A 13-level asymmetrical cascaded inverter for photovoltaic system with DC-DC flyback converter

Abstract

In recent days, multilevel inverter has widely been used for high power application. This may be due to the reduction of total harmonic distortion (THD) of the output voltage level and having low blocking voltages of switches. In the existing system, DC voltage source which is maintained constant is given as the input to the inverters which contains the series connection of fundamental block and is analyzed in symmetric and asymmetric mode of operation to produce various voltage levels. The proposed approach replaces the DC voltage source to the Photovoltaic (PV) cell has been used which has variations in the output voltage side depends on the solar irradiation level. This Photovoltaic cell uses Maximum Power Point Tracking (MPPT) algorithm to produce required voltage. As the input to the multilevel inverter (MLI) has to be maintained constant a fly back forward converter has been used in between the Photovoltaic cell and the multilevel inverter, so that the required multiple constant output voltage has been obtained on the output of the converter. Using the output of the converter 13 output voltage levels can be obtained from the multilevel inverter. The performance of the proposed system is verified by simulation through MATLAB/Simulink environment.