Battery Pack for Preventing Overheat False Diagnosis Due to Ambient Temperature and Method for Preventing False Diagnosis

Abstract

The present invention measures the internal temperature and external temperature of a battery pack at a predetermined cycle in different temperature sensors respectively disposed in a battery cell, a battery management system (BMS), and a pack case of the battery pack, compares these with predetermined reference values, performs overheat diagnosis of the battery, and in particular, provides a battery pack and an overheat diagnosis method capable of determining whether the cause of the overheat diagnosis is due to an internal factor or an external factor of the battery pack.

Description

Technical Field

[0001] The present invention relates to a technology for detecting overheating of a battery. In particular, the present invention relates to a battery pack and a detection method for distinguishing and detecting the cause of overheating of a battery between an increase in the temperature of the battery itself and an increase in temperature due to external environmental factors.

Background Art

[0002] During the operation of a battery, overheat diagnosis is often performed due to an increase in the temperature of the battery. In such cases, it is often difficult to determine whether the cause is due to an increase in the temperature of the battery itself or an increase in the temperature of the external environment.

[0003] Regarding this, Patent Document 1 discloses a problem-solving method for determining an abnormal temperature state based only on the absolute temperature of the battery cell itself without reflecting any change in the ambient temperature around the battery cell. In order to solve this problem, temperature sensors are provided on the peripheral part of the battery cell and the surface of the battery cell respectively, and the difference between the temperature of the battery cell itself and the temperature of the peripheral part of the battery cell is used to detect an increase in the ambient temperature before the temperature of the battery cell rises, and quickly diagnose the abnormal temperature state of the battery cell.

[0004] Patent Document 2 discloses a technique for measuring the temperature of a pack in a pack case to equalize the temperature of battery cells, and heating cells whose cell temperature is lower than the average value of the cell temperatures only when the temperature of the pack is lower than an appropriate temperature range to adjust the temperature of the pack to the appropriate temperature range.

[0005] However, neither of the above-mentioned conventional technologies discloses a technique for distinguishing and diagnosing whether the overheating state of the battery is due to overheating of the cells or an increase in the temperature of the external environment.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Republic of Korea Patent Publication No. 2021-0158123 (December 30, 2021) [Patent Document 2] Republic of Korea Patent Registration No. 2054202 (December 4, 2019) [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] The present invention aims to provide a method for determining whether the cause of overheat diagnosis due to an increase in the temperature of a battery pack is due to an increase in the temperature of the battery cell or an increase in the external temperature, which cannot be presented by the above-described conventional technology, and a battery pack enabling the same. [Means for Solving the Problems]

[0008] To solve the above-described problems, the present invention provides a battery pack including one or more battery cells, a battery management system (BMS) that performs overheat diagnosis of the battery pack as the internal temperature of the battery pack or the external temperature of the battery pack increases, and determines whether the cause of the overheat diagnosis is due to an increase in the internal temperature of the battery pack or an increase in the external temperature, a pack case that houses the battery cell and the BMS, one or more cell temperature sensors arranged adjacent to the battery cell to provide a measured value for determining an increase in the internal temperature of the battery pack, and one or more pack temperature sensors arranged adjacent to the pack case to provide a measured value for determining an increase in the external temperature of the battery pack.

[0009] At this time, the BMS receives the measured values from the cell temperature sensor at a predetermined period to determine an increase in the internal temperature of the battery pack, receives the measured values from the pack temperature sensor at a predetermined period to determine an increase in the external temperature of the battery pack, receives the measured values from the cell temperature sensor and the pack temperature sensor, calculates the internal temperature of the pack and the external temperature of the pack respectively, and performs overheat diagnosis of the battery pack based on the internal temperature value of the pack and the external temperature value of the pack. However, when the external temperature value of the pack rises earlier than the internal temperature value of the pack and is diagnosed as overheating, it is determined that the cause of the overheat diagnosis is due to an external factor of the battery pack.

[0010] Further, the battery pack of the present invention further includes a BMS temperature sensor arranged adjacent to the BMS. The BMS receives the measured values from the cell temperature sensor and the temperature sensor of the BMS at a predetermined period to determine an increase in the internal temperature of the battery pack. The pack temperature sensor of the present invention is attached to the inner surface or the outer surface of the pack case. When it is attached to the inner surface, the pack case is provided with a temperature measurement hole at a position corresponding to the location where the pack temperature sensor is attached, and a heat dissipation film may be attached to the upper surface of the pack temperature sensor facing the outer surface of the pack case.

