Analysis of Rotor Eccentricity Fault in IPMSM With Different Armature Winding Structures

The rotor eccentricity fault will cause the electric vehicle (EV) drive machine to generate unbalanced magnetic pull (UMP) and torque fluctuation. It may induce more complex rotor dynamics behavior and endanger the safe and reliable operation of the drive system. In this article, three spoke-type interior permanent magnet synchronous machines (IPMSMs) with different armature winding structures, which are integer-slot double-layer distributed winding, fractional-slot double-layer concentrated winding, and fractional-slot four-layer concentrated winding with star-delta (Y- Delta ) connection, are introduced. The armature magnetomotive force (MMF) analytical models of the three IPMSMs are built. Also, the air-gap permeability is analyzed when static eccentricity, dynamic eccentricity, and mixed eccentricity faults occur in IPMSMs. Furthermore, electromagnetic characteristics of the three IPMSMs under different rotor eccentricity faults are studied. Effects of static eccentricity and dynamic eccentricity faults on cogging torque, back electromotive force (EMF), radial electromagnetic force, electromagnetic torque, loss, and efficiency of the IPMSMs with three different winding structures are compared and analyzed. Research shows that the IPMSMs with integer-slot distributed winding and fractional-slot concentrated winding have different performances under rotor eccentricity faults.