Plug-In Electric Vehicle and Voltage Support for Distributed Solar: Theory and Application

This paper examines plug-in electric vehicle (PEV) grid integration, which is a specific, yet significant, component of the overall innovation being adopted by the electric power system. We propose a PEV charging policy that considers transmission and distribution integration issues and reacts to market signals across time scales and systems. More specifically, we propose that the PEV should make economic charging decisions every 5 min based on a real-time market energy price signal. On the time scale of seconds, the PEV provides voltage support for the distribution network, which may allow increased penetrations of distributed photovoltaic (PV) solar arrays. Simulation results using Electric Reliability Council of Texas wholesale power market data suggest that this voltage support service may be provided at a low cost to the individual PEV owner ($5-$50 per year). Therefore, this may prove a more attractive option for supporting distributed PV arrays than distribution network upgrades such as tap-changer-equipped transformers. Finally, we demonstrate the feasibility of our control algorithm through a test system located at the National Renewable Energy Laboratory.