Battery management system, battery management method, and computer-readable storage medium

Abstract

The present application discloses a battery management system, a battery management method, and a computer-readable storage medium. The battery management system includes a processor, a branch selector, a channel selector, a resistor device, and a plurality of parallel temperature detection branches; the first end of each temperature detection branch is connected to the reference voltage output end of the processor through the resistor device, the first end of each temperature detection branch is connected to the channel selector, and the second end of each temperature detection branch is connected to the branch selector; the channel selector and the branch selector are both connected to the processor. The battery management system of an embodiment of the present application can, when an abnormality occurs in one temperature detection branch, turn on another temperature detection branch to continue battery temperature detection, thereby extending the service life of the battery and reducing waste and cost losses.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery management system, a battery management method, and a computer-readable storage medium. Background Art

[0002] Thermal runaway of power batteries is a key issue in the field. To better detect the occurrence of thermal runaway within power batteries in real time, related technologies use NTC (negative temperature coefficient) thermistors (NTCs) within power batteries to monitor their internal temperature.

[0003] As power batteries age, NTCs are prone to failure due to abnormal resistance values ​​when frequently powered on. This abnormal resistance value can cause temperature sampling failure at the temperature collection point where the NTC is located. To address this issue, the current approach is to simply replace the power battery with a new one and scrap the old one, resulting in significant waste and cost.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the Invention

[0005] In view of the problem that in the above-mentioned related technologies, when the temperature collection point where the NTC is located fails, a new package is directly replaced and the old package is directly scrapped, resulting in great waste and cost losses, the present application provides a battery management system, a battery management method and a computer-readable storage medium, which can, when an abnormality occurs in one temperature detection branch, turn on another temperature detection branch to continue battery temperature detection, thereby extending the battery life and reducing waste and cost losses.

[0006] According to a first aspect of an embodiment of the present application, a battery management system is provided, comprising a processor, a branch selector, a channel selector, a resistor device, and a plurality of parallel temperature detection branches;

[0007] The first end of each temperature detection branch is connected to the reference voltage output end of the processor through the resistor device, the first end of each temperature detection branch is connected to the channel selector, and the second end of each temperature detection branch is connected to the branch selector; the channel selector and the branch selector are both connected to the processor.

[0008] The battery management system provided in the first aspect of the embodiments of the present application can, when an abnormality occurs in one temperature detection branch, turn on another temperature detection branch to continue battery temperature detection, thereby extending the battery life, reducing waste and cost losses, and at least partially solving the problem of waste and cost losses caused by directly replacing a new battery pack and directly scrapping the old battery pack when the temperature collection point where the NTC is located fails in the related art.

[0009] In some embodiments of the present application, the resistor device includes a first resistor, a first end of each temperature detection branch is connected to the first end of the first resistor, and a second end of the first resistor is connected to the reference voltage output terminal of the processor. The first resistor is used to assist in calculating the resistance of the conductive temperature detection branch.

[0010] In some embodiments of the present application, the battery management system also includes a voltage comparator selector; the resistance device includes multiple second resistors, and the multiple second resistors correspond one-to-one to the multiple parallel temperature detection branches; the voltage comparator selector is respectively connected to the channel selector and the first end of each temperature detection branch, the first end of each second resistor is connected to the first end of the corresponding temperature detection branch, and the second end of each second resistor is connected to the reference voltage output end of the processor.

[0011] The voltage comparison gate can select the voltage signal with the lower voltage among the voltages of each voltage sampling point to enter the multi-channel analog gate, thereby improving the accuracy of selecting the voltage signal of the conductive temperature detection branch.

[0012] In some embodiments of the present application, the branch selector includes a driving circuit and multiple switching circuits; the multiple switching circuits correspond one-to-one to the multiple parallel temperature detection branches; the driving circuit is respectively connected to the first pole of each of the switching circuits and the processor; the second pole of each of the switching circuits is connected to the second end of the corresponding temperature detection branch, and the third pole of each of the switching circuits is grounded.

[0013] A drive circuit and multiple transistors are used to realize the conduction switching of the temperature detection branch, and the response speed after receiving the control signal is fast, thereby improving the switching speed.

[0014] In some embodiments of the present application, the switching circuit includes transistors, the driving circuit is connected to a first terminal of each transistor and the processor, the second terminal of each transistor is connected to the second end of the corresponding temperature detection branch, and the third terminal of each transistor is grounded. The use of the driving circuit and multiple transistors to achieve on-off switching of the temperature detection branch provides a fast response speed after receiving a control signal, thereby improving switching speed.

[0015] In some embodiments of the present application, each of the temperature detection branches includes a temperature sensing device. The temperature sensing device has a relatively fast circuit thermal response speed, can quickly sense small changes in circuit temperature, is suitable for circuit temperature detection, and has high detection sensitivity.

[0016] In some embodiments of the present application, the multiple temperature detection branches include a first number of first branches and a second number of second branches, the vertical distance between the temperature sensing device in the first branch and the upper cover of the battery is smaller than the vertical distance between the temperature sensing device in the second branch and the upper cover; the resistance value of the temperature sensing device changes with temperature.

[0017] By comparing the temperature sampled by the temperature sensing device in the first branch with the temperature sampled by the temperature sensing device in the second branch, it is possible to promptly determine whether there is a risk of thermal runaway of the battery temperature.

[0018] A second aspect of the embodiments of the present application provides a battery management method, which is applied to the battery management system described in any embodiment of the present application; the method includes:

[0019] Controlling the branch selector to turn on a first temperature detection branch and keep the remaining temperature detection branches disconnected; the first temperature detection branch is any one of the multiple temperature detection branches;

[0020] acquiring battery temperature data corresponding to the first temperature detection branch based on the channel selector and the resistor device; wherein the battery temperature data is used to represent the difference between the temperature detected at the first temperature detection branch and the temperatures detected at other temperature sampling points in the battery;

[0021] When the battery temperature data meets a preset battery temperature condition, the branch selector is controlled to disconnect the first temperature detection branch and turn on the second temperature detection branch; the second temperature detection branch is any one of the remaining temperature detection branches; the preset battery temperature condition is a sufficient condition for an abnormality to occur in the turned-on temperature detection branch.

[0022] The battery management method provided in the second aspect of the embodiment of the present application can, when an abnormality occurs in one temperature detection branch, turn on another temperature detection branch to continue battery temperature detection, thereby extending the battery life, reducing waste and cost losses, and at least partially solving the problem of waste and cost losses caused by directly replacing a new battery pack and directly scrapping the old battery pack when the temperature collection point where the NTC is located fails in the related art.

[0023] In some embodiments of the present application, obtaining battery temperature data corresponding to the first temperature detection branch based on the channel selector and the resistor device includes:

[0024] Obtaining a first temperature sampling value based on a first signal, an effective resistance value of the resistor device, and a reference voltage at the reference voltage output terminal; the first temperature sampling value is a temperature sampling value corresponding to the first temperature detection branch; the first signal is a voltage sampling signal from the first temperature detection branch, and the first signal is transmitted by the channel selector; the effective resistance value is a resistance value of a conductive portion of the resistor device;

[0025] The absolute value of the temperature difference between the first temperature sampling value and the temperature sampling values ​​of each of the other temperature sampling points is obtained to obtain the battery temperature data. The battery temperature data can be used to determine whether there is a risk of abnormal battery temperature with high accuracy.

[0026] In some embodiments of the present application, when the battery temperature data meets a preset battery temperature condition, controlling the branch selector to disconnect the first temperature detection branch and connect the second temperature detection branch includes:

[0027] When the battery temperature data contains a temperature difference absolute value exceeding a preset threshold, the branch selector is controlled to disconnect the first temperature detection branch and connect the second temperature detection branch.

[0028] When the first temperature detection branch detects a temperature abnormality, the battery temperature data is obtained again by turning on the second temperature detection branch, thereby improving the accuracy of judging the risk of battery temperature abnormality.

