CN-115863847-B - Battery temperature control method and system

CN115863847BCN 115863847 BCN115863847 BCN 115863847BCN-115863847-B

Abstract

The invention discloses a battery temperature control method and system, the method comprises the steps of obtaining a heat collecting point temperature value and a heat radiating point temperature value of a battery, calculating a first temperature difference between the heat collecting point temperature value and the heat radiating point temperature value, heating the battery when the first temperature difference is larger than a first temperature threshold value, starting a timer, obtaining a lowest temperature value of the battery, and executing circulation operation until the heat radiating point temperature value is larger than a cut-off temperature value or the timer reaches a preset duration, under a heating state, calculating a second temperature difference between the heat radiating point temperature value and the lowest temperature value and calculating a third temperature difference between the heat radiating point temperature value and the heat collecting point temperature value, stopping heating when the second temperature difference is larger than a second temperature threshold value or the third temperature difference is larger than a third temperature threshold value, under an unheated state, calculating the second temperature difference, and continuing heating when the second temperature difference is smaller than a fourth temperature threshold value. The technical scheme provided by the invention can solve the technical problem of large temperature difference between different positions of the battery in the prior art.

Inventors

QU FANDUO
LIN ZHIHONG
YANG ZHENYU
JIANG HAIRONG
LI JIANCHANG

Assignees

蜂巢能源科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20221209

Claims (11)

1. A battery temperature control method, characterized in that the method comprises: Acquiring a heat collecting point temperature value of a heat collecting region of the battery and a heat radiating point temperature value of a heat radiating region, calculating a first temperature difference between the heat collecting point temperature value and the heat radiating point temperature value, and heating the battery in a preset heating region and starting a timer when the first temperature difference is larger than a preset first temperature threshold; acquiring the lowest temperature value of the low-temperature region of the battery, the heat-collecting point temperature value and the heat-radiating point temperature value in real time, and executing the following circulation operation until the heat-radiating point temperature value is larger than a preset cut-off temperature value or the time corresponding to the timer reaches a preset duration: (1) Calculating a second temperature difference between the heat dissipation point temperature value and the lowest temperature value and a third temperature difference between the heat dissipation point temperature value and the heat collection point temperature value in a heating state, and stopping heating the battery when the second temperature difference is larger than a preset second temperature threshold or the third temperature difference is larger than a preset third temperature threshold; (2) And in an unheated state, calculating the second temperature difference, and continuously heating the battery when the second temperature difference is smaller than a preset fourth temperature threshold value.
2. The method of claim 1, wherein said calculating a first temperature difference between said focus point temperature value and said heat sink point temperature value comprises: Calculating the first temperature difference according to the formula: Td 1 =Th 1 -Th 2 , Wherein Td 1 is the first temperature difference, th 1 is the heat-collecting point temperature value, and Th 2 is the heat-dissipating point temperature value.
3. The method of claim 1, wherein said calculating a second temperature difference between said heat sink temperature value and said minimum temperature value comprises: Td 2 =Th 2 -Th 3 , Wherein Td 2 is the second temperature difference, th 2 is the heat dissipation point temperature value, and Th 3 is the minimum temperature value.
4. The method of claim 1, wherein said calculating a third temperature difference between said heat sink temperature value and said heat focus temperature value comprises: Td 3 =Th 2 -Th 1 , Wherein Td 3 is the third temperature difference, th 2 is the heat sink temperature value, and Th 1 is the heat focusing point temperature value.
5. The method of claim 1, wherein the first temperature threshold is in a range of 1 ℃ to 4 ℃, the second temperature threshold is in a range of 2 ℃ to 8 ℃, the third temperature threshold is in a range of 0 ℃ to 8 ℃, the fourth temperature threshold is in a range of-2 ℃ to 2 ℃, and the cutoff temperature is in a range of-15 ℃ to 10 ℃.
6. The method of claim 1, wherein the predetermined duration ranges from 10 hours to 20 hours.
7. The method of claim 1, wherein the method further comprises: And after the lowest temperature value of the low temperature region of the battery, the heat collecting point temperature value and the heat radiating point temperature value are obtained in real time, if the first temperature difference is smaller than the cut-off temperature value and the lowest temperature value is also smaller than the cut-off temperature value, heating the battery is stopped.
8. A battery temperature control system, the system comprising: The battery is provided with a plurality of electric cores, the corresponding areas of the electric cores are divided into a heat collecting area, a heat dissipation area and a transition area, and the heat dissipation area comprises a heating area; the heating unit is arranged in the heating area; the sensor unit is used for acquiring a heat collecting point temperature value of the heat collecting region and a heat radiating point temperature value of the heat radiating region and acquiring a lowest temperature value of a low-temperature region of the battery in real time; A control unit for: calculating a first temperature difference between the heat collecting point temperature value and the heat radiating point temperature value, heating the battery in a preset heating area when the first temperature difference is larger than a preset first temperature threshold value, and starting a timer; And executing the following circulation operation until the temperature value of the radiating point is larger than a preset cutoff temperature value or the corresponding time of the timer reaches a preset duration: (1) Calculating a second temperature difference between the heat dissipation point temperature value and the lowest temperature value and a third temperature difference between the heat dissipation point temperature value and the heat collection point temperature value in a heating state, and stopping heating the battery when the second temperature difference is larger than a preset second temperature threshold or the third temperature difference is larger than a preset third temperature threshold; (2) And in an unheated state, calculating the second temperature difference, and continuously heating the battery when the second temperature difference is smaller than a preset fourth temperature threshold value.
9. The system of claim 8, wherein different locations of the heating unit have different heat generation power densities, wherein the heat generation power densities gradually decrease in a first direction in which the heat dissipation region is directed toward the heat collection region.
10. The system of claim 9, wherein the heating unit is one or more of an infrared heating sheet, a PTC heater, a PI heating film, or a silicone rubber heating film.
11. The system of claim 10, wherein the plurality of cells are arranged parallel to one another in the first direction, and the heating unit is disposed on a side of the cells remote from the heat accumulation region.

