A Novel Search Coil Back-wound Permanent Magnet Synchronous Fault-tolerant Motor with Short-circuit Current Suppression Ability

In order to solve the problem that the traditional permanent magnet fault-tolerant motor has insufficient fault-tolerant ability to interturn short-circuit fault(ISCF) with few turns, a back-wound permanent magnet synchronous fault-tolerant motor with search coil is proposed in this paper. The motor has an extra search coil(SC) wound in the stator yoke, and the SC requires very few turns. After the ISCF occurs in the motor, the interturn short-circuit current(ISCC) is suppressed by passing a quantitative current into the SC. This paper first introduces the basic structure of the back-wound permanent magnet synchronous fault-tolerant motor with search coil, and then analyzes the mechanism of the ISCF suppression theoretically. Through the simulation of 1-turn, 4-turn and 8-turn short-circuit, verify the feasibility of the proposed scheme. The experimental results show that the few turns ISCC can be suppressed near the effective value by passing a quantitative current into the search coil, and the required current has nothing to do with the number of short-circuit turns, which proves the correctness of the theoretical analysis.