Hybrid cascade multilevel inverter using a single DC source for open-end winding induction motors

A new hybrid multilevel inverter using a single DC source for open-end winding induction motor is proposed. This power converter uses one three phase bridge inverter and three single-phase inverters, while using only one DC source. Due to the topology and voltage values, this power converter works as three single-phase multilevel inverters. In order to maximize the inverter output voltage levels there is an asymmetry between the amplitude of the three phase bridge inverter DC source and the single-phase inverter capacitor voltages. To control the three-phase inverter a SPWM modulator is used. Since the three single-phase inverters do not have DC sources an algorithm is required to maintain the capacitor voltage balanced. In this work a sliding mode control based approach is used to control the capacitor voltage of the single-phase inverters. In order to verify the proposed topology and proposed system converter several simulation results are presented.