[0029] In some embodiments of the present application, the method further comprises:

[0030] If the battery temperature data obtained by conducting any of the multiple temperature detection branches meets the preset battery temperature condition, it is determined that the preset warning condition has been met and a warning operation is executed; the preset warning condition is the preset trigger condition for executing the warning operation. In this way, if a battery temperature anomaly is determined, the warning operation can be used to remind relevant personnel to take timely action, thereby reducing the safety risks caused by the abnormal battery temperature.

[0031] In some embodiments of the present application, the multiple temperature detection branches include a first number of first branches and a second number of second branches, the vertical distance between the temperature sensing device in the first branch and the upper cover of the battery is smaller than the vertical distance between the temperature sensing device in the second branch and the upper cover; the resistance value of the temperature sensing device changes with temperature;

[0032] The method further comprises:

[0033] In response to detecting that the operating state data exceeds a preset safety value, controlling the branch selector to enable the first temperature detection branch and the second temperature detection branch to be turned on alternately;

[0034] If the battery temperature data corresponding to the first temperature detection branch and the battery temperature data corresponding to the second temperature detection branch meet preset warning conditions, a warning operation is executed; the preset warning conditions are preset trigger conditions for executing the warning operation. This improves the detection sensitivity of abnormal battery temperature conditions, and can promptly issue warnings in the event of abnormal battery temperature to prompt relevant personnel to take corrective measures, reducing the safety risks caused by abnormal battery temperature.

[0035] In some embodiments of the present application, controlling the branch selector to enable the first temperature detection branch and the second temperature detection branch to be turned on alternately includes:

[0036] A periodic control signal is sent to the branch selector to control the branch selector to make the first temperature detection branch and the second temperature detection branch alternately turned on.

[0037] By sending a square wave signal to control the first temperature detection branch and the second temperature detection branch to be turned on alternately, the temperature sampling values ​​obtained by the two temperature detection branches are used to detect whether there is abnormal battery temperature. The detection result is accurate and timely, and abnormal battery temperature conditions can be detected in time.

[0038] According to a third aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored. The computer program is executed by a processor to implement the battery management method described in any embodiment of the present application.

[0039] The third aspect of the embodiment of the present application can achieve the same beneficial technical effects as the first aspect.

[0040] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to more clearly understand the technical means of the embodiments of the present application, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the embodiments below. The accompanying drawings are only for the purpose of illustrating the embodiments of the present application and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components.

[0042] Figure 1FIG. 4 is a schematic structural diagram of a battery management system according to one or more embodiments.

[0043] Figure 2 FIG. 4 is a schematic structural diagram of a battery management system according to one or more embodiments.

[0044] Figure 3 FIG. 4 is a schematic structural diagram of a battery management system according to one or more embodiments.

[0045] Figure 4 FIG. 4 is a schematic structural diagram of a battery management system according to one or more embodiments.

[0046] Figure 5 is a flow chart of a battery management method according to one or more embodiments.

[0047] Figure 6 The present invention is a flowchart of obtaining battery temperature data corresponding to the first temperature detection branch based on the channel selector and the resistance device according to one or more embodiments.

[0048] Figure 7 is a flow chart of a battery management method according to one or more embodiments.

[0049] Figure 8 is a schematic diagram of a computer-readable storage medium according to one or more embodiments. DETAILED DESCRIPTION

[0050] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of this application, technical terms such as "first" and "second" are used solely to distinguish different objects and should not be understood to indicate or imply relative importance, or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of this application, "plurality" means two or more (including two), unless otherwise specifically defined.

[0053] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0054] In the description of the embodiments of the present application, the term "plurality" refers to more than two (including two). Similarly. In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0055] Battery thermal runaway occurs when a battery's internal temperature rapidly rises due to overcharging or discharging, excessive external temperatures, or other improper operation, triggering a series of chain reactions that can lead to dangerous phenomena such as self-heating, gas release, fire, or explosion. Thermal runaway commonly occurs in high-energy-density batteries like lithium-ion batteries, particularly in power batteries (such as those used in electric vehicles and power tools), which operate at high power densities and carry a greater risk of thermal runaway.

[0056] Due to their high energy density, rechargeable, safe, and environmentally friendly features, power batteries are widely used in technical fields such as electric vehicles and energy storage systems. During use, thermal runaway of power batteries is a key issue in battery safety. Related technologies use an NTC (negative temperature coefficient thermistor) inside the power battery to detect the internal temperature of the power battery. As power batteries age, the NTC accumulates excessive amounts of frequent current flow and power-on usage, which can easily lead to failure due to abnormal NTC resistance. This results in failure of temperature sampling at the temperature collection point where the NTC is located. In response to failure of NTC temperature sampling of power batteries, related technologies have adopted the approach of directly replacing the power battery with a new one and scrapping the old one, which results in significant waste and cost.

[0057] In response to the problems existing in the related art, an embodiment of the present application provides a battery management system, including a processor, a branch selector, a channel selector, a resistor device, and multiple parallel temperature detection branches, wherein the first end of each temperature detection branch is connected to the reference voltage output end of the processor through the resistor device, the first end of each temperature detection branch is connected to the channel selector, and the second end of each temperature detection branch is connected to the branch selector. The channel selector and the branch selector are both connected to the processor, so that when an abnormality occurs in one temperature detection branch, another temperature detection branch can be turned on to continue battery temperature detection, thereby extending the battery life and reducing waste and cost losses. It at least partially solves the problem of waste and cost losses caused by directly replacing a new battery pack or directly scrapping the old battery pack when the temperature collection point where the NTC is located fails in the related art.

[0058] The processor in the battery management system of the embodiments of the present application can be a microprocessor in a battery management system (BMS). A battery management system, abbreviated as BMS in English, is a control device that performs battery monitoring, status assessment, charge and discharge control, and safety protection operations. It is primarily used for intelligent battery management and maintenance, reducing the probability of overcharging and overdischarging, extending battery life, and monitoring and assessing battery status. The battery management system of the embodiments of the present application can be used in application scenarios such as battery temperature detection, for example, in power vehicle power battery temperature detection, energy storage battery temperature detection, and other application scenarios. The battery in the embodiments of the present application can be, but is not limited to, a battery cell, a single cell, a battery module, or a battery pack. The battery can be of any chemical type, such as a lithium-ion battery, a nickel-cadmium battery, a nickel-metal hydride battery, or a lead-acid battery. The battery can be of any shape and structure, such as a cylindrical battery, a flat battery, a soft-pack battery, a prismatic battery, and the like. The battery can be used in any application scenario that requires a battery, and the battery can be used as a consumer electronic battery, such as in mobile phones and laptop computers. Batteries can also be used as energy storage batteries, and batteries can also be used as power batteries, such as in electric vehicles, electric bicycles, electric aircraft, electric ships, etc.

[0059] A battery management system proposed according to an embodiment of the present application is described below with reference to the accompanying drawings.

[0060] refer to Figure 1 As shown, an embodiment of the present application provides a battery management system, including a processor 1, a branch selector 2, a channel selector 3, a resistor device 4, and a plurality of parallel temperature detection branches 5.

[0061] The first end of each temperature detection branch 5 is connected to the reference voltage output end of the processor 1 through the resistor device 4, the first end of each temperature detection branch 5 is connected to the channel selector 3, and the second end of each temperature detection branch 5 is connected to the branch selector 2; the channel selector 3 and the branch selector 2 are both connected to the processor 1.

[0062] Exemplarily, a first end of each temperature detection branch 5 is connected to a first end of the resistor device 4 , and a second end of the resistor device 4 is connected to a reference voltage output end of the processor 1 .

[0063] The processor 1 includes, but is not limited to, a microprocessor in a battery management system (BMS). The branch selector 2 is a device for selecting which temperature detection branch to turn on. The branch selector 2 includes, but is not limited to, a data selector. For example, if the plurality of parallel temperature detection branches 5 are two parallel temperature detection branches 5, the branch selector 2 may be a two-way selector.

[0064] The channel selector 3 is a device for directing input signals to different channels, thereby selecting the input signal required by the processor 1. The channel selector 3 includes but is not limited to a multi-channel analog gate, and the multi-channel analog gate 31 is used to select multiple analog signals through input control signals.

