System and method for estimating battery cell surface temperature

Abstract

The present invention relates to a system and method for estimating battery cell surface temperature, and more particularly, to a system and method for estimating battery cell surface temperature that can minimize temperature measurement delay by a software algorithm method for estimating current actual cell surface temperature by reflecting a measured temperature change gradient of a battery cell.

Description

Technical Field

[0001] This invention relates to a battery cell surface temperature estimation system and method, and more specifically, to a battery cell surface temperature estimation system and method for minimizing temperature measurement delay. Background Technology

[0002] Batteries used as power sources for various portable electronic devices, including smartphones, laptops, and PDAs, may have temperatures that rise above a reference temperature due to various conditions, such as when a short circuit occurs inside the cell built into the battery, when the electronic device with the battery consumes an unusually large amount of power, or when the electronic device with the battery is exposed to a high-temperature environment.

[0003] In this way, when the battery temperature rises above the reference temperature, a large amount of gas is released due to the decomposition of the electrolyte or active materials built into the battery cell, which causes the internal pressure of the cell to rise rapidly. This results in the following problems: not only is there a risk of cell explosion, but the electrochemical characteristics of the battery cell are also degraded, thereby reducing the battery life.

[0004] To address these issues, when a temperature sensor at a specific location in contact with the battery cell measures the temperature and detects that the temperature exceeds a standard, an abnormal temperature is identified in the battery cell, and measures such as blocking the battery current are taken to prevent further temperature increases.

[0005] However, the method of measuring temperature by bringing a temperature sensor into contact with the surface of the battery cell, as described above, has the following problem: when the temperature sensor is not in close contact with the battery cell, the measurement is slower than the actual cell surface temperature due to limitations in the physical device design, such as the process, or due to time differences caused by conduction or convection.

[0006] For example, during over-discharge, the cell surface temperature rises due to heat generation, and the temperature value measured by the temperature sensor rises more slowly than the actual cell surface temperature at that time, resulting in a delay in measurement time. In this case, the determination of the battery cell's safety diagnosis is delayed because there are limitations in determining the actual current temperature of the battery cell.

[0007] (Patent Document 1) JP2013-005663A Summary of the Invention

[0008] Technical issues

[0009] The present invention aims to solve the above-mentioned problems and aims to minimize the temperature measurement delay by using a software algorithm method to estimate the current actual cell surface temperature by reflecting the measured temperature change gradient of the battery cell.

[0010] Technical solution

[0011] A battery cell surface temperature estimation system according to the present invention includes: a temperature measuring unit configured to measure the surface temperature of a cell, the surface temperature of a battery cell being charged / discharged at predetermined cycle intervals; a delay time acquisition unit configured to acquire a delay time, the delay time being the time required from the end of charging / discharging of the battery cell until the surface temperature of the cell reaches the highest temperature of each predetermined temperature range; a first storage unit configured to store, based on the delay time data obtained from the delay time acquisition unit, the delay time corresponding to each charging / discharging state of the battery cell for each predetermined temperature range into a database; a second storage unit configured to store the surface temperature values ​​of the cell measured by the temperature measuring unit; and a cell surface temperature prediction unit configured to calculate, based on the database of the first storage unit, the delay time corresponding to the current surface temperature of the cell measured by the temperature measuring unit, and to predict the current actual cell surface temperature of the battery cell using the calculated delay time.

[0012] Specifically, the cell surface temperature prediction unit includes: a current delay time calculation unit, configured to extract the temperature range to which the current measurement cell surface temperature belongs, measured by the temperature measurement unit, belongs from a predetermined temperature range stored in a first storage cell, and calculate the delay time corresponding to the current measurement cell surface temperature using the temperature value corresponding to the extracted temperature range and the delay time corresponding to the charging / discharging state of the battery cell; a temperature deviation calculation unit, configured to calculate the temperature deviation between the measurement cell surface temperature value corresponding to the previous time point and the current measurement cell surface temperature value, obtained by the delay time calculated by the current delay time calculation unit, based on the current time point; and an actual cell surface temperature estimation unit, configured to estimate the measurement cell surface temperature to be measured by adding the temperature deviation calculated by the temperature deviation calculation unit to the current measurement cell surface temperature.

