Application of the MCT to soft-switched DC-AC converters

The development of high power density and high efficiency soft-switched inverter drives for application in electric and hybrid vehicle systems is of current interest. The MOS-controlled thyristor (MCT) seems to be a good choice for this type of application due to its high power density features. Several experimental MCT evaluations either with hard-switching or soft-switching, have been performed on the first generation of MCT, developed and commercialized by the Harris Semiconductor Corporation. Soft-switching techniques are generally used for improving the power converter performance by expanding the safe operating area (SOA) of power semiconductor devices. However, the published MCT soft-switching tests have shown the device operation to be below its hard-switching rating limits. The paper shows some soft-switching experiment results, with a better understanding on the MCT full operating limits, for the purpose of soft switching DC-AC converter design