Implementing PV Analysis in Utility Operations: Goals, Activities, and Accomplishments

1. Group Meeting – Pepco Holdings, Inc. July 17, 2014

2. Objectives • Use common model and algorithms to: • Make PV analysis a standard part of: • Planning • Operations Monitoring • Evaluate impact of PV/DER at feeder and transmission level

3. 1. Activities • Topic A1 • 60 Study Circuits • Build and major validation/correction review complete • Measurement collection complete • Device setting collection continuing • Completed device setting for Voltage Headroom and DA circuits • Study feeder description • Short and stiff, long with high impedance, highly loaded, lightly loaded, mix of different type customers – residential, industrial, commercial, overhead, underground, feeders with high PV saturation, feeders that are part of a Distribution Automation scheme that can’t currently operate because of a large solar farm, and then a grouping of feeders and substations where high penetration will have an impact on the transmission system. • Remaining work • Compare analysis for base case and Voltage Headroom case

4. 1. Activities • Topic A2 • Voltage headroom circuit selected • Utilizing existing monitoring equipment and equipping a voltage regulator bank with SCADA communications and control • Remaining Year 1 Work • Complete Voltage Headroom design and define test procedure • Topic A3 • Significant analysis refinement completed • Running testing analysis using study circuits • Refining displays and time-series use of measurements and load data • Remaining Year 1 Work • Update and test PV interconnect criteria • Compare analysis results for new and old interconnect criteria

5. 1. Activities • Topic B4 • Have Forecast, Schedule, Monitor and Adjust (FSMA) • Running Conservation Voltage Reduction (CVR) using capacitors, LTC’s and Voltage Regulators • Forecasting operation • Comparing against actual results • Have method for defining load profile/scenarios • Have control parts of PV complete • Adding PV to CVR control functionality • Remaining Year 1 Work • Compare base case and controller case performance results

6. 2. Accomplishments • Accomplishments • Held on site training and analysis code feedback with PHI PV Group and Planners • Completed model builds and model build checks for 60 study circuits • Collected circuit and load measurements for analysis • Time-series load measurements set for automated attachment to all circuits • Time-series circuit measurements set for automated attachment to Voltage Headroom and Auto-reconfiguration scheme circuits

7. 3. Roadblocks • Model correction and validation • Critical part of making PV analysis a standard part planning and operation management • Taking more time to complete than planned • Breaking up into two parts: • Initial model-build, automated corrections • Main work for this is complete. Plan to continue to refine as this is used over the next 6 months • Manual corrections • Need to simplify collection and automated use of corrections made by engineers as a part of running analysis on circuits • This will be the model build focus for the next 6 month

8. 4. Lessons Learned & Questions • Lessons Learned • Questions for the DOE

9. PV Hosting Capacity Analysis Classify circuits in terms of how much PV can be added without violating operating criteria Existing Feeder Analysis: Phase balance, Cap Placement, Voltage Regulator Placement & Settings, Check protection/coordination Quantify: Improvement cost, Feeder performance impact, PV hosting impact Optimized Feeder Run optimized feeder setup to include: Voltage Head Room Configuration Autonomous Control Central Control Quantify: Improvement cost, Feeder performance impact, PV hosting impact

10. Pilot Feeder Instrumentation PV Systems. With 480 V monitors Pole-Mount Monitors Existing Monitoring

11. Pilot Feeder Instrumentation EPRI Pole Mount voltage and irradiance monitors installed March 2012

12. Pilot Feeder Instrumentation INSTALL SCADA Communications on Regulator PV Systems. With 480 V monitors Pole-Mount Monitors To be installed

13. Pilot Feeder Zone 4 Zone 2 Zone 3 V. Reg. V. Reg. V. Reg. PV Systems. Zone 1 Voltage Regulation zones

14. PV Overvoltage at Low Load High voltage occurs at PV systems in Zone 2 during min load

15. Min Load Feeder Profile PV Site Overvoltage PV penetration limited by high voltage during min load, when voltage profile is relatively flat

16. Min Load Feeder Profile • Reducing voltage in zone 2 solves overvoltage problem without creating low voltage based on model predictions SCADA control of regulator allows for manual reduction of voltage for demonstration of concept

17. PV Operations Management (FSMA) • FSMA: Forecast, Schedule, Monitor and Adjust • Use for: • Operations Monitoring • Planning and control simulation • Currently running coordinated control • LTC’s, voltage regulators and capacitors • Just added PV as controllable devices • Simulator • Separate copy of Dew that uses same model used for control, to play the role of the system

18. Model-Based Simulator • Use simulator to: • See system response to control, device state and load change • Test & develop control • Test & develop display • User can set: • Load points/curve • Capacitor states • Voltage regulator states • PV inverter control • FSMA Control • Can be run against simulator or real system

19. PV Operations Management (FSMA) • FSMA • Control can be run against simulator or real system through connection to SCADA