A Novel Demagnetization Fault Diagnosis Scheme for the IPM Motor Without Parameter Estimation

This article proposes a novel demagnetization fault diagnosis scheme for the interior permanent magnet (IPM) motor without parameter estimation. First, a feature enhancement-based disturbance observer is proposed, which incorporates the estimation error and the sliding mode surface as reinforcement factors for fault characteristics. Then, a sliding mode assessment-based demagnetization fault diagnosis method is developed, which takes the sliding mode variable structure signal of the disturbance observer as the carrier of demagnetization fault. Finally, the proposed method is validated by the hardware-in-the-loop-based platform and the real hardware platform. The test results show that the proposed method can achieve millisecond-level demagnetization fault diagnosis without being affected by mismatch in stator resistance of the IPM motor.