Architecture for Co-Simulation of Transportation and Distribution Systems with Electric Vehicle Charging at Scale in the San Francisco Bay Area

This work describes the Grid-Enhanced, Mobility-Integrated Network Infrastructures for Extreme Fast Charging (GEMINI) architecture for the co-simulation of distribution and transportation systems to evaluate EV charging impacts on electric distribution systems of a large metropolitan area and the surrounding rural regions with high fidelity. The current co-simulation is applied to Oakland and Alameda, California, and in future work will be extended to the full San Francisco Bay Area. It uses the HELICS co-simulation framework to enable parallel instances of vetted grid and transportation software programs to interact at every model timestep, allowing high-fidelity simulations at a large scale. This enables not only the impacts of electrified transportation systems across a larger interconnected collection of distribution feeders to be evaluated, but also the feedbacks between the two systems, such as through control systems, to be captured and compared. The findings are that with moderate passenger EV adoption rates, inverter controls combined with some distribution system hardware upgrades can maintain grid voltages within ANSI C.84 range A limits of 0.95 to 1.05 p.u. without smart charging. However, EV charging control may be required for higher levels of charging or to reduce grid upgrades, and this will be explored in future work.

Automated summary

This work introduces the GEMINI architecture that enables the co-simulation of distribution and transportation systems to evaluate the impact of EV charging on electric distribution systems in a metropolitan area and its surrounding rural regions with high fidelity. The current simulation focuses on Oakland and Alameda and will be extended to the full San Francisco Bay Area in future work. The findings show that with moderate EV adoption rates, inverter controls along with distribution system hardware upgrades can maintain grid voltages within ANSI C.84 range A limits without the need for smart charging. However, further research is needed to explore EV charging control for higher levels of charging or to reduce grid upgrades.