Battery pack temperature equalization system and active control method

Abstract

In order to reduce the internal friction and performance degradation which are caused by a temperature difference in a battery pack, the invention provides a power battery pack cooling system and an active temperature equalization control method. In a battery pack cooling process, stepped slow rising and slow reduction of a temperature of cooling fluid at an inlet of the battery pack are realizedby judging an average temperature and a maximum temperature difference of various sensors in the battery pack in real time, opening and closing various cooling circuits and regulating rotating speedsof a fan and a water pump, so as to reduce a dramatic temperature fluctuation caused by large temperature difference heat exchange between the cooling fluid at the inlet and the high-temperature battery pack and improve the temperature consistency, the working efficacy and the thermal safety between battery cells in the battery pack.

Description

technical field [0001] The invention belongs to the field of thermal management of electric vehicles and power batteries, and in particular relates to a method for temperature balance control of power battery packs. Background technique [0002] The power battery is a key component of electric vehicles, which directly affects the performance and range of electric vehicles. The electrochemical reaction of the battery is extremely sensitive to the influence of temperature. Severe and changeable driving conditions and high temperature environment will cause the battery temperature to be too high, which will greatly affect the battery capacity, service life and safety. The liquid medium has a stronger heat exchange capacity than the air medium, which is more conducive to the realization of two-way thermal control of cooling and heating and the construction of integrated thermal management of the whole vehicle. For large-capacity and high-power power battery packs, liquid therma...

AI Technical Summary

Problems solved by technology

[0003] At the same time, during the cooling process of the battery, when the temperature difference between the initial battery temperature and the cooling liquid flow is large, the temperature of the battery pack fluctuates violently, causing the temperature difference of each single battery to expand rapidly, and even cold shock and micro damage occur, resulting in internal resistance, voltage, The difference in parameters such as SOC increases sharply, which directly leads to the rapid attenuation of battery pack performance and life, increases the internal consumption of the battery pack and the probability of thermal runaway, and even causes safety problems such as liquid leakage and explosion under severe working conditions and high cycle times.

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