Challenges in Scheduling Electric Vehicle Charging with Discrete Charging Rates in AC Power Networks.

To meet the substantial demand for electrified transportation, a high level of penetration of electric vehicles (EVs) will be expected to incur considerable impacts on the reliability of electricity grid. Hence, there requires an intelligent scheduling mechanism for EV charging for maintaining the electricity grid within the operating limits and absorbing intermittent renewable energy. This note discusses the challenges in designing practical charging algorithms considering common discrete charging rates with minimum power requirements in various charging modes over alternating current (AC) power networks. We present the basic ideas of applying convex relaxation and proper rounding techniques to tackle the combinatorial optimization problem of EV charging.