Method and device for determining electric leakage position of battery pack, battery management system and vehicle

Abstract

The invention relates to the technical field of electric leakage detection of a battery pack, in particular to an electric leakage position determination method and device of a battery pack, a battery management system and a vehicle, and is applied to a battery management unit which comprises an electric leakage detection circuit. The electric leakage position determination method comprises the steps of detecting electric leakage resistance and electric leakage voltage of a battery pack through an electric leakage detection circuit; obtaining the number of battery cells in the battery pack, the voltage of each battery cell and the total voltage; when the leakage resistance is greater than the preset resistance, determining a leakage detection base point of the battery pack according to the leakage voltage, the number of the cells and the total voltage; determining electric leakage comparison voltage according to the electric leakage detection base point and the voltage of each battery cell; and determining the electric leakage position of the battery pack according to the electric leakage detection base point, the electric leakage voltage, the electric leakage comparison voltage and the voltage of each cell. The electric leakage position of the battery pack can be accurately determined, the problem can be quickly positioned when electric leakage occurs, effective technical support is provided for after-sale and maintenance, and safe and stable operation of the battery pack is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of leakage detection of battery packs, and in particular to a leakage position determination method and device for battery packs, a battery management system and a vehicle. BACKGROUND

[0002] During the use of a battery pack, leakage has always been an important factor affecting its safety and reliability. The leakage detection technology of the battery pack in the related art mainly focuses on the leakage of the total positive and total negative of the battery to the shell, and determines whether there is leakage by detecting the insulation resistance of the total positive and total negative of the battery pack to the ground. However, in actual applications, insulation failure does not necessarily occur at these two positions, and leakage may be caused by insulation failure at a certain battery cell inside the battery pack, making the leakage detection method in the related art have great limitations in positioning the leakage position, and it is difficult to accurately determine the specific leakage point, which brings many inconveniences to after-sales and maintenance work. When the battery pack leaks, the maintenance personnel can only know that the leakage occurs inside the battery pack, but cannot quickly and accurately find the specific battery cell where the leakage occurs, thereby prolonging the troubleshooting and repair time and reducing the use efficiency and safety of the battery pack. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, the first object of the present application is to provide a leakage position determination method for a battery pack, which can accurately determine the leakage position of the battery pack, and quickly locate the problem when leakage occurs, thereby providing effective technical support for after-sales and maintenance and ensuring the safe and stable operation of the battery pack.

[0004] The second object of the present application is to provide a leakage position determination device for a battery pack.

[0005] The third object of the present application is to provide a battery management system.

[0006] The fourth object of the present application is to provide a vehicle.

[0007] To achieve the above object, the first aspect of the present application provides a method for determining a leakage position of a battery pack, which is applied to a battery management unit including a leakage detection circuit, and comprises the following steps: detecting a leakage resistance and a leakage voltage of the battery pack by the leakage detection circuit; obtaining a number of cells, a voltage of each cell and a total voltage in the battery pack; determining a leakage detection base point of the battery pack according to the leakage voltage, the number of cells and the total voltage when the leakage resistance is greater than a preset resistance; determining a leakage comparison voltage according to the leakage detection base point and the voltage of each cell; and determining the leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each cell.

[0008] The method for determining a leakage position of a battery pack according to the present application can accurately determine the leakage position of the battery pack, quickly locate the problem when leakage occurs, provide effective technical support for after-sales and maintenance, and ensure the safe and stable operation of the battery pack.

[0009] In addition, the method for determining a leakage position of a battery pack according to the above-mentioned embodiments of the present application can further comprise the following additional technical features:

[0010] According to one embodiment of the present application, the leakage detection base point of the battery pack is determined according to the leakage voltage, the number of cells and the total voltage, which comprises the following steps: calculating a quotient value of the leakage voltage divided by the total voltage; and performing a down-round processing on a product of the quotient value and the number of cells to determine the leakage detection base point of the battery pack.

[0011] According to one embodiment of the present application, the leakage comparison voltage is determined according to the leakage detection base point and the voltage of each cell, which comprises the following steps: determining a target cell according to the leakage detection base point; and determining the leakage comparison voltage according to a voltage value between a negative electrode of the battery pack and the target cell.

[0012] According to one embodiment of the present application, the leakage position of the battery pack is determined according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each cell, which comprises the following steps: when the leakage comparison voltage is equal to the leakage voltage, determining a position of the leakage detection base point in the battery pack as the leakage position; and when the leakage comparison voltage is not equal to the leakage voltage, updating the leakage detection base point and the leakage comparison voltage, and determining a position of the updated leakage detection base point in the battery pack as the leakage position.

[0013] According to one embodiment of the present application, when the leakage comparison voltage is not equal to the leakage voltage, the updating of the leakage detection base point and the leakage comparison voltage comprises: when the leakage comparison voltage is greater than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the current cell corresponding to the leakage detection base point, the corresponding position of the previous cell of the current cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode of the battery pack and the previous cell is taken as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the current cell corresponding to the updated leakage detection base point; when the leakage comparison voltage is less than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the next cell of the current cell corresponding to the leakage detection base point, the corresponding position of the next cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode of the battery pack and the next cell is taken as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the next cell of the current cell corresponding to the updated leakage detection base point.

