Design And Analysis Of Magnetic Flux Leakage Controllable Wide-speed Adjustable Permanent Magnet Motor

With the global environmental pollution and continuous deterioration of energy security situation,the vigorous development of electric vehicles with high environmental protection,low noise,high efficiency and energy saving has become an effective means to replace traditional fuel vehicles.Rare earth permanent magnet motor has become the mainstream type in the field of automotive drive motor research at home and abroad due to its advantages such as high power/torque density,high efficiency,simple and reliable rotor structure and non-demagnetization of permanent magnets.However,due to the inherent characteristics of permanent magnet motor,the air gap magnetic field of the motor is basically constant,and there are some shortcomings,such as narrow speed range,low efficiency of high-speed weak magnetic field,which restrict the large-scale application of permanent magnet motor in the field of electric vehicle drive motor to a certain extent,and also become one of the disadvantageous factors to delay the rapid development of electric vehicle.In order to solve the above problems,a new type of controllable leakage flux wide-speed permanent magnet(CLF-WSPM)motor is designed in this paper.The motor can not only effectively broaden the speed range,but also solve the problem of low efficiency of the motor in the high-speed weak magnetic region,and achieve wide-area high efficiency under multiple operating conditions.Firstly,the research status of wide speed motor at home and abroad is analyzed and studied in this paper.Aiming at the problems existing in the current research,how to make the motor have a wide speed range and achieve wide-area and high efficiency of the motor is explored and studied.In this paper,the design method of controllable leakage flux is combined with wide speed motor,and a new type of controllable leakage flux wide-speed permanent magnet motor is proposed.Secondly,the overall design scheme of CLF-WSPM motor is given.The basic principle of electromagnetic flux leakage controllability is studied and analyzed.According to theoretical analysis and previous design experience,the initial design of CLF-WSPM motor is carried out to determine the main parameters.Then,the stator and rotor structure of CLF-WSPM motor is designed in detail,and the motor is optimized by a comprehensive optimization method combining single parameter optimization method with multi-objective optimization method,so as to determine the optimal design scheme of the motor.Next,a series of performances of CLF-WSPM motor are comprehensively evaluated by finite element method,and compared with the traditional V-type Permanent Magnet(V-PM)motor.Among them,the basic electromagnetic properties such as magnetic field distribution,no-load back EMF and air gap flux density,flux linkage characteristics,torque performance and inductance characteristics of the two motors are analyzed,and the speed regulation characteristics and efficiency operation characteristics of the motors are also studied.Through comparative analysis,the feasibility of design and optimization of controllable leakage flux wide-speed motor is verified.Finally,the principle prototype is processed,and the experimental research on CLF-WSPM prototype is carried out.The experimental contents include no-load back EMF,steady-state operation characteristics and operation characteristics under variable working conditions.The experimental results further verify the feasibility of motor design optimization and the effectiveness of simulation analysis and calculation.