Soft-switched MCT/IGBT inverter for motor drive applications

The use of MCTs in a soft switched PWM inverter application is presented. The MCTs are power devices that are capable of handling high di/dt and high dv/dt. Their weak point is high turn-off switching losses. A topology of the MCT/IGBT inverter is proposed. To minimize the switching losses, the devices are soft switched on at zero voltage switch (ZVS) conditions and turned off at zero current switch (ZCS) conditions. An auxiliary resonant commutated pole (ABCP) inverter is presented and analyzed for soft switching of MCT/IGBT modules of a PWM inverter for motor drive applications. A novel ARCP control technique is presented that is based on pre-calculated gating times. It reduces the cost of the ARCP controller with no need for high speed sensing devices.