Improved multilevel inverter with neutral point potential balancing for high power application

This paper presents low harmonic distortion and neutral-point potential (NPP) balancing in multilevel inverter using multicarrier pulse width modulation (PWM) for medium-voltage high-power industrial ac drives. This method is applicable for five-level inverters or higher. A high performance of the machine is observed experimentally at low switching frequency operation employing the proposed technique. In the past, low distortion and optimal common-mode voltage at low-switching-frequency control have been reported using proposed synchronous optimal PWM.