Battery temperature sensor fault diagnosis method and diagnosis device

Abstract

The invention discloses a battery temperature sensor fault diagnosis method and diagnosis device, and relates to the technical field of battery fault diagnosis. Wherein a plurality of temperature sampling points are arranged in the battery, each temperature sampling point is provided with a temperature sensor, and the method comprises the following steps: acquiring a sampling temperature value of each temperature sensor after the battery is powered on again under the condition that the low-voltage power-off duration of the battery is greater than a preset duration; and when the temperature difference value between the sampling temperature value of the temperature sensor and the average temperature value of the sampling temperature values of all the temperature sensors except the temperature sensor exceeds a first preset verification range, determining that the temperature sensor has a first outlier failure fault. Therefore, according to the method, based on a system architecture in which the sampling points and the temperature sensors are arranged in a one-to-one correspondence manner, the diagnosis coverage degree meeting the high function safety level requirement can be realized, and the fault diagnosis cost of the temperature sensors and the system assembly complexity are reduced.

Description

Technical Field

[0001] This application relates to the field of battery fault diagnosis technology, and in particular to a method for diagnosing battery temperature sensor faults, a device for diagnosing battery temperature sensor faults, a computer-readable storage medium, and a vehicle. Background Technology

[0002] Battery management systems (BMS) play a crucial role in electric and hybrid vehicles, managing the charging and discharging process and ensuring battery safety. BMS monitors the battery system temperature using temperature sensors located on the cells or modules, thereby controlling the charging and discharging power or providing safety warnings and monitoring based on temperature, voltage, air pressure, and other conditions.

[0003] In related technologies, in order to meet high-level functional safety requirements, multiple temperature sensors are arranged at each temperature sampling point for mutual verification. The redundant temperature acquisition circuits work together with the redundant temperature sensors to complete the requirements of temperature acquisition and sensor fault diagnosis. This method is costly and has high assembly complexity. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art. Therefore, the first objective of this application is to propose a method for diagnosing battery temperature sensors. Based on a system architecture where sampling points and temperature sensors are arranged in a one-to-one correspondence, this method can achieve diagnostic coverage that meets high functional safety requirements, while reducing the cost of temperature sensor fault diagnosis and the complexity of system assembly.

[0005] The second objective of this application is to provide a fault diagnosis device for a battery temperature sensor.

[0006] The third objective of this application is to provide a computer-readable storage medium.

[0007] The fourth objective of this application is to propose a vehicle.

[0008] To achieve the above objectives, the first aspect of this application proposes a method for diagnosing a battery temperature sensor fault. The battery includes multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor. The method includes: when the battery is powered on at low voltage for a duration longer than a preset duration, after the battery is powered on again, acquiring the sampled temperature value of each temperature sensor; and determining that the temperature sensor has a first outlier failure fault when the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range.

[0009] According to the battery temperature sensor fault diagnosis method of this application embodiment, a temperature sensor is respectively installed at multiple temperature sampling points inside the battery. When the battery is powered on at low voltage for a period longer than a preset duration, after the battery is powered on again, the sampled temperature value of each temperature sensor is acquired. If the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range, it is determined that the temperature sensor has a first outlier failure fault. Therefore, this method, based on a system architecture with a one-to-one correspondence between temperature sampling points and temperature sensors, can achieve diagnostic coverage that meets high functional safety requirements, and reduces the fault diagnosis cost of temperature sensors and the complexity of system assembly.

[0010] In addition, the battery temperature sensor fault diagnosis method according to the above embodiments of this application may also have the following additional technical features: According to one embodiment of this application, the battery temperature sensor fault diagnosis method further includes: when the battery's low-voltage power-on time is less than or equal to a preset time, or when each temperature sensor does not have a first outlier failure fault, obtaining the sampled temperature value of each temperature sensor; and when it is determined from the sampled temperature value of each temperature sensor that there is a temperature difference between adjacent temperature sensors that exceeds a second preset verification range, determining that adjacent temperature sensors have a second outlier failure fault.

