Battery temperature control method and system

Abstract

The application discloses a battery temperature control method and system, the method comprises the following steps: obtaining the heat gathering point temperature value and the heat dissipation point temperature value of the battery, calculating the first temperature difference between the two, heating the battery when the first temperature difference is greater than the first temperature threshold, and starting the timer; obtaining the lowest temperature value of the battery, and performing the following loop operation until the heat dissipation point temperature value is greater than the cut-off temperature value or the timer reaches the preset time length: in the heating state, calculating the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculating the third temperature difference between the heat dissipation point temperature value and the heat gathering point temperature value, stopping heating when the second temperature difference is greater than the second temperature threshold or the third temperature difference is greater than the third temperature threshold; in the non-heating state, calculating the second temperature difference, and continuing heating when the second temperature difference is less than the fourth temperature threshold. The technical scheme provided by the application can solve the technical problem that the temperature difference between different positions of the battery is large in the prior art.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery temperature control method and system. Background Technology

[0002] Batteries are used in various fields and installed in different devices, suitable for a wide range of scenarios. In some special applications, such as in vehicle equipment, battery packs may be exposed to low temperatures for extended periods. When the ambient temperature is too low, the periphery of the battery housing dissipates heat outwards. Inside the housing, the cells at the periphery cool down faster than those at the center, resulting in a significant temperature difference. This large temperature difference can negatively impact the overall cycle performance of the battery system.

[0003] When the cell temperature drops too quickly in the surrounding area, the battery's heat preservation performance is low. When the vehicle is used again after a long period of time, it takes a certain amount of time to heat up the battery, which affects the convenience of vehicle use and reduces the user experience.

[0004] In existing technologies, battery systems typically heat or cool the entire system, which results in a large temperature difference during the heating or cooling process. Therefore, heating through an overall heating system cannot effectively reduce the temperature difference and results in significant energy consumption. Summary of the Invention

[0005] This invention provides a battery temperature control method and system, which aims to effectively solve the technical problem of large temperature differences between different parts of the battery in the prior art.

[0006] According to one aspect of the present invention, a battery temperature control method is provided, the method comprising:

[0007] The temperature values ​​of the hot spot and the heat dissipation point of the heat-collecting area of ​​the battery are obtained. A first temperature difference between the hot spot temperature value and the heat dissipation point temperature value is calculated. When the first temperature difference is greater than a preset first temperature threshold, the battery is heated in a preset heating area and a timer is started.

[0008] The lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point are acquired in real time, and the following cyclic operation is performed until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration:

[0009] (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery.

[0010] (2) In the unheated state, calculate the second temperature difference. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery.

[0011] Further, calculating the first temperature difference between the temperature value of the hot spot and the temperature value of the heat dissipation point includes:

[0012] The first temperature difference is calculated using the following formula:

[0013] Td1 = Th1 - Th2,

[0014] Wherein, Td1 is the first temperature difference, Th1 is the temperature value of the hot spot, and Th2 is the temperature value of the heat dissipation point.

[0015] Further, calculating the second temperature difference between the heat dissipation point temperature value and the lowest temperature value includes:

[0016] Td2 = Th2 - Th3,

[0017] Wherein, Td2 is the second temperature difference, Th2 is the temperature value of the heat dissipation point, and Th3 is the lowest temperature value.

[0018] Further, calculating the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value includes:

[0019] Td3 = Th2 - Th1,

[0020] Wherein, Td3 is the third temperature difference, Th2 is the temperature value of the heat dissipation point, and Th1 is the temperature value of the hot spot.

[0021] Furthermore, the first temperature threshold ranges from 1℃ to 4℃, the second temperature threshold ranges from 2℃ to 8℃, the third temperature threshold ranges from 0℃ to 8℃, the fourth temperature threshold ranges from -2℃ to 2℃, and the cutoff temperature ranges from -15℃ to 10℃.

[0022] Furthermore, the preset duration ranges from 10 hours to 20 hours.