[0011] Furthermore, the present invention provides an overheat diagnosis system for a battery pack, which includes one or more of the above-mentioned battery packs and a higher-level control unit that receives the internal temperature of the pack and the external temperature of the pack of the battery pack to perform overheat diagnosis of the battery pack. In the overheat diagnosis system of the battery pack, when the external temperature of the battery pack rises above a predetermined reference value earlier than the internal temperature of the pack of the battery pack during the overheat diagnosis of the battery pack, it is determined that the overheat is due to an external factor of the pack.

[0012] Furthermore, an embodiment of the present invention provides a method for diagnosing overheating of a battery pack, including: an internal temperature measurement step of a battery pack for measuring the internal temperature of the battery pack at a predetermined cycle; an external temperature measurement step of a battery pack for measuring the external temperature of the battery pack at a predetermined cycle; an overheating diagnosis step of a battery pack for diagnosing the presence or absence of overheating of the battery pack based on the internal temperature and the external temperature of the pack; and a determination step of the cause of overheating diagnosis for determining that the overheating diagnosis is a misdiagnosis when the external temperature of the pack rises earlier than the internal temperature of the pack in the overheating diagnosis step.

[0013] At this time, in the overheating diagnosis step, when the internal temperature of the pack is greater than a predetermined reference value, it is diagnosed that the battery pack is overheated. In the determination step of the cause of overheating diagnosis, when the external temperature of the pack rises earlier than the internal temperature of the pack, it is determined that the cause of the overheating diagnosis is due to the rise in the external temperature. At this time, the internal temperature of the pack is obtained from a temperature sensor attached to a battery cell or BMS housed inside the pack case of the battery pack, and the external temperature of the pack is obtained from a temperature sensor attached to the pack case of the battery pack.

[0014] Furthermore, an embodiment of the present invention includes a battery pack temperature measurement step in which each battery pack measures the internal temperature and the external temperature of each battery pack, a measurement value reception step in which the upper controller receives the measured values of the internal temperature and the external temperature of each battery pack, an overheat diagnosis step in which the upper controller performs an overheat diagnosis on each battery pack based on the received measured values of the internal temperature and the external temperature of each battery pack, and an overheat diagnosis cause determination step in which it is determined whether the cause of the overheat diagnosis is due to an internal factor or an external factor of the battery pack. The present invention provides an overheat diagnosis method for a battery system including one or more battery packs each provided with a separate temperature sensor so as to measure the internal temperature and the external temperature of the battery pack, and an upper controller that receives the transmission of the internal temperature and the external temperature of each battery pack from the battery pack.

[0015] At this time, each battery pack measures the internal temperature and the external temperature from different temperature sensors attached to different positions of the battery pack. The internal temperature is obtained from a temperature sensor attached to a battery cell or BMS housed inside the pack case of the battery pack, and the external temperature is obtained from a temperature sensor attached to the pack case of the battery pack.

Advantages of the Invention

[0016] According to the embodiment of the present invention, the internal temperature and the external temperature of the battery pack are measured at a predetermined cycle by different temperature sensors disposed in each of the battery cell, BMS, and pack case of the battery pack, and these are compared with predetermined reference values to perform an overheat diagnosis of the battery. In particular, by determining whether the cause of the overheat diagnosis is due to an internal factor or an external factor of the battery pack, it is possible to prevent an overheat misdiagnosis or identify the cause of the overheat diagnosis, thereby increasing the efficiency of battery operation.

[0017] The drawings attached to this specification illustrate the desirable embodiments of the present invention and are for the purpose of further understanding the technical idea of the present invention together with the detailed description of the invention mentioned above. Therefore, the present invention should not be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0019] Hereinafter, based on the attached drawings, the structure and overheat diagnosis method of the battery pack according to the present invention will be described.

[0020] 1. Structure of the battery pack 100 according to the present invention The battery pack 100 according to the present invention includes a plurality of battery cells 10, a battery management system (BMS) 20 for managing the battery cells, a battery pack case 30 for housing the plurality of battery cells and the BMS therein, one or more first sensors 40 for measuring the temperature of the battery cells, and one or more pack temperature sensors 60 for measuring the temperature of the battery pack. Further, one or more BMS temperature sensors 50 for measuring the temperature of the BMS may be provided.

