Method for determining whether fault occurs in battery pack, battery management unit and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a method for determining whether a battery pack breaks down or not, a battery management unit, the battery pack and an electric device. The method for determining whether the battery pack breaks down or not comprises the steps that a first temperature sequence of the battery pack is obtained, a plurality of elements T11, T12,... T1n in the first temperature sequence represent the temperatures of a plurality of different positions P1, P2,... Pn of the battery pack respectively, and n is a natural number larger than 1; acquiring a second temperature sequence, wherein a plurality of elements T21, T22,..., T2n in the second temperature sequence respectively represent the temperatures of a plurality of positions P1, P2,..., Pn; when at least one of absolute values T1x-T2x of the difference between the xth element of the first temperature sequence and the xth element of the second temperature sequence is larger than a first temperature threshold value, it is determined that the battery pack does not have the thermal runaway fault, x is a natural number, and x is larger than or equal to 1 and smaller than or equal to n. According to the invention, the misjudgment of the battery pack fault is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for determining whether a battery pack has failed, a battery management unit, a battery pack, and an electrical device. Background Art

[0002] The replacement of fuel vehicles by electric vehicles has become a development trend in the automotive industry. The core of electric vehicle technology lies in the "three-electric" system, namely the electric drive system, battery system and electronic control system. Among these three systems, the battery system, also known as the battery pack, is the core of the "three-electric" system. It is used to power the electric drive system and is also the most expensive and complex system among the "three-electric". The battery management unit is the control console of the battery pack and is called the brain of the battery pack.

[0003] When a battery pack fails during operation, the battery management unit will confirm the type of fault to facilitate the next step of troubleshooting. However, if the battery management unit cannot correctly confirm the fault, it will directly affect the normal driving of the electric vehicle. Therefore, it is particularly important to design and develop a battery pack fault determination method, battery management unit, battery pack and power-consuming device that can solve the above technical defects. Summary of the invention

[0004] The present application provides a method for determining battery pack fault processing, which can determine whether a battery pack fault occurs and distinguish between different faults that occur, thereby reducing misjudgment of battery pack faults.

[0005] On the one hand, the present application proposes a method for determining whether a battery pack has a fault, comprising: obtaining a first temperature sequence of the battery pack, wherein multiple elements T11, T12, ... T1n in the first temperature sequence respectively represent the temperatures of multiple different positions P1, P2, ... Pn of the battery pack, wherein n is a natural number greater than 1; obtaining a second temperature sequence, wherein multiple elements T21, T22, ... T2n in the second temperature sequence respectively represent the temperatures of multiple positions P1, P2, ... Pn; when at least one of the absolute values ​​of the difference between the xth element of the first temperature sequence and the xth element of the second temperature sequence |T1x-T2x| is greater than a first temperature threshold, it is determined that the battery pack has not suffered a thermal runaway fault, wherein x is a natural number, 1≤x≤n.

[0006] Because this method obtains the first and second temperature sequences of the battery pack and calculates whether the temperature difference between the two temperature sequences is greater than the first temperature threshold, it is possible to determine whether the battery pack has a thermal runaway fault by judging whether the change value of the two temperature sequences is greater than the first temperature threshold, thereby reducing the misjudgment of battery pack temperature faults.

[0007] In some embodiments, when the absolute value |T1x-T2x| is greater than the first temperature threshold, the method further includes notifying the battery monitoring unit disposed at the position Px to restart.

[0008] Because this method notifies the battery monitoring unit at the position Px of the battery pack corresponding to the absolute value of the difference |T1x-T2x| greater than the first temperature threshold to restart, a method for further processing is added to determine that the battery pack has not suffered a thermal runaway failure.

[0009] In some embodiments, the method further includes, when the absolute values ​​of the differences |T1x-T2x| are both less than or equal to a first temperature threshold and greater than a second temperature threshold, determining that a thermal runaway fault occurs in the battery pack.

[0010] Since the method further includes determining that a thermal runaway fault occurs in the battery pack when the absolute value of the difference is between the first temperature threshold and the second temperature threshold, the conditions for a thermal runaway fault to occur in the battery pack are clarified.