[0011] According to one embodiment of this application, when it is determined that there is no second outlier failure fault in each temperature sensor, the battery temperature sensor fault diagnosis method further includes: obtaining the sampling temperature drop amplitude of each temperature sensor within a preset time; and determining that there is a first sampling failure fault in the temperature sensor when the sampling temperature drop amplitude of the temperature sensor is greater than a preset temperature drop threshold.

[0012] According to one embodiment of this application, when it is determined that there is no second outlier failure fault in each temperature sensor, the battery temperature sensor fault diagnosis method further includes: acquiring the operating data of each temperature sensor; and determining that there is a wire breakage fault in the temperature sensor when the operating data of the temperature sensor exceeds a preset rated range.

[0013] According to one embodiment of this application, the battery temperature sensor fault diagnosis method further includes: when the battery's low-voltage power-on time is less than or equal to a preset time, or when each temperature sensor does not have a first outlier failure fault, acquiring the output voltage and / or sampled temperature value of each temperature sensor; when the output voltage of the temperature sensor exceeds a preset voltage range or the sampled temperature value of the temperature sensor exceeds a preset temperature range, determining that the temperature sensor has a second sampling failure fault.

[0014] According to one embodiment of this application, the battery temperature sensor fault diagnosis method further includes: generating a fault alarm signal based on the fault type of the temperature sensor when it is determined that the temperature sensor is faulty.

[0015] According to one embodiment of this application, the battery temperature sensor fault diagnosis method further includes: performing a corresponding degradation and power reduction operation on the battery when it is determined that the temperature sensor is faulty.

[0016] To achieve the above objectives, a second aspect of this application provides a battery temperature sensor fault diagnosis device. The battery includes multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor. The device includes: an acquisition module, used to acquire the sampled temperature value of each temperature sensor after the battery is powered on again when the battery is powered on for a period longer than a preset time under low voltage; and a fault diagnosis module, used to determine that the temperature sensor has a first outlier failure fault when the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range.

[0017] According to the battery temperature sensor fault diagnosis device of this application embodiment, when the battery is powered on for a period longer than a preset time under low voltage, the acquisition module acquires the sampled temperature value of each temperature sensor after the battery is powered on again. If the temperature difference between the sampled temperature value of one temperature sensor and the average temperature of all temperature sensors (excluding the temperature sensor) exceeds a first preset verification range, the fault diagnosis module determines that the temperature sensor has a first outlier failure. Therefore, based on a system architecture where temperature sampling points and temperature sensors are arranged in a one-to-one correspondence, this device can achieve diagnostic coverage that meets high functional safety requirements, reducing the fault diagnosis cost of temperature sensors and the complexity of system assembly.

[0018] To achieve the above objectives, a third aspect of this application provides a computer-readable storage medium storing a battery temperature sensor fault diagnosis program thereon, which, when executed by a processor, implements the aforementioned battery temperature sensor fault diagnosis method.

[0019] According to the embodiments of this application, a computer-readable storage medium storing a battery temperature sensor fault diagnosis program thereon implements the above-described battery temperature sensor fault diagnosis method when executed by a processor. Based on the above-described battery temperature sensor fault diagnosis method, the fault diagnosis cost and assembly complexity of the temperature sensor are reduced.

[0020] To achieve the above objectives, a fourth aspect of this application provides a vehicle comprising: a battery, the battery including multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor; and a battery management system configured to, when the battery is powered on for a period exceeding a preset duration under low voltage, acquire the sampled temperature value of each temperature sensor after the battery is powered on again, and determine that the temperature sensor has a first outlier failure fault if the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range.

[0021] According to the vehicle embodiment of this application, when the battery is powered on at low voltage for a period longer than a preset duration, the battery management system acquires the sampled temperature value of each temperature sensor after the battery is powered on again. If the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range, it determines that the temperature sensor has a first outlier failure fault. This reduces the fault diagnosis cost and assembly complexity of the temperature sensor while meeting the diagnostic coverage requirements of a high functional safety level. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the architecture of a battery system according to a specific embodiment of this application; Figure 2 This is a flowchart of a battery temperature sensor fault diagnosis method according to an embodiment of this application; Figure 3 This is a flowchart of a battery temperature sensor fault diagnosis method according to a specific embodiment of this application; Figure 4 This is a connection diagram of a battery temperature sensor fault diagnosis device according to an embodiment of this application; Figure 5 This is a block diagram of a vehicle according to an embodiment of this application. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0024] The following describes in detail, with reference to the accompanying drawings, a battery temperature sensor fault diagnosis method, a battery temperature sensor fault diagnosis device, a computer-readable storage medium, and a vehicle, according to embodiments of this application.