[0023] Furthermore, the method also includes:

[0024] After acquiring the lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point in real time, if the first temperature difference is less than the cutoff temperature value and the lowest temperature value is also less than the cutoff temperature value, then heating the battery is stopped.

[0025] According to another aspect of the present invention, the present invention also provides a battery temperature control system, the system comprising:

[0026] The battery has multiple cells, and the area corresponding to each cell is divided into a heat-collecting area, a heat-dissipating area, and a transition area, wherein the heat-dissipating area includes a heating area.

[0027] A heating unit is disposed in the heating area;

[0028] The sensor unit is used to acquire the temperature values ​​of the hot spots in the heat-gathering region and the temperature values ​​of the heat dissipation points in the heat dissipation region, as well as to acquire the lowest temperature value of the low-temperature region of the battery in real time.

[0029] Control unit, the control unit is used for:

[0030] Calculate the first temperature difference between the temperature value of the hot spot and the temperature value of the heat dissipation point. When the first temperature difference is greater than a preset first temperature threshold, heat the battery in a preset heating area and start a timer.

[0031] The following loop operation is performed until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration:

[0032] (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery.

[0033] (2) In the unheated state, calculate the second temperature difference. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery.

[0034] Furthermore, different positions of the heating unit have different heat generation power densities, wherein the heat generation power density gradually decreases in the first direction from the heat dissipation area to the heat accumulation area.

[0035] Furthermore, the heating unit is one or more of an infrared heating element, a PTC heater, a PI heating film, or a silicone rubber heating film.

[0036] Furthermore, the plurality of battery cells are arranged parallel to each other in the first direction, and the heating unit is disposed on the side of the battery cell away from the heat-gathering area.

[0037] Through one or more embodiments of the above embodiments of the present invention, at least the following technical effects can be achieved:

[0038] In the technical solution disclosed in this invention, the edge heat dissipation area of ​​the battery is directionally heated. This heating strategy reduces the temperature difference between different battery cells, extends the heat preservation time, and ensures ease of use in low-temperature conditions. Active heating slows down the cooling rate of the battery system and extends the heat preservation time. Active edge heating achieves internal temperature uniformity within the battery system, and intermittent heating reduces energy consumption. Attached Figure Description

[0039] The technical solution and other beneficial effects of the present invention will become apparent from the following detailed description of specific embodiments of the invention, in conjunction with the accompanying drawings.

[0040] Figure 1 A flowchart illustrating the steps of a battery temperature control method provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of different regions of a battery provided in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of a battery temperature control system provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the heating power density of a heating unit provided in an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of a battery provided in an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the installation of a heating unit provided in an embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0048] Figure 1 The diagram shows a flowchart of the battery temperature control method provided in an embodiment of the present invention. According to one aspect of the present invention, a battery temperature control method is provided, the method comprising:

[0049] Step 101: Obtain the temperature value of the hot spot in the heat-collecting area and the temperature value of the heat dissipation point in the heat dissipation area of ​​the battery, calculate the first temperature difference between the hot spot temperature value and the heat dissipation point temperature value, and when the first temperature difference is greater than a preset first temperature threshold, heat the battery in the preset heating area and start the timer.

[0050] Step 102: Real-time acquisition of the lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point, and execution of the following cyclic operation until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration:

[0051] (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery.

[0052] (2) In the unheated state, calculate the second temperature difference. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery.

[0053] The steps described above are described in detail below.

[0054] In step 101 above, the temperature values ​​of the hot spot and the heat dissipation point of the heat-collecting area of ​​the battery are obtained, and the first temperature difference between the hot spot temperature value and the heat dissipation point temperature value is calculated. When the first temperature difference is greater than a preset first temperature threshold, the battery is heated in the preset heating area and a timer is started.

