Frequency support in a micro-grid using virtual synchronous generator based charging station

Abstract

This study focuses on the role of electric vehicle (EV) charging station (CS) to support the frequency of the islanded micro-grid (MG). Frequency deviation is a common issue in islanded MGs due to the intermittent nature of renewable energy sources (RES). This issue can be minimised by providing the inertia to the system. However, RES have low or no rotational mass and therefore, they are not able to provide the inertia to the system. In this study, the concept of virtual synchronous generator (VSG) mechanism using a CS is proposed to provide the inertia to the system, where a fleet of EVs parked in CS acts as an energy storage system for MG. Simulations have been performed in Matlab Simulink on the data taken from the MG on the island Kythnos in Greece. Case studies have been carried out to verify the frequency support of MG using VSG mechanism. In these case studies, irradiation level of the photovoltaic array and load of the MG system have been changed arbitrarily to induce the power mismatch in the system. Through simulation results, it has been verified that the frequency of the system can be supported by the bidirectional flow of power between the CS and MG using VSG control mechanism.