摘要: |
This paper summarizes recently developed soft-switching inverters and proposes two alternative options for electric propulsion drives. The newly developed soft-switching inverter employs an auxiliary switch and a resonant inductor per phase to produce a zero voltage across the main switch so that the main switch can turn on at the zero-voltage condition. Both the auxiliary switch and the resonant inductor are operating at a fractional duty, and thus are small in size as compared to the main inverter circuit components. Operation modes in a complete zero-voltage switching cycle for the single-phase soft-switching inverter are described in detail with graphical explanations. The circuit operation was first verified by a computer simulation and then tested with an 1-kW single-phase and an 100-kW three-phase inverters. Experimental results are presented to show the superior performance in efficiency improvement, EMI reduction, and dv/dt reduction of the proposed soft-switching inverters. |