Linear hall-based eccentricity diagnosis method and detection system for permanent magnet motor

A linear Hall-based eccentricity detection system for a permanent magnet motor, comprising:

• a first linear Hall element mounted in stator slots, and magnetically sensitive surfaces of the first linear Hall element are opposite surfaces of a rotor with permanent magnets;
• a second linear Hall element mounted in the stator slots and spaced apart from the first linear Hall element in a circumferential direction by an electrical angle phase difference of φs, and magnetically sensitive surfaces of the second linear Hall element are opposite surfaces of a rotor with permanent magnets;
• a third linear Hall element mounted in the stator slots and spaced apart from the first linear Hall element in a circumferential direction by an electrical angle phase difference of φs, and magnetically sensitive surfaces of the third linear Hall element are opposite surfaces of a rotor with permanent magnets;
• and
• a digital signal processor, wherein output voltages of the first to third linear Hall elements are linearly combined to obtain a quadrature signal containing a pair of quadrature components and a DC component, positive sequence signals, negative sequence signals and sideband signals are extracted from the quadrature signal, the amplitude of the negative sequence signals extracted thereby is taken as a static eccentricity indicator, the amplitude of the sideband signals extracted thereby is taken as a dynamic eccentricity indicator, a static eccentricity percentage is obtained by the ratio of the static eccentricity indicator to the amplitude of the positive sequence signals, and a dynamic eccentricity percentage is obtained by the ratio of the dynamic eccentricity indicator to the amplitude of the positive sequence signals.