Temperature correction method of battery pack, energy storage power supply and storage medium

Abstract

The invention discloses a temperature correction method of a battery pack, an energy storage power supply and a storage medium. The battery pack comprises a plurality of battery cells, the plurality of battery cells comprise a first battery cell and a second battery cell, the second battery cell is closer to the interior of the battery pack than the first battery cell, and a temperature sensor is arranged on the first battery cell; the temperature correction method comprises the following steps: acquiring an environment temperature, charging and discharging time of a battery pack, a first temperature output by a built-in temperature sensor and heating power consumption of a second battery cell; and correcting the first temperature by using the environment temperature, the charging and discharging time of the battery pack and the heating power consumption of the second battery cell to obtain a second temperature of the second battery cell. According to the temperature correction method, the timeliness and the accuracy of temperature protection measures can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage power supplies, and in particular to a temperature correction method for a battery pack, an energy storage power supply and a storage medium. Background Art

[0002] In the related art, after the battery pack is grouped, the internal cell temperature cannot be collected, and only the outer cell temperature can be collected. However, there is a certain temperature difference between the outer cell temperature and the internal cell temperature, which will cause the battery pack's protection measures based on temperature judgment to deviate and fail to provide timely protection. Summary of the invention

[0003] The embodiments of the present invention provide a temperature correction method, an energy storage power supply and a storage medium to solve at least one of the above-mentioned technical problems.

[0004] An embodiment of the present invention provides a temperature correction method for a battery pack, wherein the battery pack includes a plurality of battery cells, wherein the plurality of battery cells include a first battery cell and a second battery cell, wherein the second battery cell is closer to the inside of the battery pack than the first battery cell, and a built-in temperature sensor is arranged on the first battery cell, and the temperature correction method includes:

[0005] Acquire the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, and the heat consumption of the second battery cell;

[0006] The first temperature is corrected by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain a second temperature of the second battery cell.

[0007] In the above-mentioned temperature correction method, the first temperature of the outer first battery cell can be corrected by using the ambient temperature, the charging and discharging time of the battery pack and the heat power consumption of the second battery cell, so as to obtain the second temperature of the inner second battery cell, thereby obtaining a more accurate temperature of the battery pack, which is beneficial to improving the timeliness and accuracy of temperature protection measures.

[0008] In some embodiments, the second battery cell is obtained by arranging a calibrated temperature sensor on each of the battery cells, and determining the battery cell corresponding to the highest temperature from all temperatures output by all the calibrated temperature sensors.

[0009] In some embodiments, the first battery cell and the second battery cell are two adjacent battery cells.

[0010] In some embodiments, the plurality of battery cells include a third battery cell, the third battery cell being adjacently located between the first battery cell and the second battery cell;

[0011] Acquiring the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, and the heat consumption of the second battery cell includes:

[0012] Acquire the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, the heat power consumption of the second battery cell, and the heat power consumption of the third battery cell;

[0013] Correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell includes:

[0014] Correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the third battery cell to obtain a third temperature of the third battery cell;

[0015] The third temperature is corrected by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell.

[0016] In some embodiments, correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the third battery cell to obtain the third temperature of the third battery cell includes:

[0017] The third temperature is obtained according to a first preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack, the heat generation and power consumption of the third battery cell and the first temperature. The first preset mapping relationship is a mapping relationship in which the third temperature of the third battery cell changes with the charge and discharge time.

[0018] Correcting the third temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell includes:

[0019] The second temperature is obtained according to a second preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack, the heat generation and power consumption of the second battery cell and the third temperature. The second preset mapping relationship is a mapping relationship in which the second temperature of the second battery cell changes with the charge and discharge time.

[0020] In some embodiments, the heat consumption is determined by collecting the current of the corresponding battery cell.

[0021] In some embodiments, correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell includes:

[0022] The second temperature is obtained according to a third preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack, the heat generation and power consumption of the second battery cell and the first temperature. The third preset mapping relationship is a mapping relationship in which the second temperature of the second battery cell changes with the charge and discharge time.

[0023] In some embodiments, the preset mapping relationship is obtained by performing partial differential equation calculation using the thermal balance equation of two adjacent battery cells.

[0024] In certain embodiments, the heat balance equation is related to natural convection, convective heat transfer between two battery cells, and radiative heat transfer.

[0025] An energy storage power supply in an embodiment of the present invention includes: a control component, a battery pack and an inverter, the battery pack is electrically connected to the control component and the inverter, the control component includes a processor and a memory, the memory stores a computer program, and when the computer program is executed by the processor, the steps of the temperature correction method described in any of the above embodiments are implemented.