[0055] For example, the battery system has several cells arranged and electrically connected inside, wherein the cell area is virtually divided into several regions. Figure 2This is a schematic diagram of different regions of a battery according to an embodiment of the present invention. When the battery is in a low-temperature environment, the periphery of the battery housing dissipates heat outwards, and the temperature of the battery cells in the periphery decreases faster; therefore, the periphery of the battery is a heat dissipation area. Inside the housing, the temperature of the battery cells in the center decreases more slowly, and the cells tend to accumulate heat; therefore, the center is a heat accumulation area. The area between the heat dissipation area and the heat accumulation area is a transition area.

[0056] A significant temperature difference exists between the heat dissipation area and the heat accumulation area due to their different temperatures, and this large temperature difference can adversely affect the overall cycle performance of the battery system. The battery system has several temperature monitoring points. It is necessary to select the hottest points in the heat accumulation area and obtain their corresponding temperature values ​​using multiple temperature sensors. Similarly, several heat dissipation points are identified in the heat dissipation area, and their corresponding temperature values ​​are obtained using multiple temperature sensors. Then, the initial temperature difference between the two is calculated. When the temperature difference is too large, the battery is heated. One or more temperature sensors can be used at different locations; multiple sensors are used to ensure system reliability and avoid erroneous data acquisition due to a single abnormal temperature sensor.

[0057] In addition to determining whether to heat the battery based on the temperature difference, the system also determines whether to stop heating based on the temperature control time. Therefore, when the battery is in heating mode, a timer is started simultaneously.

[0058] In step 102 above, the lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point are acquired in real time, and the following cyclic operation is performed until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration:

[0059] (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery.

[0060] (2) In the unheated state, calculate the second temperature difference. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery.

[0061] For example, after the battery is heated, the heat dissipation point that was originally the lowest temperature is now equipped with a heating element, so it is no longer the lowest temperature point. The area that is still at the edge of the battery but does not have a heating element becomes the lowest temperature point. Therefore, during the temperature control process, it is also necessary to obtain the lowest temperature value.

[0062] During the heating process, the initially lowest heat dissipation point continues to heat up, eventually exceeding the temperature of the hot spot. Heating the battery needs to be temporarily stopped in two situations: First, if there is a reverse temperature difference between the heat dissipation point and the hot spot, and this difference exceeds a threshold, then heating should be stopped. Second, if the difference between the heat dissipation point temperature and the lowest temperature exceeds a threshold, heating should also be stopped.

[0063] After heating stops, the heat from the heat dissipation point diffuses outwards, causing the transition and heat accumulation areas to heat up. Simultaneously, the temperature of the heat dissipation point drops rapidly. When the second temperature difference is detected to be below the threshold again, the battery is reheated.

[0064] The heating and stopping process is repeated multiple times until the entire battery pack gradually heats up. When the temperature at the heat dissipation point exceeds the preset cutoff temperature or the timer reaches the preset duration, heating of the battery is stopped, taking priority based on which of the two conditions is met. The entire process achieves temperature control of the battery.

[0065] Further, calculating the first temperature difference between the temperature value of the hot spot and the temperature value of the heat dissipation point includes:

[0066] The first temperature difference is calculated using the following formula:

[0067] Td1 = Th1 - Th2,

[0068] Wherein, Td1 is the first temperature difference, Th1 is the temperature value of the hot spot, and Th2 is the temperature value of the heat dissipation point.

[0069] For example, before the battery is heated, the temperature of the hot spot is higher than the temperature of the heat dissipation point, so the first temperature difference is calculated using this formula.

[0070] Further, calculating the second temperature difference between the heat dissipation point temperature value and the lowest temperature value includes:

[0071] Td2 = Th2 - Th3,

[0072] Wherein, Td2 is the second temperature difference, Th2 is the temperature value of the heat dissipation point, and Th3 is the lowest temperature value.

[0073] For example, after the battery is heated, the heat dissipation point heats up rapidly due to the heating element. Within the heat dissipation area, there are also locations without heating elements, which become the coldest points in the entire battery. Therefore, after heating for a period of time, the temperature of the heat dissipation point is significantly higher than the temperature of the coldest point. Thus, subtracting the coldest point temperature from the heat dissipation point temperature yields the second temperature difference.

