Analysis Of The Air-gap Magnetic Field Of Stator Windings’ Inter-turn Short Circuit Fault Of PMSM

Permanent magnet synchronous motor(PMSM)has the characteristics of compact structure,small size,light weight,high efficiency,reliable operation and low noise.It’s gradually replacing the traditional induction motor and widely used in various fields,such as military,industrial,civil use and other fields.However,the permanent magnet synchronous motor is prone to failure during operation.When the permanent magnet synchronous motor in starting,braking,acceleration and deceleration,mechanical vibration,electromagnetic vibration,high temperature,humid environment could cause its failure.The winding faults of permanent magnet synchronous motor have inter-turn short circuit fault(single-phase inter-turn short circuit fault,inter-turn short circuit fault),ground fault,single-phase open circuit fault and so on.The inter-turn short circuit fault is one of the most common faults in all faults,and it is highly destructive.When the permanent magnet synchronous motor meets inter-turn short circuit fault,if not take measures,the fault will be developed into more serious fault,and cause economic losses.Therefore,it is necessary to analyze the stator winding inter-turn short circuit fault of permanent magnet synchronous motor.In this paper,the basic structure and principle of permanent magnet synchronous motor is introduced,and the characteristics of permanent magnet material and two kinds of winding faults are briefly introduced.Established the permanent magnet synchronous motor during normal operation and two winding fault(single-phase inter-turn short circuit fault,and fault of inter-turn short circuit)voltage equation and the magnetic circuit model(stator component and rotor component).Then the distribution of air gap magnetic field of healthy and fault PMSM is analyzed,and the influence of the fault on the air gap magnetic field is summarized.Next,the air gap magnetic field under different fault conditions is analyzed.It is concluded that the relationship between the fault characteristic parameters and the fault parameters will change with the degree of fault.Finally,the finite element model of permanent magnet synchronous motor is established by using ANSYS Maxwell,and the distribution of air gap magnetic field is calculated.Then carries on the FFT analysis by MATLAB,extracting the fundamental component of air gap magnetic field,which was extracted by using rbio4.4 wavelet denoising wavemenu toolbox,which verifies the correctness and validity of the magnetic circuit model.The research work and results of this paper can be used as the basis for the analysis of type and degree of fault of inter-turn short circuit fault,which is in favour of improve the fault diagnosis theory of permanent magnet synchronous motor.