A method for controlling the temperature of a lithium battery

Abstract

The invention discloses a method for controlling the temperature of a lithium battery. The method for controlling the temperature of the lithium battery comprises the following steps that a battery management system sends the internal temperature T of a lithium battery assembly, the voltage of a single cell, the power and an SOC value of the lithium battery to an electronic control unit, the electronic control unit controls the charging / discharging power of the lithium battery according to the SOC value of the lithium battery, controls the charging power of the lithium battery according to theinternal temperature T of the lithium battery assembly and the maximum voltage CV-max of the single cell and further controls the discharging power of the lithium battery according to the minimum voltage CV-min of the single cell. By adopting the method for controlling the temperature of the lithium battery, the temperature of the lithium battery can be kept within a controllable and reasonable range, and the service life of the lithium battery is prolonged.

Description

technical field [0001] The invention relates to a method for controlling an automobile electrical appliance, in particular to a method for controlling the temperature of a lithium battery. Background technique [0002] Practice shows that the lithium battery is in a high temperature state for a long time, and its life will be greatly shortened. When the vehicle accelerates and decelerates frequently during normal operation, the lithium battery assembly will be impacted by frequent high-current charging / discharging, and the temperature will rise sharply. If it is not effectively controlled, it will exceed the limit temperature that the lithium battery assembly can withstand, resulting in the loss of control of the lithium battery. , the life is shortened, and the entire 48V lithium battery system collapses. [0003] Controlling the heat balance of lithium batteries requires a good heat exchange system to release the heat generated by the battery during use; however, limited ...

AI Technical Summary

Problems solved by technology

When the vehicle accelerates and decelerates frequently during normal operation, the lithium battery assembly will be impacted by frequent high-current charging / discharging, and the temperature will rise sharply. If it is not effectively controlled, it will exceed the limit temperature that the lithium battery assembly can withstand, resulting in the loss of control of the lithium battery. , the life is shortened, and the entire 48V lithium battery system collapses

[0003] Controlling the heat balance of lithium batteries requires a good heat exchange system to release the heat generated by the battery during use; however, limited by the layout and cost of the vehicle, it is basically unrealistic to use water cooling or air cooling

According to Joule's law Q=I 2 Rt shows that reducing the internal resistance of the battery is one way, but based on the current development of the industry, it is difficult or costly to use ultra-low lithium battery internal resistance; another way is to shorten the working time of lithium batteries, which is obviously unrealistic, because It cannot satisfy the user experience; the most effective way is to optimize the charging / discharging state at the necessary time, so that the heat exchange of the lithium battery is in a balanced state, so that the temperature of the lithium battery can be kept within a controllable and reasonable range, and the 48V lithium battery system can be guaranteed Continuous work, prolong the working life of lithium battery

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