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Home My WebLink About2022-09-30 IMC Agenda and docs INTERTIE MANAGEMENT COMMITTEE (IMC) REGULAR MEETING AGENDA September 30, 2022 9:00 AM Alaska Energy Authority Board Room 813 W Northern Lights Blvd, Anchorage, AK 99503 To participate dial 1-888-585-9008 and use code 212-753-619# 1. CALL TO ORDER 2. ROLL CALL FOR COMMITTEE MEMBERS 3. PUBLIC ROLL CALL 4. PUBLIC COMMENTS 5. AGENDA APPROVAL 6. APPROVAL OF PRIOR MINUTES – July 29, 2022 7. NEW BUSINESS – NONE 8. OLD BUSINESS A. Intertie Asset Management B. Railbelt Protection Coordination C. Systems Studies Subcommittee 2022/2023 work 9. COMMITTEE REPORTS A. Budget Subcommittee i. Budget to Actuals Expense Report for 06.30. 22 B. IOC Committee C. Operator’s Report 10. MEMBERS COMMENTS 11. NEXT MEETING DATE – December 9, 2022 12. ADJOURNMENT 1 | Page Alaska Intertie Asset Management The Alaska Energy Authority (AEA) owns 170‐miles of transmission line between the Douglas Substation in Willow, Alaska and the Healy Substation in Healy, Alaska. The line is designed at 345‐kV and currently operated at 138‐kV. This line is operated by Chugach Electric Association (Chugach), Matanuska Electric Association (MEA) and Golden Valley Electric Association (GVEA) under the terms of the 3/11/14 Second Amended and Restated Alaska Intertie Agreement. Three static var substations (SVS), Goldhill SVS, Healy SVS, and Teeland SVS, as well as other transmission line equipment is also owned by AEA. These assets, located in widely diverse operating conditions, pose unique, fleet‐wide asset management challenges. Asset Management (AM) meets these challenges with a methodology that can be consistently applied to assets throughout AEA’s footprint. By identifying risk associated with AEA’s critical systems and equipment and providing data‐driven insight on mitigating that risk, AM supports a wide range of efforts that reinforces the resilience and reliability of the grid. The approach combines extensive field knowledge with input from applicable departments to enhance existing databases, perform analyses, and generate reports that inform objective decisions on budget development, capital plans, operations and maintenance practices, financial forecasting, and safety and security upgrades. Objectives  Integrate all assets into risk‐based methodologies to strategically inform capital investments.  Maximize the value of assets.  Correlate asset maintenance history, health indices, and consequence values to drive risk‐based decisions.  Use asset population and performance data to inform best maintenance practices. Goals  Gather asset data to support reliability‐centered maintenance and the 10‐year planning process. This will take us from a basic “asset inventory” approach (i.e. identifying critical equipment and systems and collecting data on their condition) to using AM processes and reports that will evolve the shape beyond maintenance and acquisition decisions. In the future, these reports can be used to provide information for developing budgets, analyzing workload, and managing vegetation and rights of way.  Integrate asset health indices and risk scores to drive condition‐based and predictive maintenance activities.  Refining reports and finding new ways to share and apply data to serve other business needs. This will present data in a way that’s easily understood by those outside AM. Current Progress  Data entry of transmission line structures plan and profile data including but not limited to structure ids, stations, span lengths, line angles, pole heights, structure foundation types, guy anchor types, conductor types and assemblies, damper types, conductor sag, etc.  Working to determine a structure for a transmission line preventative maintenance manual for the intertie.  