Complete short-circuit failure mode properties and comparison based on IGBT standard packaging. Application to new fault-tolerant inverter and interleaved chopper with reduced parts count

Epoxy molded package and silicone gel module are compared in short-circuit failure mode with respect to critical energy, I2Tmelting and explosion energy capabilities. The molded technology yields a very low and stable Rsc "residual ohmic value" of the dies in low energy short failure which are analyzed through a complete 3D reverse. A continuous thermal cycling test over a short term (duration < 1000h) also exhibits an acceptable low drift of the Rsc property. These original and not enough known properties are afterwards used for new and original fail-safe X-phase inverter or interleaved chopper. All these proposed topologies use only one paralleled safety leg that is spontaneously connected in series with the faulty devices without any additional complexity or extra cost. Finally, a first lab. set-up provides additional properties during the disconnection of the faulty leg and the automatic connection of the safety leg.