Harmonics Mitigation of Single-Phase Modified Source Switched Multilevel Inverter Topology Using OHSW-PWM Technique

In this paper, a modified source switched multilevel inverter has been proposed. The optimized harmonics stepped waveform (OHSW) switching technique has been implemented for providing the required switching to the proposed inverter. The required switching instances have been determined offline for the power semiconductor switches in order to mitigate the preselected lower order harmonics components from the output voltage waveform using MATLAB/Simulink. The modular structure and requirement of reduced number of power semiconductor devices as compared to many well established multilevel inverter topologies indicates the superiority of the proposed topology. In this work, more emphasis has been provided on the implementation of OHSW switching technique and its effect on the output response of the multilevel inverter. Detailed analysis has been presented for the circuit providing a seven-level output voltage by using the OHSW technique. In order to examine the effectiveness of the proposed system simulation has been carried out for the higher level of output response using MATLAB/Simulink and has been presented. A laboratory prototype has been developed for seven level output and corresponding results has been incorporated in order to validate the simulation results.