Charging control method and system for low-voltage battery of electric vehicle, and vehicle controller

Abstract

The invention discloses a charge control method and system for a low-voltage storage battery of an electric automobile, and a vehicle control unit and relates to the technical field of electric automobile vehicle control. The charge control method comprises the steps that after the electric automobile is started, the vehicle control unit controls a DC / DC convertor to start, and the low-voltage storage battery is precharged; after the low-voltage storage battery is precharged, the vehicle control unit controls the DC / DC convertor to stop, and voltage of the low-voltage storage battery is monitored; the vehicle control unit determines the battery state of the low-voltage storage battery according to the monitored voltage of the low-voltage storage battery; and according to the battery state of the low-voltage storage battery and / or the current operating state of the electric automobile, the DC / DC convertor is controlled to start or stop, and intermittent charge for the low-voltage storage battery is achieved. Through charge control over the low-voltage storage battery, the energy utilization ratio of the electric automobile is increased, and the service life of the low-voltage storage battery is prolonged.

Description

technical field [0001] The invention relates to the technical field of electric vehicle vehicle control, in particular to a charging control method, system and vehicle controller for a low-voltage storage battery of an electric vehicle. Background technique [0002] At present, environmental protection and energy issues are getting more and more attention. In order to cope with the environmental and energy crisis, the development and large-scale use of electric vehicles has become an inevitable trend. In the process of improving the performance of electric vehicles and gradually moving towards industrialization, it is necessary to reduce low-voltage power consumption The energy consumption of electrical accessories and the improvement of the energy utilization efficiency of the whole vehicle are important topics in the research of electric vehicles. [0003] Compared with traditional fuel vehicles, the gasoline engine is replaced by a drive motor; the fuel system is replaced...

AI Technical Summary

Problems solved by technology

[0004] The existing low-voltage batteries of electric vehicles do not have a special charge-discharge management system. Generally, when the vehicle is in the READY state (the electric vehicle can drive at any time in this state), the high-voltage circuit is connected, and the DC / DC converter always uses constant voltage for low-voltage. Battery charging, when the vehicle is in the non-READY state (the electric vehicle is in this state when the key position is improper and / or the motor, battery and other units are faulty, and the electric vehicle cannot drive at this time), the high-voltage circuit is disconnected, and the DC / DC The converter stops charging the low voltage battery

This charging and discharging method can easily cause damage to the battery. For example, when the low-voltage battery is seriously depleted, the DC / DC converter charges the low-voltage battery with too much current, which will cause battery damage. For example, if the vehicle is parked for a long time in a non-ready state And when using electrical appliances, the power of the low-voltage battery is always in a state of depletion, which may easily lead to battery damage

In addition, the DC / DC converter adopts a natural air cooling design, and the working temperature of the DC / DC converter will rise after a long time, which will cause the problem of low energy conversion efficiency

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