[0021] (1) Battery cell 10 The battery pack 100 of the present invention includes ordinary battery cells 10. One or more cell temperature sensors 40 for measuring the temperature of the cells are attached to the battery cells 10.

[0022] As shown in FIG. 2, the cell temperature sensor 40 can be attached to the battery cell via an FPCB 70 for mounting the temperature sensor. FIG. 2(a) is a cross-sectional view of two cell temperature sensors 40 attached to different positions of the battery cell 10 using the FPCB 70 for mounting the temperature sensor, viewed from the side, and FIG. 2(b) is a view of the state where the cell temperature sensor 40 is attached, looking down from above.

[0023] (2) BMS 20 The battery pack 100 of the present invention includes an ordinary BMS 20. A BMS temperature sensor 50 for measuring the temperature around the BMS 20 is attached to the substrate constituting the BMS 20. As shown in the block diagram of FIG. 3, the BMS temperature sensor 50 can be arranged around other elements 21 constituting the BMS 20. In the block diagram of FIG. 3, detailed circuit patterns such as the connection relationships between the elements are not shown.

[0024] The BMS 20 of the present invention adopts an ordinary BMS as its structure, but its function is to perform the diagnostic method for the temperature of the battery pack according to the present invention.

[0025] The BMS 20 reads the temperature measurement signals at the positions where the respective sensors are attached from the cell temperature sensor 40, the pack temperature sensor 60, or further the BMS temperature sensor 50, and calculates the temperature of the cell, the temperature of the BMS, and the temperature of the pack case based on these signals. The temperature of the pack case calculated from the measured value of the pack temperature sensor 60 calculates the ambient temperature outside the battery pack 100.

[0026] The BMS 20 performs overheat diagnosis of the battery pack using the temperature of such a cell and the pack case, or further the temperature around the BMS. When overheating is diagnosed, it is determined whether the cause of the overheat diagnosis is due to an increase in the temperature of the internal battery cell or BMS, or whether it is due to an increase in the temperature of the external environment of the battery pack 100. Specific procedures and methods for determining whether the cause of the overheat diagnosis is due to an increase in the internal temperature of the battery pack or an increase in the external temperature of the battery pack will be described below.

[0027] (3) Pack case 30 As shown in FIG. 1, the pack case 30 of the present invention houses a plurality of battery cells 10 and the BMS 20 and includes one or more pack temperature sensors 60.

[0028] As shown in FIG. 4(a), the pack temperature sensor 60 can be attached to the outer surface of the pack case 30, or as shown in FIG. 4(b), it can be attached to the inner surface of the pack case 30. When attached to the inner surface or the outer surface of the pack case 30, as shown in FIG. 4, it can be mounted and attached to the FPCB 70 for sensor mounting.

[0029] On the one hand, as shown in FIGS. 4(c) and 4(d), the pack case 30 of the present invention may be provided with a temperature measurement hole 31. The temperature measurement hole 31 is formed corresponding to the mounting position of the pack temperature sensor 60 particularly when the pack temperature sensor 60 is disposed on the inner surface of the pack case 30, so that the pack temperature sensor 60 is more affected by the external temperature than the internal temperature of the pack case 30, and the pack temperature sensor 60 is configured to be more sensitive to the temperature of the external environment.

[0030] As shown in FIG. 4(c), the upper surface of the FPCB 70 for mounting the sensor facing the inner surface of the pack case 30 of the pack temperature sensor 60, that is, the upper surface of the pack temperature sensor, is radiated by a heat dissipation film 72 that blocks heat, so that the sensitivity of the pack temperature sensor 60 to the internal temperature of the pack case 30 may be further reduced.

[0031] On the other hand, FIGS. 4(c) and 4(d) show a configuration in which a temperature transmission pin 32 is disposed in the temperature measurement hole 31 for the purpose of sealing such as water drainage or for the purpose of transmitting the external temperature. One end of the temperature transmission pin 32 is in contact with the pack temperature sensor 60 attached to the inner surface of the pack case, and the other end is exposed to the outside of the pack case 30 through the temperature measurement hole 31 to transmit the temperature outside the pack case 30 to the pack temperature sensor 60.