[0074] Further, calculating the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value includes:

[0075] Td3 = Th2 - Th1,

[0076] Wherein, Td3 is the third temperature difference, Th2 is the temperature value of the heat dissipation point, and Th1 is the temperature value of the hot spot.

[0077] For example, after the battery is heated, the heat dissipation point heats up rapidly due to the presence of a heating element, while the hot spot, lacking a heating element and located far from it, experiences a significantly higher temperature at the heat dissipation point after a period of heating. Therefore, the third temperature difference is obtained by subtracting the hot spot temperature from the heat dissipation point temperature.

[0078] Furthermore, the first temperature threshold ranges from 1℃ to 4℃, the second temperature threshold ranges from 2℃ to 8℃, the third temperature threshold ranges from 0℃ to 8℃, the fourth temperature threshold ranges from -2℃ to 2℃, and the cutoff temperature ranges from -15℃ to 10℃.

[0079] For example, the range of values ​​for the four temperature thresholds and the cutoff temperature can be used as a reference. In practical applications, they need to be determined according to the specific circumstances, and the present invention does not limit them.

[0080] Furthermore, the preset duration ranges from 10 hours to 20 hours.

[0081] For example, in the solution of the present invention, in order to save energy, temperature control will not be continuously performed. When the timer accumulates to a preset duration, the battery will no longer be heated.

[0082] Furthermore, the method also includes:

[0083] After acquiring the lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point in real time, if the first temperature difference is less than the cutoff temperature value and the lowest temperature value is also less than the cutoff temperature value, then heating the battery is stopped.

[0084] For example, there is another situation where the temperature of the entire battery has dropped below a certain level. In this case, even if the battery temperature is controlled, it will not be effective. Therefore, after heating the battery for a period of time, if the first temperature difference is less than the cutoff temperature value and the lowest temperature value is also less than the cutoff temperature value, the heating of the battery is abandoned directly.

[0085] Example 1

[0086] Assuming the battery system is set with a first temperature threshold of 2℃, a second temperature threshold of 5℃, a third temperature threshold of TD3 = 1℃, a cutoff temperature of 0℃, and a preset duration of 10h, the battery temperature control process is described below.

[0087] After the active heating mechanism is activated, the system cools naturally. When the maximum temperature difference of the system reaches 2°C, the heating function is activated. When the system reaches the set cutoff temperature or a preset time, if the temperature of the heat dissipation point exceeds the lowest temperature value (second lowest temperature point) of the system during heating, and the temperature difference between the two reaches 5°C, heating is stopped and the system cools naturally. When the system detects that the temperature at the heat dissipation point has dropped back to near the lowest temperature value, the system restarts heating, and this cycle continues until the temperature reaches the set cutoff temperature value of 0°C or the time reaches 10 hours.

[0088] The active heating mechanism can be activated or deactivated by the vehicle user through a human-machine interface, such as the instrument panel or a smart terminal. It can also be activated via pre-defined rules in the vehicle management system or battery management system, such as activating the temperature control program when the ambient temperature is below 0°C or below 10°C.

[0089] Through one or more embodiments of the above embodiments of the present invention, at least the following technical effects can be achieved:

[0090] In the technical solution disclosed in this invention, the edge heat dissipation area of ​​the battery is directionally heated. This heating strategy reduces the temperature difference between different battery cells, extends the heat preservation time, and ensures ease of use in low-temperature conditions. Active heating slows down the cooling rate of the battery system and extends the heat preservation time. Active edge heating achieves internal temperature uniformity within the battery system, and intermittent heating reduces energy consumption.

[0091] Based on the same inventive concept as the battery temperature control method in this embodiment of the invention, this embodiment of the invention provides a battery temperature control system. Please refer to... Figure 3 The system includes:

[0092] Battery 201 has multiple cells, and the area corresponding to each cell is divided into a heat dissipation area 10, a heat accumulation area 20 and a transition area 30. The heat dissipation area 10 includes a heating area.

