Acquiring ZVS with minimum switching actions and at all switching instants of a "notch" three-phase voltage source inverter

Soft-switching techniques have recently been applied to dc-ac converters to achieve better performance, higher efficiency, and higher power density. This paper identifies a specific PWM technique that, in combination with the ZVS scheme, can provide optimum overall converter switching performance. Specifically, De-side commutated zero voltage switching (ZVS) Space Vector Modulation (SVM) schemes are proposed. It is shown that the combination of the inverter topology and the proposed modulation strategies yield a soft switching environment at the lowest possible switching frequency. Reduction in switching losses is further enhanced by increasing the effective and reducing the actual switching frequency. Simulation results are presented to verify key predicted results.