[0032] In FIG. 4(d), it is shown as if there is a gap between the temperature measurement hole 31 and the temperature transmission pin 32, but this is shown for identification in the figure. Actually, for the purpose of sealing the case, the gap between the temperature transmission pin 32 and the inner peripheral surface of the temperature measurement hole 31 may be filled with the same substance as the temperature transmission pin 32, or may be filled with the same substance as the pack case 30 or a heat transfer substance. The temperature transmission pin 32 may be formed of a known heat transfer substance for the purpose of more effectively transmitting the temperature outside the pack case 30 to the pack temperature sensor 60.

[0033] As shown in FIG. 4, the pack temperature sensor 60 is mounted on an FPCB 31 (Flexible Printed Circuit Board) with wiring printed for signal connection to the BMS 20, and this FPCB is attached to the inner surface or the outer surface inside the pack case 30 so that the pack temperature sensor 60 is configured to measure the temperature of the pack case 30.

[0034] (4) Cell temperature sensor 40 The cell temperature sensor 40 is arranged on the surface of the battery cell 10 to measure the surface temperature of the cell at a predetermined cycle, and is connected so as to deliver a signal for calculating the measured temperature to the BMS.

[0035] The cell temperature sensor 40 can be attached to the surface of each of the plurality of battery cells 10 in order to calculate the temperature of each of the plurality of battery cells 10, and as shown in FIG. 2, can be attached to a plurality of positions of an individual battery cell 10.

[0036] (5) BMS temperature sensor 50 The BMS temperature sensor 50 is arranged on the BMS 20 to measure the surrounding temperature. As shown in FIG. 3, it is arranged on a printed circuit board (PCB: Printed Circuit Board) constituting the BMS 20 to measure the temperature around the BMS 20.

[0037] The arrangement position of the BMS temperature sensor 50 of the present invention is not limited to only the PCB of the BMS, and can also be configured in a form in which it is mounted on an FPCB 70 for sensor mounting and attached around the BMS 20.

[0038] (6) Pack temperature sensor 60 As described above with reference to FIG. 4, one or more pack temperature sensors 60 are attached to the inner surface or the outer surface of the pack case 30, and are configured to measure the temperature outside the pack case 30 instead of the temperature of the battery cell 10 or the BMS 20 and transmit the measured value to the BMS 20.

[0039] (7) FPCB 70 for mounting sensors In the present invention, the mounting form of the pack temperature sensor is not restricted in any way to a specific form. However, as one embodiment of the mounting form, as shown in FIG. 5, there is a case where it is mounted on the inner surface or the outer surface of the battery cell 10, the BMS 20, or the pack case 30 via the FPCB 70 for mounting sensors. In FIG. 5, illustration of the specific circuit pattern is omitted.

[0040] As shown in FIG. 5, on the FPCB 70 for mounting sensors, a sensor mounting portion 73 on which a temperature sensor is placed is formed. A temperature sensor is attached to the sensor mounting portion 73 to form at the temperature measurement location, and the temperature sensor connection lead wire 71 of the FPCB 70 for mounting sensors is connected to the wiring pattern of the FPCB 70 to which the temperature sensors 40, 50, 60 are connected so as to transmit the measured value from the sensor to the BMS 20, and the measured value of the temperature sensor is transmitted to the BMS. When the FPCB 70 for mounting sensors on which the pack temperature sensor 60 is mounted is attached to the outer surface of the pack case 30, it is connected to the inside of the pack case 30 in order to deliver the measured value of the pack temperature sensor 60 to the BMS 20. For this purpose, the pack case 30 may be formed with a wiring connection hole (not shown) for internal connection of the temperature sensor connection lead wire 71.

[0041] 2. Overheat diagnosis system 200 of battery pack FIG. 6 shows the configuration of an overheat diagnosis system 200 for a battery pack that performs overheat diagnosis of the battery pack 100 in a battery system including the above-described one or more n battery packs 100_a (a = 1, 2, 3,..., n).

[0042] The battery temperature diagnosis system is a battery system including one or more than one of n battery packs 100_a (a = 1, 2, 3,..., n). As described above, each battery pack 100 is equipped with a cell temperature sensor or a pack temperature sensor to measure the internal and external temperatures of the battery pack. When performing overheat diagnosis on each battery pack 100, the BMS 20 of each battery pack 100 uses the measured values of the cell temperature sensor or the pack temperature sensor to determine whether the cause of the overheat diagnosis is due to an increase in the internal temperature of the battery pack 100 or an increase in the external temperature, and transmits the result of the determination to the upper control unit 210.