[0014] According to one embodiment of the present application, after determining the leakage position of the battery pack, the method further comprises: taking the current cell corresponding to the leakage position and the cells within a preset number before and after the current cell as the cells to be checked; and performing detection processing on the cells to be checked to determine the leakage fault point and / or the fault cell.

[0015] According to one embodiment of the present application, the leakage detection circuit comprises a plurality of switches, and the leakage detection circuit has a first equivalent circuit and a second equivalent circuit when the plurality of switches are in different states.

[0016] According to one embodiment of the present application, the leakage resistance and the leakage voltage of the battery pack are detected by the leakage detection circuit, which comprises: establishing a plurality of first equivalent equations based on the first equivalent circuit by using the bridge method, and establishing a second equivalent equation based on the second equivalent circuit by using the bridge method; establishing a plurality of equation groups according to the second equivalent equation and the plurality of first equivalent equations, wherein each equation group comprises the second equivalent equation and one first equivalent equation; determining a plurality of leakage resistance values and a plurality of leakage voltage values according to the plurality of equation groups, wherein each equation group can determine one leakage resistance value and one leakage voltage value; and determining the average of the plurality of leakage resistance values as the leakage resistance, and determining the average of the plurality of leakage voltage values as the leakage voltage.

[0017] According to one embodiment of the present application, before the average of the plurality of leakage resistance values is determined as the leakage resistance and the average of the plurality of leakage voltage values is determined as the leakage voltage, the method further comprises: obtaining a first range value of the plurality of leakage resistance values and a second range value of the plurality of leakage voltage values; determining that the first range value is within a first preset fluctuation range and the second range value is within a second preset fluctuation range.

[0018] To achieve the above object, the second aspect of the present application provides a leakage position determination device of a battery pack, wherein the device is applied to a battery management unit, the battery management unit comprises a leakage detection circuit, and the device comprises: a detection module configured to detect a leakage resistance and a leakage voltage of the battery pack through the leakage detection circuit; an obtaining module configured to obtain a number of battery cells, a voltage of each battery cell and a total voltage in the battery pack; a determination module configured to determine a leakage detection base point of the battery pack according to the leakage voltage, the number of battery cells and the total voltage when the leakage resistance is greater than a preset resistance; the determination module is further configured to determine a leakage comparison voltage according to the leakage detection base point and the voltage of each battery cell; and the determination module is further configured to determine a leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each battery cell.

[0019] The leakage position determination device of the battery pack according to the embodiments of the present application can accurately determine the leakage position of the battery pack, and can quickly locate the problem when leakage occurs, thereby providing effective technical support for after-sales and maintenance, and ensuring the safe and stable operation of the battery pack.

[0020] To achieve the above object, the third aspect of the present application provides a battery management system comprising the leakage position determination device of the battery pack of the aforementioned embodiments of the present application.

[0021] The battery management system according to the embodiments of the present application can accurately determine the leakage position of the battery pack by adopting the leakage position determination device of the battery pack of the aforementioned embodiments of the present application, and can quickly locate the problem when leakage occurs, thereby providing effective technical support for after-sales and maintenance, and ensuring the safe and stable operation of the battery pack.

[0022] To achieve the above object, the fourth aspect of the present application provides a vehicle comprising the battery management system of the aforementioned embodiments of the present application.

[0023] The vehicle according to the embodiments of the present application can accurately determine the leakage position of the battery pack by adopting the battery management system of the aforementioned embodiments of the present application, and can quickly locate the problem when leakage occurs, thereby providing effective technical support for after-sales and maintenance, and ensuring the safe and stable operation of the battery pack.

[0024] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of a battery management unit according to an embodiment of the present application;

[0026] Figure 2 is a flowchart of a method for determining a leakage location of a battery pack according to an embodiment of the present application;

[0027] Figure 3 is a block diagram of a device for determining a leakage location of a battery pack according to an embodiment of the present application;

[0028] Figure 4 is a block diagram of a battery management system according to an embodiment of the present application;

[0029] Figure 5 is a block diagram of a vehicle according to an embodiment of the present application.

[0030] REFERENCE NUMERALS:

[0031] Battery management unit 1000, leakage detection circuit 100, analog-to-digital converter 200, micro control unit 300, battery monitoring unit 400, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, leakage resistor Rx, first capacitor C1, second capacitor C2, first switch S1, second switch S2, third switch S3, first node P1, second node P2, total voltage detection terminal Ubat, device for determining a leakage location of a battery pack 500, detection module 10, acquisition module 20, determination module 30, battery management system 2000, vehicle 3000. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described in detail below with reference to the attached drawings, which show by way of example, embodiments in which like numerals indicate like elements or elements having the same or similar function. The embodiments described below are examples intended to explain the present application, and are not to be understood as limiting the present application.

[0033] A method for determining a leakage location of a battery pack, a computer readable storage medium, a device for determining a leakage location of a battery pack, a battery management system and a vehicle according to embodiments of the present application are described below with reference to the attached drawings.

