Match Of Power System Parameteers For Pure Electric Car And Study On The Motor Control Strategies

Currently, the new energy vehicles has been developed very fast, Our government also enhance the understanding of policy and increased capital investment to the new energy vehicles, major cities and automobile manufacturers have also launched their new energy models, and put into trial operation. But there are still many problems in the development of new energy vehicles. In terms of pure electric cars, there are the continues mileage in one charge,battery life,motor and its control technology and some other issues. Before the breakthrough in battery technology development, research and develop high-performance motor drive system for the development of new energy vehicles in China is significant.Electric vehicle motor drive system has special requirements to the motor body and its control strategies. To get good motor performance, it should match good body structure design an reasonable motor control strategy, Electric vehicle have a very complex service-condition, which require the motor torque to meet different requirement, such as climbing,acceleration,idling,quick starts etc; and require to research special permanent magnet synchronous motor magnetic circuit for the electric vehicle; also require to develop a new motor control strategy which can adapt to the motor parameters change.The object of my study is a pure electric car which is designed by a company. On the base of the real motor vehicle, I researched the motor body and its control strategies with the method of theoretical analysis and experimental verification. Based on this research objective, this paper mainly completed these contents:(1)First, according to the company's design requirements, matched the vehicle dynamic system parameters, including motor,batteries power transmission and other related system. Secondly, do the motor,battery performance testing in the test bench, and get the related performance parameters which can be used in the next simulation. Then do the simulation of the vehicle dynamic performance based on Advisor. The simulation results are similar with the real vehicle test results which can indicate that the dynamic sys tem matched well.(2)After the match and the preliminary simulation test of the vehicle dynamic system, the following is motor body analysis and design based on vehicle theory and motor theory. First analyzes the performance of motor, especially the torque and speed performance, which the electric cars required. Then research the motor performance ask for what kind of body parameters, especially for the cross-axis inductance and the permanent magnet flux. Now get the relationship with vehicle performance and motor body parameters. According to the new motor parameters, it will be verified the reasonableness in the later vehicle simulation model.(3)Based on the commonly weakening control principle, it can build the electric vehicle simulation model in MATLAB/Simulink environment. This model simulation results are closed to the real vehicle test results, which indicating that the accuracy of the model. So, it provide an accuracy simulation platform to the improved control strategy.(4)In the field weakening control system, the armature reaction can change the motor body parameters(ie, permanent magnet flux linkage,direct axis inductance), while the changes of these parameters can also ask the stator current operating point transferred, which affects vehicle vector effect. So it should reduce this effection. This article uses fuzzy control strategy to compensate for the stator current. In the vehicle simulation model, the improved motor control strategy simulation results show that the improved motor control is better, and it increase the weak magnetic efficient.