[0013] At this point, the cell surface temperature prediction unit will predict the measured cell surface temperature value estimated by the actual cell surface temperature estimation unit as the current actual cell surface temperature of the battery cell.

[0014] Furthermore, the data stored in the first storage cell regarding the delay time corresponding to each charge / discharge state of the battery cell for each predetermined temperature range is updated each time the battery cell is charged / discharged.

[0015] In addition, the battery cell surface temperature estimation system also includes a temperature state diagnosis unit, which is configured to compare the current actual cell surface temperature predicted by the cell surface temperature prediction unit with a predetermined reference value, and diagnose the current temperature state of the battery cell based on the comparison result.

[0016] A battery cell surface temperature estimation method according to the present invention includes: a temperature measurement step, wherein the temperature measurement step is to measure the surface temperature of a battery cell being charged / discharged at predetermined cycle intervals; a delay time acquisition step, wherein the delay time acquisition step is to acquire a delay time, wherein the delay time is the time required from the end time of charging / discharging of the battery cell until the measured surface temperature of the battery cell measured in the temperature measurement step reaches the highest temperature of each predetermined temperature range; a database provision step, wherein the database provision step is to store the delay time corresponding to each charging / discharging state of the battery cell for each predetermined temperature range in a database based on the delay time data obtained by the temperature measurement step and the delay time acquisition step for each predetermined temperature range; and a cell surface temperature prediction step, wherein the cell surface temperature prediction step is to calculate the delay time corresponding to the current measured cell surface temperature of the battery cell based on the database obtained in the database provision step, and to predict the current actual cell surface temperature as the actual temperature value of the battery cell using the calculated delay time.

[0017] Specifically, the cell surface temperature prediction step includes: a current delay time calculation step, which involves extracting the temperature range to which the current measured cell surface temperature belongs from a predetermined temperature range in the database, and calculating the delay time corresponding to the current measured cell surface temperature of the battery cell using the temperature value corresponding to the extracted temperature range and the delay time corresponding to the charging / discharging state of the battery cell; a temperature deviation calculation step, which involves calculating the temperature deviation between the measured cell surface temperature value corresponding to the previous time point and the current measured cell surface temperature value based on the current time point using the delay time calculated in the current delay time calculation step; and an actual cell surface temperature estimation step, which involves adding the temperature deviation calculated in the temperature deviation calculation step to the current measured cell surface temperature to estimate the measured cell surface temperature to be measured after the delay time at the current time point.

[0018] At this point, the cell surface temperature prediction step will predict the measured cell surface temperature value estimated in the actual cell surface temperature estimation step as the current actual cell surface temperature of the battery cell.

[0019] In addition, the battery cell surface temperature estimation method also includes a temperature state diagnosis step, which involves comparing the current actual cell surface temperature predicted in the cell surface temperature prediction step with a predetermined reference value, and diagnosing the current temperature state of the battery cell based on the comparison result.

[0020] In addition, data on the delay time corresponding to each charge / discharge state for each predetermined temperature range of the battery cell, stored in the database, is updated each time the battery cell is charged / discharged.

[0021] Beneficial effects

[0022] This invention estimates the measurement delay time based on the current measurement temperature by reflecting the temperature change gradient of the battery cell, and predicts the value estimated as temperature based on the current measurement delay time as the current actual cell surface temperature. Therefore, the temperature of the battery cell can be monitored in real time with improved accuracy by minimizing the measurement delay that occurs when physically measuring the temperature of the battery cell.

[0023] Therefore, battery stability can be improved because the temperature state of battery cells can be diagnosed more accurately and quickly. Attached Figure Description

[0024] Figure 1 This is a block diagram schematically illustrating the overall configuration of the battery cell surface temperature estimation system according to the present invention.

[0025] Figure 2 This is a graph illustrating an example of comparing the changes in the actual cell surface temperature with the measured cell surface temperature.

