This paper presents an online fault diagnosis system for PMSM inter-turn short circuit fault based on search coil with unique structure. The presented system uses FPGA hardware platform embedded in an original DSP control system. Based on SVPWM control, the system uses the method of signal processing to identify the fault. The terminal voltage of the search coil is collected, and the negative sequence harmonic component 0th a frequency near twice the PWM switching frequency is used as the basis for identifying the fault. In order to adapt to the operation structure of FPGA, a simplified fault feature extraction algorithm based on coordinate transformation is proposed. Compared with the traditional fault diagnosis system, the proposed system has the advantages of low cost, high precision and rapid response. Experiments are done to verify the validity of the proposed methods.

permanent magnet synchronous motor; inter-turn short circuit fault; search coil; on-line fault diagnosis; FPGA;