Design And Simulation Of A Fault Tolerant Permanent Magnet Motor

In safety critical fields, such as aerospace, military, medical and automotive fields, the drive motors in the electric propulsion system are required to be fault tolerant. Since motor structure design directly impacts fault tolerant capacity, research on fault tolerant motor structure design is gaining more and more attention. Reasonable motor structure design can greatly improve motor performance and fault tolerant capacity. In this paper, a six-phase ten-pole fault tolerant permanent magnet (FTPM) motor is designed from the aspect of motor structure design.The paper analyzes the structure and characteristics of FTPM motor, discusses the parameters and the selecting principle of permanent magnet material and introduces the magnetic circuit structure and electromagnetic field analysis method according to the electromagnetism basic theory. After the main parameters are decided, the six-phase ten-pole FTPM motor is designed, including the motor major parameters, slot parameters and stator and rotor yoke thickness, and then verified by Finite Element Analysis (FEA) software, and the electromagnetic field numerical analysis and calculation is conducted. Then, the optimization design of the motor structure is conducted. The influence of the number of phases on motor phase redundancy and the complexity of motor drive is discussed and phase number selection principle is proposed. Star of slots is utilized to discuss the single-layer fractional winding. The designing method of minimizing inter-phase coupling is discussed and verified by FEA. The influence of slot/pole combination on motor fault tolerant capacity is analyzed, and the paper comes to the conclusion of the optimum slot/pole combination. At last, the full load system with speed and current double closed-loop control, when there is no fault and there is open-circuit fault in one phase, is analyzed by software to verify the rationality of the motor design.