Common Mode Voltage Elimination Scheme in Dual Inverter With Reduced Harmonic Distortion

Induction motor drive systems experience shaft voltages, bearing currents, ground leakage currents due to Common Mode Voltage (CMV) created by Pulse Width Modulation (PWM) inverters, which leads to an early motor failure. CMV reduction techniques are used by industries that rely on huge motors to keep their equipment from breaking down. The induction motor's heat production is primarily caused by the harmonics produced by the inverter. CMV is reduced in the proposed system and thereby eliminating overall CMV in dual inverter. In this paper, an LC filter and a fourth leg topology is used to accomplish Common Mode Voltage Elimination (CMVE) with reduction in Total Harmonic Distortion (THD). Contrary to a 2-level inverter, a dual inverter with a fourth leg can simultaneously attain zero CMV and the reference by synthesising the closest three vectors. The model is validated using simulation studies in MATLAB/SIMULINK. The proposed scheme significantly reduces the harmonics and improves the system.