The Behaviours of Various DC Choppers during Shading Occurrence in PV Systems

This paper investigates how the DC choppers behave during the shading occurrence at different time intervals of the year. Three types of DC choppers are implemented during the same shading conditions and intervals of time. The studied parameters are the duty cycle, output power, current, and switch losses. The mathematical model is built and implemented using the MATLAB/Simulink platform. The obtained results show that the SEPIC converter has the highest rate of duty cycle, which means more switching losses are generated. Concerning the average output power, the Modified Single Ended Primary Converter (MSEPIC) has the highest rate, while the Boost Converter has the lowest rate. The MPP power, duty cycle, and switching losses are studied under various shading rates. The duty cycle has the highest rate on the SEPIC converter, while MSEPIC has the lowest rate. Despite that, the switching losses are tremendously high at MSEPIC compared to SEPIC converters. Furthermore, simulation studies show that Boost and SEPIC converters have better performance in frequent cloudy weather conditions.