Research On Transmission System On Battery Electric Vehicle

This paper presents a new type of transmission system of Battery Electric Vehicle.The Field Modulated Permanent Magnetic Gear(FMPMG) is used in the driving system of the electric vehicle to replace the traditional mechanical gear box, so as to reduce the volume and space of the vehicle transmission system. It also can reduce the vehicle quality and improve the efficiency of the transmission.Now the torque density of the rare earth(NdFeB) is up to 400Nm/m, so the FMPMG based on Nd Fe B as its pole has advantages such as high coercive force, high magnetic energy product and high mechanical properties.Since FMPMG is still in the research stage, there is no uniform design standard for FMPMG domestic and abroad. so the structure parameter design and industrial application of FMPMG needs to be further studied.According to the four working modes of FMPMG, the magnetic field of the air gap and mathematical torque model of four kinds of work conditions are set up based on the electromagnetic field theory. And the model is simulated by using Ansoft which is a electromagnetic simulation software. And the model is validated. The theoretical and technical basis is laid for further research on the application of the pure electric the automobile transmission system.Based on the various mechanical transmission of the traditional battery electric vehicles.A new type of battery electric vehicle driving system that FMPMG can be used as its shifting system is designed. In order to solve the problem of the large volume and quality of the mechanical gearbox. It has advantages such as low noise, low vibration,maintenance free(or less) and the vehicle motion stability etc. The structural parameters of FMPMG is reversal designed based on the vehicle performance. If it can achieve the performance requirements is verified by 2D finite element simulating the torque and rotational speed of FMPMG.Since torque capacity of the transmission is the most important performance indexes of vehicle transmission system. This paper analyzes the relationship between the structure parameters and the torque of FMPMG using Ansoft based on the method of control variables,and the parameters are optimized based on the design of this paper.