[0043] The upper control unit 210 may be a battery rack BMS (Rack BMS) composed of a plurality of battery packs 100, or may be a control unit of a system including a plurality of battery packs 100 and a plurality of battery racks.

[0044] In another embodiment, the BMS 20 of the battery pack 100 transmits the temperature measurement value to the upper control unit 210. The upper control unit 210 receives the measured result value of the temperature in each battery pack 100, and based on this, performs overheat diagnosis on each battery pack 100, and determines whether the cause of the overheat diagnosis is due to an increase in the internal temperature of the battery pack or an increase in the external temperature of the battery pack.

[0045] The specific procedures and methods for determining whether the cause of the overheat diagnosis is due to an increase in the internal temperature of the battery pack or an increase in the external temperature of the battery pack will be described below.

[0046] 3. Overheat Diagnosis Method for Battery Pack Based on FIG. 7, the overheat diagnosis method for the battery pack according to the present invention will be described.

[0047] (1) Internal Temperature Measurement Step of Battery Pack (S10) In at least one or more cell temperature sensors 40 attached to the battery cell 10, the pack BMS 20 measures the temperature of the battery cell 10 at predetermined intervals.

[0048] In the internal temperature measurement step of the battery pack, further, the pack BMS 20 may include a procedure of further measuring the temperature of the BMS at a BMS temperature sensor 50 attached around the BMS in addition to the cell temperature sensor 40.

[0049] The BMS 20 can calculate the maximum value of the measured temperatures of the battery cell 10 and the BMS as the internal temperature of the battery, and compare this with a predetermined first reference value to determine overheating.

[0050] (2) External temperature measurement step of the battery pack (S20) The step in which the BMS 20 determines the external temperature of the battery pack based on the measured values from at least one or more pack temperature sensors 60 attached to the case 30 of the battery pack 100. The BMS 20 can perform an overheating determination by comparing the external temperature of the battery pack with a predetermined second reference value.

[0051] (3) Overheating diagnosis step of the battery pack (S30) The procedure in which the BMS 20 performs an overheating diagnosis of the battery pack by comparing these with a predetermined reference value based on the internal temperature of the battery and the external temperature of the battery pack measured in the steps S10 and S20.

[0052] In the overheating diagnosis step of the battery pack, if the internal temperature of the battery pack is higher than the predetermined first reference value, or if the external temperature of the battery pack is higher than the predetermined second reference value, it is diagnosed as overheating. The first reference value and the second reference value may be set to the same value as each other, or may be set to different values from each other.

[0053] In another embodiment, the overheat diagnosis step of the battery pack may be configured such that, in a predetermined temperature measurement period, even if the external temperature of the battery pack is higher than the second reference value, if the internal temperature of the battery pack is not higher than the predetermined first reference value, the battery is not diagnosed as overheated, and the battery is diagnosed as overheated only when the internal temperature of the battery pack is higher than the predetermined first reference value.

[0054] (4) Step of determining the cause of overheat diagnosis (S40) The BMS 20 performs the steps S10 to S30 at predetermined intervals, and when the battery is diagnosed as overheated in the procedure of step S30 of a predetermined interval, it determines whether the overheat is diagnosed due to an increase in the internal temperature of the battery or due to an increase in the external temperature of the battery.

[0055] That is, in a predetermined period, if the external temperature of the battery is higher than the predetermined second reference value but the internal temperature of the battery is not higher than the predetermined first reference value, even if the battery is determined to be overheated, this is determined to be diagnosed as overheated due to external factors of the battery rather than overheating of the battery cells or the BMS. Even if the internal temperature of the battery becomes higher than the predetermined first reference value in a subsequent period, it is determined whether the battery is diagnosed as overheated due to external factors of the battery or whether the overheat diagnosis is a misdiagnosis.

[0056] On the one hand, the overheat diagnosis step (S30) of the battery pack may be configured such that, in a predetermined temperature measurement cycle, even if the external temperature of the battery pack is higher than the second reference value, if the internal temperature of the battery pack is not higher than the predetermined first reference value, it is not diagnosed as overheating of the battery, and it is diagnosed as overheating of the battery only when the internal temperature of the battery pack is higher than the predetermined first reference value. However, even in this case, in the overheat diagnosis cause determination step (S40), when the internal temperature of the battery pack becomes higher than the predetermined first reference value, if the external temperature of the battery becomes higher than the predetermined second reference value first, and then the internal temperature of the battery pack becomes higher than the predetermined first reference value, it is determined that the cause of the overheat diagnosis is due to an external factor of the battery pack.