[0011] In some embodiments, the method also includes: obtaining a voltage sequence of the battery pack, and when the absolute value of the difference between any two of the elements V1, V2...Vn in the voltage sequence |Vx-Vy| is less than or equal to a voltage threshold, executing the step of obtaining a first temperature sequence of the battery pack, where y is a natural number, 1≤y≤n.

[0012] Because the method also obtains the voltage sequence of the battery pack, and when it is determined that the absolute value of the difference between any two elements is less than or equal to the voltage threshold, the first temperature sequence of the battery pack is obtained. The voltage value judgment is used as a prerequisite for the aforementioned temperature judgment, reducing the misjudgment of the battery pack voltage fault.

[0013] In some embodiments, the method further includes, when the absolute value of the difference between any two elements in the voltage sequence |Vx-Vy| is greater than a voltage threshold, determining that an abnormal voltage fault occurs in the battery pack.

[0014] Because this method also adds that when the absolute value of the difference between any two elements in the voltage sequence of the battery pack is greater than the voltage threshold, it is determined that the battery pack has an abnormal voltage fault, making the conditions for judging whether a thermal runaway fault has occurred more stringent and reducing the misjudgment of battery pack voltage faults.

[0015] In the second aspect, the present application proposes a battery management unit for determining a battery pack failure, including: an acquisition unit 131, used to acquire a first temperature sequence and a second temperature sequence from a battery monitoring unit; a calculation unit 132, used to calculate the absolute value of the difference between the xth element of the first temperature sequence and the xth element of the second temperature sequence |T1x-T2x|; a fault determination unit 133, used to determine that the battery pack has not suffered a thermal runaway failure when at least one of the absolute values ​​|T1x-T2x| is greater than a first temperature threshold, wherein x is a natural number, 1≤x≤n.

[0016] In a third aspect, the present application proposes a battery pack, comprising: a plurality of battery monitoring units, for collecting temperatures of a plurality of different positions P1, P2, ...Pn of the battery pack, where n is a natural number greater than 1; and a battery management unit as in the second aspect, for determining whether a battery pack fails based on inputs from the plurality of battery monitoring units.

[0017] The battery pack includes a battery management unit, which is used as an execution body of the battery pack fault determination method of the first aspect.

[0018] In a fourth aspect, the present application further proposes an electrical device, comprising a battery pack as in the third aspect.

[0019] The electrical equipment includes a battery pack, which is used as another execution subject of the battery pack fault determination method of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a battery pack according to an embodiment of the present application is shown;

[0021] Figure 2 A flow chart showing a method for determining whether a battery pack is faulty according to an embodiment of the present application;

[0022] Figure 3 A schematic diagram of a battery management system according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0024] In the description of the present application, it should be noted that, unless otherwise specified, “plurality” means more than two; in addition, the terms “first”, “second”, “third”, etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0025] The present application discloses an innovative method for determining whether a battery pack 100 is faulty, which is applicable to electric vehicles. Figure 1 As shown, generally, the battery pack 100 includes a plurality of battery cells 120-1, 120-2, ... 120-n, a plurality of battery monitoring units 110 (Cell Supervision Circuit, CSC) and a battery management unit 130. The plurality of battery monitoring units 110 are responsible for collecting the temperature or voltage of a plurality of positions in the plurality of battery cells 120. The battery management unit 130 is in communication connection with the battery monitoring unit 110.

[0026] The battery cell 120 includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte. The type of the battery cell 120 may include a lithium ion battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery or a magnesium ion battery, etc., which is not limited in the present embodiment.

[0027] The battery management unit 130 is the "brain" of the battery pack 100. It is connected to the battery monitoring unit 110 in communication and is used to obtain the temperature, or temperature and voltage, collected by the battery monitoring unit 110, and determine whether the battery pack 100 has a fault based on the above information. The battery management unit 130 can control the battery monitoring unit 110 to start, shut down, or reset and restart to achieve functions such as battery safety protection. The battery management unit 130 is physically located in the battery pack 100. The details of the battery management unit 130 will be described below.