[0065] The plurality of parallel temperature detection branches 5 may be two or more parallel temperature detection branches.

[0066] In some embodiments, the resistor device 4 includes a first resistor, a first end of each temperature detection branch 5 is connected to the first end of the first resistor, and a second end of the first resistor is connected to the reference voltage output terminal of the processor 1. The first resistor is used to assist in calculating the resistance of the conductive temperature detection branch 5.

[0067] In some embodiments, each temperature detection branch 5 includes a temperature sensing device. The temperature sensing device has a relatively fast circuit thermal response speed, can quickly sense small changes in temperature in the circuit, is suitable for circuit temperature detection, and has high detection sensitivity. The temperature sensing device is a type of device whose resistance value changes with temperature, including but not limited to thermistors, platinum resistors, thermocouples and other devices. Thermistors include but are not limited to negative temperature coefficient thermistors NTC and the like. Thermistors are divided into positive temperature coefficient thermistors (PTC thermistor, i.e. Positive Temperature Coefficient thermistor) and negative temperature coefficient thermistors (NTC thermistor, i.e. Negative Temperature Coefficient thermistor) according to their temperature coefficients. The resistance value of a positive temperature coefficient thermistor increases with increasing temperature, and the resistance value of a negative temperature coefficient thermistor decreases with increasing temperature. They are both semiconductor devices.

[0068] refer to Figure 2 As shown, Figure 2 A schematic diagram of the circuit structure of an exemplary battery management system is shown. The battery management system includes a microprocessor 1 of a battery management system (BMS), a two-way selector 21, a multi-way analog gate 31, a resistor device 4, and a first temperature detection branch and a second temperature detection branch connected in parallel. The resistor device 4 includes a first resistor R1; the first temperature detection branch includes a first negative temperature coefficient thermistor NTC1, and the second temperature detection branch includes a second negative temperature coefficient thermistor NTC2. When either the first temperature detection branch or the second temperature detection branch is conductive, the effective resistance of the resistor device 4 is equal to the resistance value of the first resistor R1.

[0069] The two-way selector 21 is a circuit used to select and conduct any one of the two-way data transmission paths as needed during the two-way data transmission process, and may also be referred to as a two-way selection unit or a two-way switch.

[0070] The microprocessor of the battery management system BMS can also be called a microcontroller (MCU, Microprogrammed Control Unit). It is the core control part of the BMS (Battery Management System) and is used for signal detection and command control.

[0071] In this example, a first end of a first negative temperature coefficient thermistor (NTC1) is connected to a first end of a resistor (R1), a second end of a resistor (R1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the first negative temperature coefficient thermistor (NTC1) is connected to a two-way selector 21. A first end of a second negative temperature coefficient thermistor (NTC2) is connected to a first end of a resistor (R1), a second end of a resistor (R1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the second negative temperature coefficient thermistor (NTC2) is connected to a two-way selector 21. A first end of the first resistor (R1) is connected to a multi-channel analog gate 31. The voltage of VCC includes, but is not limited to, values ​​such as 5V. The first resistor (R1) includes, but is not limited to, a pull-up resistor.

[0072] like Figure 2 As shown, V1 is the voltage sampling terminal on the first temperature detection branch, and V1 is connected to the first terminal of the first negative temperature coefficient thermistor NTC1. V2 is the voltage sampling terminal on the second temperature detection branch, and V2 is connected to the first terminal of the second negative temperature coefficient thermistor NTC2. The GPIO port of the BMS microprocessor inputs a high level and a low level to the two-way selector 21 to control the two-way selector 21 to turn on the first temperature detection branch and the second temperature detection branch, respectively, thereby collecting the voltage at V1 or the voltage at V2. For example, the GPIO port inputs a high level to the two-way selector 21 to control the two-way selector 21 to turn on the first temperature detection branch, and the GPIO port inputs a low level to the two-way selector 21 to control the two-way selector 21 to turn on the second temperature detection branch, thereby collecting the voltage at V1 or the voltage at V2.

[0073] When sampling voltage, the analog signal at V1 is input into processor 1 via a multi-channel analog gate 31. It is converted into a digital signal by the microprocessor's built-in analog-to-digital converter (ADC). The microprocessor then calculates the temperature sample value. An analog-to-digital converter, also known as an A / D converter, or ADC for short, is an electronic component that converts analog signals into digital signals. A typical analog-to-digital converter converts an input voltage signal into an output digital signal. Because digital signals themselves have no practical meaning and merely represent a relative magnitude, any analog-to-digital converter requires a reference analog quantity as a conversion standard. A common reference standard is the maximum convertible signal magnitude. The output digital quantity represents the magnitude of the input signal relative to the reference signal.

[0074] Assuming that n temperature sampling points are set in the entire battery pack, the voltage sampling signal obtained from V1 is converted into a corresponding temperature sampling value. The absolute value of the temperature difference between this temperature sampling value and the temperature sampling value of each of the remaining (n-1) sampling points in the entire battery pack is then calculated, resulting in (n-1) temperature difference absolute values. If at least m of these (n-1) temperature difference absolute values ​​exceed a preset threshold (e.g., 3.5°C, 4°C, or 4.5°C), the microprocessor actively switches the temperature detection branch to conduct. Where m ≤ n-1, n ≥ 2, and m and n are both preset positive integers.

[0075] For example, taking n=5 and m=2 as an example, that is, there are 5 temperature sampling points in the entire battery pack, the microprocessor obtains the temperature sampling value on the first temperature detection branch, and then calculates the absolute value of the temperature difference between the temperature sampling value and each of the temperature sampling values ​​of the other four sampling points, and obtains 4 temperature difference absolute values. When there are 2 or more temperature difference absolute values ​​among the 4 temperature difference absolute values ​​exceeding the preset threshold, a signal is sent to the two-way selector 21 through the GPIO port to control the two-way selector 21 to disconnect the first temperature sampling branch and switch to turn on the second temperature sampling branch; then the microprocessor obtains the second temperature detection branch The temperature sampling value on the second temperature detection branch is then calculated respectively, and the absolute value of the temperature difference between the temperature sampling value on the second temperature detection branch and the temperature sampling values ​​of the other four sampling points is also calculated, and four temperature difference absolute values ​​are also obtained. If there are two or fewer temperature difference absolute values ​​exceeding the preset threshold value among the four temperature difference absolute values, the warning operation is not performed, and the second temperature detection branch is kept on, and the temperature sampling value corresponding to the second temperature detection branch is obtained; if the temperature sampling value obtained after switching on the second temperature detection branch is still outliers, that is, if there are two or more temperature difference absolute values ​​exceeding the preset threshold value among the four temperature difference absolute values, the warning operation is performed. The warning form can be a background warning or a vehicle-end fault code jump. The warning method can be selected according to the temperature difference absolute value. For example, when the four temperature difference absolute values ​​are all greater than the preset value, the vehicle-end fault code jump warning form can be used for warning, and in other cases, the background warning form can be used for warning.

[0076] For another example, assume that n temperature sampling points are set in the entire battery pack. The voltage sampling signal obtained from V1 is converted into a corresponding temperature sampling value. The absolute value of the temperature difference between this temperature sampling value and a first temperature average value is calculated, where the first temperature average value is the average of the temperature sampling values ​​of the remaining (n-1) sampling points. If the absolute value of this temperature difference exceeds a preset threshold, the microprocessor actively switches the temperature detection branch to conduct. Where n is a preset positive integer and n ≥ 2.

[0077] In a specific example, assuming that VCC is 5V, resistor R1 is 10k, the resistance values ​​of NTC1 and NTC2 at 25°C are also 10k, and the ambient temperature is assumed to be 25°C; at this time, the first temperature detection branch is turned on, the second temperature detection branch is not turned on, NTC1 is working normally, NTC2 is not working, the microprocessor continuously samples the voltage at point V1 as 2.5V, calculates the resistance value of NTC1 to be 10k, and converts the temperature sampling value to 25°C by comparing with the corresponding relationship chart between temperature and resistance value; if the battery cell temperature at the sampling point is abnormal (for example, the temperature is too high) or the NTC1 is abnormal (for example, the temperature is too high), the absolute value of the temperature difference between the temperature sampling value corresponding to V1 and the other sampling point will exceed the preset threshold.

