A New Space-Vector PWM With Optimal Switching Selection for Multilevel Coupled Inductor Inverters

Multilevel space vector pulsewidth modulation (SVPWM) control is shown to be a very useful tool for coupled inductor inverters as six independent pulsewidth modulation (PWM) signals are required, and there is additional complexity of meeting the performance requirements for the coupled inductor while balancing the winding common-mode dc current and generating high-quality multilevel PWM output voltages. A new multilevel SVPWM technique with a five-segment switching sequence is described, where half-wave symmetrical PWM voltage waveforms are used to balance the inductor common-mode dc voltages and also to avoid all possible switching states with a high winding current ripple. The proposed SVPWM is shown to have better inverter performance, compared with traditional carrier-based and the original multilevel SVPWM schemes at low modulation depths. Inverter operation with the proposed SVPWM is validated through simulation and experimental results.