Transmission Services

Transcription

1 Available Transfer Capability Implementation Document MOD-001-1a 1. Purpose The Available Transfer Capability Implementation Document (ATCID) provides for the documentation of required information as specified in the NERC MOD Standards and the NAESB OASIS Standards regarding the calculation methodology and information sharing of Available Transfer Capability specific to this Transmission Service Provider (TSP). 2. Definitions 2.1. Terms used in this document align with the definitions identified in the NERC Glossary of Terms and the NERC MOD Standards. 2.2 Specific terms to Arizona Public Service (APS) are as listed below, all other applicable definitions are listed in Appendix A ATC Algorithms: CBM is currently defined as zero. No Load Serving Entity (LSE) serving load on the APS system has requested CBM CBMs will not be a value of anything other than zero since CBM has not been approved Counterflows For the purpose of calculating non-firm ATC the sum of counter schedules in the opposite direction of the path ATC is being calculated. Counterflows are equal to counter e-tags that have been submitted and approved in the Scheduling Horizon OSF is currently defined as zero in all cases. APS provides no other services which are not defined in Firm Transmission Service OSNF is currently defined as zero in all cases. APS provides no other services which are not defined in Non-firm Transmission Service Postbacks A parameter in the calculation of ATC that adds back capacity due a of a transmission reservation, of a reservation, or from the capacity made available due to on a firm basis, or as a value representing the unscheduled firm capacity of transmission service reservations as allowed in this ATCID Time Horizons Terminology used in OASIS for time periods are as follows: Scheduling is the next 3 real time hours (current hour plus the next two hours) Operating is prior to 1600, the rest of the real-time day after 1600, the next scheduling day(s) Planning is everything after the operating time frame Page 1 of 8

2 Timing of Calculations (MOD-001-1a R2) - ATC is calculated and posted for various time periods based upon the terms: R2.1 Hourly for current plus 7 days R2.2 Daily for current plus 31 days Weekly for current plus 4 weeks R2.3 Monthly for current plus 12 months Yearly for current plus 10 years Timing of recalculations (MOD-001-1a R8) ATC is recalculated in the following frequencies: R8.1 Hourly values, once per hour R8.2 Daily values, once per day, R8.3 Monthly values, once per week TRM is currently defined as zero in all cases. APS does not use or reserve TRM capacity for any paths TRMU is currently defined as zero in all cases. APS does not use or reserve TRM capacity for any paths. 3. Assumptions (MOD R6, R7) Assumptions used in the calculation of Total Transfer Capability (TTC) and Available Transfer Capability(ATC) are no more limiting than those used in the planning of operations for the corresponding time period studied. The assumptions include: All applicable contingencies are studied for both the TTC / ATC assessment and operations studies. A contingency set for the TTC / ATC assessment is no more limiting than the contingency set for the operations studies. TTC / ATC studies and operations studies utilize the same switching operating guides. TTC / ATC studies and operations studies utilize the same data sources for load forecast and facility outages. TTC / ATC studies and operations studies are performed on similarly built load flow cases. Since calculations for both studies may be performed at different times, the most recent information is modeled in the load flow case and used in any calculation. o Facility ratings, (emergency and continuous) o Generation models o The Transmission system models are identical in both studies. o The load model for each study is dependent on the time when the study is being performed. The most recent load forecast information is utilized depending on when the study is performed o Base case generation dispatch for either study is adjusted identically depending on the most recent load forecast. 4. Requirements 4.1. The following requirements from NERC Standard MOD-001-1a, Available Transmission System Capability are applicable to this document: Page 2 of 8