Vegetation Management plan submitted to IOC in May 2022. Respectfully, Molly Howard IMSC DATE: September 23, 2022 TO: Dan Bishop, Chair, Intertie Operating Committee THROUGH: John Bell, Chair, IOC System Studies Subcommittee FROM: IOC System Studies Subcommittee SUBJECT: IOC Planned Projects for 2022-2023 This memorandum is a summary of recent work completed by the Intertie Operating Committee’s System Studies Subcommittee, as well as a summary of planned projects to be performed over the next year. The memo is intended as a reference for the IOC and the Intertie Management Committee for use in maintaining awareness of ongoing work and to help with guidance of future work. The System Studies Subcommittee is an active subcommittee and regularly meets and performs analysis as needed for the IOC. From 2019 to 2021, the System Studies Subcommittee completed two significant study projects. During 2019 and 2020, a small signal analysis was performed for the SSS by Siemens Power Technologies International. This study informed the SSS on the nature of interarea oscillations on the Railbelt and further recommended projects to increase damping of such oscillations. Following this study, several tuning projects were completed by the utilities to mitigate oscillations. During 2020 and 2021, a reserves quality analysis was performed for the SSS Electric Power Systems. This study defined a new reserve requirement called Primary Frequency Response which is intended to ensure that utilities will not reach underfrequency load shed due to an N-1 generation or transmission line trip. An ongoing effort is to implement the recommendations from this reserves study, which will be discussed later. The study projects completed in these past years have informed the System Studies Subcommittee on future study requirements for the IOC. Following the oscillation study, the SSS identified a need for a system analysis tool which could perform modal analysis and could identify the participation factor of generators during an oscillation. Following this need, the IOC budgeted for a synchrophasor pilot project and the SSS is targeting October of 2022 to publish an RFP for a synchrophasor system. This pilot project is intended to establish a shared-access synchrophasor data system which will aid in oscillation analysis, power system model development and validation, and wide-area awareness for utility control centers if desired. If a proposal is accepted, implementation would occur during 2023. This effort will be a collaborative effort between various subcommittees, including those related to cybersecurity, communications, relay, and operations. The SSS will be presenting on the specification for this project at the upcoming NWPPA conference in November. Following the completion of the reserves study by EPS, the IOC assigned the Dispatch and System Operations Subcommittee with developing a policy to implement the Primary Frequency Response in operations. The SSS will be assisting the Dispatch and System Operations Subcommittee with the “translation” of the study report to a meaningful operational policy. This effort will be occurring from 2022 to 2023. The SSS has started discussions of what the next study could be following the synchrophasor pilot project and the reserves policy implementation. The Reserves Study recommended an analysis to coordinate settings for the planned battery energy storage systems in the Interior, Southcentral, and Kenai regions. Another important extension of the reserves analysis would be to examine Railbelt reserve requirements and stability with a projected increase in inverter-based generation, which would be primarily solar or wind renewables projects. Between the known plans for new sources of reserves in the form of energy storage, and new dynamics due to new inverted generation, the SSS feels that there is a strong need for a Railbelt-wide analysis of system stability. The scope of this study has only been discussed at a high level, and the SSS will continue discussions in detail once the current projects are closer to completion. Alaska Energy Authority AK Intertie Budget to Actual Expenses 07/01/2021 to 06/30/2022 Page 1 of 5 FY22 