Research On Control System Of Magnetic Field Modulation Doubly Fed Brushless Hybrid Excitation Motor

With the rapid development of economy,people's living standards are more and more improved.Consequently,energy crisis and environmental problems are increasingly prominent due to the rapid increase of traditional energy consumption Because of the using of electricity instead of fuel,electric vehicles(EVs)have the advantages of high efficiency,low pollution,low noise and environmental friendliness The driving motor of EVs should have the characteristics of wide speed regulating capability,high torque density and high power density.Permanent magnet vernier motors(PMVMs)operating based on the principle of magnetic field modulation have the performances of simple structure and high torque density.However,similar to the traditional permanent magnet(PM)motor,the excitation field of this kind of motor is generated by PMs,so that the speed regulating capability is limited.Combined with the concept of hybrid excitation motor,a magnetic field modulation doubly fed hybrid excitation(FMDF-HE)motor was proposed by introducing a secondary winding into the split-tooth PMVM,which prossosses the merits of high utilization ratio of motor space and wider speed regulation range.Based on the electromagnetic simulation,the operating principle of FMDF-HE motor is introduced firstly.Then its mathematical model is deduced,based on which the control system is established from the viewpoint of special operation characteristics of FMDF-HE motorFirstly,the structure and working principle of FMDF-HE motor are introduced Three modes of single winding operation,double winding operation with large torque and speed regulation with weak magnetic field are introduced.And the mathematical models in two three-phase static coordinate system and double d-q coordinate system are deduced.Then,according to the mechanical characteristic curve of the motor,the partition control strategy suitable for FMDF-HE motor is proposed,and the working state in each operation area is analyzed.Based on the conventional control strategy of flux weakening,combined with the analysis method of voltage limit circle and current limit circle,a flux weakening control strategy of fmdf-he motor based on voltage feedback and lead angle is constructed.In this paper,the region judgment module of weak magnetic control is used to judge the operation region of the motor.The control methods of each operation region are discussed,and the comprehensive motion control strategy of the motor is designed.Finally,the simulation model of FMDF-HE motor is built in MATLAB,and the accuracy of the motor model is verified by comparing electromagnetic simulation with MATLAB simulation.According to the proposed control strategy,the simulation research of each region and comprehensive operation mode is completed,and the FMDF-HE prototype is tested,including no-load induced potential,no-load induced potential and motor current,etc.,which verifies the multi-mode operation ability of the motor and the correctness of the motor model.