Design And Study On The Field Modulating Parallel Hybrid Excitation Motor

The field integrated modulation motor(FMIM)is composed of permanent magnet synchronous motor(PMSM)and magnetic gear with field modulating effect.It has the characteristics of low speed and large torque.The parallel hybrid excitation motor(PHEM)has two independent magnetic potential sources,which can effectively expand the constant power range of PMSM and reduce the risk of permanent magnet demagnetization in operation.Based on the principle of flux modulation and parallel hybrid excitation,the field modulation parallel hybrid excitation motor(FMPHEM)is studied in this dissertation.The working principle,namely the field modulation and parallel hybrid excitation were introduced in this dissertation and then the FMPHEM is proposed.The modulating relationship between pole pair number of stator,modulation blocks number and pole pair number of rotor was explained.The structure design of the motor were introduced.2D and 3D finite element simulation models of the motor were established.The radial and axial air gap flux density of the motor were extracted and harmonic decomposition was carried out by analyzing the magnetic field of the motor.The results shows that the motor satisfies the field modulation principle and parallel hybrid excitation principle.The mathematical model of FMPHEM is derived.The radial length of the modulation block and its internal and external opening angle,the size of permanent magnet and the angle of the magnetic isolation bridge which are important structural parameters related to the electromagnetic performance of FMPHEM are optimized.The finite element method was used to achieve the motor simulation analysis and the results verify the rationality of motor design.The no-load equivalent magnetic circuit of the FMPHEM is given and the field regulation range of the motor is deduced by the magnetic circuit method(MCM).The field regulation range of motor under four axial ratios was studied.The validity of the MCM is verified by FEM.Finally,the magnetic field regulation range of 60-20-20 axial ratio was tested by prototype experiment.The experimental results prove the accuracy of the magnetic circuit method.