Fault Tolerant Permanent Magnet Drives: Operating Under Open-circuit and Short-circuit Switch Faults

A series architecture providing a fault tolerant drive is proposed. The architecture includes one or two DC sources, two voltage source inverters and a PMSM. Three different operating modes are considered: normal mode, open-circuit degraded mode and short-circuit degraded mode. For each case, an adapted torque control strategy is proposed and tested. For the open phase mode, different operating criteria are considered. For short-circuit faults, two solutions are proposed. The proposed strategies are tested on an 8-pole 1 kW PM drive. They allow operating under fault conditions in real-time and their implementation is easy. The experimental results show the effectiveness of the proposed methods.