3 Information describing how the selected methodology has been implemented, in such detail that, given the same information used by the TSP, the results of the ATC calculations can be validated (R3.1) How APS TSP accounts for counterflows and states how we interpret counterflows to mean counter schedules for the calculation of ATC (R3.2) Identification of Transmission Operators and TSP from which APS receives data for use in the calculation of our ATC (R3.3) Identification of Transmission Operators and TSP to which APS provides data in the calculation of their transfer capability (TTC) (R3.4) Description of allocation processes for transfer capabilities: (R3.5) Description of how generation and transmission outages are considered in transfer capability calculations (R3.6) 5. Implementation 5.1. Methodology MOD-001-1a R APS has selected the Rated System Path Methodology, as described in MOD-029, for calculating Total Transfer Capability and Available Transfer Capability for all Posted Paths and in all ATC time horizons Except for those terms identified and defined in the Definitions section above, all parameters and terms of the ATC calculations used in this implementation match with the ATC and ETC equations expressed in NERC Standard MOD-029-1a, Rated System Path Methodology. See appendix A ATC Algorithms Those parameters that do not match are defined in the Definition section of this ATCID and will be expressed as a term or parameter used as a Firm Other Service (OSF), a term of the Firm Existing Transmission Commitments (ETCF) calculation where applicable The input parameters to the ATC Calculations may vary from path to path and be different in each of the three timing horizons. The ATC Business Practice identifies path specific ATC calculations for each time horizon Counterflows (MOD-001-1a R3.2) The TSP interprets counterflows to mean counter schedules for the calculation of ATC. (R3.2.1) Counterflows as a component of non-firm ATC are derived from the summed value of counter schedules on the associated opposite path for which non-firm ATC is being determined. (R3.2.1) Non-firm ATC in the Scheduling Horizon for those paths that have an associated opposite path will be impacted by firm counter schedules of that opposite path. Only firm counter schedules may be used to increase non-firm capacity on the associated opposite path. (R3.2.1) Firm ATC for all time horizons of all posted paths is relative only to the conditions specific to that path and will not be impacted by counterflows. (R3.2.1) Due to their non-firm nature, non-firm schedules will not impact any counterflows. (R3.2.1) Page 3 of 8

4 APS uses only reservations and tagged schedules in the calculation of ATC. Non firm counter schedules are not used in the calculation of ATC due to their unpredictable nature and higher likelihood of curtailment / bumping which in turn could unnecessarily cause considerable and unnecessary re-scheduling. (R3.2.2) 5.3. ATC Data Received from Others (MOD-001-1a R3.3) APS receives data from the following Transmission Operators for use in the calculation of ATC: Salt River Project (SRP) Western Area Power Authority (WAPA) APS does not receive data from any TSP for use in the calculation of ATC except as they may function as a Transmission Operator listed in Step above TTC Data Delivered to Others (MOD-001-1a R3.4) APS provides data to the below listed Transmission Operator or TSP for use in calculating Transfer Capability (This is interpreted as having to do with Total Transfer Capability): Salt River Project (SRP) Western Area Power Authority (WAPA) Public Service Company of New Mexico (PNM) El Paso Electric (EPE) Tucson Electric Power (TEP) Los Angeles Department of Water and Power (LADWP) California Independent System Operator (CAISO) Imperial Irrigation District (IID) Nevada Power Company (d/b/a NV Energy) San Diego Gas and Electric Company (SDG&E) Southern California Edison Company (SCE) Southern California Public Power Authority (SCPPA) represented by LADWP The above individuals will be contacted for changes in this ATCID as well as the Rocky Mountain/Desert Southwest Reliability Center. (MOD-001-1a R4, R4.1, R4.2, R4.3, R4.4, R4.5, and R4.6) 5.5. Allocation Processes (MOD-001-1a R3.5) APS has ATC Paths that have multiple owners and are allocated as follows: APS s ownership share of the FOURCORNERS230 to FOURCORNERS345 transformer is controlled and APS s ownership share of the WESTWING500 WESTWING230 transformers are controlled and APS s ownership share of the KYRENE500 KYRENE230 transformers are controlled and allocated on a pro-rata basis by Salt River Project (SRP), the path operator APS s ownership share of the MORGAN500 - NAVAJO500 (Path51) segment is controlled and APS s ownership share of the MORGAN500 WESTWING500 (Path51) segment is controlled and Page 4 of 8

