Design and Implementation of Multi Stack Voltage Equalizer for Partially Shaded Photo Voltaic Modules using Fuzzy Logic

This paper presents multi stage voltage equalizer to the improvement control performance in PV system to eliminate partial shading issues using fuzzy logic technique. In order to avoid partial shading problem here single switch is used for voltage equalizing purpose then it applied to multi stacked SEPIC converter then get the maximum energy from panels. Here, fuzzy logic concept is used to turn and off for the particular SEPIC switch. Compare to conventional equalizer, these type of single switch topology has minimum size circuits and extract maximum power also. The proposed voltage equalizer can be found by stacking capacitor-inductor-diode (CLD) filter on SEPIC converter. Here, fuzzy logic algorithms are simulated using MATLAB fuzzy logic toolbox. In this paper the fuzzy logic based control circuit is developed to give equal power in all panels. A hardware prototype with three PV panel is implemented. The equalization efficiency is higher than 98% equalization compared with the conventional analog control algorithm. Here, fuzzy logic based multi stack voltage equalizer is simulated using MATLAB/SIMULINK software.