[0028] The battery monitoring unit 110 collects the temperature and / or voltage of the battery cell 120 directly or indirectly. It usually includes multiple collectors and a processor. Multiple collectors are usually arranged on different battery cells 120 or at different positions of the same battery cell 120. The collector may include a voltage collector and a temperature collector. Usually, the processor of the battery monitoring unit 110 is electrically connected to multiple collectors to obtain temperature and / or voltage. According to design requirements, the positions of the multiple voltage collectors can be the same as or different from the positions of the temperature collectors. The specific implementation method of the battery monitoring unit 110 will be described in detail below.

[0029] In the traditional method for determining a fault in a battery pack 100, the battery management unit 130 compares the temperature with the set value. Once the temperature exceeds the set value, the battery management unit 130 will immediately notify the vehicle control system that the battery pack 100 has a temperature abnormality. The vehicle control system may take measures including cutting off the power supply of the battery pack 100 and braking the car. This may pose a safety threat to the driver of the car. The traditional method for determining a fault in a battery pack 100 may result in a misjudgment of the fault because it does not take into account factors such as a fault in the battery monitoring unit 110 and an abnormal voltage in the battery pack 100.

[0030] Compared with the traditional method for determining battery pack 100 fault, the method for determining whether the battery pack 100 has a fault in the embodiment of the present application reduces the misjudgment of battery pack 100 fault by judging whether the difference between two temperature sequences exceeds a temperature threshold.

[0031] The present application embodiment provides a method for determining whether a battery pack 100 fails. Figure 2 As shown, the method includes the following actions:

[0032] S110: Acquire a first temperature sequence of the battery pack 100, wherein a plurality of elements T11, T12, ...T1n in the first temperature sequence respectively represent temperatures of a plurality of different positions P1, P2, ...Pn of the battery pack 100, where n is a natural number greater than 1;

[0033] The battery management unit 130 obtains a first temperature sequence from the battery monitoring unit 110. The elements in the first temperature sequence can be acquired serially or in parallel. In other words, the time of acquiring the first temperature sequence can be the same moment or different moments in a certain time period, such as a time frame. When the acquisition time is the same moment, the battery management unit 130 simultaneously acquires all temperatures T11, T12, ... T1n in parallel. When the acquisition time is a certain time period, the battery management unit 130 can acquire the temperatures T11, T12, ... T1n in a serial manner. The time length of this time frame can be greater than or equal to the time length required for serial acquisition.

[0034] In some embodiments, temperature collectors are arranged at multiple different positions P1, P2, ... Pn of the battery pack 100. The temperature collector can be located on any surface of each battery cell 120 in the battery pack 100, preferably on the top surface of the battery cell 120, because the top surface of the battery cell 120 includes the battery pole, and the battery pole serves as the positive and negative poles of the battery cell 120. The closer to the pole, the more accurate the temperature collected. Alternatively, the surface jointly formed by the top surfaces of all battery cells 120 in the battery pack 100 can be divided into multiple areas, and one or more collectors are located in one area.

[0035] S120: Acquire a second temperature sequence of the battery pack 100, wherein a plurality of elements T21, T22, ...T2n in the second temperature sequence respectively represent temperatures of a plurality of positions P1, P2, ...Pn.

[0036] The first temperature sequence and the second temperature sequence are acquired at different time points. The second temperature sequence may be acquired in the previous clock cycle or the next clock cycle of the first temperature sequence. In some embodiments, the battery management unit 130 continuously acquires the first and second temperature sequence acquisition information at a certain frequency, that is, at a fixed clock cycle.

[0037] S130: When at least one of the absolute values ​​of the differences between the xth elements of the first temperature sequence and the second temperature sequence |T1x-T2x| is greater than a first temperature threshold, it is determined that the battery pack 100 has not experienced a thermal runaway failure, where x is a natural number, 1≤x≤n.

[0038] In some embodiments, the first temperature threshold may be the change in sampling temperature when the battery pack 100 does not have a thermal runaway failure, but the battery monitoring unit 110 used to collect temperature fails. The first temperature threshold may be 20°C, 30°C, 40°C or 50°C.

[0039] At least one of the absolute values ​​of the difference between the xth element of the first temperature sequence and the second temperature sequence |T1x-T2x| is greater than the first temperature threshold value, which means that at two different time points, the temperature difference at a certain position of the battery pack is higher than the temperature difference that should occur when the battery pack 100 has thermal runaway, such as the value of the temperature that should rise. This indicates that the battery pack 100 has not had a thermal runaway failure at this time.