[0026] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by the processor, the steps of the temperature correction method of any of the above embodiments are implemented.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figures 1 to 4 is a schematic flow chart of a temperature correction method according to an embodiment of the present invention;

[0030] Figure 5 is a schematic structural diagram of a battery pack in a group according to an embodiment of the present invention;

[0031] Figure 6 is a schematic structural diagram of an ungrouped battery pack according to an embodiment of the present invention;

[0032] Figure 7 Another structural schematic diagram of an ungrouped battery pack according to an embodiment of the present invention

[0033] Figure 8 is a schematic diagram of a module of an energy storage power supply according to an embodiment of the present invention;

[0034] Fig. 9is a line graph of the temperature output by the calibration sensor under different working conditions according to the embodiment of the present invention;

[0035] Fig.10 It is a line graph of the temperatures output by the built-in temperature sensor of the embodiment of the present invention and the calibration sensor corresponding to the battery cell with the highest temperature under different working conditions.

[0036] Description of main component symbols:

[0037] Energy storage power source 1, control component 2, memory 21, processor 22, battery pack 3, first battery cell 31, second battery cell 32, third battery cell 33, bus 34. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of the present invention, and cannot be understood as limiting the embodiments of the present invention.

[0039] See also Figure 1 and Figure 5 The embodiment of the present invention provides a temperature correction method for a battery pack 3, wherein the battery pack 3 includes a plurality of battery cells, wherein the plurality of battery cells include a first battery cell 31 and a second battery cell 32, wherein the second battery cell 32 is closer to the inside of the battery pack 3 than the first battery cell 31, and a built-in temperature sensor is arranged on the first battery cell 31, and the temperature correction method includes:

[0040] Step S01, obtaining the ambient temperature, the charge and discharge time of the battery pack 3, the first temperature output by the built-in temperature sensor, and the heat consumption of the second battery cell 32;

[0041] Step S03 , correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack 3 , and the heat generation and power consumption of the second battery cell 32 to obtain a second temperature of the second battery cell 32 .

[0042] Specifically, the battery pack 3 may be the core energy storage component in the energy storage power supply 1. In the energy storage power supply 1, the battery pack 3 is responsible for storing electrical energy and outputting electrical energy to external devices when needed. The battery pack 3 includes a battery management system and multiple battery cells. The battery management system is used to monitor and manage the status of each battery cell in the battery pack 3, including voltage, current, temperature, etc., to ensure the safe operation and performance optimization of the battery pack 3. Multiple battery cells may be connected in series, in parallel, or in hybrid connection, where hybrid connection means that multiple battery cells are connected in series and in parallel.

[0043] Please combine Figure 5 , Figure 5A schematic diagram of the structure of a grouped battery pack 3 is shown, in which the battery cells are welded into a group through a bus 34. In the energy storage power supply 1, the energy storage power supply 1 is usually equipped with a built-in temperature sensor for monitoring the temperature of the battery pack 3. However, due to the limited internal space of the battery pack 3 after the battery pack 3 is grouped, and the limitations of the assembly process, it is difficult to install the built-in temperature sensor on the surface of each battery cell inside the battery pack 3. For this reason, the built-in temperature sensor is usually installed on the surface of the battery cell close to the outside of the battery pack 3, resulting in the built-in temperature sensor being able to collect only the temperature data of the outer battery cell, while the temperature of the internal battery cell cannot be directly detected, resulting in deviations in the protection measures taken by the battery management system based on the data (first temperature) collected by the built-in temperature sensor.

[0044] In addition, during the operation of the energy storage power source 1, heat is accumulated as time goes by, and Joule heat and heat exchange phenomena occur. The heat exchange is mainly carried out by convection heat transfer and radiation heat transfer. Therefore, it is necessary to comprehensively consider the heat transfer between the ambient air and the battery cell, the heat generated by the battery cell itself, the charging and discharging time, and the influence of the external battery cell on the temperature of the internal battery cell.

[0045] In the embodiment of the present invention, the first battery cell 31 refers to the battery cell located outside the battery pack 3, and the second battery cell 32 refers to the target battery cell located inside the battery pack 3. During the operation of the energy storage power supply 1, the energy storage power supply 1 can use the ambient temperature, the charge and discharge time of the battery pack 3, and the heat power consumption of the second battery cell 32 to correct the first temperature to obtain the second temperature of the second battery cell 32, that is, to obtain the temperature of the internal battery cell.

