Harmonic Current Conpensation in a Single-Phase Grid Connected Photovoltaic System Sypplying Nonlinear Load

This paper is focused on the enhancement of the grid current quality at the Point of Common Coupling (PCC) of a single-phase grid connected photovoltaic system supplying a nonlinear load. Due to a specific control strategy of the PV inverter, the PV system achieves the transfer of the PV power with the rejection of the grid harmonic currents introduced by the nonlinear load. This control strategy uses a proposed current control technique having the advantage to reduce the harmonic currents. In this aim, a new and an efficient algorithm able to extract the correct grid harmonic current is implemented to improve the effectiveness of the considered current control technique where a Proportional - Resonant (PR) controller is used as the current controller. In this paper, the theoretical principle of the used PV current control technique is investigated, and its effectiveness is shown through the simulated PV inverter control strategy under two different load conditions and variable PV system power.