Study On CPPM Double-permanent Synchronous Motor In Electric Vehicle

A wide range of weaking magnetic be made higher demand in drive motor ofelectric vehicles. However, as there is a high reluctance of permanent magnet pole indirect axis magnetic circuit of the rare earth permanent magnet synchronous motor, a lotof direct-axis armature current is required for weak magnetic, leading to an increase incopper loss, especially the deterioration of the air gap magnetic field waveform, largeiron loss are generated with high-speed, at the same time a risk of demagnetization isexisted by the permanent magnet.Hybrid excitation synchronous motors are usuallybrush into the excitation current, reducing the operational reliability. There is serioussaturated in CPPM weaking magnetic, which declines the motor magnetic transfercapability. So, a new fashioned CPPM double-permanent synchronous motor is studiedin this paper, the motor is not only able to meet the requirements for a wide range ofelectric vehicles, but also retain the capability of low-speed large torque, which have agood application prospect in the field of electric vehicle drive motor.In this paper, the summary of drive motor of electric vehicle are firstly introduced,the characteristics of permanent magnet synchronous motor, hybrid excitationsynchronous motor and CPPM are analyzed, and the purpose and significance of thisresearch ara described. Second, the structure of the CPPM double-permanentsynchronous motor are introduced, and a more detailed analysis of the basic relationshipof the motor, the weaking ability of CPPM double-permanent synchronous motor arediscussed significantly, and some main parameters and operating characteristicproperties are calculated, verified by experiment some features. Then theelectromagnetics of CPPM double-permanent synchronous motor are designed, whichcontain comparative analysis on three pole slot combinations with8-pole24-slot,8-pole36-slot and12-pole36-slot, electromagnet and stress field of three different rotorstructures, which is "一"type,"--"type and "V" type, are analyzed, as well ascomparasion of permanent magnet material between NdFeB and ferrite. Finally, aprototype is trial-manufactured according to the optimized design and the existingconditions of the laboratory, which a more systematic tests are made, including theno-load back-EMF experiment, no-load characteristic experiment and load test, the testresults show that the design of the prototype is reasonable.