Approved Budget BUDGET 07/01/2021 - 06/30/2022 Actuals YTD Actuals as a % of Total Annual Budget OVER (UNDER) YTD Variance Revenue From Utilities AKI-GVEA 1,703,854 1,703,854 2,075,721 122%371,867 AKI-CEA 225,259 225,259 265,259 118%40,000 AKI-MEA 361,596 361,596 413,239 114%51,642 Total Revenue From Utilities 2,290,710 2,290,710 2,754,219 120%463,509 Interest/Capital Credits - - 1,668 0%1,668 Total Revenues 2,290,710 2,290,710 2,755,887 120%465,177 Total Revenues 2,290,710 2,290,710 2,755,887 120%465,177 56200 Station Expenses Golden Valley Electric AK Intertie-Substation Electricity Usage 8,000 8,000 45,889 574%37,889 Golden Valley Electric Total 8,000 8,000 45,889 574%37,889 56600 Misc Transmission Expense Alaska Energy Authority AK Intertie-Cell Phone Comm. Svc. for Wx Monitorin 12,000 12,000 12,025 100%25 Alaska Energy Authority Total 12,000 12,000 12,025 100%25 Chugach Electric Association Chugach Electric Association Total - - - 0%- Golden Valley Electric AK Intertie-Private Line Telephone Service SCADA 18,000 18,000 5,556 31%(12,444) AK Intertie-Misc Studies as needed 100,000 100,000 75,375 75%(24,625) Golden Valley Electric Total 118,000 118,000 80,931 69%(37,069) Matanuska Electric Association AK Intertie-Misc Studies as needed 100,000 100,000 69,952 70%(30,048) Matanuska Electric Association Total 100,000 100,000 69,952 70%(30,048) 56601 Weather Monitoring Batteries Alaska Energy Authority AK Intertie-SLMS Support and Intertie Grnd Patrol 100,000 100,000 150,692 151%50,692 Alaska Energy Authority Total 100,000 100,000 150,692 151%50,692 56700 Rents Alaska Energy Authority AK Intertie-Alaska Railroad 700 700 700 100%- Alaska Energy Authority Total 700 700 700 100%- Matanuska Electric Association AK Intertie-Talkeetna Storage 7,200 7,200 7,200 100%- AK Intertie-Equipment Rental - - 375 0%375 Matanuska Electric Association Total 7,200 7,200 7,575 105%375 56900 Maintenance of Structures Alaska Energy Authority Alaska Energy Authority Total - - - 0%- 57000 Maintenance of Station Equip Chugach Electric Association AK Intertie-Teeland Substation 85,000 85,000 115,365 136%30,365 AK Intertie-Douglas Substation Communications - - 1,742 0%1,742 Chugach Electric Association Total 85,000 85,000 117,107 138%32,107 Golden Valley Electric AK Intertie-Healy, Cantwell, Goldhill 74,340 74,340 63,163 85%(11,177) AK Intertie-SCADA Maint Healy, Cantwell, Goldhill 5,000 5,000 - 0%(5,000) AK Intertie-Cantwell 4S2 Switch Repair 266,000 266,000 182,606 69%(83,394) AK Intertie-Maint & Repaint Reactors Healy SVC Yd 80,000 80,000 7,452 9%(72,548) AK Intertie-Healy&Goldhill Digital Fault Recorders 90,000 90,000 53,255 59%(36,745) ALASKA ENERGY AUTHORITY AK INTERTIE BUDGET TO ACTUAL EXPENSES FOR THE PERIOD 07/01/2021 THROUGH 06/30/2022 Page 2 of 5 FY22 Approved Budget BUDGET 07/01/2021 - 06/30/2022 Actuals YTD Actuals as a % of Total Annual Budget OVER (UNDER) YTD Variance ALASKA ENERGY AUTHORITY AK INTERTIE BUDGET TO ACTUAL EXPENSES FOR THE PERIOD 07/01/2021 THROUGH 06/30/2022 AK Intertie-Goldhill SVC Cooling 65,000 65,000 460 1%(64,540) Golden Valley Electric Total 580,340 580,340 306,936 53%(273,404) Matanuska Electric Association Matanuska Electric Association Total - - - 0%- 57100 Maint of OH Lines Golden Valley Electric AK Intertie-Northern Maintenance 78,000 78,000 107,641 138%29,641 Golden Valley Electric Total 78,000 78,000 107,641 138%29,641 Matanuska Electric Association AK Intertie-Special Patrols (Incl Foundation Insp) 5,000 5,000 599 12%(4,401) AK Intertie-Southern Maint. (Incl Ground Insp) 200,000 200,000 191,358 96%(8,642) AK Intertie-Equipment Repair and Replacement 640,000 640,000 - 0%(640,000) Matanuska Electric Association Total 845,000 845,000 191,957 23%(653,043) 57102 Maint OH Lines-ROW Clearing Golden Valley Electric AK Intertie-Northern ROW Clearing 73,000 73,000 68,882 94%(4,118) Golden Valley Electric Total 73,000 73,000 68,882 94%(4,118) Matanuska Electric Association AK Intertie-Southern ROW Clearing 150,000 150,000 168,367 112%18,367 