[0078] Taking two temperature sampling points in the entire battery pack as an example, the microprocessor determines the temperature sampling value of V1 in real time and compares it with the temperature sampling value obtained from another sampling point in the entire battery pack. The absolute value of the temperature difference between the temperature sampling value corresponding to V1 and the temperature sampling value obtained from the other sampling point is calculated. If the absolute value of the temperature difference exceeds a preset threshold (for example, 3.5°C, 4.0°C, or 5°C), the microprocessor controls the two-way selector 21 to disconnect the first temperature detection branch and switch to the second temperature detection branch. The switching process usually takes milliseconds. The NTC2 starts working and samples the voltage at V2, converts it into a temperature sampling value, and calculates the absolute value of the temperature difference between the temperature sampling value corresponding to V2 and the temperature sampling value obtained from the other sampling point. If the absolute value of the temperature difference does not exceed the preset threshold, it means that the temperature sampling value obtained at this time is within the normal range, and the second temperature detection branch is kept on for voltage sampling. If the absolute value of the temperature difference exceeds the preset threshold, it means that the temperature sampling value obtained at this time is not within the normal range, indicating that the actual temperature of the temperature sampling point is abnormal, and an early warning operation is performed. The form of the warning operation is selected according to the degree of temperature abnormality (the difference between the absolute value of the temperature difference and the preset threshold value represents the degree of temperature abnormality) to select the background warning or vehicle-end alarm and other warning forms. For example, if the difference between the absolute value of the temperature difference and the preset threshold value is less than the preset first value, a background warning is performed. If the difference between the absolute value of the temperature difference and the preset threshold value is not less than the preset first value, a vehicle-end alarm is executed.

[0079] In some embodiments, the battery management system further includes a voltage comparator 6; the resistor device 4 includes multiple second resistors, each corresponding to a plurality of parallel temperature detection branches; the voltage comparator 6 is connected to the channel selector 3 and the first end of each temperature detection branch, respectively; the first end of each second resistor is connected to the first end of the corresponding temperature detection branch, and the second end of each second resistor is connected to the reference voltage output terminal of the processor 1. The voltage comparator 6 selects the lower voltage signal from the voltages at each voltage sampling point and enters the multi-channel analog gate 31, thereby improving the accuracy of selecting the voltage signal of the conductive temperature detection branch.

[0080] refer to Figure 3 As shown, the battery management system includes a processor 1, a two-way selector 21, a multi-way analog selector 31, a resistor device 4, a voltage comparator selector 6, and a first temperature detection branch and a second temperature detection branch connected in parallel. The resistor device 4 includes resistors r1 and r2 connected in parallel. The first temperature detection branch includes a first negative temperature coefficient thermistor NTC1, and the second temperature detection branch includes a second negative temperature coefficient thermistor NTC2. When the first temperature detection branch is conductive, the effective resistance value of the resistor device 4 is equal to the resistance value of resistor r1. When the second temperature detection branch is conductive, the effective resistance value of the resistor device 4 is equal to the resistance value of resistor r2.

[0081] A first end of a first negative temperature coefficient thermistor (NTC1) is connected to a first end of a resistor (r1), a second end of the resistor (r1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the first negative temperature coefficient thermistor (NTC1) is connected to a two-way selector. A first end of a second negative temperature coefficient thermistor (NTC2) is connected to a first end of a resistor (r2), a second end of the resistor (r2) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the second negative temperature coefficient thermistor (NTC2) is connected to a two-way selector 21. A first end of the resistor (r1) is connected to a voltage comparator (6), and a first end of the resistor (r2) is connected to a voltage comparator (6).

[0082] Figure 3 In the example, V1 is the voltage sampling terminal on the first temperature detection branch, connected to the first terminal of the first negative temperature coefficient thermistor NTC1. V2 is the voltage sampling terminal on the second temperature detection branch, connected to the first terminal of the second negative temperature coefficient thermistor NTC2. The BMS microprocessor's GPIO port inputs high and low levels to control the two-way selector 21 to switch between the first and second temperature detection branches, thereby sampling the voltage at V1 or the voltage at V2.

[0083] NTC is a variable resistor with a negative temperature coefficient. The NTC resistance can be calculated by voltage division and then the temperature of the sampling point can be determined by comparing it with a resistance-temperature table. However, a single NTC may have reliability issues during frequent current flow or temperature rise, causing the temperature sampling at that point to fail, thereby affecting the acquisition of temperature information for the entire battery pack.

[0084] In order to extend the service life of the battery pack and reduce after-sales maintenance costs, a two-way temperature detection branch structure is adopted in this example, in which one temperature detection branch serves as a backup branch. The voltages at points V1 and V2 are collected, and then the voltage signal with the lower voltage is selected through the voltage comparison selector 6 and input into the multi-way analog selector 31. Since the first temperature detection branch and the second temperature detection branch will not be turned on at the same time, the voltage at the voltage sampling point of the temperature detection branch that is not turned on is consistent with VCC. In this way, the selected voltage signal can be the voltage signal of the temperature detection branch that is turned on. When the temperature sampling value corresponding to the voltage signal is detected to be abnormal inside the microprocessor, the temperature detection branch that is turned on will be switched on first through the two-way selector 21, and then a logical judgment will be performed. If the temperature sampling value of the temperature detection branch after switching on is within the normal temperature range, no warning will be issued and the current battery usage status will be maintained. Otherwise, a warning operation will be executed.

[0085] In this example, resistors R1 and R2 are both pull-up resistors. The first negative temperature coefficient thermistor NTC1 and the second negative temperature coefficient thermistor NTC2 can be selected with specifications of 10k, 50k, or 100k as needed. In this case, the corresponding pull-up resistors should also be selected with specifications of 10k, 50k, or 100k to meet the requirements of different temperature sampling ranges.

[0086] In some embodiments, the branch selector 2 includes a drive circuit 22 and multiple switch circuits; the multiple switch circuits correspond one-to-one with the multiple parallel temperature detection branches 5; the drive circuit 22 is connected to each switch circuit and the processor 1; each switch circuit is connected to the second end of the corresponding temperature detection branch 22, and each switch circuit is grounded. Using the drive circuit and multiple switch circuits to switch the temperature detection branches on and off quickly after receiving a control signal, thereby improving switching speed.

[0087] Exemplarily, the switching circuit includes transistors, and the branch selector 2 includes a drive circuit 22 and multiple transistors. The multiple transistors correspond one-to-one to the multiple parallel temperature detection branches. The drive circuit 22 is connected to the first terminal of each transistor and the processor. The second terminal of each transistor is connected to the second end of the corresponding temperature detection branch, and the third terminal of each transistor is grounded. Using the drive circuit 22 and multiple transistors to achieve on-off switching of the temperature detection branches, the temperature detection branches respond quickly after receiving a control signal, thereby improving switching speed.

[0088] Transistors include, but are not limited to, NMOS transistors, PMOS transistors, and triodes. MOS transistors stand for Metal Oxide Semiconductor Field Effect Transistor. NMOS transistors are N-type Metal Oxide Semiconductor Field Effect Transistors. PMOS transistors are P-type Metal Oxide Semiconductor Field Effect Transistors.

[0089] refer to Figure 4 As shown, Figure 4 A circuit structure diagram of an exemplary battery management system is shown, which includes a processor 1, a branch selector 2, a multi-channel analog gate 31, a resistor device 4, and a first temperature detection branch and a second temperature detection branch connected in parallel.

[0090] The resistor device 4 includes a first resistor R1; the first temperature detection branch includes a first negative temperature coefficient thermistor NTC1; and the second temperature detection branch includes a second negative temperature coefficient thermistor NTC2.

[0091] The branch selector 2 includes a driving circuit 22 and two transistors; the two transistors are NMOS transistors. The two transistors are a first NMOS transistor and a second NMOS transistor. Figure 4 In the figure, the first NMOS transistor is marked as MOS1, and the second NMOS transistor is marked as MOS2.

