Electromagnetic Field Analysis Of Permanent Magnet Synchronous Motor In Electric Vehicles

ABSTRACT: As the problem of energy continuously put forward, energy saving and environmental protection has become synonymous with the new century. Electric vehicles has gotten people’s great attention as a new idea to solve the energy problem, The motor attracts people’s in-depth study as one of the key components of electric vehicles.Permanent magnet synchronous motor stand out with its high efficiency, high power density in electric vehicles drive motor. Compared with the electrically excited motor, it eliminates excitation winding. So it has significant advantages such as simple structure, low loss, flexible shape and size etc. So the analysis of permanent magnet synchronous motors in electric vehicles becomes the focus of the research work.The motor’s electromagnetic field analysis is the study of motor’s performance, the paper aims to discuss the superiority of PMSM in electric vehicles. The magnetic circuit method is fast and simple, but its calculation accuracy is relatively poor due to the rotor shape and size constraints, therefore we analysis and calculate of PMSM with the finite element method.Starting with basic structure and theory of PMSM, we briefly discuss of the motor performance of steady-state, establish the calculation model with Ansoft, simulate no-load magnetic field and calculate the main parameters.Then we use the Load method to the iterative calculation of the motor rated load field, and calculate the motor parameters quadrature axis and direct axis armature reaction reactance. We simulated variable-frequency operation of electric vehicles, and calculate motor’s electromagnetic parameters and operating results in static magnetic field and transient field. Through analysis and contrast, sum up the motor superior frequency characteristics.Next come the important performance parameters of PMSM in electric vehicles. With the change of motor main dimensions, we discuss influence of permanent magnet size (the length of the magnetization direction of the permanent magnet, permanent magnet width), the air gap length and armature slot width on performance parameters, summarize the relationship between the structure parameters and performance parameters of the motor.