[0034] Before introducing the method and device for determining a leakage location of a battery pack according to the present application, the battery management unit and the leakage detection circuit according to the present application are described, in particular, as follows. Figure 1As shown, the battery management unit 1000 includes a leakage detection circuit 100, an analog-digital converter 200, a micro control unit 300 and a battery monitoring unit 400. The leakage detection circuit 100 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a leakage resistor Rx, a first capacitor C1, a second capacitor C2, a first switch S1, a second switch S2 and a third switch S3. One end of the leakage resistor Rx is connected to a leakage detection end of the battery pack, and the other end of the leakage resistor Rx is connected to one end of the first switch S1, one end of the first capacitor C1 and one end of the second capacitor C2, respectively. The other end of the first switch S1 is connected to one end of the second resistor R2 and one end of the third resistor R3, and has a first node P1. The other end of the third resistor R3 is connected to one end of the second switch S2, and the other end of the second switch S2 is connected to a second input end of the analog-digital converter 200 and one end of the fourth resistor R4, and has a second node P2. The other end of the fourth resistor R4 is grounded. The other end of the second resistor R2 is connected to one end of the third switch S3 and one end of the first resistor R1, respectively. One end of the fifth resistor R5 is connected to a first input end of the analog-digital converter 200 and one end of the sixth resistor R6. The positive electrode of the battery pack is connected to the other end of the first capacitor C1, the other end of the first resistor R1 and the other end of the fifth resistor R5, and has a total voltage detection end Ubat. The negative electrode of the battery pack is connected to the other end of the second capacitor C2, the other end of the third switch S3, the other end of the sixth resistor R6 and one end of a current sensor. The other end of the current sensor is connected to a third input end of the analog-digital converter 200. The output end of the analog-digital converter 200 is connected through the micro control unit 300 and the battery monitoring unit 400. The battery monitoring unit 400 is used to obtain the voltage of each cell of the battery pack.

[0035] Figure 2 is a flowchart of a method for determining a leakage position of a battery pack according to an embodiment of the present application.

[0036] Specifically, in some embodiments of the present application, the battery management unit includes a leakage detection circuit, such as Figure 1 As shown, the method for determining a leakage position of a battery pack includes:

[0037] S101, detecting the leakage resistance and the leakage voltage of the battery pack by the leakage detection circuit.

[0038] Specifically, in this embodiment, detecting the leakage resistance and the leakage voltage of the battery pack by the leakage detection circuit includes the following steps:

[0039] S1, the micro control unit of the battery management unit implements obtaining the voltage information of each cell of the battery pack through the battery monitoring unit.

[0040] S2, the micro control unit sends a command to control the first switch and the second switch to be in a closed state, and the third switch to be in an open state.

[0041] S3, after waiting for a preset time, the signal is stable, and the first current, the first voltage and the second voltage are collected through the analog-digital converter. The first voltage is obtained through the first input end of the analog-digital converter, the second voltage is obtained through the second input end of the analog-digital converter, and the first current is obtained through the third input end of the analog-digital converter.

[0042] S4, the micro control unit continuously obtains a preset number of first currents, first voltages and second voltages through the analog-digital converter, and calculates the range values of the first currents, the first voltages and the second voltages.

[0043] S5, when the range values of the first current, the first voltage and the second voltage are all within the allowable limit, the average value of the first voltage and the average value of the second voltage are obtained.

[0044] S6, according to the average value U bats1 of the first voltage and the average value U ios1 of the second voltage, the voltage Up1 of the first node and the voltage Ubat1 of the total voltage detection end are calculated through the following formula.

[0045]

[0046]

[0047] S7, the voltage Up1 of the first node and the voltage Ubat1 of the total voltage detection end are substituted into the following formula 1.

[0048]

[0049] Wherein, Ux represents the leakage voltage, and Rx represents the leakage resistance.

[0050] S8, the micro control unit sends a command to control the third switch to be in a closed state, and repeats steps S3 to S5 to obtain the updated average value of the first voltage and the average value of the second voltage.

[0051] S9, according to the updated average value U bats2 of the first voltage, the updated voltage Up2 of the first node is calculated through the following formula.

[0052]

[0053] S10, the voltage Up2 of the first node is substituted into the following formula 2.

[0054]

[0055] wherein Ux represents the leakage voltage, and Rx represents the leakage resistance.

[0056] S11, leakage voltage Ux and leakage resistance Rx are calculated according to Formula 1 in step S7 and Formula 2 in step S10.

[0057] S12, Formula 1 is obtained by repeating steps S1 to S7 for data update, and new leakage resistance and leakage voltage are calculated according to Formula 1 and Formula 2 in step S10, and so on, until a preset number of leakage resistance and leakage voltage are obtained.

[0058] S13, the range of the leakage resistance and the leakage voltage in the preset number is calculated, and when the range of the leakage resistance and the leakage voltage is within the allowable limit, the average value Ravr of the leakage resistance and the average value Uavr of the leakage voltage in the preset number are calculated, and the average value of the leakage resistance in the preset number is taken as the leakage resistance of the battery pack detected by the leakage detection circuit, and the average value of the leakage voltage in the preset number is taken as the leakage voltage of the battery pack detected by the leakage detection circuit.

[0059] S102, the number of cells in the battery pack, the voltage of each cell and the total voltage are obtained.

