The Design And Research On The New Transmission Of Electric Vehicle

In the context of emphasis on energy conservation and environmental protection, new energy vehicles represented by electric vehicle is a development trend of the automotive industry. But the high requirement of quality and the exorbitant price have become the bottleneck in the development of electric vehicle industry. The way of solving the cost issue by using ordinary AC motors rather than permanent magnetic motors or switched reluctance motors needs to be found urgently. In view of the problems in electric vehicles, a new transmission based on permanent magnet drive is proposed in this paper inspired by the theories and characteristics of permanent magnet coupler and permanent magnet retarder.The research work of this paper is mainly done in three aspects:the structure design of the new transmission, the design of the key parts and the performance simulation with parameter optimization. The specific contents are as follows:Firstly, the structure and theory of relevant technology are studied, basic knowledge about permanent transmission is elaborated and the structure of the new transmission is designed for electric vehicles in this paper. There are different transmission types according to different drive train types. Besides, an electric bus is set as an example, according to the torque model that has to be transferred, the main components of the regulator and the reducing gear are designed in this paper. Finally, the 2 dimensional transient magnet field of the regulator is optimized and simulated with the analysis of Ansoft Maxwell. Static strength simulation analysis of the permanent magnet rotor and the gear pair was carried on with the application of Ansys.The result shows that, the designed new transmission for electric vehicles could realize a soft start for the drive motor, reducing the requirement of motor performance, thus the ordinary and cheap AC motors could be used in designing an electric vehicle, and the vehicles don’t have to be complicatedwith motor controllers and clutches any more. The permanent magnet regulation part of the transmission could achieve continuously variable regulation at a rather wide range. The result of the simulation shows that the transmission could meet the output requirements, which is 560 N·m for the torque and 88kW for the power, the static strength requirements could also be met.