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The lithium-ion battery used in the pure electric vehicle has poor charging ability at low temperature, it can renew only after being heated. In general, the lithium-ion battery discharges to self-heat to a certain value in the low temperature environment, then the normal charging mode can be started. However, it will result in that the charging time is too long, or the battery cannot be fully charged during the default time. Moreover, it wouldn't be charged since insufficiency of the reserve battery power. In this paper, a detailed design about the power battery charging heating of pure electric vehicle by using the external power in low temperature is proposed, and finally the scheme is validated through the environment chamber and real vehicle test. The results show that this scheme can satisfy the demand of the real vehicle application and is with practical use value.

This study presents different control methods to approach motions for an electric vehicle driven by two rear hub-motors. Vehicle dynamics modeling with 11 degree-of-freedom is constructed. Accordingly, simulation model is established in MATLAB/Simulink environment. Simulation is performed when PID controller, fuzzy-PID controller and no controller are used to the modeling respectively. Simulation results show that controllers can improve yaw rate and body roll when steering input is applied to the model. The proposed controllers are helpful to develop electric vehicles with hub-motors.

Modeling, simulation analysis of vertical and lateral dynamics of an electric vehicle driven by two rear hub-motors are presented. An eleven-DOF model of the electric vehicle and the road surface input model are all established. A PID controller is used to adjust yaw rate to the desired one when slip ratio of the driving wheels is less than peak slip ratio. Simulation is performed considering inputs of steering angle of the front wheels, acceleration pedal and road inputs to four wheels. Simulation results show that yaw rate and trajectory are improved when steering input is applied. The proposed controller can provide reference to development of electric vehicles with hub-motors.

A control strategy applied to steering control was used to an electric vehicle driven by two hub-motors, which distributes the driving torque of the driving wheels according to control of actual yaw rate. The proposed fuzzy PID controller adjusts the actual yaw rate to the desired yaw rate. Comparisons between fuzzy PID controller, PID controller and no controller are performed. Simulation results show that the performance of fuzzy PID controller is satisfactory, which is helpful to improve the steering stability.