[0026] Figure 3 This is a table illustrating an example of a database according to the present invention.

[0027] Figure 4 This is a flowchart illustrating a method for estimating the surface temperature of a battery cell according to the present invention. Detailed Implementation

[0028] In the following description, embodiments of the invention will be illustrated in detail with reference to the accompanying drawings, so that those skilled in the art can readily implement the invention. However, the invention can be implemented in various forms and is not limited to the embodiments described herein. In the drawings, for clarity of description, parts irrelevant to the description have been omitted, and the same reference numerals refer to the same elements throughout the specification.

[0029] The invention will now be described in detail with reference to the accompanying drawings.

[0030] 1. A battery cell surface temperature estimation system according to the present invention

[0031] Figure 1 This is a schematic block diagram illustrating the overall configuration of a battery cell surface temperature estimation system according to the present invention. The system of the present invention includes a temperature measurement unit 100, a delay time acquisition unit 200, a first storage unit 300, a second storage unit 400, an actual cell surface temperature prediction unit 500, and a temperature state diagnosis unit 600.

[0032] 1.1. Temperature Measurement Unit 100

[0033] The temperature measuring unit is configured to measure the temperature of the battery cell 10 during charging / discharging at predetermined cycle intervals. Specifically, the temperature measuring unit is disposed at a predetermined location on the surface of the battery cell 10 to measure the cell surface temperature. Hereinafter, the temperature of the battery cell measured by such a temperature measuring unit will be referred to as the measured cell surface temperature and described accordingly.

[0034] 1.2. Delay Time Acquisition Unit 200

[0035] The delay time acquisition unit is configured to measure and acquire the delay time, which is the time taken from the end of the charging / discharging time of the battery cell until the surface temperature of the measuring cell, as measured by the temperature measuring unit 100, reaches the highest temperature of each predetermined temperature range.

[0036] For example, if the temperature range is set to 10-degree intervals and the surface temperature of the measuring unit at the end of the charging / discharging time is approximately 25 degrees, then the time taken for the surface temperature of the measuring unit to reach 30 degrees (i.e., the highest temperature in the 20-30 degree range) from that point, the time taken to reach the highest temperature of 40 degrees in the 30-40 degree range, the time taken to reach the highest temperature of 50 degrees in the 40-50 degree range, and the time taken to reach the highest temperature of 60 degrees in the 50-60 degree range are measured, and the time obtained for each temperature range is the delay time.

[0037] In other words, the delay time refers to the time difference between the end of charging / discharging and the time when the surface temperature of the measuring unit reaches the highest temperature of the corresponding temperature range for each temperature range.

[0038] 1.3. First storage unit 300

[0039] The first storage unit is a configuration of a database, and stores the delay time corresponding to each charging / discharging state of the battery cell for each predetermined temperature range based on the delay time data obtained from the delay time acquisition unit 200 each time the battery cell is charged / discharged.

[0040] For example, such as Figure 3 As shown in the table, the charging delay time 3 and the discharging delay time 3 at 30 degrees mean that it takes 3 seconds from the end of the charging of the battery cell until the surface temperature of the measured cell reaches 30 degrees, and 3 seconds from the end of the discharging of the battery cell until the surface temperature of the measured cell reaches 30 degrees.

[0041] The first storage unit forms a database and stores the delay time data for each charge / discharge state in each temperature range in a tabular form.

[0042] Simultaneously, the first storage unit updates and stores the data obtained from the delay time acquisition unit 200 for each charge / discharge of the battery cell. Therefore, since recent temperature change trends can be reflected in the prediction of the actual temperature of the battery cell, the actual surface temperature of the battery cell can be predicted with improved accuracy.

[0043] 1.4. Second storage unit 400

[0044] The second storage unit is configured to store the surface temperature values ​​of the measuring unit measured by the temperature measuring unit 100 at predetermined cycles.