[0093] Heating unit 202, wherein the heating unit 202 is disposed in the heating area;

[0094] Sensor unit 203 is used to acquire the temperature value of the hot spot of the heat-gathering region 20 and the temperature value of the heat dissipation point of the heat dissipation region 10, and to acquire the lowest temperature value of the low temperature region of the battery 201 in real time.

[0095] Control unit 204, the control unit 204 being used for:

[0096] Calculate the first temperature difference between the temperature value of the hot spot and the temperature value of the heat dissipation point. When the first temperature difference is greater than a preset first temperature threshold, heat the battery 201 in a preset heating area and start a timer.

[0097] The following loop operation is performed until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration:

[0098] (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery 201.

[0099] (2) In the unheated state, calculate the second temperature difference. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery 201.

[0100] For example, the system includes a battery 201, with a plurality of cells arranged and electrically connected inside the battery frame 40. The cell area is virtually divided into a heat dissipation area 10, a heat accumulation area 20 and a transition area 30. The heat dissipation area 10 has a heat dissipation point 11 and a minimum temperature point 12. The heat accumulation area 20 has a heat accumulation point 21. The heat dissipation area 10 includes a heating area.

[0101] The heating unit 202 adopts a low heating power design, with an average heating power of less than 800W per square meter. In order to achieve the technical effect of this solution and save energy, a heating power of less than 400W per square meter is preferred.

[0102] Furthermore, different positions of the heating unit 202 have different heat generation power densities, wherein the heat generation power density gradually decreases in the first direction from the heat dissipation area 10 to the heat accumulation area 20.

[0103] For example, Figure 4 This is a schematic diagram of the heating power density of a heating unit 202 provided in an embodiment of the present invention, as shown below. Figure 4As shown, heating unit 202 adopts a non-uniform heating power density design, with the heating power density near the lowest temperature point of natural cooling being higher than that at other locations within the same heating unit 202. The temperature distribution in different areas can be obtained through simulation analysis or experimental calibration. Since there may be temperature differences within the same heating unit 202, different heating power densities are set for the heating unit 202.

[0104] Furthermore, the heating unit 202 is one or more of an infrared heating element, a PTC heater, a PI heating film, or a silicone rubber heating film.

[0105] For example, infrared heating has the advantage of achieving good heating results without requiring complete adhesion to the heating surface. Alternatively, a PI heating film or a silicone rubber heating film can be used, achieving temperature increases by tightly adhering to the heated surface. The heating unit 202 can also employ a PTC, where the heating power decreases as the temperature increases.

[0106] Furthermore, the plurality of battery cells are arranged parallel to each other in the first direction, and the heating unit 202 is disposed on the side of the battery cell away from the heat-gathering region 20.

[0107] For example, Figure 5 This is a schematic diagram of a battery provided in an embodiment of the present invention. Figure 6 This is a schematic diagram of the installation of a heating unit provided in an embodiment of the present invention.

[0108] The heating unit 202 is located at the end of each row of cells in the battery 201 system. It can be located between the end cells and the crossbeam or frame, or between several end cells.

[0109] The heating unit 202 is connected to a control switch, such as a relay. The battery management system 201 controls the working state of the heating unit 202 by controlling the on / off state of the switch connected to the heating unit 202.

[0110] Other aspects and implementation details of the battery temperature control system are the same as or similar to the battery temperature control method described above, and will not be repeated here.

[0111] According to another aspect of the invention, the invention also provides a storage medium storing a plurality of instructions adapted to be loaded by a processor to execute any of the battery temperature control methods described above.

