Fault-Tolerant Control of Demagnetization for Ultra-High-Speed PMSM Based on Improved Equivalent-Input-Disturbance Approach

Demagnetization fault of ultra-high-speed permanent magnet synchronous motor (PMSM) is a significant issue, which may cause abnormal heating and eventually affect the security of the system. An equivalent-input-disturbance (EID) method based on super twisting algorithm sliding mode observer (STA-SMO) is proposed in this paper to perform fault-tolerant control for the demagnetization. First, a mathematical model for a demagnetizated PMSM is established. Then, the STA-SMO is designed to observe the variation of flux linkage. Finally, take the variation as the equivalent to the input disturbance for compensation control. Simulation results show the effectiveness of the proposed method.