CMV analysis of 5 level Cascaded H Bridge MLI with equal and unequal DC sources using Variable Frequency SPWM Techniques

This paper, investigates the Common Mode Voltage (CMV)between neutral point of the star connected RL load and system ground.CMV also known as zero sequence voltage results in adverse effects like bearing currents, shaft voltages and electromagnetic interference.CMV also causes premature failure of bearings of induction motor and is necessary to reduce. In this paper, Variable Frequency Sinusoidal Pulse Width Modulation (VFSPWM) techniques are used to investigate CMV in Cascaded H-Bridge Multilevel Inverter (CHB-MLI). Comparison of 5-level CHB-MLI with equal and unequal DC sources in terms of CMV is also presented. Simulation of circuit is carried out in MATLAB environment