[0092] A first end of a first negative temperature coefficient thermistor (NTC1) is connected to a first end of a resistor (R1), a second end of a resistor (R1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the first negative temperature coefficient thermistor (NTC1) is connected to a two-way selector 21. A first end of a second negative temperature coefficient thermistor (NTC2) is connected to a first end of a resistor (R1), a second end of a resistor (R1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the second negative temperature coefficient thermistor (NTC2) is connected to a two-way selector 21. A first end of resistor (R1) is connected to a multi-channel analog gate 31. When either the first temperature detection branch or the second temperature detection branch is conductive, the effective resistance of resistor device 4 is the resistance of first resistor (R1).

[0093] The driving circuit 22 is respectively connected to the gate of the first NMOS transistor MOS1, the gate of the second NMOS transistor MOS2 and the processor 1; the drain of the first NMOS transistor MOS1 is connected to the second end of the first negative temperature coefficient thermistor NTC1, the drain of the second NMOS transistor MOS2 is connected to the second end of the second negative temperature coefficient thermistor NTC2, and the source of the first NMOS transistor MOS1 and the source of the second NMOS transistor MOS2 are both grounded.

[0094] refer to Figure 4As shown, V1 is the voltage sampling terminal on the first temperature detection branch, connected to the first terminal of the first negative temperature coefficient thermistor NTC1. V2 is the voltage sampling terminal on the second temperature detection branch, connected to the first terminal of the second negative temperature coefficient thermistor NTC2. The BMS microprocessor's GPIO port inputs high and low levels to control the two-way selector 21 to switch between the first and second temperature detection branches, thereby sampling the voltage at V1 or the voltage at V2.

[0095] The branch selector 2 in this example includes a drive circuit and two transistors. The microprocessor sends high and low level signals through the GPIO interface, which are sent to the gates of the two MOS transistors through the drive circuit, thereby controlling the conduction switching of the two temperature detection branches.

[0096] In some embodiments, the plurality of temperature detection branches include a first number of first branches and a second number of second branches, wherein the vertical distance between the temperature sensing device in the first branch and the upper cover of the battery is less than the vertical distance between the temperature sensing device in the second branch and the upper cover; and the resistance value of the temperature sensing device changes with temperature. The first number and the second number are both positive integers. By comparing the temperature sampled by the temperature sensing device in the first branch with the temperature sampled by the temperature sensing device in the second branch, it is possible to promptly determine whether there is a risk of thermal runaway of the battery temperature.

[0097] Exemplarily, the first number and the second number are both 1. The temperature sensing device in the first branch is a first negative temperature coefficient thermistor NTC1, and the temperature sensing device in the second branch is a second negative temperature coefficient thermistor NTC2.

[0098] A first end of a first negative temperature coefficient thermistor (NTC1) is connected to a first end of a resistor (R1), a second end of the resistor (R1) is connected to a reference voltage output terminal (VCC) of a microprocessor, and a second end of the first negative temperature coefficient thermistor (NTC1) is connected to a two-way selector 21. A first end of a second negative temperature coefficient thermistor (NTC2) is connected to a first end of a resistor (R1), a second end of the resistor (R1) is connected to a reference voltage output terminal (VCC) of a processor 1, and a second end of the second negative temperature coefficient thermistor (NTC2) is connected to a two-way selector 21. A first end of the resistor (R1) is connected to a multi-channel analog gate 31.

[0099] A vertical distance between the first negative temperature coefficient thermistor NTC1 and the upper cover of the battery is smaller than a vertical distance between the second negative temperature coefficient thermistor NTC2 and the upper cover.

[0100] The voltage sampling terminal V1 on the first temperature detection branch is connected to the first terminal of the first negative temperature coefficient thermistor NTC1; the voltage sampling terminal V2 on the second temperature detection branch is connected to the first terminal of the second negative temperature coefficient thermistor NTC2. A high level input to the GPIO port of the BMS microprocessor controls the two-way selector 21 to turn on the first temperature detection branch, while a low level input controls the two-way selector 21 to turn on the second temperature detection branch, thereby sampling the voltage at V1 or the voltage at V2.

[0101] The BMS can detect the working condition of the battery. When it is detected that the battery charging power exceeds the preset safety value of the battery charging power, the battery discharging power exceeds the preset safety value of the battery discharging power, or the battery ambient temperature exceeds the preset safety value of the battery ambient temperature, the BMS microprocessor can send a square wave signal to the two-way selector 21 to make the first negative temperature coefficient thermistor NTC1 and the second negative temperature coefficient thermistor NTC2 alternately turn on. The first negative temperature coefficient thermistor NTC1 is arranged on the side close to the upper cover of the battery, and the second negative temperature coefficient thermistor NTC2 is arranged on the side close to the upper cover of the battery. On one side of the battery cell, when thermal runaway is about to occur, the battery cell heats up first, and the temperature at the battery cell rises earlier than the temperature near the upper cover. The temperature detected by the second negative temperature coefficient thermistor NTC2 rises first. At this time, the temperature detected by the second negative temperature coefficient thermistor NTC2 is higher than the temperature detected by the first negative temperature coefficient thermistor NTC1. At this time, the temperature difference between the second negative temperature coefficient thermistor NTC2 and the first negative temperature coefficient thermistor NTC1 is calculated. Based on this temperature difference, it can be determined whether there is a thermal runaway risk at present, thereby more accurately achieving single-cell thermal runaway warning and protecting the safety of the entire battery pack.

[0102] In related technologies, a single NTC is used for battery temperature detection. Frequent power-on and overuse of the NTC can lead to abnormal NTC resistance, which can cause temperature errors at the temperature collection point where the NTC is located, leading to false alarms. The battery management system of the present embodiment can, when one temperature detection branch detects an abnormal battery temperature, switch on another temperature detection branch to continue battery temperature detection, thereby further verifying whether the battery temperature is abnormal. This improves the accuracy of the battery temperature detection results, reduces the probability of battery temperature detection errors due to an erroneous detection result from one temperature detection branch, and reduces false alarms.

[0103] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0104] In a specific example, a battery management system includes a microprocessor of a battery management system (BMS), a two-way selector 21, a multi-way analog gate 31, a resistor device 4, and a first temperature detection branch and a second temperature detection branch connected in parallel. The resistor device 4 includes a first resistor R1; the first temperature detection branch includes a first negative temperature coefficient thermistor NTC1; and the second temperature detection branch includes a second negative temperature coefficient thermistor NTC2. When either the first temperature detection branch or the second temperature detection branch is conductive, the effective resistance of the resistor device 4 is equal to the resistance value of the first resistor R1.

[0105] A first end of a first negative temperature coefficient thermistor (NTC1) is connected to a first end of a resistor (R1), a second end of a resistor (R1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the first negative temperature coefficient thermistor (NTC1) is connected to a two-way selector 21. A first end of a second negative temperature coefficient thermistor (NTC2) is connected to a first end of a resistor (R1), a second end of a resistor (R1) is connected to a reference voltage output terminal (VCC) of processor 1, and a second end of the second negative temperature coefficient thermistor (NTC2) is connected to a two-way selector 21. A first end of the first resistor (R1) is connected to a multi-channel analog gate 31. The voltage of VCC includes, but is not limited to, 5V. The first resistor (R1) is a pull-up resistor.

[0106] The voltage sampling terminal V1 on the first temperature detection branch is connected to the first terminal of the first negative temperature coefficient thermistor NTC1. The voltage sampling terminal V2 on the second temperature detection branch is connected to the first terminal of the second negative temperature coefficient thermistor NTC2. The GPIO port of the BMS microprocessor inputs a high level to the binary selector 21, controlling the binary selector 21 to turn on the first temperature detection branch, thereby sampling the voltage at V1. When the GPIO port inputs a low level to the binary selector 21, controlling the binary selector 21 to turn on the second temperature detection branch, the voltage at V2 can be sampled.