Matanuska Electric Association Total 150,000 150,000 168,367 112%18,367 58302 Operating Committee Exp-Legal Alaska Energy Authority AK Intertie-IMC Admin Cost (Audit, meeting, legal) - - 27,178 0%27,178 Alaska Energy Authority Total - - 27,178 0%27,178 58306 Misc Admin Alaska Energy Authority AK Intertie-IMC Admin Cost (Audit, meeting, legal) 17,500 17,500 1,465 8%(16,035) Alaska Energy Authority Total 17,500 17,500 1,465 8%(16,035) 58307 Professional consultants Alaska Energy Authority AK Intertie-IMC Admin Cost (Audit, meeting, legal) - - 633 0%633 Alaska Energy Authority Total - - 633 0%633 58401 Insurance Premiums Alaska Energy Authority AK Intertie-Insurance 21,517 21,517 21,488 100%(29) Alaska Energy Authority Total 21,517 21,517 21,488 100%(29) Matanuska Electric Association AK Intertie-Insurance 14,133 14,133 15,645 111%1,512 Matanuska Electric Association Total 14,133 14,133 15,645 111%1,512 Total Station Expenses 2,210,390 2,210,390 1,395,063 63%(815,327) Total Operating Expenses 2,210,390 2,210,390 1,395,063 63%(815,327) 71001 Total Expense, Budget Alaska Energy Authority Total 220,000 220,000 - 0%(220,000) 72510 Admin Per Diem-In State Alaska Energy Authority Total - - 399 0%399 72512 Admin Per Diem-Out of State Alaska Energy Authority Total - - 168 0%168 73115 Other Professional Services Alaska Energy Authority Total - - - 0%- 73141 Legal Services-SOA Alaska Energy Authority Total - - - 0%- Page 3 of 5 FY22 Approved Budget BUDGET 07/01/2021 - 06/30/2022 Actuals YTD Actuals as a % of Total Annual Budget OVER (UNDER) YTD Variance ALASKA ENERGY AUTHORITY AK INTERTIE BUDGET TO ACTUAL EXPENSES FOR THE PERIOD 07/01/2021 THROUGH 06/30/2022 73150 AIDEA Staff-Prof Services Alaska Energy Authority Total - - 148,249 0%148,249 73160 Temporary Staffing Services Alaska Energy Authority Total - - 20,533 0%20,533 73905 Recording Fees Alaska Energy Authority Total - - - 0%- Total Total Expense, Budget 220,000 220,000 169,350 77%(50,650) Total AEA Administration Expenses 220,000 220,000 169,350 77%(50,650) Total Expenses 2,430,390 2,430,390 1,564,413 64%(865,977) Surplus (Shortage)(139,680)(139,680)1,191,474 -853%1,331,154 Page 4 of 5 Alaska Intertie FY22 Budget to Actuals Status Report for the Period 07/01/2021 through 06/30/2022 Budgeted Usage Actual Usage to Date GVEA MEA CEA ML&P TOTAL GVEA MEA CEA ML&P TOTAL MONTH MWH MWH MWH MWH MWH MONTH MWH MWH MWH MWH MWH Jul 11,050 1,795 - - 12,845 Jul 4,815 1,863 - - 6,678 Aug 8,973 2,008 - - 10,981 - Aug 12,415 1,905 - - 14,320 Sep 13,749 1,952 - - 15,701 Sep 3,283 1,870 - - 5,153 Oct 28,741 1,821 - - 30,562 Oct 13,008 1,959 - - 14,967 Nov 10,171 1,786 - - 11,957 Nov 8,519 2,300 - - 10,819 Dec 8,962 2,048 - - 11,010 Dec 6,423 2,343 - - 8,766 Jan 12,043 2,395 - - 14,438 Jan 20,852 2,350 - - 23,202 Feb 8,513 2,070 - - 10,583 Feb 36,168 1,996 - - 38,164 Mar 5,617 2,168 - - 7,785 Mar 30,015 2,207 - - 32,222 Apr 12,448 1,798 - - 14,246 Apr 24,644 2,019 - - 26,663 May 9,247 1,966 - - 11,213 May 27,507 2,143 - - 29,650 Jun 32,274 1,940 - - 34,214 Jun 11,533 2,106 - - 13,639 TOTAL 161,788 23,747 - - 185,535 TOTAL 199,182 25,061 - - 224,243 INTERTIE PROJECTED ENERGY USAGE TO DATE (MWH) 185,535 INTERTIE ACTUAL ENERGY USAGE TO DATE (MWH) 224,243 Budgeted Operating Costs for the period 2,210,390$ Actual Operating Costs for the period 1,395,063$ (based on amended budget) Budgeted Usage Revenue for the period 1,654,972$ Actual (Billed) Usage Revenue for the period 2,000,248$ (budgeted rate x projected usage) (budgeted rate x actual usage) Estimated Budgeted Energy Rate per MWH 9.95$ (based on to date budgeted costs and usage) Annual Budgeted Energy Rate (Billed Rate) 8.92$ Projected Actual Energy Rate per MWH 5.19$ (based on minimum contract value) (based on to date actual costs and usage) Page 5 of 5 Intertie Management Committee Meeting IOC Report September 30, 2020 1. Intertie Operating Committee a. A letter from AEA formalizing the transfer of distribution assets at Cantwell Substation to Golden Valley Electric