[0057] On the other hand, as shown in FIG. 6, in a system including a plurality of battery packs 100a (a = 1, 2,..., n) and in which the upper control unit 210 performs overheat diagnosis of the plurality of battery packs, the method by which the upper control unit 210 performs overheat diagnosis of each battery pack is the same. The upper control unit 210 receives the overheat diagnosis result or the measured value of the internal temperature of the battery pack and the measured value of the external temperature of the battery pack from each battery pack 100a via the procedures of the steps S10 to S40 by the BMS 20 of each battery pack, and based on this, performs overheat diagnosis on each battery pack and determines the cause of the overheat diagnosis.

[0058] That is, the present invention provides a method for diagnosing overheating of a battery system, which includes one or more battery packs each provided with a separate temperature sensor for measuring the internal temperature and the external temperature of the battery pack, and a host controller that receives the transmission of the internal temperature and the external temperature of each battery pack from the battery pack. The method comprises: a temperature measurement step of each battery pack measuring the internal temperature and the external temperature of its own battery pack; a measurement value reception step of the host controller receiving the measured values of the internal temperature and the external temperature of each battery pack; an overheating diagnosis step of the host controller diagnosing overheating of each battery pack based on the received measured values of the internal temperature and the external temperature of each battery pack; and a determination step of determining whether the cause of the overheating diagnosis is due to an internal factor or an external factor of the battery pack.

[0059] At this time, each of the battery packs measures the internal temperature and the external temperature using different temperature sensors attached to different positions of the battery pack. The internal temperature is obtained from a temperature sensor attached to a battery cell or a BMS housed inside the pack case of the battery pack, and the external temperature is obtained from a temperature sensor attached to the pack case of the battery pack. These temperature sensors correspond to the above-mentioned cell temperature sensor 40, BMS temperature sensor 50, and pack temperature sensor 60.

[0060] It should be easily understood by ordinary technicians that the overheating diagnosis of each battery pack or the determination of the cause of the overheating diagnosis according to the present invention described above can be performed by installing a series of processor execution algorithms for performing each procedure of steps S10 to S40 of the overheating diagnosis method in the BMS 20 or the host control unit 210 of each battery pack.

[0061] Thus, according to the battery pack and the overheat diagnosis method of the battery pack according to the present invention, when performing overheat diagnosis for stable operation of the battery, it is possible to distinguish whether it is an overheat diagnosis due to overheating of the battery cells or the BMS itself constituting the battery pack, or an overheat diagnosis due to external environmental factors of the battery pack, and thus perform more accurate operation of the battery.

[0062] The drawing reference numerals and names of each component used in the present invention are as follows.

Explanation of Reference Numerals

[0063] 100 Battery Pack 200 Overheat Diagnosis System of Battery Pack 10 Battery Cell 20 BMS 30 Pack Case 31 Temperature Measurement Hole 32 Temperature Transmission Pin 40 Cell Temperature Sensor 50 BMS Temperature Sensor 60 Pack Temperature Sensor 70 FPCB for Mounting Sensors 71 Temperature Sensor Connection Conductor 72 Heat Dissipation Film 73 Sensor Mounting Portion 210 Upper Control Unit

Claims

1. In a battery pack configured to perform overheat diagnosis of the battery pack, one or more battery cells, a battery management system that performs overheat diagnosis of the battery pack as the internal temperature of the battery pack rises or the external temperature of the battery pack rises, and determines whether the cause of the overheat diagnosis is due to the rise in the internal temperature of the battery pack or the rise in the external temperature, a pack case that houses the battery cells and the battery management system, one or more cell temperature sensors arranged adjacent to the battery cells and providing measurement values for determining the rise in the internal temperature of the battery pack, one or more pack temperature sensors attached to the inner surface or the outer surface of the pack case and providing measurement values for determining the rise in the external temperature of the battery pack, A battery pack comprising:

2. The battery management system receives measurement values from the cell temperature sensors at a predetermined cycle and determines the rise in the internal temperature of the battery pack, The battery pack according to claim 1, wherein measurement values from the pack temperature sensors are received at a predetermined cycle and the rise in the external temperature of the battery pack is determined.

