P-channel MOS-controlled thyristor static and dynamic behaviour

The MOS controlled thyristor (MCT) is a relatively new power switch that has promising characteristics for medium power conversion systems. This paper is a contribution to the development of test methods and circuits to determine the steady state and transient operating characteristics of medium power (up to 75 A, 1000 V) MCTs, including latch-up behaviour under overload conditions. A simple and reliable gate drive circuit, driven by a microcontroller, applies a nonrepetitive double pulse to the MCT, with controllable turn-on and turn-off currents. The switching times, forward voltage drops and conduction losses are accurately determined, talking into account the effect of temperature, gate voltage and load current, The latch-up phenomenon is investigated by means of a nondestructive set-up, suitable for short circuit testing and using a series IGBT. A wide spectrum of results are presented, allowing comparison with data supplied by the manufacturer