5 APS s ownership share of the WESTWING500 MOENKOPI500 (Path51) segment is controlled and APS s ownership share of the MORGAN500 PINNACLEPEAK230 segment is controlled and APS s ownership share of the MEAD500 WESTWING500 (Path49) is controlled and allocated on a pro-rata basis by Western Area Power authority (WAPA), the path operator APS s ownership share of the NORTHGILA500 PALOVERDE500 (Path49) is controlled and allocated on a pro-rata basis by Arizona Public Service (APS), the path operator APS s ownership share of the PALOVERDE500 PVWEST500 (Path49) is controlled and allocated on a pro-rata basis by Arizona Public Service (APS), the path operator APS s ownership share of PALOVERDE500 RUDD500 are controlled and allocated on a pro-rata basis by Salt River Project (SRP), the path operator APS s ownership share of PALOVERDE500 WESTWING500 path which acts as a cut plane between PALOVERDE500 WESTWING500 AND PALOVERDE500 KYRENE500 is controlled and allocated on a pro-rata basis by Salt River Project (SRP), the path operator APS s ownership share of the NAVAJO500 MOENKOPI500 (Path49) is controlled and allocated on a pro-rata basis by Arizona Public Service (APS), the path operator APS does not have or utilize forward looking congestion management and seams coordination processes. 5.6 Generation and Transmission Outages (MOD-001-1a R3.6) APS does not currently have any generation outages which cause an impact to TTC calculations. Should a generation outage occur, APS Transmission expects that schedules (e-tags) will be adjusted for the appropriate amount of time, thus changing the ATC calculation accordingly APS has certain transmission outages that may affect TTC, and thus affect ATC. If an outage should occur, TTC on the path will be adjusted accordingly through OASIS and schedules using that path (e-tags) may be subject to curtailment When a transmission outage occurs, and is in effect for part of a day, it will only affect those hours for which the outage is in place. If the outage is ended early or extended, it will be adjusted in OASIS for the affected hours only. R When a transmission outage occurs, and is in effect for part of a month, it will only affect those hours or days for which the outage is in place. If the outage is ended early or extended, it will be adjusted in OASIS for the affected time only. R When outage from other TSPs that cannot be mapped to the transmission model occurs, APS will evaluate the impact to the APS transmission system and will adjust TTC accordingly, if applicable. R ATC Information (MOD-001-1a R5) Besides being sent to all participants in section 5.4, the ATCID is posted and available on the AZPS OASIS website for all additional individuals. Page 5 of 8

6 7.0 Requests for ATC Information (MOD-001-1a R9) Questions regarding APS s ATC Calculation methodology or ATC results may be directed to any one of the following points of contact: APS ATC information address: OASISADM@apsc.com Or Contact one of the individuals listed on the AZPS OASIS website under ATC CONTACT INFORMATION. Requested information will be provided within 30 days and will include the information specified in the standard. R9. The information will be retained and provided in the format required by MOD-001-1a. R9.1, R9.1.1, R9.1.2, R9.1.3, and R9.2. Appendix A ATC Algorithms ATCF is the firm Available Transfer Capability for the ATC Path for that period. ATCNF is the non-firm Available Transfer Capability for the ATC Path for that period. CBM is the Capacity Benefit Margin for the ATC Path during that period. CBMS is the Capacity Benefit Margin for the ATC Path that has been scheduled during that period. CounterflowsF are adjustments to firm Available Transfer Capability as determined by the TSP and specified in their ATCID. CounterflowsNF are adjustments to non-firm Available Transfer Capability as determined by the TSP and specified in its ATCID. ETCF is the sum of existing firm commitments for the ATC Path during that period. ETCNF is the sum of existing non-firm commitments for the ATC Path during that period. GFNF is the non-firm capacity set aside for grandfathered Transmission Service and contracts for energy and/or Transmission Service, where executed prior to the effective date of a TSP s Open Access Transmission Tariff or safe harbor tariff. NITSNF is the non-firm capacity set aside for Network Integration Transmission Service serving Load (i.e., secondary service), to include losses, and load growth not otherwise included in Transmission Reliability Margin or Capacity Benefit Margin. NITSF is the firm capacity reserved for Network Integration Transmission Service serving Load, to include losses, and Load growth, not otherwise included in Transmission Reliability Margin or Capacity Benefit Margin. Page 6 of 8

