In this paper, a novel failure-detection technique and its analog circuit for insulated gate bipolar transistors (IGBTs), under open-and short-circuit failures, are proposed. This technique is applied to a three-phase induction-motor (IM) drive system. The detection technique is adapted to detect failures of short-circuit and open-circuit in the IGBT, which is based on gate-signal monitoring. The most important issue of this technique is the reduction of time for fault detection. This is very important in a failure-tolerant IM drive based on the material-redundancy approach or protection systems since the detection must be done before the device is damaged, in approximately less than 10 mu s. The experimental test and simulations are presented in order to validate the proposed fault-detection technique, and it is validated, achieving replacement of the damaged element in the most suitable time.
Analog circuits; driver circuits; fault location; insulated gate bipolar transistors (IGBTs); semiconductor-device measurements; time delay