Fault Interrupting Methods and Topologies for Interior PM Machine Drives

This work investigates methods to interrupt the phase currents induced when interior permanent magnet (IPM) machine drives suffer short-circuit or uncontrolled generator mode faults. A fault-tolerant silicon switch is proposed in which the antiparallel diode in a reverse-blocking inverter switch is replaced by a thyristor. A reduced-parts-count fault-interrupting topology is also proposed which consists of delta-connected thyristors inserted at the center star point of wye-connected IPM machine stator windings. Control of the proposed reduced-parts-count fault-tolerant drive is discussed and simulation results are presented to verify operation of the proposed topology.