Common Mode Voltage Elimination in Single-Phase Multilevel Inverter using a 3rd Leg

Abstract

It is well known that common mode voltage (CMV) in power inverters is responsible for various critical issues like EMI, leakage current, grid current distortion etc. This paper presents a novel technique to eliminate common mode voltage (CMV) in single phase multilevel inverters (MLI) by inserting a 3rd leg in the power stage The third inverter leg or arm is used to address the issue of CMV in single phase MLIs. A generalized solution for MLI to eliminate CMV using 3rd leg arm is presented. The given solution is applied to a 5-level inverter by providing it with a third arm. A novel PWM strategy is also proposed to operate the proposed topology with CMVE. A simulation model of the proposed scheme is developed in PLECS software. Various simulation results are presented to justify the various claims. Experimental work is underway and would be included in the final version of the paper.