[0045] 1.5. Unit Surface Temperature Prediction Unit 500

[0046] The cell surface temperature prediction unit is configured to calculate, based on the database of the first storage unit 300, a delay time corresponding to the cell surface temperature measured by the temperature measurement unit 100 at the current time, and to predict the actual cell surface temperature at the current time using the calculated delay time. This cell surface temperature prediction unit may include the following detailed configuration.

[0047] A. Current delay time calculation unit 510

[0048] The current delay time calculation unit can extract the temperature range to which the surface temperature of the current measuring unit belongs, which is measured by the temperature measuring unit 100, from the temperature range stored in the first storage unit 300, and calculate the delay time corresponding to the surface temperature of the current measuring unit by using the temperature value corresponding to the extracted temperature range and the delay time corresponding to the charging / discharging state of the current battery unit.

[0049] Reference Figure 3As an example, if the current battery cell is discharging and the current measured cell surface temperature is 45 degrees Celsius, then the temperature range of the current measured cell surface temperature is between 40 and 50 degrees Celsius, and the delay times corresponding to the temperature values ​​of 40 and 50 degrees Celsius in the discharge state are 9 and 13 seconds, respectively. In this case, the delay time corresponding to the current measured cell surface temperature can be calculated as approximately 11 seconds using the expression {(9+13) / 2}.

[0050] In this way, the current delay time calculation unit can calculate the delay time corresponding to the current measurement unit surface temperature based on the database of the first storage unit 300.

[0051] The delay time calculated here is the time that the measurement in the temperature measurement unit 100 is delayed compared to the actual unit surface temperature state at present, that is, it means that the measurement in the temperature measurement unit 100 is slower than the actual unit surface temperature by the calculated delay time.

[0052] B. Temperature Deviation Calculation Unit 520

[0053] The temperature deviation calculation unit can calculate the difference between the surface temperature value of the measuring unit corresponding to the previous time point and the current surface temperature value of the measuring unit, obtained by the delay time calculated by the current delay time calculation unit 510, based on the current time point.

[0054] For example, if the delay time calculated by the current delay time calculation unit 510 as described above is 11 seconds, then the difference between the surface temperature value of the measuring unit 11 seconds ago and the current surface temperature value of the measuring unit is calculated based on the current time point. If the surface temperature value of the measuring unit 11 seconds ago was 40 degrees, then 5 degrees is calculated, which is the difference between the current surface temperature value of the measuring unit (45 degrees).

[0055] D. Actual unit surface temperature estimation unit 530

[0056] The actual unit surface temperature estimation unit estimates the measured unit surface temperature after a delay time by adding the temperature deviation value calculated by the temperature deviation calculation unit 520 to the current measured unit surface temperature value, and predicts it as the current actual unit surface temperature.

[0057] For example, if the current surface temperature of the measuring unit is 45 degrees, the delay time calculated by the current delay time calculation unit 510 is 11 seconds, and the temperature deviation calculated by the temperature deviation calculation unit 520 is 5 degrees, then the surface temperature value of the measuring unit to be measured in the temperature measuring unit 100 11 seconds from the current time point is estimated to be 50 degrees (which is the value obtained by adding 45 degrees to 5 degrees), and this is predicted as the current actual surface temperature of the unit. Since the surface temperature of the measuring unit is delayed by 11 seconds compared to the actual surface temperature of the unit, it is assumed that the same fluctuation caused by the difference between the surface temperature of the measuring unit 11 seconds ago and the current surface temperature of the measuring unit based on the current temperature will continue after 11 seconds. Therefore, the value obtained by adding the temperature difference to the current surface temperature of the measuring unit is estimated as the surface temperature of the measuring unit to be measured 11 seconds later, and this is predicted as the actual surface temperature of the unit.

[0058] The reason is that, although the temperature sensor measuring the cell surface is in contact with the cell surface, a time difference will occur due to contact design, conduction, etc., and as... Figure 2 As the graph shows, the temperature measurement is slower than the actual cell surface temperature. Therefore, for example, there is a difference in the time point at which the highest temperature is shown at the end of the discharge, and if the actual cell surface temperature drops immediately after the end of the discharge, the measured cell surface temperature shows the highest temperature after a delay time after the end of the discharge and then drops.

