Liang Min Lawrence Livermore National Laboratory HPC for Power System Planning Panel Discussion

1. Scalable Coupled ICT and Power Grid Simulation- High-performance Coupled Transmission, Distribution, and Communication Simulation Tool15PESGM2794 Liang Min Lawrence Livermore National Laboratory HPC for Power System Planning Panel Discussion July 29, Denver CO LLNL-PRES-673302

2. 2 Decoupled transmission and distribution simulations are insufficient for complex smart grid systems • 2500-house distribution system model • 2500-house distribution system model with high penetration of PV Renewables and electric energy storage in the distribution network will have significant impacts throughout the entire network LLNL-PRES-673302

3. We have built a HPC architecture to couple T&D simulation to address pending complex smart grid systems The grid simulation assumption was made that the time-scales on the distribution network do not impact the transmission system. f, g and h are all functions of V1, V2, , and LLNL-PRES-673302

4. We have developed our own transmission simulator and enhanced the distribution simulator for HPC • We have built our own transmission simulator prototype. It is written in C++ and use SUNDIALS/IDA and KINSOL as the solvers. Software components are independent, reusable, and replaceable. • Distribution simulator (GridLab-D) was modified and enhanced for HPC. LLNL-PRES-673302

5. Test Case – Coupled Transmission and Distribution System Model PG&E Feeder Model WECC Transmission Model • Assigned one distribution feeder simulation to one core, the whole transmission simulation to one core. • Increased load on Bus 140 by connecting more distribution feeders to that transmission bus and monitored what happens to the bus voltage. • Goal is to run larger distribution problem in same amount of time IEEE 13 Feeder Model LLNL-PRES-673302

6. Test Case – Using scaled-up demand response at the distribution level to offset the need for load shedding to avoid voltage collapse • As CAISO studied, after the SONGS retirement, voltage stability collapse became the limiting constraint in LA basin. • The urgency to scale-up demand response is high to maintain a reliable electric system, particularly in Southern California, in the absence of the San Onofre Nuclear Generating Station (SONGS). LLNL-PRES-673302

7. Grid transformation also needs coupled power systems and communication network simulations • Smart grid = Electricity infrastructure + “Intelligence” infrastructure. • We need a power systems and communication co-simulation to answer very important questions: • What will happen to the electric grid: • - If data is dropped or delayed? • - If data is modified in transit? • - … • With this capability, we can help utilities better design their wide-area control schemes and ensure system security and reliability. NIST Smart Grid Reference Diagram The interdependencies of communication and power systems are becoming increasingly important LLNL-PRES-673302

8. Time advancement is key for achieving correctness in federated systems LLNL-PRES-673302

9. We have developed a FSKIT (Federated Simulation Toolkit) for high-fidelity and cross-domain modeling and analysis • Small toolkit for coupling continuous and discrete time simulations. It provides • Time control for advancing state of federated simulators • Communication between objects in federated simulators • Designed for HPC • Asynchronous API design • MPI used as communication layer • Parallel conservative granted time window synchronization algorithm B. M. Kelley, P. Top, S. G. Smith, C. S. Woodward, and L. Min, “A federated simulation toolkit for electric power grid and communication network co-simulation “,2015 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), Seattle, WA, USA, April 13, 2015. LLNL-PRES-673302

10. Test Case - Coupled Transmission and Communication Network Model Original Single Line Diagram IEEE 39-bus System Resultant Communication System Model LLNL-PRES-673302

11. Test Case – Using the co-simulator to validate different protection control schemes Ad-hoc (peer to peer) protection relay systems scenario: Bus fault at Bus 4 at t=0.2s and clear the fault at t=0.25s Supervisory (master agent) wide area control scenario: fault at Bus 4 at t=0.2s and clear the fault at t=0.35s We could vary the line latency and the throughput to assess different control schemes. As the WAN latency increases, trip times increase, which affects system voltage recovery. Delayed Voltage Recovery due to long fault clear time LLNL-PRES-673302

12. We are extending this capability to support industry to build large-scale HIL for smart grid technologies testing • To address the need of a grid connected testing facility for large-scale smart grid hardware and software testing, we are interfacing the scaled-up coupled transmission and distribution simulator at LLNL and the PG&E’s Distribution Test Yard to form a close-loop validation environment. LLNL-PRES-673302

13. Thank You LLNL-PRES-673302