[0060] Specifically, in this embodiment, the micro control unit can obtain the number of cells in the battery pack and the voltage of each cell through the battery monitoring unit, and the micro control unit can obtain the total voltage of the total voltage detection end in the leakage detection circuit through the analog-digital converter.

[0061] S103, when the leakage resistance is greater than a preset resistance, the leakage detection base point of the battery pack is determined according to the leakage voltage, the number of cells and the total voltage.

[0062] Specifically, in this embodiment, when the leakage resistance is greater than a preset resistance, it indicates that the battery pack has a leakage situation, for example, when the leakage resistance is greater than a first resistance, it can be determined that the leakage situation is a normal leakage situation, when the leakage resistance is greater than a second resistance, it can be determined that the leakage situation is a dangerous leakage situation, and when the leakage resistance is greater than a third resistance, it can be determined that the leakage situation is a serious leakage situation, wherein the resistance value of the first resistance is less than the resistance value of the second resistance, and the resistance value of the second resistance is less than the resistance value of the third resistance. The quotient of the leakage voltage divided by the total voltage can be calculated, and the product of the quotient and the number of cells is rounded down to determine the leakage detection base point of the battery pack, and the specific calculation formula is as follows:

[0063]

[0064] wherein N represents the number of cells, N1 represents the leakage detection base point of the battery pack, U avr represents the leakage voltage, Ubat a quotient of the total voltage.

[0065] S104, determining a leakage comparison voltage according to the leakage detection base point and the voltages of the battery cells.

[0066] Specifically, in this embodiment, assuming that the leakage detection base point N1 is a value of 7, and the voltage of each battery cell is 30 volts. Then, the target battery cell can be determined according to the leakage detection base point N1 = 7, that is, the 7th battery cell from the negative electrode PACK- of the battery pack, since the battery cells of the battery pack are connected in series, the voltage value between the negative electrode PACK- of the battery pack and the 7th battery cell can be obtained by accumulating the voltage values of the previous 7 battery cells, that is, the voltage value between the negative electrode PACK- of the battery pack and the 7th battery cell is the sum of the voltage values of the previous 7 battery cells, that is, 30V x 7 = 210V, so the leakage comparison voltage Uadd is determined to be 210V.

[0067] S105, determining a leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltages of the battery cells.

[0068] Specifically, in this embodiment, when the leakage comparison voltage is equal to the leakage voltage, the position of the leakage detection base point in the battery pack is determined as the leakage position. In addition, the battery cells in the battery pack are arranged in order from the negative electrode to the positive electrode of the battery pack, when the leakage comparison voltage is greater than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the current battery cell corresponding to the leakage detection base point, the corresponding position of the previous battery cell of the current battery cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode of the battery pack and the previous battery cell is taken as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the current battery cell corresponding to the updated leakage detection base point; while when the leakage comparison voltage is less than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the next battery cell of the current battery cell corresponding to the leakage detection base point, the corresponding position of the next battery cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode of the battery pack and the next battery cell is taken as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the next battery cell of the current battery cell corresponding to the updated leakage detection base point. Further, the position of the updated leakage detection base point in the battery pack is determined as the leakage position.

[0069] Further, in some embodiments of the present application, the leakage detection base point of the battery pack is determined according to the leakage voltage, the number of battery cells and the total voltage, comprising: calculating a quotient of the leakage voltage divided by the total voltage; and performing down-round processing on the product of the quotient and the number of battery cells to determine the leakage detection base point of the battery pack.

[0070] Specifically, in this embodiment, when the leakage voltage is Uavr and the quotient of the total voltage is Ubat, the product of the quotient and the number of battery cells is rounded down to determine the leakage detection base point of the battery pack, and the calculation formula is as follows:

[0071]

[0072] wherein N represents the number of battery cells, and N1 represents the leakage detection base point of the battery pack.

[0073] Further, in some embodiments of the present application, the leakage comparison voltage is determined according to the leakage detection base point and the voltage of each battery cell, comprising: determining a target battery cell according to the leakage detection base point; and determining the leakage comparison voltage according to the voltage value between the negative electrode of the battery pack and the target battery cell.

[0074] Specifically, in this embodiment, if the leakage detection base point is a value of 9, the target battery cell can be determined as the 9th battery cell from the negative electrode PACK- of the battery pack to the positive electrode PACK+ of the battery pack, and the 9th battery cell is taken as the target battery cell, so that the leakage comparison voltage can be determined according to the voltage value between the negative electrode PACK- of the battery pack and the 9th battery cell. Figure 1

[0075] Further, in some embodiments of the present application, the leakage position of the battery pack is determined according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each battery cell, comprising: when the leakage comparison voltage is equal to the leakage voltage, the position of the leakage detection base point in the battery pack is determined as the leakage position; and when the leakage comparison voltage is not equal to the leakage voltage, the leakage detection base point and the leakage comparison voltage are updated, and the position of the updated leakage detection base point in the battery pack is determined as the leakage position.

[0076] Specifically, in this embodiment, when the leakage comparison voltage is equal to the leakage voltage, the position of the leakage detection base point in the battery pack is determined as the leakage position, and each battery cell in the battery pack is arranged in order from the negative electrode of the battery pack to the positive electrode; and when the leakage comparison voltage is not equal to the leakage voltage, the leakage detection base point and the leakage comparison voltage are updated.

