Comparison between PI and PR Current Controllers of a Grid-Connected Photovoltaic System Supplying Nonlineare Load

Abstract

This paper presents a three-phase grid-connected PV system supplying nonlinear load, which controls active power and harmonic compensation. A Proportional-Resonant (PR) controller is used for replacing the conventional Proportional-Integral (PI) controller in this system. By comparison with the conventional PI control method, the PR control can introduce an infinite gain at the fundamental frequency and hence can achieve zero steady-state error and the grid current can be noticeable sinusoidal and current harmonics generated by the nonlinear load will be compensated. In order to examine the effectiveness of the suggested control, a simulation using the Matlab/Simulink software has been done. The simulation results confirm the validation of the presented control and shows the efficiency of the PR controller especially with respect to the harmonics created by the nonlinear load, which proves that the use of this type of controller ensure a better energy transport to grid with fewer harmonics.