Study of stability and power quality of parallel grid-connected inverters for vehicle-to-grid application

The number of distributed energy resources are increasing in modern power systems. Vehicle-to-grid power transfer is envisioned to become another type of distributed energy resource and support energy needs of the grid under various circumstances. This paper investigates the stability and power quality of a parallel grid-connected inverter system for vehicle-to-grid application using modeling and simulation. The grid-connected inverter includes a three-phase voltage source inverter, LCL output filter, and closed-loop control. In this research, stability analysis of grid-connected inverters is investigated by assessing closed loop poles of system. The dynamic simulation results obtained from MATLAB Simulink are used to demonstrate the importance of controller gain and grid conditions on system stability and power quality for a parallel grid-connected inverter system.