Energy management system for electric automobile and management method therefor

Abstract

The invention provides a system which is capable of carrying out the optimal management on the electric energy of a complete automobile and a corresponding management method, aiming at the characteristics of a power storage device of the existing electric automobile with an electric driving device. The system comprises a power battery, a super capacitor, a motor driving control unit and a driving motor, wherein the power battery is connected with the super capacitor in series and is connected to the driving motor by the motor driving control unit; the system also comprises a power distributing circuit which is connected with a branch circuit in parallel; the branch circuit is connected with the power battery and the super capacitor in series; the power distributing circuit comprises a transformer and two switching tubes which are respectively connected with two coils of the transformer in series; and the connection and the disconnection of the switching tubes are controlled by a management unit connected with the switching tubes. The system and the method realize the active control on electric current and power flow and prevent the power battery from being overcharged by excessive brake feedback electric current of the automobile, thereby prolonging the service life of the power battery, making full use of the capacitor and achieving the double effects of economy and energy saving.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to energy management systems for hybrid and pure electric vehicles. Background technique [0002] Electric vehicles have the characteristics of environmental protection, energy saving and high energy conversion efficiency. Pure electric and hybrid vehicles with electric drive devices are an important development direction of new energy vehicles in the future. The key issue of energy saving for electric vehicles is to optimize the management of energy distribution among electric drive devices, energy storage devices and auxiliary power units, especially the optimal configuration of energy storage and release of different types of energy storage devices. [0003] The most commonly used energy storage device in electric vehicles is the power battery. The discharge efficiency of the power battery decreases with the increase of the discharge current. However, when the power bat...

AI Technical Summary

Problems solved by technology

The simplest way is to connect the power battery and the supercapacitor directly on the vehicle power line in parallel, which can significantly equalize the peak current of the power battery and reduce its voltage drop. The disadvantage is that its power flow cannot be actively controlled, and the super The energy of the capacitor cannot be fully utilized

Connecting a two-quadrant DC / DC converter between the power battery and the supercapacitor can solve the above problems, but the requirements for the DC / DC converter are high and the cost is expensive, which will significantly increase the cost of the entire system

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