3. The battery management system receives measurement values from the cell temperature sensors and the pack temperature sensors, calculates the internal temperature of the battery pack and the external temperature of the battery pack from each, performs overheat diagnosis of the battery pack based on the internal temperature value of the battery pack and the external temperature value of the battery pack, The battery pack according to claim 2, wherein when the external temperature value of the battery pack rises earlier than the internal temperature value of the battery pack and is diagnosed as overheating, it is determined that the cause of the overheat diagnosis is due to an external factor of the battery pack.

4. further comprising a battery management system temperature sensor arranged adjacent to the battery management system, The battery management system according to claim 3, wherein measurement values from the cell temperature sensors and the battery management system temperature sensors are received at a predetermined cycle and the rise in the internal temperature of the battery pack is determined.

5. The pack temperature sensor is attached to the inner surface of the pack case, The pack case The battery pack according to claim 1, comprising a temperature measurement hole at a position corresponding to the location where the pack temperature sensor is attached.

6. The pack case The battery pack according to claim 5, further comprising a temperature transmission pin that transmits the external temperature of the battery pack to the pack temperature sensor attached to the inner surface of the pack case through the temperature measurement hole.

7. The battery pack according to claim 5, wherein a heat dissipation film for blocking heat is attached to the upper surface of the pack temperature sensor facing the inner surface of the pack case.

8. Comprising one or more battery packs according to any one of claims 1 to 7, A battery pack overheat diagnosis system comprising an upper control unit that receives measured values of the internal temperature and the external temperature of the battery pack from the battery pack and performs overheat diagnosis of the battery pack.

9. The upper control unit When performing overheat diagnosis of the battery pack, if the external temperature of the battery pack rises above a predetermined reference value earlier than the internal temperature of the battery pack, it is determined that the overheat is due to an external factor of the battery pack. The battery pack overheat diagnosis system according to claim 8.

10. An internal temperature measurement step of the battery pack for measuring the internal temperature of the battery pack at a predetermined cycle, An external temperature measurement step of the battery pack for measuring the external temperature of the battery pack at a predetermined cycle, An overheat diagnosis step of diagnosing the presence or absence of overheat of the battery pack based on the internal temperature and the external temperature of the battery pack, In the overheat diagnosis step, when the external temperature of the battery pack rises earlier than the internal temperature of the battery pack, a step of determining the cause of the overheat diagnosis that determines that the overheat diagnosis is a misdiagnosis, A method for diagnosing overheat of a battery pack, including

11. In the overheat diagnosis step, When the internal temperature of the battery pack is greater than a predetermined reference value, it is diagnosed that the battery pack is overheated. In the step of determining the cause of the overheat diagnosis, The method for diagnosing overheating of a battery pack according to claim 10, wherein when the external temperature of the battery pack rises earlier than the internal temperature of the battery pack, it is determined that the cause of the overheating diagnosis is due to the rise in the external temperature.

12. The internal temperature of the battery pack is obtained from a temperature sensor attached to a battery cell housed inside the pack case of the battery pack or a battery management system, The external temperature of the battery pack is obtained from a temperature sensor attached to the pack case of the battery pack. The method for diagnosing overheating of a battery pack according to claim 10 or 11.

13. A method for diagnosing overheating of a battery system including one or more battery packs each provided with a separate temperature sensor for measuring the internal temperature and the external temperature of the battery pack, and a host control unit for receiving the transmission of the internal temperature and the external temperature of each battery pack from the battery pack, each battery pack includes a battery pack temperature measurement step of measuring the internal temperature and the external temperature of each battery pack, a measurement value reception step of receiving, by the host control unit, the measured values of the internal temperature and the external temperature of each battery pack, an overheating diagnosis step of the host control unit performing an overheating diagnosis of each battery pack based on the received measured values of the internal temperature and the external temperature of each battery pack, an overheating diagnosis cause determination step of determining whether the cause of the overheating diagnosis is due to an internal factor or an external factor of the battery pack, The method for diagnosing overheating of a battery system including.

14. The method for diagnosing overheating of a battery system according to claim 13, wherein each battery pack performs the measurement of the internal temperature and the measurement of the external temperature at different temperature sensors attached to different positions of each battery pack.

15. The internal temperature is obtained from a temperature sensor attached to a battery cell housed inside the pack case of the battery pack or a battery management system, The external temperature is obtained from a temperature sensor attached to an external surface or an internal surface of the pack case of the battery pack. The method for diagnosing overheating of a battery system according to claim 14.

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