[0059] Therefore, this invention calculates the current measurement delay time by using the temperature change of the battery cell and the time difference between measuring the highest temperature after charging / discharging, and reflects and estimates the actual cell surface temperature at the current time point to improve its accuracy. Thus, the problem of delay in diagnosing the temperature state of the battery cell caused by measurement delay can be prevented.

[0060] 1.6. Temperature Status Diagnostic Unit 600

[0061] When the cell surface temperature prediction unit 500 predicts the current actual cell surface temperature, the temperature state diagnosis unit compares it with a predetermined reference value and diagnoses the current temperature state of the battery cell based on the comparison result. The temperature state diagnosis unit can use conventional methods to diagnose the current temperature state of the battery cell.

[0062] 2. The battery cell surface temperature estimation method according to the present invention

[0063] Figure 4 This is a flowchart illustrating a method for estimating the surface temperature of a battery cell according to the present invention. (Refer to...) Figure 4 Each step will be described.

[0064] 2.1 Temperature Measurement Procedure S100

[0065] The temperature measurement step is a step of measuring the surface temperature of the measuring cell, which is the temperature value of the battery cell that is being charged / discharged at a predetermined cycle interval, and this step is performed by a temperature measuring unit 100 located at a predetermined position on the surface of the battery cell.

[0066] 2.2. Delay Time Acquisition Step S200

[0067] The delay time acquisition step is the step of measuring and acquiring the delay time, which is the time taken from the end of the charging / discharging time of the battery cell until the surface temperature of the measuring cell, as measured in the temperature measurement step S100, reaches the highest temperature of each predetermined temperature range. This step is performed by the delay time acquisition unit 200, and since it has already been described above, its detailed description will be omitted.

[0068] 2.3. Database provision step S300

[0069] The database provisioning step consists of the following steps: based on the data on delay time obtained through the temperature measurement step S100 and the delay time acquisition step S200 for each predetermined temperature range, the delay time corresponding to each charging / discharging state is stored in the database for each predetermined temperature range.

[0070] Specifically, each time the battery cell is charged / discharged, the acquired data on the delay time for each predetermined temperature range is accumulated and learned by repeatedly executing the delay time acquisition step (S200), thereby, for example, Figure 3 As shown in the table, a database can be provided that includes the delay time corresponding to each charge / discharge state for each predetermined temperature range.

[0071] At this time, through the temperature measurement step S100 and the delay time acquisition step S200, the data included in the database (i.e., the delay time value for each charging / discharging state for each predetermined temperature range) is updated based on the delay time data for each charging / discharging of the battery cell to reflect the real-time temperature state of the battery cell.

[0072] 2.4. Unit Surface Temperature Prediction Step S400

[0073] The cell surface temperature prediction step comprises the following steps: calculating a delay time corresponding to the current measured cell surface temperature based on the database obtained in the database provision step, and using the calculated delay time to predict the actual cell surface temperature (which is the actual temperature value of the current battery cell), and this step may include the following steps.

[0074] A. Current delay time calculation step S410

[0075] First, the temperature range to which the surface temperature of the current measurement unit belongs is extracted from the temperature range stored in the database. Then, the delay time corresponding to the surface temperature of the current measurement unit is calculated using the temperature value corresponding to the extracted temperature range and the delay time corresponding to the charging / discharging state of the current battery cell.

[0076] Reference Figure 3 As an example, if the current battery cell is discharging and the current measured cell surface temperature is 45 degrees Celsius, then the temperature range of the current measured cell surface temperature is between 40 and 50 degrees Celsius, and the delay times corresponding to the temperature values ​​of 40 and 50 degrees Celsius in the discharge state are 9 and 13 seconds, respectively. In this case, the delay time corresponding to the current measured cell surface temperature can be calculated as approximately 11 seconds using the expression {(9+13) / 2}.

[0077] In this way, the delay time corresponding to the current surface temperature of the measurement unit can be calculated based on the database.