[0025] In some embodiments of this application, the battery includes multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor.

[0026] Specifically, such as Figure 1 As shown, a battery system typically consists of a battery, high-voltage accessories (current sensors, relays), and a battery management system. The battery comprises multiple battery modules, denoted by 1, 2, ..., n. Multiple cells within each battery module are electrically connected in series and parallel. Multiple battery modules are also electrically connected in series and parallel to establish a battery system that meets the voltage platform and capacity requirements of the entire vehicle.

[0027] Multiple temperature sampling points can be arranged in each battery module, and a temperature sensor is arranged at each temperature sampling point to collect the module temperature and feed the acquired module temperature back to the battery management system. The cell voltage is usually collected by the analog front-end voltage acquisition circuit of the battery management system, while the module temperature is usually collected by the analog front-end acquisition circuit of the battery management system in conjunction with the temperature sensors arranged in each module. The battery management system can control the positive relay, negative relay, and pre-charge relay to open and close the battery system circuit. After detecting an abnormality in the battery system, the battery management system can disconnect the high-voltage connection of the battery system to the outside through the relays. The battery temperature sensor fault diagnosis method of this application embodiment can be implemented by the battery management system or by another controller (such as the vehicle controller), and there is no specific limitation.

[0028] Reference Figure 2 The battery temperature sensor fault diagnosis method according to this application includes the following steps: S1, when the battery is powered on for a period of time longer than a preset time under low voltage, acquire the sampled temperature value of each temperature sensor after the battery is powered on again.

[0029] Specifically, low-voltage discharge of a battery refers to the battery discharging to a lower voltage, at which point the battery stops outputting energy and the battery system enters a dormant or shut-down state. After entering the low-voltage discharge state, the battery temperature gradually decreases, and eventually the temperature of each part of the battery tends to match the ambient temperature, reaching a state of thermal equilibrium.

[0030] The preset duration can be set according to actual conditions, such as based on parameters like ambient temperature and battery performance, to determine whether the battery has reached thermal equilibrium. For example, if experiments determine that the battery can reach thermal equilibrium after being charged at low voltage for N hours, then the preset duration is N hours.

[0031] If the battery is powered on at low voltage for a longer period than the preset duration, the battery system will enter the working state when the battery is powered on again (such as entering the low voltage power-on state, high voltage power-on state, etc.). At this time, the sampling temperature value of each temperature sensor in the battery module will be obtained through the analog front-end acquisition circuit of the battery management system.

[0032] S2, if the temperature difference between the sampled temperature value of the temperature sensor and the average temperature value of all sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds the first preset verification range, it is determined that the temperature sensor has a first outlier failure fault.

[0033] Specifically, assume that the battery contains n battery modules, and each battery module is equipped with 4 temperature sensors. The temperature sensors are coded as 11, 12, 13, 14, 21, ..., n1, n2, n3, n4. Here, 11, 12, 13, 14 are the codes for the four temperature sensors in battery module 1, and so on, n1, n2, n3, n4 are the codes for the four temperature sensors in battery module n.

[0034] Taking temperature sensor 11 as an example, all other temperature sensors besides temperature sensor 11 are those coded as 12, 13, 14, 21, ..., n1, n2, n3, n4. Assume the sampled temperature value of temperature sensor 11 at the current moment is T. 11 Then, the sampled temperature value of all temperature sensors except the temperature sensor at the current moment is T. 12 T 13 ...T n3 T n4 , for T 12 T 13 ...T n3 T n4 The average temperature value (T0) of the sampled temperature values ​​from all temperature sensors except the temperature sensor is calculated by averaging. 11 The temperature difference between T0 and T is ΔT = T 11 -T0, if △T is within the first preset verification range, it is determined that the temperature sensor 11 does not have the first outlier failure fault; if △T is outside the first preset verification range, it is determined that the temperature sensor 11 has the first outlier failure fault.

