A soft-switched high frequency nonresonant link integral pulse modulated DC-AC converter for AC motor drive

Soft-switched high frequency link power conversion has a number of attractive features, and for this reason, it is a favorite topic of R&D in the literature. The paper describes a high frequency nonresonant link soft-switched DC-AC converter for AC motor drive that operates on the principle of integral pulse modulation. A light-weight ultra-low leakage inductance transformer in the high frequency link provides the advantages of isolation, voltage level boost in the secondary, and auxiliary power supplies. All the devices in the converter are ideally soft-switched by zero voltage switching. In spite of additional components compared to traditional converters, the scheme has the overall advantages of good efficiency, good power density and improved reliability in the total system particularly when used with MCT-PEBB (power electronics building block) based modules. A complete converter system has been analyzed, designed, control strategy has been developed, modeled for simulation study, and performance has been evaluated with a four-quadrant vector-controlled 5 hp induction motor drive using the link frequency of 20 kHz. A laboratory test of 5 hp drive is in progress.