[0040] In some embodiments, thermal runaway failure means that when the battery cell 120 is damaged due to internal structural damage or abnormal electrochemical reaction, the battery cell 120 will be in an uncontrollable state, causing the temperature inside the battery to rise linearly until the battery cell 120 burns and explodes. The battery pack 100 does not have a thermal runaway failure, which means that the battery pack 100 has a failure despite the aforementioned temperature rise. This failure does not belong to thermal runaway, but to a failure of the battery monitoring unit 110, and the failure of the battery monitoring unit 110 will be described in detail below.

[0041] Compared with the conventional method for determining the fault of the battery pack 100, the present method obtains the first temperature sequence and the second temperature sequence of the battery pack 100, and calculates whether the difference between the elements in the two temperature sequences is greater than the first temperature threshold. Thus, by judging whether the corresponding change values ​​of the two temperature sequences are greater than the first temperature threshold, it is possible to judge whether the battery pack 100 has a thermal runaway fault, thereby avoiding misjudgment of the fault of the battery pack 100.

[0042] In some embodiments, when the absolute value |T1x-T2x| is greater than the first temperature threshold, the method further includes S140 (not shown): notifying the battery monitoring unit (110) disposed at the position Px to restart.

[0043] In some embodiments, notifying the battery monitoring unit 110 to restart means sending a reset signal to the battery monitoring unit 110 to reset the circuit of the battery monitoring unit 110 and restore it to its initial state. A battery monitoring unit failure means that the battery monitoring unit 110 may be affected by the environment during operation, such as static electricity, temperature, and humidity, etc., causing the parameters of the battery monitoring unit 110 itself to drift, affecting the process of receiving and processing the temperature and / or voltage value. After the battery monitoring unit 110 is restarted, the temperature and / or voltage value received and processed by the battery monitoring unit 110 will be consistent with the actual temperature and / or voltage value of the battery cell 120.

[0044] Since this method notifies the battery monitoring unit 110 to restart, a method for further processing is added to determine that the battery pack 100 has not experienced a thermal runaway fault. In other words, a method for further processing is added to determine that a battery monitoring unit 110 fault has occurred in the battery pack 100. After the corresponding battery monitoring unit 110 is notified to restart, the fault is restored, and the battery management unit 110 will obtain a temperature value without a fault in the next acquisition cycle. Therefore, the battery management unit 110 will not notify the vehicle control system to cut off the power supply of the battery pack 100 or brake the car, thereby ensuring the safety of the driver.

[0045] In some embodiments, the method further includes, when the absolute values ​​of the differences |T1x-T2x| are both less than or equal to the first temperature threshold and greater than the second temperature threshold, determining that a thermal runaway fault occurs in the battery pack 100 .

[0046] The second temperature threshold may be a temperature change value at a time interval when the battery pack 100 has not experienced thermal runaway and the battery monitoring unit 110 has not failed. The second temperature threshold may be 1°C, 1.5°C, 2°C or 2.5°C.

[0047] Determining that the battery pack 100 has a thermal runaway fault means that when the difference between the two temperature sequences meets the above conditions, it means that the temperature change value of the battery pack 100 within a certain period of time exceeds the reasonable temperature change value when the battery pack 100 is working, and is lower than the value of the aforementioned temperature change when the battery monitoring unit 110 fails. When the battery management unit collects this value and makes the above judgment, it determines that the battery pack has a thermal runaway fault. The battery management unit will send the fault condition to the vehicle control system.

[0048] Since the method also includes determining whether the battery pack 100 has a thermal runaway fault, the conditions for the battery pack 100 to have a thermal runaway fault are clarified, thereby reducing misjudgment of the thermal runaway fault.

[0049] In some embodiments, the method further includes S111: acquiring a voltage sequence of the battery pack 100 , the voltage sequence including elements V1 , V2 . . . Vn.

[0050] Acquiring the voltage sequence of the battery pack 100 may be acquiring the voltages of a plurality of battery cells 120 and composing them into a voltage sequence. The time when the battery management unit 110 performs the acquisition action may be a certain moment or a certain time period. When it is a certain moment, the acquisition method may be parallel acquisition. When it is a certain time period, the acquisition method may be serial acquisition. The certain time period may be 0.5s, 0.6s or 0.7s.