[0107] When voltage sampling is performed, the analog signal at V1 is input to the processor 1 through the multi-channel analog selector 31, converted into a digital signal by the analog-to-digital converter ADC built into the microprocessor, and the temperature sampling value is obtained through calculation by the microprocessor.

[0108] Taking the example of two temperature sampling points in the entire battery pack, the microprocessor determines the temperature sampling value of V1 in real time and compares it with the temperature sampling value obtained at another sampling point in the entire battery pack. The difference between the temperature sampling value corresponding to V1 and the temperature sampling value obtained at the other sampling point is calculated. If the difference exceeds a preset threshold (for example, 3.5°C), the microprocessor controls the two-way selector 21 to disconnect the first temperature detection branch and switch to the second temperature detection branch. The switching process usually takes milliseconds. NTC2 starts working, samples the voltage at V2 at this time, and converts it into a temperature sampling value. The absolute value of the temperature difference between the temperature sampling value corresponding to V2 and the temperature sampling value obtained at the other sampling point is calculated. If the absolute value of the temperature difference does not exceed the preset threshold, it means that the temperature sampling value obtained at this time is within the normal range, and the second temperature detection branch is kept on for voltage sampling. If the absolute value of the temperature difference exceeds the preset threshold, it means that the temperature sampling value obtained at this time is not within the normal range, which means that the actual temperature of the temperature sampling point is abnormal, and an early warning operation is performed. The form of the warning operation is selected according to the degree of temperature abnormality (the difference between the absolute value of the temperature difference and the preset threshold value represents the degree of temperature abnormality) to select the background warning or vehicle-end alarm and other warning forms. For example, if the difference between the absolute value of the temperature difference and the preset threshold value is less than the preset first value, a background warning is performed. If the difference between the absolute value of the temperature difference and the preset threshold value is not less than the preset first value, a vehicle-end alarm is executed.

[0109] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0110] refer to Figure 5 As shown, another embodiment of the present application provides a battery management method, which is applied to the battery management system of any embodiment of the present application; the method may include steps S10-S30:

[0111] S10 , controlling the branch selector to turn on the first temperature detection branch and keep the remaining temperature detection branches disconnected.

[0112] The first temperature detection branch is any one of the multiple temperature detection branches.

[0113] Exemplarily, the GPIO port of the BMS microprocessor inputs a high level and a low level to the two-way selector 21 to control the two-way selector 21 to turn on the first temperature detection branch and the second temperature detection branch, respectively, thereby collecting the voltage at V1 or the voltage at V2. For example, the GPIO port inputs a high level to the two-way selector 21 to control the two-way selector 21 to turn on the first temperature detection branch, and the GPIO port inputs a low level to the two-way selector 21 to control the two-way selector 21 to turn on the second temperature detection branch, thereby collecting the voltage at V1 or the voltage at V2.

[0114] S20 . Acquire battery temperature data corresponding to the first temperature detection branch based on the channel selector and the resistance device.

[0115] The battery temperature data is used to represent the difference between the temperature detected at the first temperature detection branch and the temperatures detected at the remaining temperature sampling points in the battery.

[0116] refer to Figure 6 As shown, in some embodiments, obtaining battery temperature data corresponding to the first temperature detection branch based on the channel selector and the resistor device includes:

[0117] S201 : Acquire a first temperature sampling value according to a first signal, an effective resistance value of a resistance device, and a reference voltage at a reference voltage output terminal.

[0118] The first temperature sampling value is a temperature sampling value corresponding to the first temperature detection branch; the first signal is a voltage sampling signal from the first temperature detection branch transmitted by the channel selector.

[0119] The effective resistance is the resistance of the conductive portion of the resistor. Figure 2 and Figure 4 In the example shown, the resistor device 4 includes a first resistor R1 . When the first temperature detection branch or the second temperature detection branch is turned on, the effective resistance value of the resistor device 4 is the resistance value of the first resistor R1 . Figure 3 In the example shown, the resistance device 4 includes a resistor r1 and a resistor r2 connected in parallel; when the first temperature detection branch is turned on, the resistor r1 is turned on, and the effective resistance value of the resistance device 4 is the resistance value of the resistor r1; when the second temperature detection branch is turned on, the resistor r2 is turned on, and the effective resistance value of the resistance device 4 is the resistance value of the resistor r2.

[0120] For example, a first sampled voltage value may be obtained according to the first signal, and then a first temperature sampled value corresponding to the first sampled voltage value may be obtained according to the first sampled voltage value, the effective resistance value of the resistor device, and the reference voltage of the reference voltage output terminal.

[0121] Specifically, obtaining a first temperature sampling value corresponding to the first sampling voltage value based on the first sampling voltage value, the effective resistance value of the resistance device, and the reference voltage of the reference voltage output end may include: calculating the product of the reference voltage of the reference voltage output end and the effective resistance value of the resistance device; calculating the difference between the reference voltage of the reference voltage output end and the first sampling voltage value; calculating the ratio of the aforementioned product to the aforementioned difference to obtain the resistance value of the temperature sensing device in the first temperature detection branch; obtaining the first temperature sampling value based on the resistance value of the temperature sensing device and the correspondence between the pre-acquired resistance value and the battery temperature.

[0122] For example, when the first temperature detection branch is turned on, UV1 / U VCC =R NTC1 / (R NTC1 +R1), where U V1 is the voltage at V1, U VCC is the voltage of VCC, and the resistance value R of the first negative temperature coefficient thermistor NTC1 can be obtained. NTC1 =U V1 *R1 / (U VCC -U V1 ). Then, according to the resistance value R of the first negative temperature coefficient thermistor NTC1 NTC1 And the correspondence between the previously acquired resistance value and the battery temperature, find out the resistance value R NTC1 The corresponding first temperature sampling value.

[0123] S202: Obtain the absolute value of the temperature difference between the first temperature sampling value and the temperature sampling value at each of the remaining temperature sampling points to obtain battery temperature data. This battery temperature data can be used to determine whether there is a risk of abnormal battery temperature with high accuracy. The battery temperature data corresponding to the first temperature detection branch includes the absolute value of the temperature difference between the first temperature sampling value and the temperature sampling value at each of the remaining temperature sampling points.

[0124] For example, the absolute value of the difference between the first temperature sampling value and the temperature sampling values ​​of each other sampling point in the battery is calculated to obtain battery temperature data. The battery temperature data represents the difference between the first temperature sampling value and the temperature sampling values ​​of the other sampling points.

[0125] S30 . When the battery temperature data meets a preset battery temperature condition, control the branch selector to disconnect the first temperature detection branch and connect the second temperature detection branch.

[0126] The second temperature detection branch is any one of the remaining temperature detection branches; the preset battery temperature condition is a sufficient condition for an abnormality in the connected temperature detection branch. That is, if the battery temperature data meets the preset battery temperature condition, it can be determined that the connected temperature detection branch has an abnormality. If the battery temperature data corresponding to the first temperature detection branch meets the preset battery temperature condition, the branch selector is controlled to disconnect the first temperature detection branch and connect the second temperature detection branch. If the battery temperature data corresponding to the first temperature detection branch meets the preset battery temperature condition, it means that the first temperature detection branch has detected a temperature abnormality.

[0127] In some embodiments, the preset battery temperature condition may be, for example, the presence of an absolute temperature difference exceeding a preset threshold value in the battery temperature data; the battery temperature data satisfies the preset battery temperature condition, i.e., the presence of an absolute temperature difference exceeding the preset threshold value in the battery temperature data. When the battery temperature data satisfies the preset battery temperature condition, controlling the branch selector to disconnect the first temperature detection branch and connect the second temperature detection branch may include: when the battery temperature data contains an absolute temperature difference exceeding the preset threshold value, controlling the branch selector to disconnect the first temperature detection branch and connect the second temperature detection branch. If the first temperature detection branch detects a temperature anomaly, the battery temperature data is acquired again by connecting the second temperature detection branch, thereby improving the accuracy of determining the risk of battery temperature anomaly.

[0128] refer to Figure 7 As shown, in some embodiments, the method may further include:

[0129] S40 , based on the battery temperature data obtained when any one of the plurality of temperature detection branches is turned on, satisfying the preset battery temperature condition, determining that the preset warning condition is met, and executing a warning operation.