Association, Inc. was received by email on August 22, 2022. The letter also included documentation of the transfer of overhead distribution lines to GVEA that occurred in 1988. b. A presentation that outlines the proposed strategic plan for the Alaska Intertie was revised at the IOC meeting of September 23, 2022. c. An alternative product to the existing Snow Load Monitoring System (SLMS) was introduced. The product offered by Linevision may be an economically attractive alternative to updating the existing SLMS because it doesn’t require modifications to sensors that are near the energized conductors, and is installed at a modest height above the ground. It also doesn’t require instrumentation cables to extend from the datalogger equipment at the base of the structure to the insulator strings. d. An updated list of IMC committee and subcommittee members was circulated. e. The IOC discussed details of the event on GVEA’s 69kV system that caused loadshed throughout the Railbelt. f. New and revised assignments were given to subcommittees for various tasks. See below for additional details. 2. Maintenance Subcommittee a. The maintenance subcommittee sent a brief update for the IOC meeting of September 23, 2022. b. Installation of the load break transmission switches (345kV/230kV) at Cantwell will be delayed until spring or early summer 2023 to coincide with outage for installation of aerial marker balls. c. Aerial marker balls are expected to arrive at MEA in September, but will be in storage until spring or early summer of 2023. d. The vegetation management plan was updated. The next step for the vegetation management plan is to integrate AEA’s comments. 3. System Studies Subcommittee a. The System Studies Subcommittee (SSS) sent a memo with a brief update of their planned projects for the coming year. b. The committee has over the previous months completed two major studies - an oscillation study and a system reserve study. These point us in future direction of studies and improvements needed. c. The SSS will be introducing their work toward implementing a Railbelt-wide synchrophasor system at the NWPPA E&O conference in Anchorage at the end of the month. d. A new project, adding the effect of the dividers to the Bradley generator governor model, was assigned to the SSS. e. A new project, analysis of the effect of increased renewables on the performance of the Railbelt grid, was assigned to the SSS. 4. Engineering, Relay, and Reliability Subcommittee a. The Engineering, Relay, and Reliability Subcommittee (ERRS) was assigned the task of working with other utilities to share lessons learned about system protection in the context of the July event on GVEA’s 69kV system. b. This Subcommittee will work with the SSS to evaluate the impact of inverter-based resources (i.e. generation or batteries) on protective relaying. c. This subcommittee will continue working toward completion of its previous assignment to evaluate and implement appropriate out-of-step relaying for the Alaska Intertie. 5. Dispatch and Operations Subcommittee a. The Dispatch and Operations Subcommittee was assigned the task of translating the reserve study into policies that could be used by dispatch centers, in collaboration with the System Studies Subcommittee. b. The subcommittee was assigned the task of working toward a uniform approach to implement inadvertent accounting. c. The subcommittee was assigned the task of working on a uniform policy to return to tie line bias after a disturbance. PART 2: EVENT SUMMARY 09/21/2022 TO01/01/2022 12/31/2022 IOC ANNUAL RELIABILITY REPORT Event Num Date/Time Duration Description Freq extreme Intertie Kenai opened opened Unit Line Trip Trip BESS Silos Load Shed Comments 1,161 01/07/2022 02:28:42 HLP ST2 Trip 59.50 X 0.0 0.0 0.01.3 1,165 01/21/2022 08:34:57 Teeland-Douglas B-Phase line fault trip. 60.63 X X 0.0 0.0 24.60.1 1,166 01/02/2022 02:12:04 NCC ST trip 59.83 X 0.0 0.0 0.00.5 1,167 01/29/2022 12:39:55 AK Intertie Trip - Teeland-Douglas A-phase fault 60.73 X X 0.0 4.9 20.80.1 1,168 01/30/2022 14:35:24 SPP 11 trip due to fuel pressure differential. 