Download Stakeholder Comment and Rationale Form AESO AUTHORITATIVE DOCUMENT PROCESS Stakeholder Consultation Draft

Stakeholder Comment and Rationale Form
AESO AUTHORITATIVE DOCUMENT PROCESS
Stakeholder Consultation Draft
2012-11-29
Proposed New ISO Rules Section 502.5 Version 2.0 Generating Unit Technical Requirements (“New ISO Rules Section 502.5 Version 2.0”)
Date of Request for Comment [yyyy/mm/dd]:
Period of Consultation [yyyy/mm/dd]:
2012/11/29
2012/11/29
Comments From:
TransAlta Corporation
Date [yyyy/mm/dd]:
January 18, 2013
through
2012/12/14
Contact:
Bob Smith
Phone:
403-267-7119
E-mail:
[email protected]
Listed below is the summary description of changes for the proposed new, removed or amended sections of the ISO rules. Please refer back to the Letter of Notice under the “Attachments to Letter
of Notice” section to view the actual proposed content changes to the ISO rules. Please place your comments / reasons for position underneath (if any).
1. ISO Rules
(c) New
Proposed New ISO Rules Section 502.5 Version 2.0 sets out the minimum
technical requirements for a legal owner connecting a generating unit to the
transmission system.
After considering stakeholder comments on proposed New ISO Rules Section
502.5, the AESO is proposing New ISO Rules Section 502.5 Version 2.0, which
includes the following key changes from proposed New ISO Rules Section 502.5:
1. Amended the language to improve clarity without any intended change to the
technical requirements;
Stakeholder Comments and/or Alternative Proposal
AESO Replies
Please refer the detailed comments below
1 TransAlta is unclear on how the new Section 502.5
version 2.0 subsections 1, 2, and 6 adequately cover
the previous Section 502.5 version 1.0 subsection 9.
2. References to existing and new generating units have been removed to avoid
confusion. Proposed New ISO Rules Section 502.5 Version 2.0 applies to
both new and existing generating units. This resulted in subsections 2 and 3
of proposed New ISO Rules Section 502.5 being removed in its entirety from
proposed New ISO Rules Section 502.5 Version 2.0;
3. Subsection 6 has been removed to improve clarity although elements of
Issued for Stakeholder Consultation: 2012-11-29
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subsection have been inserted into the appropriate relevant subsections;
4. Removed subsection 12.3 of proposed New ISO Rules Section 502.5 so that
this requirement can be more fully consulted on at some future time;
5. Amended subsection 15 to clarify what would be considered a simultaneous
trip of multiple generating units and to allow for the trip of a combustion
turbine to result in the trip of a steam turbine in combined cycle plants;
6. Removed the operating requirements and relocated these operating
requirements into proposed New ISO Rules Section 502.6 Generating Unit
Operating Requirements (“New ISO Rules Section 502.6”) such that proposed
New ISO Rules Section 502.5 Version 2.0 now only contains technical
requirements. Click here to access the Letter of Notice for proposed New ISO
Rules Section 502.6;
7. Removed content related to the submission of modeling data to eliminate
duplication with ISO OPP 1306 Reporting Equipment Changes;
8. Removed appendices where the content was determined to be informational
in nature;
.
9. Added an appendix relating to voltage-ride-through requirements for existing
generating units; and
10. Removed the subsection referencing reactive power requirements for
generating units with power purchase agreements. The AESO agreed with
stakeholder comments that a single section referencing the requirements for
all generating units was sufficient and improves clarity.
The AESO is seeking comments from stakeholders with regard to the following
matters:
1. In developing proposed New ISO Rules Section 502.5 Version 2.0, the AESO
did not intentionally change the intent of the technical requirements from
proposed New ISO Rules Section 502.5. If you disagree, please identify the
specific requirement(s) where you believe the intent has changed.
2. Proposed New ISO Rules Section 502.5 Version 2.0 remains consistent with
the AESO’s Generator and Load Interconnection Standard, except for the
specific requirements added, which are only applicable to new generating
Issued for Stakeholder Consultation: 2012-11-29
Page 2 of 6
units, and where the functional specification references ISO Rules Section
502.5, once effective, or if specific equipment is changed on planned basis. If
you disagree please identify the specific requirements that are not consistent
with the AESO’s Generator and Load Interconnection Standard.
3. Are there any subsections where stakeholders feel that language does not
clearly articulate the requirement for either the AESO or a market participant?
If yes, please indicate the subsections and suggest language that would
improve the clarity.
