PV-Assisted Off-Board Electric Vehicle Charger for Low-Inertia Power System Stability: Virtual DC and AC Inertia Concepts

Accurate coordination between the DC-link and AC-side power of power electronic converters (PECs) employed in the electric vehicle off-board chargers (EVOBCs) can maximize the charging station (CS) contribution to the voltage stability of low-inertia power system (LIPS). This paper presents a novel approach for emulating the DC/DC and DC/AC converters of EVOBCs based on the virtual DC and AC inertia (VDCI-VACI) concepts. The proposed hybrid virtual inertia-based control system enables LIPS-side converter of EVOBC to generate the required VACI for the LIPS voltage stability through the on-time and precise injection of VDCIs made from the PV-connected and high voltage EV battery (HVEVB)-connected DC/DC converters. For further assessment, the VDCI and VACI generated in the PECs structures of EVOBCs are estimated using the global stability concept. The simulation results in MATLAB®/SIMULINK® environment are provided to confirm the validity of proposed method in different operation conditions.