59.57 X 2.1 0.0 10.60.1 1,169 02/10/2022 17:46:31 Sullivan #9 - ramp to idle due to water flow transmitter failure. 59.75 X 0.0 0.0 16.90.0 1,170 02/16/2022 19:51:27 Sullivan #9 trip due to IGV feedback error. 59.71 X 0.0 0.0 16.50.2 1,171 02/15/2022 13:43:36 NPC GT3 Trip due to communications failure to the unit 59.77 X 0.0 0.0 25.10.8 1,172 02/17/2022 18:39:51 Douglas 1B1 Trip due to C-ground fault. 60.82 X X 6.4 19.3 24.40.0 1,173 02/22/2022 03:25:27 AK Tie Trip - Douglas-Healy loss of Bradley AGC control 60.62 X X 11.7 10.0 25.30.0 1,174 02/24/2022 02:23:59 Sullivan 10 Ramp Down and Trip (no tie outages) 59.72 X 0.0 0.0 11.10.0 1,175 03/11/2022 07:05:23 AK Intertie trip Teeland -Douglas due to A-Phase Fault 60.62 X X 8.1 6.9 25.10.1 1,176 03/27/2022 21:11:19 HLP ST2 Trip 59.40 X 10.9 0.0 16.31.0 1,177 03/12/2022 00:06:53 NPC & BESS Trip 59.48 X 9.7 10.5 16.44.6 1,178 03/28/2022 10:24:39 HLP ST2 Trip 59.64 X 0.0 1.9 16.40.8 1,179 03/29/2022 02:48:41 HLP ST2 Trip 59.55 X 0.0 0.0 9.80.7 *has sub event Event Num Date/Time Duration Description Freq extreme Intertie Kenai opened opened Unit Line Trip Trip BESS Silos Load Shed Comments 1,180 04/06/2022 23:37:09 NPC GT3 Trip (Thermocouple failure) 59.76 X 0.0 0.0 1.10.6 1,181 05/03/2022 05:47:34 NPC GT3 Trip 59.73 X 0.0 0.0 15.03.0 1,182 05/26/2022 21:23:50 138 kV JCS-PTS Trip (Tower Failure) 59.80 X 0.0 7.9 0.02.2 1,183 06/09/2022 06:01:04 Loss of Bradley transmission south of Soldotna due to lightning strike 60.27 X X 0.0 0.0 0.00.0 1,184 05/25/2022 22:05:29 SPP Plant Trip and UFLS 59.47 X 0.0 32.3 0.50.3 1,185 06/10/2022 16:54:36 HLP ST1 Trip 59.82 X 0.0 0.0 0.42.4 1,186 06/20/2022 17:10:13 138 kV NIS-NPS Trip (lighting) 60.32 X 0.0 35.8 2.11.3 1,187 07/03/2022 21:43:31 HLP ST1 Trip 59.82 X 0.0 0.0 0.04.1 1,188 07/05/2022 01:04:54 69kV FWS-SSS-GHS Line Trip 60.22 X 0.0 28.1 0.00.9 1,189 07/06/2022 14:57:58 NPP GT2 Trip 59.50 X 0.0 0.0 0.01.8 1,190 07/11/2022 20:53:46 138kV GHS-FKS Trip (lightning) 60.26 X 0.0 25.2 0.01.3 1,191 07/20/2022 12:12:38 HLP ST1 Trip 59.88 X 0.0 0.0 0.00.3 1,192 07/20/2022 15:13:58 HLP ST1 Trip 59.80 X 0.0 0.0 0.01.8 1,193 07/21/2022 14:33:42 69 kV GHS-SSS-FWS Trip 58.91 X 0.0 87.0 0.01.3 1,194 08/01/2022 06:43:29 University-Hope Line Trip due to fault between Portage and Hope. 59.81 X 0.0 0.0 0.00.1 1,195 08/01/2022 15:52:29 NPC Ramp Offline (Thermocouple Failure) 59.76 X 0.0 0.0 0.06.0 1,196 08/15/2022 08:46:50 Teeland-Douglas Trip, No Cause Found 60.39 X 0.0 0.0 22.00.1 1,197 07/25/2022 16:23:44 138 kV CSS-GHS Trip (tree fault during wind storm) 59.23 X 0.0 29.8 0.00.2 1,198 07/25/2022 16:29:03 ZNS-GHS 69 kV Line Trip (test energize failure) 59.53 X 0.0 0.0 0.00.2 1,199 07/25/2022 17:23:02 CSS-GHS 138 kV Line Trip (test energize failure) 59.79 X 0.0 0.0 0.00.1 1,200 07/25/2022 19:30:12 FWS-SSS-GHS 69 kV Line Trip 60.23 X 0.0 30.9 0.01.2 1,201 07/25/2022 20:15:55 FKS Closes into fault on their distribution 59.76 X 0.0 9.1 0.00.1 *has sub event Event Num Date/Time Duration Description Freq extreme Intertie Kenai opened opened Unit Line Trip Trip BESS Silos Load Shed Comments 1,202 08/14/2022 16:37:25 HLP ST2 Trip 59.22 X 0.0 0.0 7.81.7 1,203 08/16/2022 15:38:12 HLP ST2 Trip 59.35 X 3.0 0.0 13.51.2 1,204 08/24/2022 17:03:17 Bradley 2 Trip, cause unknown 59.71 X 0.0 0.0 0.00.0 1.04Average Duration *has sub event Alaska Intertie Strategic Planning Update September 23, 2022 revision Proposed Vision for the Alaska IntertieVision: The Alaska Intertie will play a key role in the RailbeltGrid by reliably transmitting economic power, including renewables, at levels sufficient to meet the needs of Railbeltstakeholders for the remaining life of the asset.GoalsoComplete an Alaska Intertie Asset Management Plan, including a predictive maintenance schedule and vegetation management plan, to maximize its useful life and valueoDetermine appropriate Alaska Intertie voltage