Method for preventing small storage battery from being fed when charging electric vehicle

Abstract

The invention discloses a method for preventing a small storage battery from being fed when charging an electric vehicle, wherein when a charger is working, a battery management system (BMS) is awakened through a hard wire, at the same time, a vehicle control unit (VCU) and a direct current direct current converter (DCDC) need to be awakened. When the VCU detects that the whole vehicle is in a charging state, a pre-charge circuit of a motor controller and a main positive relay are sequentially closed, the DCDC is enabled to be in a working state by preset enabled DCDC for charging a small storage battery. When the charging process is over or finished, the enabled DCDC is controlled to close by the VCU, then the main positive relay of the motor is switched off to make the motor enter a discharging state, and after finishing discharging, the DCDC and the VCU enter a dormant state. The method has the advantages that the situation that the charger overheats during charging is relieved, theservice life of the charger is extended, the problem that the charging is stopped due to overheat of the charger in the charging process is solved, the charging time is shortened, and the situation that the small storage battery is fed due to the operation of a heat-removal system in the charging process is effectively relieved.

Description

technical field [0001] The invention relates to the technical field of electric vehicle power management, in particular to a method for preventing small storage batteries from feeding power when the electric vehicle is charging. Background technique [0002] At present, electric vehicles have been popularized in a large range. While implementing various functions of electric vehicles, major OEMs are gradually paying attention to improving the performance of the vehicle, especially the improvement of the cruising range of the vehicle. Improving the cruising range will inevitably involve the improvement of battery power and battery energy density. [0003] The increase in battery power also brings pressure to charging. If the charging current is small, the charging time will be prolonged. If the charging current is large, the cooling system of the whole vehicle is required to cool down the charger. When the on-board charger is working, in addition to converting AC power to DC...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the disadvantages of existing electric vehicles that easily lead to small battery feeding when charging, and that the charging machine is easily caused to overheat and stop charging when the electric vehicle is charged, and to provide an electric vehicle. The method that prevents small storage battery from feeding power, thereby solves the above-mentioned problem

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