[0046] The energy storage power supply 1 may include an ambient temperature sensor for real-time monitoring of the ambient temperature. The battery management system may record and calculate the start and end time of charging and discharging of the energy storage power supply 1, thereby obtaining the charging and discharging time of the battery pack 3. The first temperature of the first battery cell 31 may be obtained by a built-in temperature sensor. The battery management system may detect the current of the second battery cell 32, and obtain the heat power consumption of the second battery cell 32 through the current-power consumption curve.

[0047] In the above-mentioned temperature correction method, the first temperature of the outer first battery cell 31 can be corrected by utilizing the ambient temperature, the charging and discharging time of the battery pack 3 and the heat consumption of the second battery cell 32, so as to obtain the second temperature of the inner second battery cell 32, thereby obtaining a more accurate temperature of the battery pack 3, which is beneficial to improving the timeliness and accuracy of the temperature protection measures.

[0048] In some embodiments, the second battery cell 32 is obtained by arranging a calibrated temperature sensor on each battery cell and determining the battery cell corresponding to the highest temperature from all temperatures output by all calibrated temperature sensors.

[0049] Specifically, please combine Figure 6 , Figure 6 The schematic diagram of the structure of the ungrouped battery pack 3 is shown, and the cells are not welded to form a group through the busbar 34. Portable energy storage power sources are mostly air-cooled, and the air-cooling heat dissipation capacity is limited. Therefore, the heat accumulation of the cells in the middle area is more serious, resulting in the cells in the middle area generally having a higher temperature and the outer cells having a lower temperature.

[0050] It is understandable that the temperature of the battery cells in the center area is higher, and the temperature of the outer battery cells is lower. When the temperature of the battery cells in the center area has reached the threshold where temperature control measures need to be taken, if temperature control measures are taken based on the output data of the built-in sensor, it may lead to untimely temperature control measures, causing the battery cells in the center area to be at risk of thermal runaway. Therefore, in an embodiment of the present invention, it is determined that the battery cell with the highest temperature under different operating conditions is the second battery cell 32, that is, the target battery cell, so that the temperature correction method in the embodiment of the present invention can be used to correct the first temperature of the first battery cell 31 to obtain the second temperature of the second battery cell 32, which is beneficial to the timeliness of temperature control measures.

[0051] Please combine Fig. 9 and Fig.10 Before the battery pack 3 is grouped, calibrated temperature sensors are set on all battery cells, and the temperature of each battery cell is measured at different ambient temperatures and different charge and discharge times, so as to determine that the battery cell with the highest temperature at different ambient temperatures and different charge and discharge times is the second battery cell 32.

[0052] It is understandable that after the second battery cell 32 is determined, the difference ΔT1 between the temperature of the first battery cell 31 and the temperature of the second battery cell 32 under different ambient temperatures and different charge and discharge times can be obtained.

[0053] It is understandable that the second temperature of the second battery cell 32 can be acquired in step S03 , so that the difference ΔT2 between the first temperature of the first battery cell 31 and the second temperature of the second battery cell 32 can be acquired.

[0054] It is understandable that ΔT1 is obtained by directly measuring the temperatures of the first battery cell 31 and the second battery cell 32 using a calibration sensor, and ΔT2 is obtained by directly measuring the first temperature of the first battery cell 31 and the second temperature of the second battery cell 32 obtained in step S03 using a built-in temperature sensor.

[0055] Optionally, when determining the cell corresponding to the highest temperature from all the temperatures output by all the calibrated temperature sensors to obtain ΔT1, the first temperature of the first cell 31 and the second temperature of the second cell 32 obtained in step S03 can be directly measured according to the built-in temperature sensor to obtain ΔT2, and ΔT1 can be used to evaluate the reliability of ΔT2, thereby evaluating the reliability of step S03 in the embodiment of the present invention. Exemplarily, by comparing ΔT1 and ΔT2, if the difference between ΔT1 and ΔT2 is within the expected range, ΔT2 has a higher reliability, that is, step S03 in the embodiment of the present invention has a higher reliability.

[0056] In the above embodiment, by arranging the calibration sensor when the battery pack 3 is not grouped, it can be effectively determined that the battery cell with the highest temperature under different working conditions is the second battery cell 32 .

[0057] In some embodiments, please combine Figures 5 and 6 , the first battery cell 31 and the second battery cell 32 are two adjacent battery cells.