rating for near‐term and long‐term Railbelt needsoMinimize adverse impacts on Railbelt G&T entities and power customers from Alaska Intertie events such as faults, equipment failures, etc.oMaximize the benefit of coordinating generation and energy storage resources north and south of the Alaska IntertieoUpdate the Alaska Intertie agreements as needed to ensure fair and equitable access to this resourceoMaintain, repair, and operate the Alaska Intertie as directed by AEA and the Railbelt Utilities to maximize the benefit to the ratepayersSeptember 21, 2022| Pg. 2 Background• Alaska Intertie was commissioned in 1984• 170 miles from Healy Substation to Douglas Sub (near Willow) • Connected to the Southcentral area 230kV & 115kV transmission at Teeland Substation through 26 miles of 138kV transmission line owned by MEA • Three SVC systems (Teeland, Healy, & Gold Hill)• Rated transfer capacity is about 78MW (per AIA)• Capacity is limited by transient stability, not thermal rating of conductors or voltage dropSeptember 21, 2022| Pg. 3 Background• Transmission towers and conductors between Healy and Douglas Substations were designed to operate at 345kV• Currently operated at 138kV• 766 structures, mostly steel X towers• Bundled 954 MCM “Rail” conductorSeptember 21, 2022| Pg. 4 Selected Construction, Repair and Upgrade Events• 2020-2022: Marker ball replacement • 2018: Douglas Substation upgrade. $790k.• 2018: Tower #748 repairs for $1.2M• 2015: SVC’s replaced by Alstom Grid with a $10M state appropriation• 2012: Tower #195 replacement for $2.4M• 2007: Tower #692• 1984: Construction cost was $124 million in State appropriationsSeptember 21, 2022| Pg. 5 Ongoing Work• SVC scheduled maintenance• SVC POD tuning to address oscillation risk• Marker ball replacement• Development of preventive maintenance plan, leading to an asset management plan• Development of vegetation & wildfire management plansSeptember 21, 2022| Pg. 6 ReliabilitySeptember 21, 2022| Pg. 7• 2012-2021 Forced outage rate: 0.41%• 2012-2021 All outages: 1.28%• Compares favorably to NERC, which averaged 1.84% for 200kV+ lines, 2011-2015.Alaska Intertie All Outages Summary 2012‐2021 average duration: 15.9 hours2012‐2021 total count: 862012‐2021 average per year: 8.62012‐2021 longest outage: 275.6 hours2012‐2021 total duration: 1121.3 hours2012‐2021 all outages rate: 1.28%Alaska Intertie Forced Outage Summary 2012‐2021 average duration: 9.7 hours2012‐2021 total count: 372012‐2021 average per year: 3.72012‐2021 longest outage: 111.6 hours2012‐2021 total duration: 358.5 hours2012‐2021 forced outage rate: 0.41% Challenges• Effects of unbalanced snow loading• Aging Equipment• Melting Permafrost•Erosion• Wildfire risk• Clearing vegetation• Access September 21, 2022| Pg. 8 Proposed Strategic Plan to accomplish Vision• Develop specifics of plan using a combination of bottom up and top down approaches • Bottom up• Asset management plan and software• GIS• Equipment database (e.g. Cascade, Maximo, etc.)• Structural analysis• LIDAR study collected detailed data• Update previous engineering analysis using modern tools• Equipment inspection schedules, standards & forms• Substation equipment maintenance plans• Vegetation & Wildfire management plans• History documentation of previous repairs/ maintenanceSeptember 21, 2022| Pg. 9 Proposed Strategic Plan to accomplish Vision• Combined bottom up / top down approach (cont.)• Top Down – set informed goals for performance based on cost-benefit analysis• Economic dispatch studies to determine value of improved transfer capacity• ACEP study• ERO IRP process• Resource evaluations (wind, hydro, etc)• Take advantage of geographically diverse wind resources• Example: MEA’s proposed Railbelt wind resource assessment• Electrical performance studies (e.g. refresh AEA’s 2017 Railbelt transmission plan)• Transient stability limits• Electrical losses• Railbelt Reliability standardsSeptember 21, 2022| Pg. 10 Proposed Strategic Plan to accomplish Vision• Proposed Components of the Strategic Plan• Periodically updated vision and associated specific objectives for cost, reliability, losses, and transfer capacity.