7 NLF is the firm capacity set aside to serve peak Native Load forecast commitments for the time period being calculated, to include losses, and Native Load growth, not otherwise included in Transmission Reliability Margin or Capacity Benefit Margin. OSF is the firm capacity reserved for any other service(s), contract(s), or agreement(s) not specified above using Firm Transmission Service as specified in the ATCID. OSNF is the non-firm capacity reserved for any other service(s), contract(s), or agreement(s) not specified above using non-firm transmission service as specified in the ATCID. PostbacksF are changes to firm Available Transfer Capability due to a change in the use of Transmission Service for that period, as defined in Business Practices. PostbacksNF are changes to non-firm Available Transfer Capability due to a change in the use of Transmission Service for that period, as defined in Business Practices. PTPF is the firm capacity reserved for confirmed Point-to-Point Transmission Service. PTPNF is non-firm capacity reserved for confirmed Point-to-Point Transmission Service. RORF is the firm capacity reserved for Roll-over rights for contracts granting Transmission Customers the right of first refusal to take or continue to take Transmission Service when the Transmission Customer s Transmission Service contract expires or is eligible for renewal. TRM is the Transmission Reliability Margin for the ATC Path during that period. TRMU is the Transmission Reliability Margin for the ATC Path that has not been released for sale (unreleased) as non-firm capacity by the TSP during that period. TTC is the Total Transfer Capability of the ATC Path for that period. The ATC Algorithms are presented here encompass all APS OASIS posted paths. Terms and definitions in the NERC Standard MOD-029-1, Rated System Path Methodology, are consistent with the like terms used in this document. Terms below grouped in GREEN are components of the Firm Existing Transmission Commitments (ETCF) as described in the NERC ATC MODs. Terms below grouped in RED are components of the Non-Firm Existing Transmission Commitments (ETCNF) as described in the NERC ATC MODs. FIRM ATC CALCULATIONS: Scheduling Horizon: ATCF = TTC (NLF + NITSF + GFF + PTPF + RORF + OSF) CBM TRM + PostbacksF + CounterflowsF Operating Horizon: ATCF = TTC (NLF + NITSF + GFF + PTPF + RORF + OSF) CBM TRM + PostbacksF + CounterflowsF Planning Horizon: ATCF = TTC (NLF + NITSF + GFF + PTPF + RORF + OSF) CBM TRM + PostbacksF + CounterflowsF Page 7 of 8

8 NON-FIRM ATC CALCUATIONS: Scheduling Horizon: ATCNF = TTC (NLF + NITSF + GFF + PTPF + RORF + OSF) (NITSNF + GFNF + PTPNF+ OSNF) CBMS TRMU + PostbacksNF + CounterflowsNF Operating Horizon: ATCNF = TTC (NLF + NITSF + GFF + PTPF + RORF + OSF) (NITSNF + GFNF + PTPNF+ OSNF) CBMS TRMU + PostbacksNF + CounterflowsNF Planning Horizon: ATCNF = TTC (NLF + NITSF + GFF + PTPF + RORF + OSF) (NITSNF + GFNF + PTPNF+ OSNF) CBMS TRMU + PostbacksNF + CounterflowsNF Version History: Version Effective Date Changes Author Standard Original 4/1/11 New R. Bean MOD /19/2012 Technical Review - No R. Bean MOD changes 2 5/24/2018 Update from APSATC@aps.com to OASISADM@apsc.com j. Bordenkircher MOD Page 8 of 8