[0077] ​When the leakage comparison voltage is greater than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the current battery cell corresponding to the leakage detection base point, the corresponding position of the previous battery cell of the current battery cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode of the battery pack and the previous battery cell is taken as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the current battery cell corresponding to the updated leakage detection base point. For example, if the leakage voltage is 232V and the leakage detection base point is the value 9, the target battery cell can be determined to be the 9th battery cell from the negative electrode PACK- of the battery pack to the positive electrode PACK+ of the battery pack, and the 9th battery cell is taken as the target battery cell. The voltage of each battery cell is 30V, so the leakage comparison voltage can be determined according to the voltage value between the negative electrode PACK- of the battery pack and the 9th battery cell. The leakage comparison voltage is 270V, and the difference between the leakage comparison voltage 270V and the leakage voltage 232V is greater than or equal to the voltage 30V of the 9th battery cell. The corresponding position of the 8th battery cell before the 9th battery cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode PACK- of the battery pack and the 8th battery cell is taken as the updated leakage comparison voltage. The updated leakage comparison voltage 240V and the leakage voltage 232V have a difference less than the voltage 30V of the 8th battery cell, and the 8th battery cell can be taken as the position of the leakage battery cell.

[0078] When the leakage comparison voltage is less than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the next battery cell corresponding to the current battery cell of the leakage detection base point, the corresponding position of the next battery cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode of the battery pack and the next battery cell is taken as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the next battery cell corresponding to the current battery cell of the updated leakage detection base point. For example, if the leakage voltage is 312V and the leakage detection base point is the value 9, the target battery cell can be determined to be the 9th battery cell from the negative electrode PACK- of the battery pack to the positive electrode PACK+ of the battery pack, and the 9th battery cell is taken as the target battery cell. The voltage of each battery cell is 30V, so the leakage comparison voltage can be determined according to the voltage value between the negative electrode PACK- of the battery pack and the 9th battery cell. The leakage comparison voltage is 270V, and the difference between the leakage comparison voltage 270V and the leakage voltage 312V is greater than or equal to the voltage 30V of the 9th battery cell. The corresponding position of the next battery cell of the 9th battery cell is taken as the updated leakage detection base point, and the voltage value between the negative electrode PACK- of the battery pack and the 10th battery cell is taken as the updated leakage comparison voltage. The updated leakage comparison voltage 300V and the leakage voltage 312V have a difference less than the voltage 30V of the 10th battery cell, and the 10th battery cell can be taken as the position of the leakage battery cell.

[0079] Further, in some embodiments of the present application, after determining the leakage position of the battery pack, the method further comprises: taking the current battery cell corresponding to the leakage position and the battery cells within a preset number before and after the current battery cell as the battery cells to be investigated; and performing detection processing on the battery cells to be investigated to determine the leakage fault point and / or the faulty battery cell.

[0080] Specifically, in this embodiment, after determining the leakage position of the battery pack, the current battery cell corresponding to the leakage position and the battery cells within a preset number before and after the current battery cell are taken as the battery cells to be investigated, and then the maintenance personnel disassemble the battery pack to find the above-mentioned battery cells to be investigated, disconnect them from the battery pack, and perform re-measurement and confirmation through the leakage detection device. Then, it is investigated whether all the conductive materials of these battery cells are in contact with other conductors, whether the insulation protection is damaged, and whether all the conductive leads (such as sampling lines, copper bars, power lines, etc.) are damaged and leaked. At the same time, the connector of the conductive lead (such as the controller) is investigated. In this way, from near to far, the specific leakage fault point and the faulty battery cell are accurately investigated. Further, the leakage fault point and the specific battery cell with faults in the battery pack can be efficiently and accurately determined, which provides a clear basis for subsequent maintenance or replacement and guarantees the safety and reliability of the battery pack.

[0081] Further, in some embodiments of the present application, the leakage detection circuit comprises a plurality of switches, and the leakage detection circuit has a first equivalent circuit and a second equivalent circuit when the plurality of switches are in different states.

[0082] Specifically, in this embodiment, the leakage detection circuit comprises a first switch, a second switch and a third switch, the leakage detection circuit has a first equivalent circuit when the first switch and the second switch are in a closed state and the third switch is in an open state, and the leakage detection circuit has a second equivalent circuit when the first switch, the second switch and the third switch are in a closed state.

[0083] Further, in some embodiments of the present application, the leakage resistance and the leakage voltage of the battery pack are detected by the leakage detection circuit, which comprises: establishing a plurality of first equivalent equations based on the first equivalent circuit by using the bridge method, and establishing a second equivalent equation based on the second equivalent circuit by using the bridge method; establishing a plurality of equation groups according to the second equivalent equation and the plurality of first equivalent equations, wherein each equation group comprises the second equivalent equation and one first equivalent equation; determining a plurality of leakage resistance values and a plurality of leakage voltage values according to the plurality of equation groups, wherein each equation group can determine one leakage resistance value and one leakage voltage value; and determining the average of the plurality of leakage resistance values as the leakage resistance and the average of the plurality of leakage voltage values as the leakage voltage.