[0078] The delay time calculated here is the delay time of the measurement in the temperature sensor compared to the current actual unit surface temperature state, that is, the delay time calculated by the temperature measurement unit 100 being slower than the actual unit surface temperature.

[0079] B. Temperature Deviation Calculation Steps S420

[0080] When the delay time at the current time point is calculated through the current delay time calculation step S410, the difference between the surface temperature value of the measurement unit corresponding to the previous time point and the current surface temperature value of the measurement unit is calculated based on the current time point.

[0081] For example, if the delay time calculated in the current delay time calculation step S410 is 11 seconds, then the difference between the surface temperature value of the measuring unit 11 seconds ago and the current surface temperature value of the measuring unit is calculated based on the current time point. If the surface temperature of the measuring unit 11 seconds ago was 40 degrees and the current surface temperature of the measuring unit is 45 degrees, then the difference between them is calculated, which is 5 degrees.

[0082] C. Actual cell surface temperature estimation step S430

[0083] The actual cell surface temperature estimation steps are as follows: if the difference between the measured cell surface temperature before the current delay time and the current measured cell surface temperature is calculated, then the difference is used to estimate the measured cell surface temperature to be measured after the current delay time, and the estimated temperature is predicted as the current actual cell surface temperature.

[0084] For example, if the current surface temperature of the measuring unit is 45 degrees, the current delay time is 11 seconds, and the difference between the surface temperature of the measuring unit 11 seconds ago and the current surface temperature is 5 degrees, then the surface temperature of the measuring unit to be measured 11 seconds from the current time point is estimated to be 50 degrees (which is 45 degrees plus 5 degrees), and this is predicted as the current actual surface temperature of the unit. Since the surface temperature of the measuring unit is delayed by 11 seconds compared to the actual surface temperature, it is assumed that the same fluctuation caused by the difference between the surface temperature of the measuring unit 11 seconds ago and the current surface temperature will continue after 11 seconds. Therefore, the current surface temperature of the measuring unit plus the temperature difference between the past and the present is estimated as the surface temperature of the measuring unit to be measured 11 seconds later, and this is predicted as the actual surface temperature of the unit.

[0085] 2.5. Temperature Status Diagnostic Step S500

[0086] The temperature state diagnosis step consists of the following steps: comparing the temperature value predicted as the current actual cell surface temperature by the cell surface temperature prediction step S400 with a predetermined reference value, and diagnosing the current temperature state of the battery cell based on the comparison result. This can be done using conventional methods to diagnose the current temperature state of the battery cell.

[0087] On the other hand, although the technical concept of the present invention has been specifically described according to the above embodiments, it should be noted that the above embodiments are for illustrative purposes and not for limitation. Furthermore, those skilled in the art will understand that various embodiments are possible within the spirit and scope of the present invention.

Claims

1. A battery cell surface temperature estimation system, comprising: A temperature measuring unit is configured to measure the surface temperature of a measuring unit, which is the surface temperature of a battery cell that is being charged / discharged at predetermined cycle intervals. A delay time acquisition unit is configured to acquire a delay time, which is the time required from the end of the charging / discharging time of the battery cell until the surface temperature of the measuring unit reaches the highest temperature of each predetermined temperature range. The first storage unit is configured to store the delay time corresponding to each charge / discharge state of the battery cell for each predetermined temperature range into a database based on the delay time data obtained from the delay time acquisition unit. The second storage unit is configured to store the surface temperature value of the measuring unit as measured by the temperature measuring unit; as well as A cell surface temperature prediction unit is configured to calculate a delay time corresponding to the current measured cell surface temperature measured by the temperature measurement unit based on the database of the first storage unit, and to predict the current actual cell surface temperature of the battery cell based on the change in the measured cell surface temperature during the calculated delay time.