[0058] Specifically, in the embodiment of the present invention, the first battery cell 31 and the second battery cell 32 may be adjacent to each other left and right, adjacent to each other up and down, or adjacent to each other diagonally. The first battery cell 31 is located outside the battery pack 3. The first battery cell 31 is provided with a built-in temperature sensor. The temperature data output by the built-in temperature sensor can reflect the temperature of the first battery cell 31, that is, the first temperature. During the operation of the energy storage power supply 1, the charge and discharge time of the battery pack 3 can be obtained, and the current of the second battery cell 32 can be detected to determine the heat power consumption of the second battery cell 32, and the ambient temperature can be obtained through the ambient temperature sensor, so that the first temperature can be corrected using the ambient temperature, the charge and discharge time of the battery pack 3, and the heat power consumption of the second battery cell 32 to obtain the second temperature of the second battery cell 32.

[0059] In the above embodiment, the first battery cell 31 is adjacent to the second battery cell 32 , so that the first temperature output by the built-in temperature sensor can be corrected based on the heat transfer relationship between the environment and the first battery cell 31 and the heat transfer relationship between the first battery cell 31 and the second battery cell 32 to obtain the second temperature of the second battery cell 32 .

[0060] In some embodiments, please combine Figure 2 and Figure 7 , the plurality of battery cells include a third battery cell 33, and the third battery cell 33 is adjacently located between the first battery cell 31 and the second battery cell 32;

[0061] Step S01 includes:

[0062] Step S011, obtaining the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, the heat power consumption of the second battery cell 3232 and the heat power consumption of the third battery cell 33;

[0063] Step S03 includes:

[0064] Step S031, correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack 3 and the heat generation and power consumption of the third battery cell 33 to obtain a third temperature of the third battery cell 33;

[0065] Step S033 , the third temperature is corrected by using the ambient temperature, the charge and discharge time of the battery pack 3 , and the heat generation and power consumption of the second battery cell 32 to obtain the second temperature of the second battery cell 32 .

[0066] Specifically, the third battery cell 33 is adjacently located between the first battery cell 31 and the second battery cell 32, that is, the first battery cell 31 and the third battery cell 33 are two adjacent battery cells, and the second battery cell 32 and the third battery cell 33 are two adjacent battery cells. The first battery cell 31 and the third battery cell 33 can be adjacent to each other left and right, adjacent to each other up and down, or adjacent to each other diagonally. The third battery cell 33 and the second battery cell 32 can be adjacent to each other left and right, adjacent to each other up and down, or adjacent to each other diagonally.

[0067] In this embodiment, since the first battery cell 31 is not adjacent to the second battery cell 32 , the first battery cell 31 can obtain the second temperature of the second battery cell 32 through the third temperature of the third battery cell 33 adjacent to both the first battery cell 31 and the second battery cell 32 .

[0068] In the embodiment of the present invention, the first battery cell 31 is located outside the battery pack 3, and the second battery cell 32 and the third battery cell 33 are located inside the battery pack 3. The first battery cell 31 is provided with a built-in temperature sensor, and the temperature data output by the built-in temperature sensor can reflect the temperature of the first battery cell 31, that is, the first temperature. During the operation of the energy storage power supply 1, the charge and discharge time of the battery pack 3 can be obtained, and the current of the third battery cell 33 can be detected to determine the heat power consumption of the third battery cell 33, and the ambient temperature can be obtained through the ambient temperature sensor, so that the first temperature can be corrected using the ambient temperature, the charge and discharge time of the battery pack 3 and the heat power consumption of the third battery cell 33 to obtain the third temperature of the third battery cell 33.

[0069] After the third temperature of the third battery cell 33 is obtained, the third temperature may be corrected using the ambient temperature, the charge and discharge time of the battery pack 3 , and the heat generation and power consumption of the second battery cell 32 to obtain the second temperature of the second battery cell 32 .

[0070] In the above embodiment, the first battery cell 31 is adjacent to the third battery cell 33, and the third battery cell 33 is adjacent to the second battery cell 32, so that the first temperature of the first battery cell 3131 can be corrected based on the heat transfer relationship between the environment and the first battery cell 31 and the heat transfer relationship between the first battery cell 31 and the third battery cell 33 to obtain the third temperature of the third battery cell 33, and then the third temperature of the third battery cell 33 can be corrected based on the heat transfer relationship between the environment and the third battery cell 33 and the heat transfer relationship between the third battery cell 33 and the second battery cell 32 to obtain the second temperature of the second battery cell 32.

