Extend the Use of Auxiliary Circuit to Start up, Shut down, and Balance of the Modified Diode Clamped Multilevel Inverter

Abstract

The diode clamped multilevel inverter (DCMLI) is an attractive high voltage multilevel inverter due to its robustness. The main draw back of the DCMLI is dc link capacitor voltage imbalance. A diode clamped inverter has been used in this research. The method used to balance the dc link capacitors is based on auxiliary switch-mode circuits, which are operated in a discontinuous inductor current mode. This research is focused on how to use auxiliary SMPS circuits to start up, balance, and shutdown the inverter. These functions are an issue in high voltage applications of the multilevel inverter. Simulation and experimental results are presented for the proposed auxiliary circuits operational technique.