Five level diode clamped inverter to eliminate common mode voltage and reduce dv/dt in medium voltage rating induction motor drives

The High power induction machines are designed at medium voltage (MV) rating for better performance. The multilevel inverters (MLI) are able to provide medium voltage with high quality output at low switching frequency as compared to conventional two-level inverter. In addition to this, MLI reduces dv/dt, switching losses and leakage current. In this paper, approaches to reduce and eliminate the common mode voltage (CMV) using five-level diode clamped multilevel inverter (DCMLI) are presented. The CMV spikes are also eliminated by shifting dead-time across the phase pole. A novel technique for the selection of switching states to synthesize the desire vector is proposed. This paper realizes the implementation of five-level diode clamped MLI for three phase induction motor. Experimental results demonstrate the feasibility of the proposed solution.