[0071] It is understandable that the number of the third battery cells 33 can be one or more. When the number of the third battery cells 33 is multiple (such as four: third battery cell a, third battery cell b, third battery cell c, third battery cell d), all the third battery cells 33 are adjacent to each other. After obtaining the third temperature of the third battery cell a adjacent to the first battery cell 31, the third temperature of another third battery cell b adjacent to the third battery cell a is obtained in sequence, until the third temperature of the third battery cell d adjacent to the second battery cell 32 is obtained, and finally the second temperature of the second battery cell 32 is obtained through the third temperature of the third battery cell d.

[0072] In some embodiments, the heat consumption is determined by collecting the current of the corresponding battery cell.

[0073] Specifically, during the operation of the energy storage power supply 1, when current flows through the battery cell, the internal resistance consumes a portion of the electrical energy and converts it into heat energy, thereby causing the temperature of the battery cell to increase.

[0074] The battery management system can collect the current data of the battery cell in real time and obtain the corresponding heat power consumption by comparing the current-power consumption curve. Generally, the greater the heat power consumption, the more heat is generated.

[0075] In the above implementation, the heat power consumption is determined by collecting the current of the corresponding battery cell, which can effectively reflect the heat generation process of the corresponding battery cell itself, thereby improving the reliability of the battery cell temperature determined based on the heat power consumption.

[0076] In some embodiments, please combine Figure 3 , step S031 includes:

[0077] Step S31A, acquiring the third temperature according to the first preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack 3, the heat generation and power consumption of the third battery cell 33, and the first temperature, wherein the first preset mapping relationship is a mapping relationship between the third temperature of the third battery cell 33 and the charge and discharge time;

[0078] Step S033 includes:

[0079] Step S33B, obtaining the second temperature according to the second preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack 3, the heat generation and power consumption of the second battery cell 32 and the third temperature. The second preset mapping relationship is the mapping relationship between the second temperature of the second battery cell 32 and the charge and discharge time.

[0080] Specifically, in the embodiment of the present invention, the energy storage power supply 1 includes a third battery cell 33, and the third battery cell 33 is adjacently located between the first battery cell 31 and the second battery cell 32, that is, the first battery cell 31 is adjacent to the third battery cell 33, and the third battery cell 33 is adjacent to the second battery cell 32. The first preset mapping relationship represents the relationship between the second temperature of the third battery cell 33 and the ambient temperature, the charge and discharge time of the battery pack 3, the heat generation and power consumption of the third battery cell 33, and the first temperature. The second preset mapping relationship represents the relationship between the second temperature of the second battery cell 32 and the ambient temperature, the charge and discharge time of the battery pack 3, the heat generation and power consumption of the second battery cell 32, and the third temperature.

[0081] In the above embodiment, the battery management system can obtain the temperature of the internal battery cell according to the first preset mapping relationship and the second preset mapping relationship, that is, obtain the second temperature of the second battery cell 32, thereby avoiding deviations in the temperature control measures taken by the battery management system based on the first temperature of the first battery cell 31 to a certain extent.

[0082] In some embodiments, please combine Figure 4 , step S03 comprises:

[0083] Step S03C, obtaining the second temperature according to the third preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack 3, the heat generation and power consumption of the second battery cell 32 and the first temperature. The third preset mapping relationship is the mapping relationship between the second temperature of the second battery cell 32 and the charge and discharge time.

[0084] Specifically, in an embodiment of the present invention, the first battery cell 31 and the second battery cell 32 are two adjacent battery cells, and the third preset mapping relationship represents the relationship between the second temperature of the second battery cell 32 and the ambient temperature, the charge and discharge time of the battery pack 3, the heat generation and power consumption of the second battery cell 32 and the first temperature.

[0085] In the above embodiment, the battery management system can obtain the temperature of the internal battery cell according to the third preset mapping relationship, that is, obtain the second temperature of the second battery cell 32, thereby avoiding deviations in the temperature control measures taken by the battery management system based on the first temperature of the first battery cell 31 to a certain extent.

[0086] In some embodiments, the preset mapping relationship is obtained by performing partial differential equation calculation using the thermal balance equation of the thermal balance equation of two adjacent battery cells.

[0087] In the above embodiment, a preset mapping relationship is obtained based on the thermal balance equation of two adjacent battery cells, so that the first temperature of the first battery cell 31 can be corrected according to the preset mapping relationship to obtain the second temperature of the second battery cell 32, thereby avoiding deviations in the temperature control measures taken by the battery management system to a certain extent.

[0088] Specifically, in the embodiment of the present invention, the second battery cell 32 and the first battery cell 31 are two adjacent battery cells.

