Novel safety management method and device for power battery pack of electric vehicle

Abstract

The invention discloses a novel safety management method and a novel safety management device for a power battery pack of an electric vehicle. A data acquisition system and a charging/discharging management system are used for sequentially detecting, analyzing and calculating four parameters of single air pressure, single temperature, single voltage and power battery pack charging/discharging current of the power battery pack to further control the charging/discharging state of the power battery pack, wherein the single air pressure, the single temperature, the single voltage and the power battery pack charging/discharging current of the power battery pack are detected through a normally closed air pressure switching sensor, a temperature sensor, a voltage sensor and a Hall sensor respectively. According to the method and the device, the charging/discharging of the power battery pack is instantly stopped when one of the four parameters reaches a charging/discharging stopping condition in a process of detecting the four parameters, and the four parameters are continuously detected if all is normal, so that all single power batteries are effectively prevented from being over-charged or over-discharged, the service life of the power battery pack is prolonged, and the safety of the power battery pack is improved.

Description

Technical field [0001] The invention belongs to the technical field of electric vehicle power battery management, and specifically relates to a new type of safety management system for electric vehicle power battery packs. Background technique [0002] At present, the technology of electric vehicles is not mature enough, especially the power battery and its management technology are immature. Fires and explosions caused by battery overcharging or overdischarging of electric vehicles occur from time to time, which not only brings severe challenges to the safety of life and property At the same time, it also has a serious negative impact on the development, promotion and application of electric vehicles. [0003] At present, the safety management of the power battery pack of pure electric vehicles is mainly embodied in the charge / discharge management, that is, the management is carried out according to the state of charge of the power battery pack, the maximum / minimum voltage of the ...

AI Technical Summary

Problems solved by technology

[0004] First, because the estimated value of the state of charge of the battery pack is affected by various complex factors such as battery charge and discharge rate, battery temperature, battery internal resistance and self-discharge rate, and cumulative error, the estimation accuracy is not high, and the estimated value of the state of charge is difficult to accurately reflect The actual state of charge of the battery pack

In addition, due to differences in battery materials, processes, internal resistance, self-discharge rate, etc., there are often large differences in battery cells.

Therefore, taking the state of charge of the power battery pack as the basis for safety management will often lead to overdischarging of the lowest battery cell and overcharging of the highest battery cell, which will greatly affect the battery life, and in severe cases will cause the battery to burn or explode.

[0005] Second, the maximum / minimum voltage and maximum / minimum temperature values ​​of the safe charge / discharge of the power battery cell are affected by various factors such as charge and discharge current, ambient temperature, battery internal resistance, etc., and it is difficult to accurately determine the safe charge of the battery cell. / Discharged battery cell maximum / minimum voltage and maximum / minimum temperature

In addition, whether the battery cell will be dangerous is mainly reflected in the internal pressure and temperature of the battery. Although some systems monitor the battery temperature, the current battery safety management system does not monitor the internal pressure of the battery. The potential danger of battery leakage, short circuit or even combustion and explosion due to internal pressure rise cannot be monitored

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