[0112] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A battery temperature control method, characterized in that, The method includes: The temperature values ​​of the hot spot and the heat dissipation point of the heat-collecting area of ​​the battery are obtained. A first temperature difference between the hot spot temperature value and the heat dissipation point temperature value is calculated. When the first temperature difference is greater than a preset first temperature threshold, the battery is heated in a preset heating area and a timer is started. The battery has multiple cells, and the area corresponding to each cell is divided into a heat-collecting area, a heat dissipation area, and a transition area. The heat dissipation area includes the heating area. The lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point are acquired in real time, and the following cyclic operation is performed until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration: (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery. (2) Calculate the second temperature difference in the unheated state. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery.

2. The method as described in claim 1, characterized in that, The calculation of the first temperature difference between the temperature value of the hot spot and the temperature value of the heat dissipation point includes: The first temperature difference is calculated using the following formula: Td1 = Th1 - Th2, Wherein, Td1 is the first temperature difference, Th1 is the temperature value of the hot spot, and Th2 is the temperature value of the heat dissipation point.

3. The method as described in claim 1, characterized in that, The calculation of the second temperature difference between the heat dissipation point temperature value and the lowest temperature value includes: Td2 = Th2 - Th3, Wherein, Td2 is the second temperature difference, Th2 is the temperature value of the heat dissipation point, and Th3 is the lowest temperature value.

4. The method as described in claim 1, characterized in that, The calculation of the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value includes: Td3 = Th2 - Th1, Wherein, Td3 is the third temperature difference, Th2 is the temperature value of the heat dissipation point, and Th1 is the temperature value of the hot spot.

5. The method as described in claim 1, characterized in that, The first temperature threshold ranges from 1℃ to 4℃, the second temperature threshold ranges from 2℃ to 8℃, the third temperature threshold ranges from 0℃ to 8℃, the fourth temperature threshold ranges from -2℃ to 2℃, and the cutoff temperature ranges from -15℃ to 10℃.

6. The method as described in claim 1, characterized in that, The preset duration ranges from 10 hours to 20 hours.

7. The method as described in claim 1, characterized in that, The method further includes: After acquiring the lowest temperature value of the low-temperature region of the battery, the temperature value of the hot spot, and the temperature value of the heat dissipation point in real time, if the first temperature difference is less than the cutoff temperature value and the lowest temperature value is also less than the cutoff temperature value, then heating the battery is stopped.

8. A battery temperature control system, characterized in that, The system includes: The battery has multiple cells, and the area corresponding to each cell is divided into a heat-collecting area, a heat-dissipating area, and a transition area, wherein the heat-dissipating area includes a heating area. A heating unit is disposed in the heating area; The sensor unit is used to acquire the temperature values ​​of the hot spots in the heat-gathering region and the temperature values ​​of the heat dissipation points in the heat dissipation region, as well as to acquire the lowest temperature value of the low-temperature region of the battery in real time. Control unit, the control unit is used for: Calculate the first temperature difference between the temperature value of the hot spot and the temperature value of the heat dissipation point. When the first temperature difference is greater than a preset first temperature threshold, heat the battery in a preset heating area and start a timer. The following loop operation is performed until the temperature value of the heat dissipation point is greater than the preset cutoff temperature value or the time corresponding to the timer reaches the preset duration: (1) In the heating state, calculate the second temperature difference between the heat dissipation point temperature value and the lowest temperature value, and calculate the third temperature difference between the heat dissipation point temperature value and the hot spot temperature value. When the second temperature difference is greater than the preset second temperature threshold or the third temperature difference is greater than the preset third temperature threshold, stop heating the battery. (2) Calculate the second temperature difference in the unheated state. When the second temperature difference is less than the preset fourth temperature threshold, continue to heat the battery.

9. The system as described in claim 8, characterized in that, The heating unit has different heating power densities at different locations, wherein the heating power density gradually decreases in the first direction from the heat dissipation area to the heat concentration area.

10. The system as described in claim 9, characterized in that, The heating unit is one or more of an infrared heating element, a PTC heater, a PI heating film, or a silicone rubber heating film.

11. The system as claimed in claim 10, characterized in that, The plurality of battery cells are arranged parallel to each other in the first direction, and the heating unit is disposed on the side of the battery cell away from the heat-gathering area.

Images