[0084] Specifically, in this embodiment, the leakage detection circuit has a first equivalent circuit when the first switch and the second switch are in a closed state and the third switch is in an open state, and the micro control unit obtains voltages Upx1 of a plurality of first nodes and voltages Ubatx1 of a plurality of total voltage detection ends in the leakage detection circuit through an analog-to-digital converter within a preset time, and then pairs the obtained voltages Upx1 of the plurality of first nodes and the voltages Ubatx1 of the plurality of total voltage detection ends one by one and substitutes them into the following formula to obtain a plurality of first equivalent equations.

[0085]

[0086] wherein Ux represents a leakage voltage and Rx represents a leakage resistance.

[0087] The leakage detection circuit has a second equivalent circuit when the first switch, the second switch and the third switch are in a closed state, and the micro control unit obtains a voltage Upx2 of a first node in the leakage detection circuit through an analog-to-digital converter, and then substitutes the obtained voltage Upx2 of the first node into the following formula to obtain a second equivalent equation.

[0088]

[0089] wherein Ux represents a leakage voltage and Rx represents a leakage resistance.

[0090] Each first equivalent equation is paired with the second equivalent equation to establish a plurality of equation groups, and then a plurality of leakage resistance values and a plurality of leakage voltage values are determined according to the plurality of equation groups, wherein each equation group can determine one leakage resistance value and one leakage voltage value, so as to determine an average value of the plurality of leakage resistance values as the leakage resistance and an average value of the plurality of leakage voltage values as the leakage voltage.

[0091] Further, in some embodiments of the present application, before the average value of the plurality of leakage resistance values is determined as the leakage resistance and the average value of the plurality of leakage voltage values is determined as the leakage voltage, the method further comprises: obtaining a first range value of the plurality of leakage resistance values and a second range value of the plurality of leakage voltage values; determining that the first range value is within a first preset fluctuation range and the second range value is within a second preset fluctuation range.

[0092] Specifically, in this embodiment, a first range value of the plurality of leakage resistance values and a second range value of the plurality of leakage voltage values are obtained, and the calculation method of the range value is to subtract the minimum value from the maximum value in the measurement data, so as to quantify the fluctuation degree of the data. Then, it is determined whether the first range value is in a first preset fluctuation range and whether the second range value is in a second preset fluctuation range. When the first range value is in the first preset fluctuation range and the second range value is in the second preset fluctuation range, the average values of the leakage resistance and the leakage voltage can be further calculated, so as to ensure that the leakage resistance and the leakage voltage data used have good consistency and reliability, avoid measurement errors and misjudgments caused by too large data fluctuations, and provide reliable data support for subsequent accurate determination of the leakage position.

[0093] In summary, according to the leakage position determination method of the battery pack in the embodiment of the present application, the leakage position of the battery pack can be accurately determined, and when leakage occurs, the problem can be quickly located, which provides effective technical support for after-sales and maintenance, and guarantees the safe and stable operation of the battery pack.

[0094] Based on the leakage position determination method of the battery pack in the foregoing embodiment of the present application, the present embodiment further provides a computer readable storage medium having a leakage position determination program of the battery pack stored thereon, and the leakage position determination program of the battery pack is executed by a processor to realize the leakage position determination method of the battery pack in the foregoing embodiment of the present application.

[0095] According to the computer readable storage medium in the embodiment of the present application, by executing the leakage position determination program of the battery pack by the processor, the leakage position of the battery pack can be accurately determined, and when leakage occurs, the problem can be quickly located, which provides effective technical support for after-sales and maintenance, and guarantees the safe and stable operation of the battery pack.

[0096] Figure 3 is a block schematic diagram of the leakage position determination device of the battery pack in the embodiment of the present application.

[0097] Specifically, the leakage position determination device is applied to a battery management unit, and the battery management unit includes a leakage detection circuit, such as Figure 3 As shown in the figure, the leakage position determination device 500 of the battery pack includes a detection module 10, an acquisition module 20 and a determination module 30.

[0098] The detection module 10 is configured to detect the leakage resistance and the leakage voltage of the battery pack through the leakage detection circuit; the acquisition module 20 is configured to acquire the number of battery cells, the voltage of each battery cell and the total voltage in the battery pack; the determination module 30 is configured to determine the leakage detection base point of the battery pack according to the leakage voltage, the number of battery cells and the total voltage when the leakage resistance is greater than the preset resistance; the determination module 30 is further configured to determine the leakage comparison voltage according to the leakage detection base point and the voltage of each battery cell; and the determination module 30 is further configured to determine the leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each battery cell.

[0099] In some embodiments of the present application, the determination module 30 is specifically configured to calculate the quotient value of the leakage voltage divided by the total voltage; and the leakage detection base point of the battery pack is determined by performing down-round processing on the product of the quotient value and the number of battery cells.

[0100] In some embodiments of the present application, the determination module 30 is further configured to determine the target battery cell according to the leakage detection base point; and the leakage comparison voltage is determined according to the voltage value between the negative electrode of the battery pack and the target battery cell.

