Design And Research Of A Novel Series Hybrid Excitation Compound Motor

Traditional permanent magnet synchronous motor(PMSM)can not take into account both low speed and large torque output and wide constant power speed range.The magnetic gear compound motor and hybrid excitation motor provide ideas for solving this problem.The former realizes the low speed and high torque output of the motor according to the principle of flux modulation,while the latter changes the air gap magnetic field through the DC excitation winding,realizes the weak magnetic field from the motor body,and enlarges the constant power speed range of the motor.According to the characteristics of magnetic gear compound motor and hybrid excitation motor,a novel series hybrid excitation compound motor(SHECM)with adjustable flux is proposed in this paper.By introducing direct current excitation to the outer stator side,the motor combines the flux modulation principle with the concept of hybrid excitation to realize low speed and high torque output of the motor.This paper introduces the working principle of hybrid excitation compound motor,which is based on the principle of flux modulation and the working principle of hybrid excitation motor.Through the combination of the two principles,a novel SHECM structure is proposed,and the structure characteristics of the motor are introduced.According to the traditional mathematical model of permanent magnet synchronous motor,the mathematical model of the motor is established,and the difference between them is pointed out.The analysis method of voltage limit circle and current limit circle of the motor is improved.The two-dimensional finite element simulation model of the motor is established.The special parameters which have great influence on the performance of the motor,such as the radial height of the modulation ring,the circumferential width of the modulation part,the radial height of the permanent magnet and the arc coefficient of the permanent magnet,are optimized and studied.The reasonable structure parameters of the motor are obtained.The magnetic field of the motor is calculated by finite element method,and the principle of flux modulation and hybrid excitation motor are verified.The electromagnetic parameters of the optimized motor are calculated,including three-phase flux linkage,d-q axis flux linkage,self-inductance and mutual inductance of single-phase armature winding,d-q axis inductance.The torque characteristics of the motor are analyzed by the finite element method,including the steady-state torque and the relationship between the torque and the current phase angle.According to the idea of zoning control,the working area of the motor is divided,and a certain working point in each area is selected for magnetic field analysis and loss calculation.