[0051] In some embodiments, when the absolute value of the difference between any two elements in the voltage sequence |Vx-Vy| is less than or equal to the voltage threshold, step S110 is executed to obtain the first temperature sequence of the battery pack 100, where y is a natural number, 1≤y≤n.

[0052] The voltage threshold may be one of the differences in voltage values ​​of multiple battery cells 120 without thermal runaway failure within a collected time period. The voltage threshold is set differently in different types of battery cells 120. For example, the voltage threshold may be 0.6V, 0.4V or 0.2V in a ternary lithium battery, and the voltage threshold may be 0.4V, 0.3V or 0.2V in a lithium iron phosphate battery.

[0053] When the absolute value of the difference between any two in the voltage sequence |Vx-Vy| satisfies the above conditions, step S110 is executed. At this time, it is assumed that the battery pack 100 will not acquire the temperature sequence at the same time when executing the voltage sequence acquisition, but will decide whether to continue to execute the temperature sequence acquisition after waiting for the voltage fault judgment to be completed. Because this method realizes the voltage value judgment as a prerequisite for the aforementioned temperature judgment, by judging the voltage, it can be known in advance whether the battery pack 100 has a thermal runaway fault, reducing the misjudgment of the battery pack 100 fault.

[0054] In some embodiments, the method further includes determining that a voltage abnormality fault occurs in the battery pack 100 when an absolute value |Vx-Vy| of a difference between any two of the voltage sequences V1 , V2 . . . Vn is greater than a voltage threshold.

[0055] In some embodiments, the abnormal voltage fault may be a fault in the voltage collector of the battery monitoring unit 110, or a voltage drop caused by thermal runaway of the battery pack 100. The voltage acquisition fault may be a damage to the voltage collector, or a disconnection in the acquisition circuit. After determining that the battery pack 100 has an abnormal voltage fault, the battery management unit 130 will notify the vehicle control system of the fault and will not continue to execute step S110, thereby avoiding the battery management unit 130 from continuing to perform a misjudgment of a temperature fault.

[0056] like Figure 3As shown, the present application proposes a battery management unit 130 for determining a fault of a battery pack 100. The battery management unit 130 is in communication connection with a battery monitoring unit 110. The battery management unit 130 includes: an acquisition unit 131 for acquiring a first temperature sequence and a second temperature sequence collected from the battery monitoring unit 110.

[0057] In some embodiments, the acquisition unit 131 can also be used to acquire the voltage sequence V1, V2...Vn of the battery pack 100. When the acquisition unit 131 acquires the voltage and temperature, the two do not interfere with each other. As mentioned above, acquiring the voltage sequence v1, v2...vn can be a prerequisite for acquiring the first temperature sequence T11, T12,...T1n.

[0058] The battery management unit 130 further includes a calculation unit 132. After the acquisition unit 131 acquires the temperature sequence or the voltage sequence, it sends it to the calculation unit 132. The calculation unit 132 calculates the absolute value of the difference between the xth element of the first temperature sequence and the second temperature sequence |T1x-T2x|.

[0059] In some embodiments, the calculation unit 132 may also be used to calculate whether the absolute value |Vx-Vy| of the difference between any two of the elements V1, V2, . . . Vn in the voltage sequence is less than or equal to the voltage threshold.

[0060] The battery management unit 130 also includes a fault determination unit 133, which is used to determine whether the battery pack has a fault. Specifically, after the calculation unit 132 obtains the above-mentioned calculation result, the fault determination unit 133 will compare the calculation result with the above-mentioned corresponding temperature threshold or voltage threshold. It is determined whether the battery pack 100 has a thermal runaway fault or whether the battery monitoring unit 110 has a fault, or whether the battery pack 100 has a voltage fault.

[0061] The battery management unit 130 includes an acquisition unit 131 , a calculation unit 132 and a fault determination unit 133 , and implements the aforementioned fault determination method of the battery pack 100 .

[0062] The present application also proposes a battery pack 100, comprising: a plurality of battery monitoring units 110, for collecting the temperatures of a plurality of different positions P1, P2, ...Pn of the battery pack 100, where n is a natural number greater than 1; and the aforementioned battery management unit 130, for determining whether a fault occurs in the battery pack 100 based on the inputs of the plurality of battery monitoring units 110.

