Compensation of voltage sag caused by partial shading in grid-connected PV system through the three-level SVM inverter

Abstract

This study is aimed to evaluate the grid-connected PV system in partial shading conditions through the three-level SVM inverter and compensation of inverter output voltage sag caused by the partial shading using the dynamic voltage restorer (DVR). A function per time and the amount of radiation has been used to create the partial shading condition in the photovoltaic system. The advantages of three-level SVM inverter include the complete region detection method even in the boundary points between two regions through boundary lines equations and complete online solution of those equations. Also the reduction of total harmonic distortion (THD) through the switching table is appropriate. The results show that in the partial shading conditions the three-level SVM inverter decreased THD in the presence or absence of DVR. DVR also compensate the voltage sag to a suitable level. MATLAB/Simulink based simulation results are presented for validation of the entire system.