Development of stationary frame PR current controller for performance improvement of grid tied PV inverters

This paper focuses on modelling and simulation of a single phase grid connected photovoltaic (PV) system using Matlab/Simulink software. The PV system is interfaced with the grid by a single phase voltage source inverter (VSI). A maximum power point tracking (MPPT) controller is designed to draw maximum power from the PV array. The DC-DC boost converter carries out the task of MPP tracking and amplifies the output voltage of PV array to desired level. A control strategy to regulate the quality of power injected by the grid connected VSI is proposed. Two controllers are designed for the grid side VSI one is the proportional integral (PI) voltage controller and the other is the Proportional + Resonant (PR) current controller which maintains the current injected by the inverter into grid in phase with the grid voltage. A harmonic compensator (HC) is cascaded with PR controller to mitigate selective odd harmonic components present in the output current of inverter and minimize the total harmonic distortion (THD). Simulation results validate the effectiveness of the proposed control strategy.