EV Charging Coordination Based Energy Management System for a Grid-tied Charging Station Integrated with PV-ESS

Abstract

This paper proposes an energy management system (EMS) for the EV charging station with a hybrid inverter for central power supply from PV, grid, and energy storage system (ESS). The objective is to minimize the operation cost of charging station while incorporating ESS degradation cost. The proposed EMS is formulated as a mixed integer linear program (MILP) problem for optimal power scheduling among grid, PV, and ESS. Secondly, a non-linear programming (NLP) based electric vehicle (EV) charging coordination scheme is utilized to tackle load forecasting error and maximize the EV charging profit. Additionally, the dynamic pricing, along with the preference set by EV owner, is considered. Furthermore, the proposed method has been tested with two different pricing schemes: real-time pricing and TOU tariff. The results indicate that the proposed method reduced the operating cost by 11% and maximized the EV charging profit by 9% with respect to the uncontrolled EV charging method.