[0101] In some embodiments of the present application, the determination module 30 is further configured to determine the position of the leakage detection base point in the battery pack as the leakage position when the leakage comparison voltage is equal to the leakage voltage; and the leakage detection base point and the leakage comparison voltage are updated, and the position of the updated leakage detection base point in the battery pack is determined as the leakage position when the leakage comparison voltage is not equal to the leakage voltage.

[0102] In some embodiments of the present application, the battery cells in the battery pack are sequentially arranged from the negative electrode to the positive electrode of the battery pack, and the determination module 30 is further configured to, when the leakage comparison voltage is greater than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the current battery cell corresponding to the leakage detection base point, determine the corresponding position of the previous battery cell of the current battery cell as the updated leakage detection base point, and determine the voltage value between the negative electrode of the battery pack and the previous battery cell as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the current battery cell corresponding to the updated leakage detection base point; and when the leakage comparison voltage is less than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the next battery cell of the current battery cell corresponding to the leakage detection base point, determine the corresponding position of the next battery cell as the updated leakage detection base point, and determine the voltage value between the negative electrode of the battery pack and the next battery cell as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the next battery cell of the current battery cell corresponding to the updated leakage detection base point.

[0103] In some embodiments of the present application, after determining the leakage position of the battery pack, the determining module 30 is further configured to determine the current battery cell corresponding to the leakage position and the battery cells within a preset number before and after the current battery cell as the battery cells to be checked; and perform detection processing on the battery cells to be checked to determine the leakage fault point and / or the faulty battery cell.

[0104] In some embodiments of the present application, the leakage detection circuit includes a plurality of switches, and the leakage detection circuit has a first equivalent circuit and a second equivalent circuit when the plurality of switches are in different states.

[0105] In some embodiments of the present application, the detection module 10 is specifically configured to establish a plurality of first equivalent equations based on the first equivalent circuit using the bridge method, and establish a second equivalent equation based on the second equivalent circuit using the bridge method; establish a plurality of equation groups according to the second equivalent equation and the plurality of first equivalent equations, wherein each equation group includes the second equivalent equation and one first equivalent equation; determine a plurality of leakage resistance values and a plurality of leakage voltage values according to the plurality of equation groups, wherein each equation group can determine one leakage resistance value and one leakage voltage value; and determine an average value of the plurality of leakage resistance values as the leakage resistance and an average value of the plurality of leakage voltage values as the leakage voltage.

[0106] In some embodiments of the present application, before determining the average value of the plurality of leakage resistance values as the leakage resistance and the average value of the plurality of leakage voltage values as the leakage voltage, the detection module 10 is further configured to obtain a first range value of the plurality of leakage resistance values and a second range value of the plurality of leakage voltage values; and determine that the first range value is within a first preset fluctuation range and the second range value is within a second preset fluctuation range.

[0107] It should be noted that other specific embodiments of the leakage position determination device of the battery pack according to the embodiments of the present application can refer to the specific embodiments of the leakage position determination method of the battery pack of the aforementioned embodiments of the present application. To reduce redundancy, they will not be described here.

[0108] In summary, the leakage position determination device of the battery pack according to the embodiments of the present application can accurately determine the leakage position of the battery pack, and quickly locate the problem when leakage occurs, providing effective technical support for after-sales and maintenance, and ensuring the safe and stable operation of the battery pack.

[0109] Figure 4 is a block schematic diagram of a battery management system according to an embodiment of the present application.

[0110] As shown in Figure 4 , the battery management system 2000 includes the leakage position determination device 500 of the battery pack according to the embodiments of the present application.

[0111] The battery management system according to the embodiment of the present application can accurately determine the leakage position of the battery pack, and quickly locate the problem when leakage occurs, thereby providing effective technical support for after-sales and maintenance, and ensuring safe and stable operation of the battery pack.

[0112] Figure 5 is a block diagram of a vehicle according to an embodiment of the present application.

[0113] As shown in Figure 5 , the vehicle 3000 comprises the battery management system 2000 according to the embodiment of the present application.

[0114] The vehicle according to the embodiment of the present application can accurately determine the leakage position of the battery pack, and quickly locate the problem when leakage occurs, thereby providing effective technical support for after-sales and maintenance, and ensuring safe and stable operation of the battery pack.

[0115] In addition, other configurations and functions of the vehicle according to the embodiment of the present application are known to those skilled in the art, and are not described herein to avoid redundancy.

[0116] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- based system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or in conjunction with which the instructions can be executed. For the purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical apparatus), a portable computer diskette (magnetic apparatus), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical apparatus), and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or another suitable medium upon which the program is printed, because the program can be electronically obtained, for example, by optical scanning of the paper or other medium, followed by electronic

[0117] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the embodiments described above, various steps or methods can be implemented, for example, through software or firmware in storage media which are executable by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their combinations, can be employed: discrete logic circuitry having logic gates for implementing logic functions upon an application of data signals, application-specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field-programmable gate arrays (FPGA), and so on.

[0118] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present description, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0119] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0120] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0121] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", and the like should be construed in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0122] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0123] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for determining the leakage location of a battery pack, characterized in that, The application is applied to a battery management unit including a leakage detection circuit, and the method comprises: detecting the leakage resistance and leakage voltage of the battery pack through the leakage detection circuit; obtaining the number of battery cells, the voltage of each battery cell and the total voltage in the battery pack; when the leakage resistance is greater than a preset resistance, determining the leakage detection base point of the battery pack according to the leakage voltage, the number of battery cells and the total voltage; determining the leakage comparison voltage according to the leakage detection base point and the voltage of each battery cell; determining the leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each battery cell.

