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Medium voltage high-power applications are usually realized using high voltage semiconductors (3.3 kV and above) operated in the hard switching mode with low switching frequencies (several hundreds of hertz). However, for high-power dc–dc converters employing a transformer for galvanic isolation, it is attractive to increase the switching frequency so that the transformer size can be reduced. An increase of the switching frequency implies an increase of the switching losses, and this has to be mitigated somehow, usually by choice of resonant topologies or soft switching techniques. Main focus of the paper is on the operation of the insulated gate bipolar transistor (IGBT) within a high-power dc–dc LLC resonant converter, in order to explore interactions between semiconductor and circuit properties, which both must be simultaneously considered in order to achieve the best utilisation of a high voltage power semiconductor operating at higher switching frequencies. For these purposes, switching properties of a standard 6.5 kV IGBT are compared with switching properties of two different optimized versions of a 6.5 kV IGBT. Experimental results are included to support theoretical considerations and findings.

In this paper, a 3300V Bimode Insulated Gate Transistor BIGT chip utilizing an Enhanced Trench MOS cell is demonstrated. The paper provides an insight into the ET-BIGT device design along with the static and dynamic electrical results obtained from the first manufactured prototypes. The combined advantages of a low loss Enhanced Trench cell concept and BIGT chip integration sets a new milestone for delivering higher output power for the next generation BIGT power modules.

The BIGT is a Reverse Conducting IGBT device which combines functionality of a high power IGBT and fast diode on a single chip. In this paper, an investigation of the IGBT mode short circuit performance of the BIGT is carried out. The behavior of the BIGT under IGBT mode short circuit conditions is illustrated by measurements on a 3.3kV 1500A HiPak1 module and then supported by circuit and detailed device physics simulations. The short circuit conditions of type II and type III are discussed, with the variations introduced due to the gate control of the BIGT when operated in reverse conducting mode. Comparison to standard IGBTs with Soft-Punch-Through (SPT) technology in a HiPak2 module is also provided.