(d) Other
Stakeholders wishing to comment on specific provisions are requested to copy
the provision into this area and provide comments.
2(1) The ISO must, in accordance and generally consistent with this section
502.5 and any other applicable ISO rules, approve of a functional specification
containing further details, work requirements, and specifications for the design,
construction and operation of a generating unit connection project and any
associated transmission system connection facilities.
(2) The functional specification for the generating unit referred to in subsection
2(1) must be generally consistent with the provisions of this section 502.5, but
may contain material variances the ISO approves of based upon its discrete
analysis of any one (1) or more of the technical, economic, safety, operational and
reliability requirements of the interconnected electric system related to the
specific connection project.
5(2) The generating unit and any approved external reactive power resources must have
the capability to operate in accordance with subsection 5(3) by both:
5(3) The reactive power capability of the generating unit must be in compliance
with the following minimum requirements:
(a) zero point nine (0.9) power factor, over-excited; and
(b) zero point nine five (0.95) power factor, under-excited;
based on the maximum authorized real power of the generating unit over the
entire real power operating range, down to the applicable minimum gross real
power.
(4) The generating unit, subject to subsections 5(5), must not have limiters
set to reduce the reactive power capability set out in subsection 5(3).
Issued for Stakeholder Consultation: 2012-11-29
Comment # 2:
2(1)(2) TransAlta recommends to reword section 2(2) to
incorporate the need for the GFO to review and agree
with any AESO analysis of issues that impact the GFO.
5(3)(4) TransAlta recommends to re-word section 5(4)
to indicate the suitable application of limiters as per
industry practice, to protect the generator based on the
individual unit’s design/condition/risk considerations.
TransAlta submits that the reactive capability of the
generator will need to be in line with industry standards
as well as any specific OEM design considerations and
capability curves that may be issued. Note that the OEM
can issue specific design limitations and capability
curves based on present day industry experience of
generator failures and the subsequent studies of
generator design. These studies have used modern
analysis techniques to assess design deficiencies.
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(5) (5) The legal owner of a generating unit with the capability to meet the
reactive power requirements of this subsection 5 but which has stability concerns
must submit in writing to the ISO:
(a) a request for approval of a proposed reduction in the reactive power capability
requirement set out in subsection 5(3)(b) due to generating unit stability concerns;
and
(5) (5) TransAlta submits that, in addition to any
reduction due to any stability concerns, provision shall
be provided for any reduction in reactive power due to
machine design considerations/revised manufacturer
capability curves as a result of condition/risk
considerations.
(b) a detailed study in support of the request which is specific for the generating
unit at its location and completed by a qualified professional engineer,
demonstrating the reactive power capability set out in subsection 5(3)(b) should be
reduced by a limiter because that reactive power capability will cause the
generating unit to become unstable.
(5) (7) The legal owner of a generating unit without the capability to meet the reactive
power capability must submit to the ISO a request in writing for approval of the use of an
external dynamic reactive power resource to compensate for the lack of capability such that
the combined capability of the generating unit and external dynamic reactive power
resource meets the requirements of subsection 5(3).
(5) (7) TransAlta submits that any external dynamic
reactive power resources should be designed and
implemented by the AESO.
(6)(2) The legal owner of a generating unit must determine the root mean square
phase-to-phase voltage value at the high voltage side of the transmission system
step-up transformer to be used as the one hundred percent (100%) voltage value to
determine the voltage ride-through requirements for the generating unit.
(3) A generating unit must be capable of meeting the following voltage ridethrough requirements:
(a) continuous operation between ninety percent (90%) and one hundred and ten
percent (110%) of the voltage value documented under subsection 6(2); and
(b) not tripping or going off-line during or as a result of a voltage dip or posttransient voltage deviation resulting from a normally cleared disturbance on the
transmission system on any phase or combination of phases at or beyond the
point of connection as illustrated in Appendix 1.
(4) The normal clearing time used in subsection 6(3)(b) must be based on the
specific location where the generating unit is connected to the transmission
system.
(6-3) (a) TransAlta submits that the continuous
operation capability of the generator is 95%-105% of the
generator rated terminal voltage as per IEEE. Based on
this, there may be concerns with the continuous
operation of the generator for a voltage range of 90%110% at the HV side of the GSU and this will need to be
studied.
Issued for Stakeholder Consultation: 2012-11-29
(6-3) (b) TransAlta submits that AESO requirements of
the shaded region transient voltage no-trip zone of
625ms (Appendix 1) is not clear and contradicts the
solid time curve. The shaded zone should be removed
from the plot for clarity.
