Virtual Synchronous Machine based Electric Vehicle charger for meeting Ancillary Services

This paper presents a Virtual Synchronous Machine (VSM) based Electric Vehicle (EV) charging station to support ancillary services such as voltage regulation, frequency regulation, active power control, reactive power control and harmonic current mitigation. The increase in the penetration of power electronics based renewable sources raises the serious reliability concerns in the grid due to the less inertia and low kinetic energy. However, the conventional synchronous generator with automatic voltage regulator and load frequency control has the capability to respond to the voltage and frequency variation in the grid. So, the power electronic based converter system with virtual synchronous machine characteristics can increase the stability of the grid. In this article, the control algorithm of the EV charging station is modified by emulating synchronous generator characteristics. So, the electric vehicles that are parked in the office or at the home may be used as a grid connected energy storage system and behaves like a VSM to provide inertia to the system. This proposed VSM based charging station with EV can operate seamlessly between grid connected and standalone modes to supply local loads even in the absence of a grid power supply. The novelty of the work lies in the control algorithm of the EV to supply local non-linear load current harmonics. The control strategy of this proposed EV charging stations are verified by performing real-time simulation studies in an OPAL-RT system under different possible test cases.