[0130] The preset warning condition is a preset trigger condition for executing the warning operation. If the battery temperature data meets the preset warning condition, the warning operation is triggered. If the battery temperature data obtained by any of the multiple temperature detection branches meets the preset battery temperature condition, it can be determined that the battery temperature is abnormal and a warning is required, that is, the preset warning condition has been met.

[0131] In this way, when it is determined that there is an abnormal battery temperature, an early warning operation can be used to remind relevant personnel to take timely treatment measures, thereby reducing the safety risks caused by abnormal battery temperature.

[0132] For example, the preset battery temperature condition may include the presence of an absolute temperature difference exceeding a preset threshold value in the battery temperature data obtained when any one of the plurality of temperature detection branches is turned on. Specifically, based on the presence of an absolute temperature difference exceeding the preset threshold value in the battery temperature data obtained when any one of the plurality of temperature detection branches is turned on, it is determined that the preset warning condition has been met, and a warning operation is executed.

[0133] The forms of early warning operations include but are not limited to background early warning, vehicle-end fault code jump, etc.

[0134] Exemplarily, when there are only two branches in the device, namely the first temperature detection branch and the second temperature detection branch, the preset battery temperature condition includes that the battery temperature data corresponding to the first temperature detection branch has an absolute value of a temperature difference exceeding a preset threshold, and the battery temperature data corresponding to the second temperature detection branch has an absolute value of a temperature difference exceeding a preset threshold.

[0135] In some embodiments, the plurality of temperature detection branches include a first number of first branches and a second number of second branches, the vertical distance between the temperature sensing device in the first branch and the upper cover of the battery is smaller than the vertical distance between the temperature sensing device in the second branch and the upper cover; the resistance value of the temperature sensing device changes with temperature; and the method may further include:

[0136] S50 , in response to detecting that the operating status data exceeds a preset safety value, controlling the branch selector to enable the first temperature detection branch and the second temperature detection branch to be turned on alternately.

[0137] The operating status data includes but is not limited to battery charging power, battery discharging power, and the battery's ambient temperature, etc. The preset safety values ​​include but are not limited to battery charging power preset safety values, battery discharging power preset safety values, and the battery's ambient temperature preset safety values, etc.

[0138] When it is detected that at least one of the battery charging power, the battery discharging power and the ambient temperature of the battery exceeds the corresponding preset safety value, the control branch selector enables the first temperature detection branch and the second temperature detection branch to be turned on alternately.

[0139] In some embodiments, controlling the branch selector to alternately conduct the first temperature detection branch and the second temperature detection branch may include: sending a periodic control signal to the branch selector to control the branch selector to alternately conduct the first temperature detection branch and the second temperature detection branch. By sending the periodic control signal to control the alternate conduction of the first temperature detection branch and the second temperature detection branch, detecting whether there is a battery temperature abnormality based on temperature sampling values ​​obtained by the two temperature detection branches, the detection result is accurate and timely, and abnormal battery temperature conditions can be detected in a timely manner.

[0140] The periodic control signal includes but is not limited to square wave signals, triangle wave signals, sine wave signals and the like.

[0141] S60 , executing a warning operation according to whether the battery temperature data corresponding to the first temperature detection branch and the battery temperature data corresponding to the second temperature detection branch meet a preset warning condition.

[0142] In this way, the detection sensitivity of abnormal battery temperature conditions is improved, and an early warning can be issued in time when the battery temperature is abnormal to remind relevant personnel to take treatment measures, thereby reducing the safety risks caused by abnormal battery temperature.

[0143] Exemplarily, the battery temperature data corresponding to the first temperature detection branch may further include a temperature sampling value of the first temperature detection branch, and the battery temperature data corresponding to the second temperature detection branch may further include a temperature sampling value of the second temperature detection branch. The preset warning condition is that the absolute value of the difference between the temperature sampling value of the first temperature detection branch and the temperature sampling value of the second temperature detection branch exceeds a preset threshold.

[0144] For example, in Figure 2-Figure 4 In the example shown, the absolute value of the difference between the temperature corresponding to the second temperature detection branch and the temperature corresponding to the first temperature detection branch is calculated. When the absolute value of the difference is greater than a preset threshold, it is determined that the preset warning condition is met. When the absolute value of the difference is not greater than the preset threshold, it is determined that the preset warning condition is not met.

[0145] For example, when it is detected that the battery charging power exceeds a preset safety value of the battery charging power, the battery discharging power exceeds a preset safety value of the battery discharging power, or the ambient temperature of the battery exceeds a preset safety value of the ambient temperature of the battery, the BMS microprocessor can send a square wave signal to the two-way selector 21 to make the first negative temperature coefficient thermistor NTC1 and the second negative temperature coefficient thermistor NTC2 alternately turn on. The first negative temperature coefficient thermistor NTC1 is arranged on the side close to the upper cover of the battery, and the second negative temperature coefficient thermistor NTC2 is arranged on the side close to the battery cell. When a thermal runaway condition is about to occur, the battery cell heats up first, and the temperature detected by the second negative temperature coefficient thermistor NTC2 rises first. The temperature detected by the second negative temperature coefficient thermistor NTC2 is higher than the temperature detected by the first negative temperature coefficient thermistor NTC1. By calculating the temperature difference between the second negative temperature coefficient thermistor NTC2 and the first negative temperature coefficient thermistor NTC1, a single-cell thermal runaway warning can be more accurately achieved, thereby protecting the safety of the entire battery pack.

[0146] The battery management method of the embodiment of the present application, when one temperature detection branch detects that the battery temperature is abnormal, turns on the other temperature detection branch to continue battery temperature detection, thereby further verifying whether the battery temperature is abnormal, improving the accuracy of the battery temperature detection result, reducing the probability of battery temperature detection error due to an erroneous detection result of one of the temperature detection branches, and reducing the situation of false alarms.

[0147] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0148] In a specific example, a battery management method is applied to a battery management system; the battery management system includes a microprocessor of a battery management system (BMS), a two-way selector 21, a multi-way analog selector 31, a resistor device 4, and a first temperature detection branch and a second temperature detection branch connected in parallel. The resistor device 4 includes a first resistor R1; the first temperature detection branch includes a first negative temperature coefficient thermistor NTC1; and the second temperature detection branch includes a second negative temperature coefficient thermistor NTC2. When either the first temperature detection branch or the second temperature detection branch is conductive, the effective resistance value of the resistor device 4 is equal to the resistance value of the first resistor R1. The first end of the first negative temperature coefficient thermistor NTC1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the reference voltage output terminal VCC of the processor 1, and the second end of the first negative temperature coefficient thermistor NTC1 is connected to the two-way selector 21. The first end of the second negative temperature coefficient thermistor NTC2 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the reference voltage output terminal VCC of the processor 1, and the second end of the second negative temperature coefficient thermistor NTC2 is connected to the two-way selector 21. The first end of the first resistor R1 is connected to the multi-channel analog gate 31. The voltage of VCC includes, but is not limited to, 5V. The first resistor R1 is a pull-up resistor. The voltage sampling terminal V1 on the first temperature detection branch is connected to the first end of the first negative temperature coefficient thermistor NTC1. The voltage sampling terminal V2 on the second temperature detection branch is connected to the first end of the second negative temperature coefficient thermistor NTC2.

[0149] The battery management method includes:

[0150] Controlling the branch selector to turn on the first temperature detection branch and keep the remaining temperature detection branches disconnected: The GPIO port of the BMS microprocessor inputs a high level and a low level to the two-way selector 21 to control the two-way selector 21 to turn on the first temperature detection branch and the second temperature detection branch, respectively, thereby sampling the voltage at V1 or the voltage at V2. For example, the GPIO port inputs a high level to the two-way selector 21 to control the two-way selector 21 to turn on the first temperature detection branch, and the GPIO port inputs a low level to the two-way selector 21 to control the two-way selector 21 to turn on the second temperature detection branch, thereby sampling the voltage at V1 or the voltage at V2.