[0089] First, the thermal balance equation of the second battery cell 32 is as follows:

[0090]

[0091] in, The change rate of the second temperature represents the change of the second temperature of the second battery cell 32 in unit time. A positive value means that the second temperature increases with the charge and discharge time. A negative value means that the second temperature decreases with the charge and discharge time.

[0092] Indicates the temperature change rate caused by the internal heat of the second battery cell 32. It reflects the influence of the heat spontaneously generated by the second battery cell 32 on the temperature. The greater the heat consumption P, the faster the second battery cell 32 heats up.

[0093] This item describes the heat exchange process between the first battery cell 31 and the second battery cell 32. It indicates the temperature change caused by convection heat transfer and radiation heat transfer.

[0094] T represents the second temperature of the second battery cell 32, Tnt represents the first temperature of the first battery cell 31, P represents the heat dissipation of the second battery cell 32, and ρ represents the density of the second battery cell 32 (unit: kilograms per cubic meter, kg / m 3 ), V represents the volume of the second battery cell 32 (unit: cubic meter, m 3 ), c represents the specific heat capacity of the second battery cell 32 (unit: joule per kilogram per Kelvin, J / (kg·K)), Hint represents the heat transfer coefficient between the first battery cell 31 and the second battery cell 32 (unit: watt per square meter per Kelvin, W / (m 2 ·K).

[0095] Secondly, the thermal balance equation of the first battery cell 31 is as follows:

[0096]

[0097] in, The change rate of the first temperature represents the change of the first temperature of the first battery cell 31 within a unit time. A positive value means that the first temperature increases with the charge and discharge time. A negative value means that the first temperature decreases with the charge and discharge time.

[0098] Indicates the temperature change rate caused by the internal heat of the first battery cell 31. It reflects the influence of the heat spontaneously generated by the first battery cell 31 on the temperature. The greater the heat power consumption P, the faster the first battery cell 31 heats up.

[0099] This item describes the heat exchange process between the first battery cell 31 and the environment. It indicates the temperature change caused by convection heat transfer and radiation heat transfer.

[0100] Ta represents the ambient temperature, Tnt represents the first temperature of the first battery cell 31, P represents the heat dissipation of the first battery cell 31, and ρ represents the density of the first battery cell 31 (unit: kilograms per cubic meter, kg / m 3 ), V represents the volume of the first battery cell 31 (unit: cubic meter, m 3 ), c represents the specific heat capacity of the first battery cell 31 (unit: joule per kilogram per Kelvin, J / (kg·K)), Hint represents the heat transfer coefficient between the first battery cell 31 and the second battery cell 32 (unit: watt per square meter per Kelvin, W / (m 2 ·K), H represents the heat exchange coefficient between the first battery cell 31 and the environment.

[0101] In summary, a preset mapping relationship can be obtained by performing partial differential equation calculation according to the thermal balance equation of the second battery cell 32 and the thermal balance equation of the first battery cell 31. The preset mapping relationship is as follows:

[0102]

[0103] Wherein, T(t) represents that the second temperature of the second battery cell 32 changes with the charge and discharge time, C is a constant related to the geometry and fluid properties of the battery cell, and t is the charge and discharge time of the battery pack 3 .

[0104] It should be noted that, in the embodiment of the present invention, the first battery cell 31 and the second battery cell 32 have the same heat consumption P, density ρ, volume V, and specific heat capacity c.

[0105] It should be noted that H can be calculated by the following empirical formula:

[0106] H=C·(Tnt-Ta) n

[0107] Wherein, Ta represents the ambient temperature, Tnt represents the first temperature of the first battery cell 31, and C and n are constants related to the geometry and fluid properties of the battery cell.

[0108] It should be noted that in the embodiment of the present invention, there is air between the battery cells and there is no direct contact. Therefore, the main heat transfer between the first battery cell 31 and the second battery cell 32 is mainly convection heat transfer and radiation heat transfer, wherein the convection heat transfer is mainly natural convection heat transfer. Hint can be calculated by the following formula:

[0109]

[0110] in, represents the convective heat transfer coefficient hconv.

[0111] ∈·σ·(Tint 2 +Text 2 )·(Tint+Text) represents the radiation heat transfer coefficient hrad.

[0112] R represents the gap size between the first battery cell 31 and the second battery cell 32, T represents the second temperature of the second battery cell 32, Tnt represents the first temperature of the first battery cell 31, Kair represents the thermal conductivity of air, ∈ is the emissivity of the battery cell surface (usually between 0.1 and 0.95, depending on the material), σ is the Steffen-Boltzmann constant, σ=5.67×10 -8 W / m 2 ·K 4 , Nu represents the Nusselt number, and the Nusselt number Nu can be calculated by the following formula:

[0113] Nu=C·(Gr·Pr) n

[0114] Where C and n are constants related to the geometry of the cell and the fluid properties, and the Prandtl number Pr = ν / α, where ν is the kinematic viscosity of air and α is the thermal diffusivity of air. g is the acceleration due to gravity, β is the volume expansion coefficient (for air, β≈1 / Ta), and Ta represents the ambient temperature.

