Diagnosis of air-gap eccentricity and partial demagnetisation of an interior permanent magnet synchronous motor based on inverse transient complex inductance vector theory

摘要

On the basis of predecessors, a theory named inverse transient complex inductance vector is proposed for air-gap eccentricity fault diagnosis of interior permanent magnet synchronous motors, and a specific voltage sequence injection method with simple implementation is proposed here. It is a real-time visualised diagnostic approach. A unique fault index is proposed to diagnose eccentricities. The absolute value of the fault index is positively correlated with the total eccentricity degree. Three types of artificial eccentricities and one type of artificial partial demagnetisation are tested. Both simulations and experiments match the proposed theory and diagnostic approach. The approach gives a clear distinction in detecting air-gap eccentricity and partial magnet demagnetisation. It performs best in the low-speed operating condition.