A Modulation Method to Enhance the DC Bus Voltage Utilization of the Dual Inverter with a Floating Capacitor for Motor Drive

The dual inverter with a floating capacitor at a voltage ratio of 1:0.5 lacks redundant switching states to regulate the capacitor voltage in the high modulation region, which results in the DC bus voltage utilization failing to reach the desired value. In this paper, the number of switching states available to regulate the capacitor voltage is increased by the linear combination of virtual vectors. The DC bus voltage utilization and capacitor voltage regulation capability of the dual inverter with a floating capacitor are significantly enhanced by the proposed method. Simulation and experimental results demonstrate the effectiveness of the proposed method.