[0115] In an example, Nu may be as follows:

[0116]

[0117] It is understandable that in other embodiments, please combine Figure 4 The energy storage power supply 1 includes a third battery cell 33 , and the third battery cell 33 is adjacently located between the first battery cell 31 and the second battery cell 32 .

[0118] Specifically, the preset mapping relationship is as follows:

[0119]

[0120] In step S31A, for the first preset mapping relationship, T represents the third temperature of the third battery cell 33, Tnt represents the first temperature of the first battery cell 31, P represents the heating power of the third battery cell 33, Hint represents the heat exchange coefficient between the third battery cell 33 and the first battery cell 31, t represents the charge and discharge time, and ρ represents the density of the third battery cell 33 (unit: kilograms per cubic meter, kg / m 3 ), V represents the volume of the third battery cell 33 (unit: cubic meter, m 3 ), c represents the specific heat capacity of the third battery cell 33 (unit: joule per kilogram per Kelvin, J / (kg·K)).

[0121] In step S33B, for the second preset mapping relationship, T represents the second temperature of the second battery cell 32, Tnt represents the second temperature of the second battery cell 32, P represents the heating power of the second battery cell 32, Hint represents the heat exchange coefficient between the second battery cell 32 and the third battery cell 33, t represents the charge and discharge time, and ρ represents the density of the second battery cell 32 (unit: kilograms per cubic meter, kg / m 3 ), V represents the volume of the second battery cell 32 (unit: cubic meter, m 3 ), c represents the specific heat capacity of the second battery cell 32 (unit: joule per kilogram per Kelvin, J / (kg·K)).

[0122] It should be noted that, in the embodiment of the present invention, the first battery cell 31 , the second battery cell 32 and the third battery cell 33 have the same heating power, density, specific heat capacity and volume.

[0123] It can be understood that the preset mapping relationship can map the temperature relationship between two adjacent battery cells. When the first battery cell 31 is adjacent to the second battery cell 32, the second temperature of the second battery cell 32 can be directly obtained through the first temperature of the first battery cell 31 and the preset mapping relationship; when the energy storage power supply 1 includes a third battery cell 33, and the third battery cell 33 is adjacent to the first battery cell 31 and the second battery cell 32, it is necessary to first obtain the third temperature of the third battery cell 33 through the first temperature of the first battery cell 31 and the preset mapping relationship, and then obtain the second temperature of the second battery cell 32 through the third temperature of the third battery cell 33 and the preset mapping relationship.

[0124] It is understandable that, in an optional embodiment, the temperature data of all the cells in the battery pack 3 can be iterated in sequence starting from the outer cells of the battery pack 3, that is, starting from the cells with their own temperature sensors, according to the preset mapping relationship in the embodiment of the present invention, so as to be more flexibly adapted to different scenarios. For example, under extreme or special working conditions, there is a situation where the temperature of the internal cells is low and the temperature of the outer cells is high. After the temperatures of all the cells are iterated in sequence according to the preset mapping relationship, appropriate temperature control measures are selected according to the temperature data of all the cells.

[0125] In certain embodiments, the heat balance equation relates to natural convection, convective heat transfer between two cells, and radiative heat transfer.

[0126] Specifically, during the operation of the energy storage power supply 1, there is heat exchange between the environment and the cells on the outside of the battery pack 3, and there is heat exchange between the cells in the battery pack 3. The exchange mechanism between the environment and the cells on the outside of the battery pack 3 is mainly natural convection.

[0127] In the embodiment of the present invention, heat is mainly transferred between the battery cells by air without direct contact. Therefore, the exchange mechanism between the battery cells is mainly convective heat transfer and radiative heat transfer, and the convective heat transfer is mainly natural convection.

[0128] In the above implementation, the heat balance equation is designed by comprehensively considering natural convection, convective heat transfer between two battery cells and radiation heat transfer, and the internal battery cell is determined based on the heat balance equation, thereby achieving the purpose of correcting the temperature data output by the built-in temperature sensor.