[0151] When the first temperature detection branch is turned on, U V1 / U VCC =R NTC1 / (R NTC1 +R1), where U V1 is the voltage at V1, UVCC is the voltage of VCC, and the resistance value R of the first negative temperature coefficient thermistor NTC1 can be obtained. NTC1 =U V1 *R1 / (U VCC -U V1 ). Then, according to the resistance value R of the first negative temperature coefficient thermistor NTC1 NTC1 And the correspondence between the previously acquired resistance value and the battery temperature, find out the resistance value R NTC1 The corresponding first temperature sampling value.

[0152] The first temperature sampling value is the temperature sampling value corresponding to the first temperature detection branch; the first signal is the voltage sampling signal from the first temperature detection branch, transmitted by the channel selector. The effective resistance value is the resistance value of the conductive portion of the resistor device. Resistor device 4 includes a first resistor R1. When either the first temperature detection branch or the second temperature detection branch is conductive, the effective resistance value of resistor device 4 is the resistance value of first resistor R1.

[0153] The absolute value of the difference between the first temperature sampling value and the temperature sampling values ​​at each other sampling point in the battery is calculated to obtain battery temperature data. This battery temperature data represents the difference between the first temperature sampling value and the temperature sampling values ​​at the other sampling points. The battery temperature data is used to represent the difference between the temperature detected at the first temperature detection branch and the temperatures detected at the remaining temperature sampling points in the battery.

[0154] When the absolute value of the temperature difference in the battery temperature data exceeds a preset threshold, the control branch selector is configured to disconnect the first temperature detection branch and connect the second temperature detection branch.

[0155] A warning operation is performed based on the battery temperature data corresponding to the first temperature detection branch and the battery temperature data corresponding to the second temperature detection branch meeting a preset warning condition. The preset warning condition includes the presence of an absolute temperature difference exceeding a preset threshold in the battery temperature data corresponding to the first temperature detection branch and the presence of an absolute temperature difference exceeding a preset threshold in the battery temperature data corresponding to the second temperature detection branch.

[0156] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0157] Another embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the method of any of the above embodiments. Figure 8As shown, the computer-readable storage medium is a CD 20 on which a computer program (ie, a program product) is stored. When the computer program is run by a processor, the method provided by any of the aforementioned embodiments is executed.

[0158] It should be noted that examples of computer-readable storage media may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0159] The computer-readable storage medium provided in the above-mentioned embodiments of the present application and the method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0160] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0161] It should be noted that:

[0162] The algorithm and display provided herein are not inherently related to any particular computer, virtual device or other equipment. Various general-purpose devices can also be used together with examples based on this. According to the above description, it is obvious that the structure required for constructing this type of device. In addition, the application is not directed to any specific programming language yet. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the application.

[0163] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the flowcharts of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0164] The above embodiments merely represent implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A battery management system, characterized in that: It includes a processor, a branch selector, a channel selector, a resistor device, and a plurality of parallel temperature detection branches; The first end of each temperature detection branch is connected to the reference voltage output end of the processor through the resistor device, the first end of each temperature detection branch is connected to the channel selector, and the second end of each temperature detection branch is connected to the branch selector; the channel selector and the branch selector are both connected to the processor; The battery management system also includes a voltage comparator selector; the resistor device includes multiple second resistors, and the multiple second resistors correspond one-to-one to the multiple parallel temperature detection branches; the voltage comparator selector is respectively connected to the channel selector and the first end of each temperature detection branch, the first end of each second resistor is connected to the first end of the corresponding temperature detection branch, and the second end of each second resistor is connected to the reference voltage output end of the processor.

2. The battery management system according to claim 1, characterized in that: The resistor device includes a first resistor, a first end of each temperature detection branch is connected to a first end of the first resistor, and a second end of the first resistor is connected to a reference voltage output end of the processor.

3. The battery management system according to claim 1 or 2, characterized in that: The branch selector includes a drive circuit and a plurality of switch circuits; the plurality of switch circuits correspond one to one with the plurality of parallel temperature detection branches; the drive circuit is connected to each of the switch circuits and the processor respectively; Each of the switch circuits is connected to the second end of the corresponding temperature detection branch, and each of the switch circuits is grounded.

4. The battery management system according to claim 3, characterized in that: The switch circuit includes a transistor, and the drive circuit is connected to the first electrode of each transistor and the processor respectively; the second electrode of each transistor is connected to the second end of the corresponding temperature detection branch, and the third electrode of each transistor is grounded.

5. The battery management system according to claim 1 or 2, characterized in that: Each of the temperature detection branches includes a temperature sensing device.

6. The battery management system according to claim 5, characterized in that: The multiple temperature detection branches include a first number of first branches and a second number of second branches, the vertical distance between the temperature sensing device in the first branch and the upper cover of the battery is smaller than the vertical distance between the temperature sensing device in the second branch and the upper cover; the resistance value of the temperature sensing device changes with temperature.

7. A battery management method, characterized in that: A battery management system according to any one of claims 1 to 6; the method comprising: Controlling the branch selector to turn on a first temperature detection branch and keep the remaining temperature detection branches disconnected; the first temperature detection branch is any one of the multiple temperature detection branches; acquiring battery temperature data corresponding to the first temperature detection branch based on the channel selector and the resistor device; wherein the battery temperature data is used to represent a difference between a temperature detected at the first temperature detection branch and temperatures detected at other temperature sampling points in the battery acquired in advance; When the battery temperature data meets a preset battery temperature condition, the branch selector is controlled to disconnect the first temperature detection branch and turn on the second temperature detection branch; the second temperature detection branch is any one of the remaining temperature detection branches; the preset battery temperature condition is a sufficient condition for an abnormality to occur in the turned-on temperature detection branch.

8. The method according to claim 7, characterized in that The acquiring, based on the channel selector and the resistor device, battery temperature data corresponding to the first temperature detection branch includes: Obtaining a first temperature sampling value based on a first signal, an effective resistance value of the resistor device, and a reference voltage at the reference voltage output terminal; the first temperature sampling value is a temperature sampling value corresponding to the first temperature detection branch; the first signal is a voltage sampling signal from the first temperature detection branch, and the first signal is transmitted by the channel selector; the effective resistance value is a resistance value of a conductive portion of the resistor device; The absolute value of the temperature difference between the first temperature sampling value and the temperature sampling value of each of the remaining temperature sampling points is obtained to obtain the battery temperature data.

9. The method according to claim 7 or 8, characterized in that When the battery temperature data meets a preset battery temperature condition, controlling the branch selector to disconnect the first temperature detection branch and connect the second temperature detection branch includes: When the battery temperature data contains a temperature difference absolute value exceeding a preset threshold, the branch selector is controlled to disconnect the first temperature detection branch and connect the second temperature detection branch.

10. The method according to claim 7 or 8, characterized in that The method further comprises: According to the battery temperature data obtained by turning on any one of the multiple temperature detection branches, the preset battery temperature condition is met, and the preset warning condition is determined to be reached, and the warning operation is executed; the preset warning condition is a preset trigger condition for executing the warning operation.

11. The method according to claim 7 or 8, characterized in that The multiple temperature detection branches include a first number of first branches and a second number of second branches, wherein a vertical distance between the temperature sensing device in the first branch and the upper cover of the battery is smaller than a vertical distance between the temperature sensing device in the second branch and the upper cover; The resistance value of the temperature sensing device changes with temperature; The method further comprises: In response to detecting that the operating state data exceeds a preset safety value, controlling the branch selector to enable the first temperature detection branch and the second temperature detection branch to be turned on alternately; According to the battery temperature data corresponding to the first temperature detection branch and the battery temperature data corresponding to the second temperature detection branch meeting the preset warning condition, the warning operation is performed; the preset warning condition is a preset trigger condition for performing the warning operation.

12. The method according to claim 11, characterized in that The controlling the branch selector to make the first temperature detection branch and the second temperature detection branch alternately turned on includes: A periodic control signal is sent to the branch selector to control the branch selector to make the first temperature detection branch and the second temperature detection branch alternately turned on.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the battery management method according to any one of claims 7 to 12.

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