A Non-Rare-Earth Doubly Salient Flux Controllable Motor Capable of Fault-Tolerant Control

Facing the price fluctuation and unstable supply of rare-earth material, motors that do not employ rare-earth permanent magnets (PMs) have been gaining research popularity recently. This paper proposes a non-rare-earth doubly salient flux controllable (DSFC) motor that incorporates the flux tunable characteristics of AlNiCo PMs and the hybrid excitation function of dc windings, realizing the goal of high power density and wide speed range simultaneously. Furthermore, the AlNiCo PMs can be fully demagnetized in the fault condition, and the DSFC motor will operate as a switched reluctance motor, which provides a high fault-tolerant capability. The simulation results illustrate that the output torque of DSFC motor with hybrid excitation is able to match that of a rare-earth doubly salient PM motor, while the speed range of the former is superior to the latter because of the tunable flux. In addition, the simulation and experimental results of flux control and fault-tolerant operation verify the flux weakening and fault-tolerant capability of the DSFC motor.