2. The battery cell surface temperature estimation system according to claim 1, wherein, The unit surface temperature prediction unit includes: The current delay time calculation unit is configured to extract the temperature range to which the surface temperature of the current measuring unit, measured by the temperature measuring unit, belongs from the predetermined temperature range stored in the first storage unit, and to calculate the delay time corresponding to the surface temperature of the current measuring unit by using the temperature value corresponding to the extracted temperature range and the delay time corresponding to the charging / discharging state of the battery unit. A temperature deviation calculation unit is configured to calculate, based on the current time point, the temperature deviation between the surface temperature value of the measuring unit corresponding to the previous time point, obtained by a delay time calculated by the current delay time calculation unit, and the current surface temperature value of the measuring unit; and The actual unit surface temperature estimation unit is configured to add the temperature deviation calculated by the temperature deviation calculation unit to the current measurement unit surface temperature as the estimated temperature of the measurement unit surface after the delay time at the current time point.

3. The battery cell surface temperature estimation system according to claim 2, wherein, The cell surface temperature prediction unit predicts the measured cell surface temperature value estimated by the actual cell surface temperature estimation unit as the current actual cell surface temperature of the battery cell.

4. The battery cell surface temperature estimation system according to claim 1, wherein, Data stored in the first storage unit regarding the delay time corresponding to each charge / discharge state of the battery cell for each predetermined temperature range is updated each time the battery cell is charged / discharged.

5. The battery cell surface temperature estimation system according to claim 3 further includes a temperature state diagnosis unit, the temperature state diagnosis unit being configured to compare the current actual cell surface temperature predicted by the cell surface temperature prediction unit with a predetermined reference value, and to diagnose the current temperature state of the battery cell based on the comparison result.

6. A method for estimating the surface temperature of a battery cell, comprising: A temperature measurement step is used to measure the surface temperature of a measuring unit, wherein the surface temperature of the measuring unit is the surface temperature of a battery cell that is being charged / discharged at a predetermined cycle interval. The delay time acquisition step is used to acquire the delay time, which is the time required from the end time of charging / discharging of the battery cell until the surface temperature of the measuring cell, as measured in the temperature measurement step, reaches the highest temperature of each predetermined temperature range. The database provides steps for storing, based on data regarding delay times for each predetermined temperature range obtained through the temperature measurement step and the delay time acquisition step, the delay times corresponding to each charge / discharge state of the battery cell for each predetermined temperature range into the database; and The cell surface temperature prediction step is used to: calculate a delay time corresponding to the current measured cell surface temperature of the battery cell based on the database obtained in the database providing step, and predict the current actual cell surface temperature as the actual temperature value of the battery cell based on the change of the measured cell surface temperature during the calculated delay time.

7. The battery cell surface temperature estimation method according to claim 6, wherein, The unit surface temperature prediction step includes: The current delay time calculation step is used to: extract the temperature range to which the current measurement unit surface temperature belongs from the predetermined temperature range of the database, and calculate the delay time corresponding to the current measurement unit surface temperature of the battery unit by using the temperature value corresponding to the extracted temperature range and the delay time corresponding to the charging / discharging state of the battery unit. A temperature deviation calculation step is used to calculate, based on the current time point, the temperature deviation between the surface temperature value of the measuring unit corresponding to the previous time point obtained by the delay time calculated in the current delay time calculation step and the current surface temperature value of the measuring unit; and The actual unit surface temperature estimation step is used to add the current measurement unit surface temperature to the temperature deviation calculated in the temperature deviation calculation step, and estimate the measurement unit surface temperature to be measured after the delay time at the current time point.

8. The battery cell surface temperature estimation method according to claim 7, wherein, The cell surface temperature prediction step predicts the measured cell surface temperature value estimated in the actual cell surface temperature estimation step as the current actual cell surface temperature of the battery cell.

9. The battery cell surface temperature estimation method according to claim 8 further includes a temperature state diagnosis step, used to compare the current actual cell surface temperature predicted in the cell surface temperature prediction step with a predetermined reference value, and to diagnose the current temperature state of the battery cell based on the comparison result.

10. The battery cell surface temperature estimation method according to claim 6, wherein, Data on the delay time corresponding to each charge / discharge state of the battery cell for each predetermined temperature range, stored in the database, is updated each time the battery cell is charged / discharged.

Images