Study Of Fault Detection And Diagnosis Method For A Fault Tolerant Permanent Magnet Motor Drive With Redundancy

Electrical propulsion system possesses many advantages, such as flexible to control, high efficiency and little contamination, thus it is widely used and gradually replaces traditional hydraulic system and baric system. In the fields such as aerospace, military, transportation and medical, electrical propulsion system is required to be highly reliable, and can continue to operate under partial failure. Therefore, motor and its control system should be fault tolerant. Fault tolerant permanent magnet (FTPM) motors are gaining more and more concern with its good fault tolerant capability. In order to improve the reliability of FTPM motor and its control system, and control the motor after failures occur, this paper studies the fault detection and diagnosis of dual FTPM motor system.Since the structure of FTPM motor is special, H-bridge inverter is used. First, the paper analyzes the potential electrical faults of FTPM motor, especially the way to diagnose the open-circuit and short-circuit fault of inverter and motor winding, and proposes the fault detection and diagnosis method. Then, hardware circuits are established to verify the feasibility of the diagnosis method. The hardware circuits include the power drive circuit, main circuit, inverter circuit, open-circuit fault detection circuit, short-circuit fault detection circuit, fault signal process circuit etc. The motor controller uses a 32-bit fixed-point processor, TMS320F2812, which is developed by TI Corporation. SPWM control and fault detection program, which is suitable for FTPM motor is developed in IDE CCS 3.3. Finally, hardware and software are debugged, open-circuit and short-circuit experiments are conducted, waveforms under normal situation and fault situation are provided. According to experiment results, the method proposed can effectively detect the inverter and motor winding faults.