worst case conditions this requires the
Offshore Generator or Offshore Power Park
Module to remain connected to the system for
voltage dips of 15% retained voltage or above.
During the period of the fault each Offshore
Generating Unit or Offshore Power Park
Module is required to provide Active Power at
least in proportion to the retained voltage at
the LV Side of the Offshore Platform except in
the case of an Offshore Power Park Module
where there has been a reduction in the
intermittent power source in the time range in
Figure 6 that restricts the Active Power below
this level.
In addition, each Offshore
Generating Unit or Offshore Power Park
Module shall generate maximum reactive
current without exceeding the transient rating
limits of the Offshore Generating Unit or
Offshore Power Park Modules.
Faults greater than 140ms in duration:
In addition to the requirements for faults lasting
up to 140ms, each Offshore Power Park
Module and Offshore Generating Unit is
required to remain transiently stable and
connected to the System without tripping for
any balanced voltage dip on the LV Side of the
Offshore Platform and associated durations
anywhere on or above the heavy black line
shown in Figure 7. In addition each Offshore
Generating Unit or Offshore Power Park
Module shall provide Active Power output
during voltage dips on the LV Side of the
Offshore Platform as described in Figure 7 at
least in proportion to the retained balanced or
unbalanced or unbalanced voltage at the LV
60
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
Side of the Offshore Platform except in the
case of an Offshore Power Park Module where
there has been a reduction in the intermittent
Power Source that restricts the active power
below this level and in addition shall generate
maximum reactive current (where the voltage
at the Offshore Grid Entry Point is outside the
limits specified in CC.6.1.4) without exceeding
the transient rating limits of the Offshore
Generating Unit or Offshore Power Park
Module. In addition within 1 second of the
restoration of the voltage at the LV Side of the
Offshore Platform (to the minimum levels
specified in CC.6.1.4) restore Active Power to
at least 90% of the Offshore Generating Units
or Offshore Power Park Modules immediate
pre-disturbed value unless there has been a
reduction in the intermittent Power Source in
the time range in Figure 7 that restricts the
Active Power below this level.
System Restoration
Requirements
applicable to
Offshore Power
Park Modules
(GB CC.6.3.5,
CC.6.3.7(c)
ENTSO-E – Article
22)
General System
Management
Requirements
Applicable to
Offshore Power
Park Modules
(GB CC.6.2.2.2,
CC.6.5.6, PC,
CC.6.6, BC.1.A.1.1,
CC.6.3.11,
CC.6.1.5, C.6.1.6
and CC.6.1.8
In addition, Offshore Generators (which
includes Offshore Generating Units and
Offshore Power Park Modules) are required to
also meet the requirements of CC.6.3.15.3
which are the same as the Onshore
requirements.
Blank Start (CC.6.3.5) – Specified by NGET in
the Bilateral Agreement.
Island Operation (CC.6.3.7(c) –
onshore requirement in CC.6.3.7(c).
As
< 10MW
Black Start and Island Operation – Not applicable
Resynchronisation – Specified in Bilateral
Agreement between NGET and the User.
System Restoration (Article 22)
Type C and D Offshore Power Park Modules
The System Restoration requirements defined respectively in Article 9(5) (a)
(Black Start Capability), Article 9(5)(b) (Island Operation) and Article 9(5)(d)
(resynchronisation) shall apply to any Offshore Power Park Modules irrespective
of its configuration.
As per Large except for:Neutral Earthing (CC.6.3.11)
General System Management Requirements (Article 23(1))
Type B Offshore Power Park Modules
The general system management requirements defined respectively in Article 8
(General Requirements to Type B Units) shall apply to any Offshore Power Park
Module irrespective of its configuration.
per
Resynchronisation – Specified in the Bilateral
Agreement between NGET and the User.
General Type B Requirements (Controllability
of Active Power, Reconnection requirements,
Control Schemes and Settings and information
exchange) are captured above in the Onshore
Table.
Protection Schemes and Settings (CC.6.2.2.2)
The applicable protection requirements for
Offshore Generators are the same as for
Onshore Generators in accordance with
CC.6.2.2.2. These are covered in detail in the
above Onshore Table.
