Design And Analysis Of Asymmetric Consequent-pole Permanent Magnet Synchronous Reluctance Motor Based On Flux Linkage Phase Shifting Principle

Permanent magnet motors are widely used in electric vehicles.However,the conventional permanent magnet synchronous motor is N-S permanent magnet array structure,which has a large amount of permanent magnet and high cost.Although permanent magnet synchronous reluctance motors(PMSynRM)have high torque density,high power density,and wide speed range,and effectively reduce the amount of permanent magnets used.However,the maximum permanent magnet torque and reluctance torque of traditional PMSynRM are not located at the same current phase angle,which cannot fully utilize the permanent magnet torque and reluctance torque.In this paper,a novel asymmetric consequent-pole permanent magnet synchronous reluctance motor(ACP-PMSynRM)is proposed.Based on the phase shift principle of permanent magnet flux linkage,consequent-pole permanent magnet arrays,asymmetric magnetic poles,and flux barriers are combined to achieve the superposition of the maximum values of permanent magnet torque and reluctance torque under the same current phase angle.It can not only improve the utilization rates of permanent magnet and reluctance torque,but also enhance output torque capacity,and reduce the volume of permanent magnets.The electromagnetic performances of the traditional PMSynRM,consequent pole PMSynRM and ACP-PMSynRM were compared and analyzed by the finite element method,which demonstrates the feasibility of the proposed motor topology.Finally,a prototype with48 slots and 14 poles was fabricated to verify its feasibility.The main research contents of this paper are as follows:1.The principle,main characteristics,and mathematical model of PMSynRM are analyzed,and the method of ACP-PMSynRM magnetic linkage phase shifting is studied.The mechanism of achieving maximum permanent magnet torque and reluctance torque simultaneously at the same current phase angle is investigated.Therefore,the mathematical model of ACP-PMSynRM is established.2.The harmonic winding factors corresponding to different slot and pole combinations,as well as the phase shift angles and corresponding winding factors of various dual three-phase motor slot and pole combinations,are studied.By comparing and analyzing the electromagnetic performance of various asymmetric rotor structures and permanent magnet position distributions,an ACP-PMSynRM topology is proposed,achieving full coincidence of the current phase angle corresponding to the maximum permanent magnet torque and the current phase angle corresponding to the maximum reluctance torque.Permanent magnet torque and reluctance torque are fully utilized to improve the output torque capability of the motor.3.By comparing and analyzing the no-load and load characteristics of traditional PMSynRM,alternating pole PMSynRM,and ACP-PMSynRM,it is determined that the amount of permanent magnet used in ACP-PMSynRM is the minimum,and the maximum permanent magnet torque and reluctance torque are achieved at the same current phase angle,improving the torque density and efficiency of the motor.4.The impact of the third harmonic component of the no-load back-electromotive force on torque ripple was thoroughly investigated,and the effects of forward and reverse rotations on performance were analyzed for ACP-PMSynRM.5.A prototype is fabricated based on the ACP-PMSynRM model,and an experimental platform is established.The no-load back EMF and output torque of the prototype are measured and compared with the simulation results,verifying the theoretical analysis.