Network-aware EV charging and discharging in unbalanced distribution grids: A distributed, robust approach against communication failures

Abstract

This paper proposes a distributed optimization-based algorithm for electric vehicle (EV) charging and discharging, incorporating EV customer economics and distribution network constraints enforced on an unbalanced distribution grid. Building on a consensus-based alternating direction method of multipliers (ADMM), the algorithm is designed such that EVs coordinate by means of exchanging limited information with their neighboring EVs in a connected communication network. Specifically, an iterative routine is executed, whereby EVs cooperatively determine their charge-discharge profiles that maintain the distribution grid voltages and transformer core temperatures within safe operating limits. Importantly, the algorithm is robust against communication failures potentially arising in real-world implementations. Numerical simulations are conducted to verify the efficacy of the proposed EV charging algorithm in terms of network-aware operation and communication-failure tolerant operation.