Proposed New ISO Rules Section Version 2.0 Generating Unit Technical Requirements ( New ISO Rules Section Version 2.

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1 Stakeholder Comment and Rationale Form AESO AUTHORITATIVE DOCUMENT PROCESS Stakeholder Consultation Draft Proposed New ISO Rules Section Version 2.0 Generating Unit Technical Requirements ( New ISO Rules Section Version 2.0 ) Date of Request for Comment [yyyy/mm/dd]: 2012/11/29 Period of Consultation [yyyy/mm/dd]: 2012/11/29 through 2012/12/14 Comments From: TransAlta Corporation Date [yyyy/mm/dd]: January 18, 2013 Contact: Bob Smith Phone: bob_smith@transalta.com 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 Stakeholder Comments and/or Alternative Proposal AESO Replies (c) New Proposed New ISO Rules Section 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 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; Please refer the detailed comments below 1 TransAlta is unclear on how the new Section version 2.0 subsections 1, 2, and 6 adequately cover the previous Section version 1.0 subsection References to existing and new generating units have been removed to avoid confusion. Proposed New ISO Rules Section Version 2.0 applies to both new and existing generating units. This resulted in subsections 2 and 3 of proposed New ISO Rules Section being removed in its entirety from proposed New ISO Rules Section Version 2.0; 3. Subsection 6 has been removed to improve clarity although elements of Issued for Stakeholder Consultation: Page 1 of 6

2 subsection have been inserted into the appropriate relevant subsections; 4. Removed subsection 12.3 of proposed New ISO Rules Section 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 Generating Unit Operating Requirements ( New ISO Rules Section ) such that proposed New ISO Rules Section 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 Version 2.0, the AESO did not intentionally change the intent of the technical requirements from proposed New ISO Rules Section If you disagree, please identify the specific requirement(s) where you believe the intent has changed. 2. Proposed New ISO Rules Section 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: Page 2 of 6

3 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 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). 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. Issued for Stakeholder Consultation: Page 3 of 6

4 (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 (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) (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. (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. (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 Issued for Stakeholder Consultation: Page 4 of 6

5 (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 (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. Issued for Stakeholder Consultation: Page 5 of 6

6 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 10(3) Please note that references of 11(1) and 11(2) should be 10(1) and 10(2). 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; 11(2) AESO to include reference to IEEE C for GSU sizing methodology. 12(1) TransAlta suggests to add subject to normal operating conditions. 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, 18(1) TransAlta submits that the modifications to protection systems are to be elaborated as replacement of the complete set of protection relays. Issued for Stakeholder Consultation: Page 6 of 6