Type C and D Offshore Power Park Modules
In addition to the requirements applicable to Type B Offshore Power Park
Modules, Type C and D Offshore Power Park Modules shall also be required to
satisfy the requirements of Article 9(6)(b) (Protection schemes and Settings),
Article 9(6)(c) Priority ranking of Protection and Control), Article 9(6)(d)
(disconnection/tripping
in the event of loss of stability), Article 9(6)(e)
61
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
ENTSO-E Article
23(1)
< 10MW
(Instrumentation, Dynamic System Monitoring, fault recording, Article 9(6)(f)
(submission of simulation models including electromagnetic transient
simulations), Article 9(6)(g) (requirements to install additional devices to preserve
and restore system operation or security pursuant to the requirements of Article
4(3)), Article 9(6)(h) (maximum and minimum limits on rates of change of Active
Power), Article 9(6)(i) (Earthing requirements for the neutral point of a step up
transformer),
Article
9(6)(j)(Power
Quality
requirements),
Article
9(6)(k)(Requirements for modernised or replaced plant and equipment)
Instrumentation and Monitoring (CC.6.5.6 and
CC.6.6). The requirements for Operational
Metering (CC.6.5.6) and Dynamic System
Monitoring (CC.6.6) are the same as the
Onshore requirements although the Offshore
Transmission Licensee will have responsibility
for transfer of this data to the Onshore
Transmission Licensee.
Synchronisation Requirements (Article 23(2))
Type C and D Offshore Power Park Modules
The synchronisation requirement as defined in Article 9(6)(a) (Synchronisation
requirements) shall apply to Offshore Power Park Modules of Configurations
1,2,3, 4 and 5.
Submission of Models and Data (PC)
The full data requirements including models
are captured under the Grid Code Planning
Code.
There is no significant difference
between the Offshore Data requirements and
Offshore Data requirements. The European
Grid Code requires electromagnetic transient
simulations which the GB Grid Code does not.
Installation of additional devices to install
additional devices to preserve and restore
system operation or security
Defined in the Bilateral Agreement pursuant to
the requirements of the Grid Code
Limits on Maximum Rates of Change of Active
Power (BC.1.A.1.1)
Defined in Grid Code BC.1.A.1.1 for each BM
Participant at the Grid Entry Point
For a change up to 300MW - No Limit
For a change greater than 300MW and less
than 1000MW – 50MW/min
For a change of 1000MW or more 40MW /min
This requirement equally applies to Onshore
and Offshore Connections.
Earthing Points for the Neutral Point of a Step
up transformer (CC.6.3.11)
As per an Onshore Generator – At nominal
system voltages of 132kV or above the higher
voltage windings of a transformer of a
Generating Unit, DC Converter or Power Park
Module must be star connected with the star
point suitable for connection to earth.
Power Quality (CC.6.1.5, CC.6.1.6 and
CC.6.1.8)
The same power quality requirements onshore
62
Requirement
Large
TABLE 3 – OFFSHORE ENTSO-E RfG to GB GRID CODE
GB Power Station Type
ENTSO-E – RfG -Generating Unit Type
Small
Offshore Power Park Modules
> 10 MW
apply offshore other than in respect of Phase
unbalance and Voltage fluctuations where
such requirements are specified in the Bilateral
Agreement.
< 10MW
Requirements for modernisation of plant
(Classified as a Modification under the Grid
Code Glossary and Definitions)
Where plant is modernised or replaced, the
requirements applicable to the new plant will
fall under a “Modification” which is defined
under the Grid Code Glossary and Definitions.
A Modification is defined as any proposed
replacement,
renovation,
modification
alteration or construction which may have a
material effect on NGET or a User. In general
the Bilateral Agreement would be updated and
the new item of plant or equipment would be
required to meet the latest Grid Code
requirements where applicable.
The
requirement is equally applicable to both
Onshore Generators.
Synchronisation Requirements
Specified under the Bilateral Agreement and
as detailed in the Relevant Electrical
Standards
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