• Funding plan –• Establish a reserve fund for capital expenditures• Consider financing if appropriate• Recurring study of estimated long-term repair and replacement costs (similar to BPMC’s D.Hittle report)• Asset inventories• Condition reports for various components (structures, foundations, lightning protection, etc.) • Preventive maintenance plan• Asset management plan, data & software• Vegetation management plan • Access plan (land based)• Real time data sharing • Appendices (background information)September 21, 2022| Pg. 11 Proposed Strategic Plan to accomplish Vision• Appendices• Clearing reports • Structure inspection reports• Snow Load Monitoring System information and reports• Electrical disturbance results with root cause analysis• Agreements (selected examples)• Alaska Intertie Agreement• Douglas substation lease• Maintenance agreements with utilities• 1986 transmission services agreement (TLS-DGS)• 1984 Joint Use agreement• Property transfer history (Cantwell distribution equip)• LIDAR study results and recommendations• System PSS/E studies• Economic dispatch studies• Reliability standards (pre-ERO) • Railbelt IRPs prepared by EROSeptember 21, 2022| Pg. 12 Loss Reductions & Transfer Capacity Increases• With a 230kV upgrade, transfer limit increases are likely to beabout 250%.• Transmission line voltage upgrade to 230 kV will cut the losses byabout 60%September 27, 2022| Pg. 13 Next Steps• Continued collaboration between IMC, IOC, and subcommittees todevelop ensure that the approach and progress is consistent with theIMC’s expectations.• Continued development of the Strategic Plan by the IOC and itssubcommittees. For example:• Vegetation management Plan–Maintenance Subcommittee• Asset Management Plan – Maintenance Subcommittee• Refresh 2017 Railbelt transmission plan – System Studies Subcommittee• Expeditiously arrive at a formal consensus regarding the ultimate uppervoltage at which the Intertie will be operated, based on economicdispatch studies and electrical performance studies (preliminaryindications are 230kV).• Will determine constraints on modifications to existing structures to addressstructural issues.• Will determine upgrades required between Teeland and Douglas substations.• Will provide a clear direction for voltage rating of any new equipment.September 27, 2022| Pg. 14 Questions? Intertie Management Committee Meeting Operator Report September 23, 2022 1. Alaska Intertie usage report a. MWh usage – Measured at Douglas Substation GVEA MEA Total i. July – August FY23 30,513 4,478 34,991 ii. July – August FY22 17,230 3,768 20,998 iii. Delta - FY23 to FY22 77.1% 18.8% 66.6% 2. No Alaska Intertie trips to report 3. Date Event SCADA Indication Cause 8/15/2022 AK Tie Trip Line to line fault, Teeland and Douglas No cause found 4. IOC quarterly Reliability Report For generation trips or transmission line trips where the loss of load is known, the Railbelt-wide frequency response is calculated. The magnitude of the tripped power and the change in frequency from the pre-trip value to the peak or nadir are used to calculate the MW/0.1Hz value often known as ‘Beta’. Chugach has calculated the Beta for several events and the table of the results is pasted below. Events without data for the MW magnitude of the trip were excluded, as were events that did not cause a frequency deviation of greater than 0.2 Hz. Frequency data is sourced from the Teeland Tesla disturbance fault recorder. MW data is sourced from Chugach SCADA, which receives data from other utilities via ICCP. Event Date MW Tripped Pre-Trip Frequency (Hz) High /Low Frequency (Hz) Frequency Response (MW/0.1Hz) University-Hope Trip 8/1/2022 17.0 60.05 59.81 7.1 Healy 2 Trip 8/14/2022 57.0 60.03 59.26 7.4 Teeland-Douglas Trip 8/15/2022 33.3 60.03 60.39 9.4 Healy 2 Trip 8/16/2022 60.7 60.01 59.34 9.0 Bradley 2 Trip 8/24/2022 35.1 60.01 59.71 11.9