[0063] In some embodiments, multiple battery monitoring units 110 can collect temperatures at multiple different positions P1, P2, ... Pn of the battery pack 100 on average, so that each battery monitoring unit 110 has the same collection burden. Usually, the number of temperatures at different positions that need to be collected is a multiple of the number of battery monitoring units 110. Assume that a battery pack includes 32 battery cells 120, and the temperature of each battery cell 120 needs to be collected. The number of temperatures at different positions collected by each battery monitoring unit 110 can be 4, 5, or 6, and the corresponding number of battery monitoring units 110 can be 8, 7, or 6.

[0064] The battery pack 100 includes a battery management unit 130, which is used as an execution body of the above-mentioned method for determining whether a fault occurs in the battery pack 100.

[0065] The present application also proposes an electrical device, including the aforementioned battery pack 100. The electrical device may have an electrical main body, and the battery cell 120 of the battery pack 100 may supply power to the electrical main body. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, an unmanned aerial vehicle, an electric two-wheeled vehicle (such as an electric motorcycle, an electric bicycle, etc.), an electric tricycle, an electric car, a ship, an energy storage device, and the like. Among them, the energy storage device may include physical energy storage, chemical energy storage, and electromagnetic energy storage, such as pumped energy storage, battery energy storage, and capacitor energy storage.

[0066] The electric device includes a battery pack 100 or a battery management unit 130, which is used as another execution subject of the battery pack 100 fault determination method of the first aspect. In some embodiments, the battery management unit 130 also includes a notification unit 135, which is used to receive the fault condition of the fault determination unit 134. When the fault determination unit 134 determines that the battery pack has a thermal runaway fault or a voltage abnormality fault, the fault determination unit 134 sends these fault conditions to the notification unit 135, and the notification unit 135 sends these fault conditions to the vehicle control system to facilitate the driver to take subsequent fault handling measures.

[0067] In some embodiments, the battery management unit 130 also includes a memory 134. The memory 134 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 134 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a tape, or a universal serial bus (USB) drive or a combination of two or more of these. In some instances, the memory 134 may include a removable or non-removable medium, or the memory is a non-volatile solid-state memory. In some embodiments, the memory 134 may be inside or outside the battery pack 100. In some instances, the memory 134 may be a read-only memory (ROM). In one instance, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM) or a flash memory or a combination of two or more of these. The memory 134 may include a read-only memory (ROM), a random access memory (RAM), a disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Therefore, the memory 134 includes one or more tangible computer-readable storage media encoded with software including computer-executable instructions, and when the software is executed, it is operable to perform the operations described with reference to the method according to one aspect of the present disclosure. The memory 134 stores the control program of the above-mentioned method for confirming whether a fault has occurred in the battery pack 100, which is executed by the acquisition unit 131, the calculation unit 132, the fault determination unit 133, and the notification unit 135 respectively. The control program stored in the memory 134 includes message information, and stores temperature thresholds and voltage thresholds. To achieve Figure 2 The method / steps in the embodiment shown in the figure can achieve Figure 2 The example shown executes the method / steps to achieve the corresponding technical effects, and the specific execution methods / steps of the embodiments are as described above.

[0068] In some embodiments, the battery monitoring unit 110 includes a voltage collector. It can be a bonding wire (BondingWires), which is also called a bonding wire or a bonding wire. The bonding wire is usually made of copper, aluminum, gold or a combination of the three, and has high conductivity, good plasticity and stable chemical properties. The bonding wire is connected to the pole of the battery cell and the wire of the battery monitoring unit 110, and the battery monitoring unit 110 can directly obtain the voltage value of the battery cell.

[0069] In some embodiments, the battery monitoring unit 110 includes a temperature collector. It can be a thermistor, and the resistance of the thermistor changes with the temperature. It is small in size and suitable for temperature collection of battery cells. The battery monitoring unit 110 calculates the current value of the thermistor through its processor to obtain the temperature at the location of the thermistor.

