Analysis of Inter-Turn-Short Fault in High-Speed Permanent Magnet Generators Considering Effect of Structure Windings

The inter-turn-short fault (ITSF) causing degradation of the electromagnetic properties of the machine to deteriorate and the vibration of the machine to increase, resulting in the machine not operating normally. Especially in the high-speed machines with fewer winding turns, the harm will be more serious. In this article, the influence of ITSF on the properties of high-speed permanent magnet generators (HSPMG) with the toroidal winding (TW) and the distributed winding (DW) is studied. The fault models of the TW and the DW are established, and the electromagnetic characteristics of the HSPMG after the ITSF are analyzed by the field-circuit coupling method. The temporal and spatial distribution of the air-gap magnetic field under fault is given, and the mechanism of asymmetry in magnetic field is revealed. Secondly, based on the Fourier transform method, the characteristics of the electromagnetic force under different working conditions are analyzed, and the characteristics of the electromagnetic force harmonic caused by the short-circuit current are obtained. In addition, the vibration acceleration response of the generator stator is calculated by the modal and harmonic response analysis, and the vibration characteristics of the generator after the ITSF are obtained. Finally, the electromagnetic performance of the prototype is tested to verify the correctness of the theoretical analysis.