[0035] The first preset verification range can be set according to the temperature distribution of the battery system under normal operating conditions. For example, the temperature sampling values ​​of all temperature sensors under normal operating conditions can be pre-statistically counted, the maximum temperature value and the minimum temperature value among the temperature sampling values ​​of all temperature sensors can be determined, and the average temperature value can be calculated. The temperature difference between the maximum temperature value and the average temperature value, and the temperature difference between the average temperature value and the minimum temperature value can be obtained. The larger value between the two temperature differences is x, and then [-x, +x] is used as the first preset verification range.

[0036] Furthermore, the first preset verification range can also be set based on parameters such as the placement position of each temperature sensor, the sampling accuracy of the temperature sensor, the battery condition, and the accuracy requirements of the battery system. For example, the first preset verification range under preset conditions is first obtained as [-x, +x] using the above method. Then, the first preset verification range is adjusted according to the placement position of each temperature sensor and the sampling accuracy of the temperature sensor. For example, when the temperature rise effect at the placement position of the temperature sensor is poor, the first preset verification range can be shifted to the left by a preset threshold, that is, the preset thresholds for -x and +x can be decreased; when the temperature rise effect at the placement position of the temperature sensor is high, the first preset verification range can be shifted to the right by a preset threshold, that is, the preset thresholds for -x and +x can be increased.

[0037] The first outlier failure refers to a temperature sensor's sampled temperature value deviating significantly from the expected value or the normal distribution of other temperature sensors. The set of all temperature sensors constitutes a group. If the deviation between the sampled temperature value of a particular temperature sensor and the average sampled temperature value of other temperature sensors exceeds a first preset calibration range, then that temperature sensor is considered to have a first outlier failure. It is understood that the first outlier failure is determined based on temperature sampled values ​​at the same time.

[0038] This embodiment ensures the battery enters thermal equilibrium after the power-on time exceeds a preset duration under low voltage. Then, it performs fault diagnosis on the temperature sensor based on the sampled temperature value after power-on, improving the accuracy and stability of temperature measurement and the precision of fault diagnosis. At the same time, this embodiment, based on a system architecture with a one-to-one correspondence between temperature sampling points and temperature sensors, completes the fault diagnosis of outlier failures of temperature sensors. Under the premise of meeting the diagnostic coverage requirements of high functional safety level, it reduces the fault diagnosis cost of temperature sensors.

[0039] In some embodiments of this application, the battery temperature sensor fault diagnosis method further includes: when the battery's low-voltage power-on time is less than or equal to a preset time, or when each temperature sensor does not have a first outlier failure fault, obtaining the sampled temperature value of each temperature sensor; and when it is determined, based on the sampled temperature value of each temperature sensor, that there is a temperature difference between adjacent temperature sensors that exceeds a second preset verification range, determining that adjacent temperature sensors have a second outlier failure fault.

[0040] Specifically, adjacent temperature sensors can be pre-bound according to their arrangement positions and their mapping relationships can be stored. Each temperature sensor includes at least one adjacent temperature sensor.

[0041] When the battery's low-voltage power-on time is less than or equal to the preset time, the battery has not yet reached thermal equilibrium and cannot achieve high-precision judgment of the first outlier failure. At this time, the temperature difference between each group of adjacent temperature sensors is obtained based on the preset mapping relationship, and the second outlier failure is determined based on the temperature difference between each group of adjacent temperature sensors.

[0042] When it is determined that there is no first outlier failure fault in each temperature sensor, the temperature difference value between each group of adjacent temperature sensors is further obtained based on the preset mapping relationship, and the second outlier failure fault is determined based on the temperature difference value between each group of adjacent temperature sensors.

[0043] The second outlier failure fault is used to characterize whether there is a possibility of outlier failure between two temperature sensors in a group of adjacent temperature sensors. If the temperature difference between a group of adjacent temperature sensors exceeds the second preset verification range, it is determined that there is a second outlier failure fault between two temperature sensors in the group of adjacent temperature sensors; if it does not exceed the second preset verification range, it is determined that there is no second outlier failure fault between two temperature sensors in the group of adjacent temperature sensors.