[0129] Please refer to Figure 8 An energy storage power supply 1 according to an embodiment of the present invention includes a control component 2, a battery pack 3 and an inverter. The battery pack 3 is electrically connected to the control component 2 and the inverter. The control component 2 includes a processor 22 and a memory 21. The memory 21 stores a computer program. When the computer program is executed by the processor 22, the steps of the temperature correction method of any of the above embodiments are implemented.

[0130] Specifically, the control component 2 may be located in a battery management system, or be connected to the battery management system in communication to manage and monitor the state of the battery pack 3, and to implement the steps of the temperature correction method of any embodiment. When the energy storage power supply 1 supplies power to an external device, the inverter may convert the direct current output by the energy storage power supply 1 into the alternating current required by the external device.

[0131] An embodiment of the present invention provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by the processor 22, the steps of the temperature correction method of any of the above embodiments are implemented.

[0132] In some embodiments, when the computer program is executed by the processor 22, the temperature correction method implemented includes:

[0133] Step S01, obtaining the ambient temperature, the charge and discharge time of the battery pack 3, the first temperature output by the built-in temperature sensor, and the heat consumption of the second battery cell 32;

[0134] Step S03 , correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack 3 , and the heat generation and power consumption of the second battery cell 32 to obtain a second temperature of the second battery cell 32 .

[0135] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0136] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable actions for implementing a specific logical function or process step, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0137] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, combine, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for correcting the temperature of a battery pack, characterized in that: The battery pack includes a plurality of battery cells, the plurality of battery cells include a first battery cell and a second battery cell, the second battery cell is closer to the inside of the battery pack than the first battery cell, the first battery cell is provided with a built-in temperature sensor, and the temperature correction method includes: Acquire the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, and the heat consumption of the second battery cell; The first temperature is corrected by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain a second temperature of the second battery cell.

2. The temperature correction method according to claim 1, characterized in that: The second battery cell is obtained by arranging a calibrated temperature sensor on each of the battery cells and determining the battery cell corresponding to the highest temperature from all temperatures output by all the calibrated temperature sensors.

3. The temperature correction method according to claim 1, characterized in that: The first battery cell and the second battery cell are two adjacent battery cells.

4. The temperature correction method according to claim 1, characterized in that: The plurality of battery cells include a third battery cell, and the third battery cell is adjacently located between the first battery cell and the second battery cell; Acquiring the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, and the heat consumption of the second battery cell includes: Acquire the ambient temperature, the charge and discharge time of the battery pack, the first temperature output by the built-in temperature sensor, the heat power consumption of the second battery cell, and the heat power consumption of the third battery cell; Correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell includes: Correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the third battery cell to obtain a third temperature of the third battery cell; The third temperature is corrected by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell.

5. The temperature correction method according to claim 4, characterized in that: Correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the third battery cell to obtain the third temperature of the third battery cell includes: Acquire the third temperature according to a first preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack, the heat generation and power consumption of the third battery cell, and the first temperature, wherein the first preset mapping relationship is a mapping relationship between the third temperature of the third battery cell and the charge and discharge time; Correcting the third temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell includes: The second temperature is obtained according to a second preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack, the heat generation and power consumption of the second battery cell and the third temperature. The second preset mapping relationship is a mapping relationship in which the second temperature of the second battery cell changes with the charge and discharge time.

6. The temperature correction method according to claim 1, characterized in that: The heat consumption is determined by collecting the current of the corresponding battery cell.

7. The temperature correction method according to claim 1, characterized in that: Correcting the first temperature by using the ambient temperature, the charge and discharge time of the battery pack, and the heat generation and power consumption of the second battery cell to obtain the second temperature of the second battery cell includes: The second temperature is obtained according to a third preset mapping relationship, the ambient temperature, the charge and discharge time of the battery pack, the heat generation and power consumption of the second battery cell and the first temperature. The third preset mapping relationship is a mapping relationship in which the second temperature of the second battery cell changes with the charge and discharge time.

8. The temperature correction method according to claim 5 or 7, characterized in that: The preset mapping relationship is obtained by performing partial differential equation calculation using the thermal balance equation of two adjacent battery cells.

9. The temperature correction method according to claim 8, characterized in that: The heat balance equation is related to natural convection, convective heat transfer between two cells and radiative heat transfer.

10. An energy storage power supply, comprising a control component, a battery pack and an inverter, wherein the battery pack is electrically connected to the control component and the inverter, the control component comprises a processor and a memory, the memory stores a computer program, and when the computer program is executed by the processor, the steps of the temperature correction method according to any one of claims 1 to 9 are implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the temperature correction method according to any one of claims 1 to 9 are implemented.

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