Grid-Edge Dynamic Volt-VAr Control Solution to Mitigate System Impacts Caused by Vast EV Charging Infrastructure Integration

Abstract

Electric vehicle (EV) sales are booming everywhere. Extensive EV charging infrastructure integration into the legacy distribution networks may cause several system vulnerabilities, including system voltage drop. In this paper, Dynamic VAr Controllers (DVC) are proposed as a cost-effective, non-wires alternative (NWA) and distributed control solution to mitigate the impacts on system voltage. In this approach, the single-phase DVCs are deployed at the secondary of the service transformers at locations with lowest voltages to provide voltage support through dynamic VAr injection. To verify the mitigating effect of DVCs, several scenario-based time-series simulations are performed in OpenDSS on actual distribution networks, using historical load and EV profiles, while the DVC controller is modeled in Python. Simulation results confirm the significant performance of DVCs in resolving the under-voltage issue, as well as system voltage unbalance. The proposed solution is a promising alternative to costly distribution infrastructure expansion and electro-mechanical voltage control devices.