Analysis of Electromagnetic Torque Characteristic of Permanent Magnet Vernier Motor with Split Pole and Concentrated Winding
In order to study the electromagnetic torque characteristics of permanent magnet vernier motor(PMVM)with split teeth and concentrated windings,based on the magnetic field modulation theory,the magnetomotive force permeance model of PMVM was es-tablished.The expression of the number and speed of the air gap magnetic density harmonics under the independent action of the perma-nent magnet and armature winding was given.The harmonics number that generated the average torque and torque ripple was analyzed.Maxwell stress tensor method was used to calculate the torque generated by each dominating harmonics,and the influence of each domi-nating harmonics on electromagnetic torque was determined.The analysis results were verified by finite element analysis.The results show that the electromagnetic average torque of PMVM is mostly generated by the 16th harmonic,accounting for 98.83%,and the torque rip-ple is mainly generated by the 16th,34th and 48th harmonic,accounting for 52.29%.The source of PMVM electromagnetic average torque is mainly the air gap magnetic density fundamental harmonic of the permanent magnet,so the amount and shape of the permanent magnet can be changed to increase the air gap magnetic density fundamental harmonic generated by it to improve the electromagnetic torque performance of PMVM.
permanent magnet vernier motor(PMVM)magnetic field modulation theoryelectromagnetic torquefinite element analysis