Since checks will be needed to confirm a ride through
capability, TransAlta requires time to study the
implications of this requirement.
(4) TransAlta suggests for AESO to identify the normal
clearing time at the specific generating locations
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(7)(2) The legal owner of a generating unit must determine the root mean square
phase-to-phase voltage value at the transmission system step-up transformer of
the generating unit to be used as the one hundred percent (100%) voltage value to
determine the voltage ride through requirements for the generating unit.
(3) The legal owner of a new generating unit must ensure the generating unit is
capable of meeting the following voltage ride-through requirements:
(a) continuous operation between ninety percent (90%) and one hundred and ten
percent (110%) of the voltage value documented under subsection 7(2); and
(b) not tripping or going off-line during or as a result of a voltage dip or posttransient voltage deviation resulting from a normally cleared transmission system
disturbance on any phase or combination of phases at or beyond the point of
connection as illustrated in Appendix 2; and
(c) the time that the voltage remains at zero point zero percent (0.0%) must be
based on the normal clearing time for a three (3) phase fault at the specific location
where the generating unit is connected to the transmission system.
(4) The normal clearing time used in subsection 7(3)(b) must be based on the
specific location where the generating unit is connected to the transmission
system.
(5) Notwithstanding any other provision of this subsection 7, a generating unit is
not required to ride-through a transmission system fault that:
(a) causes a forced outage of a radial transmission line connecting the generating
unit to the transmission system;
(b) occurs on the generating unit side of the point of connection, including the
lower voltage network and the substation; or
(c) results in a transfer trip or anti-islanding protection scheme to activate at the
generating unit which will cause the generating unit to be disconnected from the
transmission system.
(8)(2)(c) be capable of manual set point adjustments to a percentage between
ninety five percent (95%) and one hundred and five percent (105%) of the operating
voltage value determined under subsection 6(1); and
Issued for Stakeholder Consultation: 2012-11-29
(7)(3) (a) TransAlta submits that the continuous
operation capability of the generator is 95%-105% of the
generator rated terminal voltage as per IEEE. Based on
this, there may be concerns with the continuous
operation of the generator for a voltage range of 90%110% at the HV side of the GSU and this will need to be
studied.
(7)(3) (b) AESO to clarify why voltage dip is down to 0
% instead of 15 %?
(7)(3) (c) TransAlta suggests for AESO to identify the
normal clearing time at the specific generating locations
(7)(4) TransAlta suggests for AESO to identify the
normal clearing time at the specific generating locations
(7)(5) TransAlta recommends to add -(d) which will cause the generating unit to be
disconnected from the transmission system.
(8)(2)(b) and (c) TransAlta submits that the AVR can
only control voltage on the generator terminals and not
on the HV side of the GSU transformer
(8)(2)(c) Please note reference to Subsection (6)(1) is
not correct.
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10(3) Notwithstanding subsection 11(1) and 11(2), a power system stabilizer is not
required to be installed on a generating unit if the closed loop phase lag between the
generating unit stator winding terminals voltage and the automatic voltage regulator
11(2) The legal owner of a generating unit may subtract the amount of auxiliary and
excitation system load in apparent power from the apparent power capability of the
generating unit at the maximum authorized real power to determine the net real power
and reactive power requirements of the transmission system step-up transformer referred
to in subsection 11(1), but only if any of that auxiliary and excitation system load is
connected between the generating unit stator winding terminals and the transmission
system step-up transformer.
12(1)(a) Each generating unit must have auxiliary systems designed so that the
failure of a single component will not result in the simultaneous tripping or shutdown
of two (2) or more generating units;
Synchrophasor Measurement System
18(1) A new generating unit or an existing generating unit that undergoes a
modification replacing the protection system must have a synchrophasor
measurement system in compliance with the specifications contained in any related
synchrophasor measurement system rule or standard.
(3) The legal owner of the generating unit must design a system that is capable of
downloading and retaining the recordings set out in subsection 18(2) for a period of one (1)
calendar year from the date of the initial recording unless the ISO otherwise designates in
the functional specification for the generating unit,
Issued for Stakeholder Consultation: 2012-11-29
10(3) Please note that references of 11(1) and 11(2)
should be 10(1) and 10(2).
11(2) AESO to include reference to IEEE C57.116 for
GSU sizing methodology.
12(1) TransAlta suggests to add “subject to normal
operating conditions”.
18(1) TransAlta submits that the modifications to
protection systems are to be elaborated as replacement
of the complete set of protection relays.
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