Electric vehicle low electric quantity working condition high voltage control method based on BMS

Abstract

The invention discloses a BMS (Battery Management System)-based high-voltage control method for an electric vehicle under a low-electric-quantity working condition, which comprises the following steps that: the BMS detects the electric quantity of a power battery in real time, enters a low-electric-quantity state when a low-electric-quantity triggering condition is reached, and sends a low-electric-quantity prompt in the low-electric-quantity state while controlling the high-voltage system state of the whole vehicle according to collected battery state data. The method has the advantages that the aim of effective reminding is achieved through segmented reminding in a low-voltage state; the power of the power battery is controlled in a low-voltage state, so that the risk of over-discharge and anchor drop in the low-voltage state is further ensured, the running reliability of the vehicle is improved, and a driver can be effectively reminded to charge in time by combining reminding and low-power running; and the high-voltage state during low-power continuous driving is controlled, so that over-discharge is effectively avoided.

Description

technical field [0001] The invention relates to the field of electric vehicle discharge control, in particular to a BMS-based high-voltage control method for low-battery working conditions of electric vehicles. Background technique [0002] With the popularity of new energy electric vehicles, most new energy vehicles have developed the terminal discharge of power batteries to the extreme in order to increase battery life. According to the analysis of the voltage characteristic curve of the lithium battery, the battery voltage drops faster when it is discharged to the end, and the SOC calculation accuracy error will increase accordingly. The inaccurate SOC accuracy at the end of the discharge directly leads to the discharge of most new energy vehicles until the end of the vehicle is directly applied to the high voltage, and the whole vehicle reports a fault. The battery is over-discharged and the vehicle breaks down. Some faults even affect the charging, resulting in the fail...

AI Technical Summary

Problems solved by technology

The inaccurate SOC accuracy at the end of the discharge directly leads to the discharge of most new energy vehicles until the end of the vehicle directly under high voltage, the whole vehicle reports a fault, the battery is over-discharged and the vehicle breaks down, and even some faults will affect the charging, resulting in the problem of being unable to charge after the discharge breaks down

[0003] Reporting a fault after the electric vehicle is empty and broke down will give customers an illusion that there is a problem with the vehicle itself, and over-discharging will also cause damage to the battery itself, which affects the user experience and reduces the service life of the battery

Most new energy vehicles discharge to the end of the vehicle and directly apply high voltage, the whole vehicle reports a fault, the battery is over-discharged and the vehicle breaks down, and some faults even affect the charging, resulting in the problem of being unable to charge after the discharge breaks down

Images