[0070] In some embodiments, the battery management unit 130, the battery monitoring unit 110 and the vehicle control system may also include a communication interface for realizing communication between the modules, devices, units and / or equipment in the embodiments of the present application. The communication interface may adopt any known communication protocol applicable to the present embodiment, preferably a controller area network (CAN, Controller Area Network) bus protocol or a local interconnect network (LIN, Local Interconnect Network) bus protocol. The message in the embodiment of the present application may be a message under the corresponding communication protocol. When the message protocol is the CAN bus protocol, the message protocol may be a data frame or a remote frame message in the CAN protocol. The message header may include CAN00 or CAN01, and the message content may include an arbitration segment, a control segment, a data segment, a CRC segment, an ACK segment and a frame end segment, wherein the data segment may be omitted. When the message protocol is the LIN bus protocol, the message header may include LIN00 or LIN01, and the message content may include a synchronization interval segment, a synchronization segment, a protected ID segment, a data segment and a checksum segment.

Claims

1. A method for determining whether a battery pack (100) fails, comprising: Acquiring (S110) a first temperature sequence, wherein a plurality of elements T11, T12, ... T1n in the first temperature sequence respectively represent temperatures of a plurality of different positions P1, P2, ... Pn of the battery pack (100), wherein n is a natural number greater than 1; Acquiring (S120) a second temperature sequence, wherein a plurality of elements T21, T22, ..., T2n in the second temperature sequence respectively represent the temperatures of the plurality of positions P1, P2, ..., Pn; When at least one of the absolute values ​​of the difference between the xth element in the first temperature sequence and the xth element in the second temperature sequence |T1x-T2x| is greater than a first temperature threshold, it is determined (S130) that the battery pack (100) has not suffered a thermal runaway failure, where x is a natural number, 1≤x≤n.

2. The method according to claim 1, characterized in that The method further includes notifying (S140) a battery monitoring unit (110) disposed at a position Px to restart when the absolute value |T1x-T2x| is greater than a first temperature threshold.

3. The method according to any one of claims 1 to 2, characterized in that: It also includes determining (S210) that the battery pack (100) has the thermal runaway fault when the absolute values ​​of the differences |T1x-T2x| are both less than or equal to the first temperature threshold and greater than a second temperature threshold.

4. The method according to any one of claims 1 to 3, characterized in that: The obtaining (S110) of the first temperature sequence also includes: obtaining (S111) the voltage sequence of the battery pack (100), when the absolute value of the difference between any two of the elements V1, V2...Vn in the voltage sequence |Vx-Vy| is less than or equal to a voltage threshold, obtaining (S110) the first temperature sequence, wherein y is a natural number, 1≤y≤n.

5. The method according to claim 4, characterized in that Also includes: When the absolute value |Vx-Vy| of the difference between any two of the elements V1, V2 . . . Vn in the voltage sequence is greater than a voltage threshold, it is determined (S133) that an abnormal voltage fault occurs in the battery pack (100).

6. A battery management unit (130), for determining whether a battery pack (100) fails, comprising: An acquisition unit (131) is used to acquire a first temperature sequence, wherein a plurality of elements T11, T12, ... T1n in the first temperature sequence respectively represent the temperatures of a plurality of different positions P1, P2, ... Pn of the battery pack (100), wherein n is a natural number greater than 1; the acquisition unit (131) is also used to acquire a second temperature sequence, wherein a plurality of elements T21, T22, ... T2n in the second temperature sequence respectively represent the temperatures of the plurality of positions P1, P2, ... Pn; A calculation unit (132), configured to calculate an absolute value of a difference between an x-th element of the first temperature sequence and an x-th element of the second temperature sequence |T1x-T2x|, where 1≤x≤n; A fault determination unit (133) is used to determine that the battery pack (100) has not had a thermal runaway fault when at least one of the absolute values ​​|T1x-T2x| is greater than a first temperature threshold.

7. A battery pack (100), characterized in that: include: A plurality of battery monitoring units (110) for collecting temperatures at a plurality of different positions P1, P2, ... Pn of the battery pack (100), wherein n is a natural number greater than 1; as well as The battery management unit (130) according to claim 6, is used to determine whether the battery pack (100) fails based on the inputs of the plurality of battery monitoring units (110).

8. An electrical device, characterized in that: include: The battery pack (100) as claimed in claim 7.

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