2. The method of claim 1, wherein, Determining the leakage detection base point of the battery pack according to the leakage voltage, the number of battery cells and the total voltage comprises: calculating the quotient value of the leakage voltage divided by the total voltage; downward rounding the product of the quotient value and the number of battery cells to determine the leakage detection base point of the battery pack.

3. The method of claim 1, wherein, Determining the leakage comparison voltage according to the leakage detection base point and the voltage of each battery cell comprises: determining a target battery cell according to the leakage detection base point; determining the leakage comparison voltage according to the voltage value between the negative electrode of the battery pack and the target battery cell.

4. The method of claim 1, wherein, Determining the leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage and the voltage of each battery cell comprises: when the leakage comparison voltage is equal to the leakage voltage, determining the position of the leakage detection base point in the battery pack as the leakage position; when the leakage comparison voltage is not equal to the leakage voltage, updating the leakage detection base point and the leakage comparison voltage, and determining the position of the updated leakage detection base point in the battery pack as the leakage position.

5. The method of claim 4, wherein, When the leakage comparison voltage is not equal to the leakage voltage, updating the leakage detection base point and the leakage comparison voltage comprises: when the leakage comparison voltage is greater than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the current battery cell corresponding to the leakage detection base point, then taking the corresponding position of the previous battery cell of the current battery cell as the updated leakage detection base point, and taking the voltage value between the negative electrode of the battery pack and the previous battery cell as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the current battery cell corresponding to the updated leakage detection base point; when the leakage comparison voltage is less than the leakage voltage, if the difference between the leakage comparison voltage and the leakage voltage is greater than or equal to the voltage of the next battery cell of the current battery cell corresponding to the leakage detection base point, then taking the corresponding position of the next battery cell as the updated leakage detection base point, and taking the voltage value between the negative electrode of the battery pack and the next battery cell as the updated leakage comparison voltage, until the difference between the updated leakage comparison voltage and the leakage voltage is less than the voltage of the next battery cell of the current battery cell corresponding to the updated leakage detection base point.

6. The method of claim 5, wherein, After determining the leakage position of the battery pack, the method further comprises: taking the current battery cell corresponding to the leakage position and the battery cells within a preset number before and after the current battery cell as to-be-inspected battery cells; detecting the to-be-inspected battery cells to determine a leakage fault point and / or a fault battery cell.

7. The method of claim 1, wherein, The leakage detection circuit comprises a plurality of switches, and the leakage detection circuit has a first equivalent circuit and a second equivalent circuit when the plurality of switches are in different states.

8. The method of claim 7, wherein, The leakage detection circuit detects the leakage resistance and the leakage voltage of the battery pack, comprising: establishing a plurality of first equivalent equations based on the first equivalent circuit using the bridge method, and establishing a second equivalent equation based on the second equivalent circuit using the bridge method; establishing a plurality of equation groups according to the second equivalent equation and the plurality of first equivalent equations, wherein each equation group comprises the second equivalent equation and one first equivalent equation; determining a plurality of leakage resistance values and a plurality of leakage voltage values according to the plurality of equation groups, wherein each equation group can determine one leakage resistance value and one leakage voltage value; determining the average of the plurality of leakage resistance values as the leakage resistance, and determining the average of the plurality of leakage voltage values as the leakage voltage.

9. The method of claim 8, wherein, Before determining the average of the plurality of leakage resistance values as the leakage resistance, and determining the average of the plurality of leakage voltage values as the leakage voltage, the method further comprises: obtaining a first range value of the plurality of leakage resistance values and a second range value of the plurality of leakage voltage values; determining that the first range value is within a first preset fluctuation range and the second range value is within a second preset fluctuation range. 10.A battery pack electric leakage position determination device, characterized by, The battery management unit comprises a leakage detection circuit, and the device comprises: a detection module for detecting the leakage resistance and the leakage voltage of the battery pack through the leakage detection circuit; an acquisition module for acquiring the number of battery cells, the voltage of each battery cell, and the total voltage in the battery pack; a determination module for determining a leakage detection base point of the battery pack according to the leakage voltage, the number of battery cells, and the total voltage when the leakage resistance is greater than a preset resistance; the determination module is further configured to determine a leakage comparison voltage according to the leakage detection base point and the voltage of each battery cell; the determination module is further configured to determine a leakage position of the battery pack according to the leakage detection base point, the leakage voltage, the leakage comparison voltage, and the voltage of each battery cell.

11. A battery management system, characterized by, The battery management system comprises the leakage position determination device of the battery pack of claim 10, or the leakage position determination method of the battery pack of claims 1-9.

12. A vehicle characterized by comprising: The battery management system comprises the leakage position determination device of the battery pack of claim 10, or the leakage position determination method of the battery pack of claims 1-9. The battery management system comprises the leakage position determination device of the battery pack of claim 10, or the leakage position determination method of the battery pack of claims 1-9.

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