Description

Battery temperature control method and system Technical Field The present invention relates to the field of battery technologies, and in particular, to a method and a system for controlling battery temperature. Background Batteries are used in various fields and mounted on different devices, and are suitable for various scenes, wherein a battery pack may be subjected to a low-temperature environment for a long period of time in some special use situations, such as vehicle devices. When the environmental temperature is too low, the periphery of the box body for placing the battery dissipates heat outwards, the temperature of the battery cells at the periphery position in the box body is reduced faster, and the temperature of the battery cells at the center position is reduced slowly, so that obvious temperature difference is caused, and the larger temperature difference can have adverse effect on the overall cycle performance of the battery system. When the temperature of the battery core at the peripheral position is reduced too quickly, the heat insulation performance of the battery is lower, and the battery needs to be heated for a certain time when the vehicle is reused after a long time, so that the convenience of vehicle use is affected, and the user experience is reduced. In the prior art, the battery system generally heats or cools the whole system, so that a large temperature difference is generated in the heating or cooling process, and therefore, the temperature difference cannot be effectively reduced when the whole system is heated, and large energy consumption is generated. Disclosure of Invention The invention provides a battery temperature control method and system, which aims to effectively solve the technical problem of large temperature difference between different positions of a battery in the prior art. According to an aspect of the present invention, there is provided a battery temperature control method including: acquiring a heat collecting point temperature value of a heat collecting region and a heat radiating point temperature value of a heat radiating region of the battery, calculating a first temperature difference between the heat collecting point temperature value and the heat radiating point temperature value, heating the battery in a preset heating region when the first temperature difference is larger than a preset first temperature threshold value, and starting a timer; acquiring the lowest temperature value of the low-temperature region of the battery, the heat-collecting point temperature value and the heat-radiating point temperature value in real time, and executing the following circulation operation until the heat-radiating point temperature value is larger than a preset cut-off temperature value or the time corresponding to the timer reaches a preset duration: (1) Calculating a second temperature difference between the heat dissipation point temperature value and the lowest temperature value and a third temperature difference between the heat dissipation point temperature value and the heat collection point temperature value in a heating state, and stopping heating the battery when the second temperature difference is larger than a preset second temperature threshold or the third temperature difference is larger than a preset third temperature threshold; (2) And in an unheated state, calculating the second temperature difference, and continuously heating the battery when the second temperature difference is smaller than a preset fourth temperature threshold value. Further, the calculating a first temperature difference between the focus point temperature value and the heat dissipation point temperature value includes: Calculating the first temperature difference according to the formula: Td1＝Th1-Th2, Wherein Td 1 is the first temperature difference, th 1 is the heat-collecting point temperature value, and Th 2 is the heat-dissipating point temperature value. Further, the calculating a second temperature difference between the heat sink temperature value and the lowest temperature value includes: Td2＝Th2-Th3, Wherein Td 2 is the second temperature difference, th 2 is the heat dissipation point temperature value, and Th 3 is the minimum temperature value. Further, the calculating a third temperature difference between the heat sink temperature value and the heat focus temperature value includes: Td3＝Th2-Th1, Wherein Td 3 is the third temperature difference, th 2 is the heat sink temperature value, and Th 1 is the heat focusing point temperature value. Further, the value range of the first temperature threshold is 1-4 ℃, the value range of the second temperature threshold is 2-8 ℃, the value range of the third temperature threshold is 0-8 ℃, the value range of the fourth temperature threshold is-2 ℃, and the value range of the cut-off temperature value is-15-10 ℃. Further, the value range of the preset duration is 10 hours to 20 hours. Further, the method further compri