[0044] The second preset verification range can be set based on the temperature distribution under normal battery system operating conditions. For example, by statistically analyzing the maximum absolute value of the temperature difference between two adjacent temperature sensors under normal operating conditions, if the maximum value is y, then [-y, +y] is used as the second preset verification range. Furthermore, the second preset verification range can also be set based on parameters such as sampling accuracy, temperature rise performance, and battery operating conditions between each group of adjacent temperature sensors. For example, a mapping relationship between preset sampling accuracy, temperature rise performance, battery operating conditions, and adjustment coefficients can be defined. If the second preset verification range for this group of adjacent temperature sensors is determined to be [-y, +y] based on the above method, during fault detection, the sampling accuracy, temperature rise performance, and battery operating conditions are acquired, and the corresponding adjustment coefficients are determined by looking up a table. The second preset verification range of [-y, +y] is then adjusted using these adjustment coefficients to serve as the second preset verification range for this fault diagnosis, thereby improving the accuracy of fault diagnosis.

[0045] This embodiment evaluates the second outlier failure of adjacent temperature sensors based on a second preset verification range, improving the comprehensiveness of temperature sensor fault diagnosis and providing support for meeting higher-level functional safety temperature acquisition requirements.

[0046] In some embodiments of this application, when it is determined that there is no second outlier failure fault in each temperature sensor, the battery temperature sensor fault diagnosis method further includes: obtaining the sampling temperature drop amplitude of each temperature sensor within a preset time; and determining that there is a first sampling failure fault in the temperature sensor when the sampling temperature drop amplitude of the temperature sensor is greater than a preset temperature drop threshold.

[0047] Specifically, the preset time and preset temperature drop threshold can be set according to actual conditions. For example, after the battery stops charging and discharging, the temperature will gradually decrease. This is a slow process. If the temperature drop is too large within a specific time period without external intervention, the temperature sensor may be faulty. Based on this characteristic of battery temperature change, the preset time for the battery to be in the stopped charging and discharging condition is set to 1 second, and the preset temperature drop threshold is set to 10°C. When the battery is in the stopped charging and discharging condition, the sampled temperature drop of each temperature sensor within 1 second is obtained. If the sampled temperature drop of the temperature sensor within 1 second is greater than 10°C, the temperature sensor is considered to have a first sampling failure fault; if the sampled temperature drop of the temperature sensor within 1 second is less than or equal to 10°C, the temperature sensor is considered not to have a first sampling failure fault.

[0048] Furthermore, the preset time and preset temperature drop threshold can be determined based on parameters such as the battery operating condition, the ambient temperature, and the temperature change characteristics of the battery module (such as the temperature change characteristics of the battery module itself and the temperature change characteristics caused by the battery's temperature control components). Specifically, a mapping table between the location of the temperature sensor, the battery operating condition, the ambient temperature, the operating parameters of the battery temperature control components, and the preset time and preset temperature drop threshold can be established in advance. In the actual fault detection process, the preset time and preset temperature drop threshold corresponding to each temperature sensor can be obtained by looking up the table to assess whether there is a first sampling failure fault.

[0049] This embodiment determines the first sampling failure fault based on the temperature drop of each temperature sensor within a preset time, which improves the detection accuracy of sampling failure faults and further enhances the comprehensiveness of fault detection.

[0050] In some embodiments of this application, when it is determined that there is no second outlier failure fault in each temperature sensor, the battery temperature sensor fault diagnosis method further includes: acquiring the operating data of each temperature sensor; and determining that there is a wire break fault in the temperature sensor when the operating data of the temperature sensor exceeds a preset rated range.

[0051] Specifically, assuming that no second outlier failure fault exists in each temperature sensor, the operating data of each temperature sensor is acquired. This operating data may include one or more data types from the temperature sensor, such as current, voltage, and impedance. Different preset rated ranges are set for different data types and acquisition methods. The operating data of each temperature sensor is compared with the corresponding preset rated range to determine if a wire break fault exists. A wire break fault is specifically manifested as a sudden change in temperature, such as from 45 degrees to -30 degrees, or from -30 degrees to 45 degrees. Such a fault is considered a wire break fault. If a wire break fault is not accurately identified, it will lead to false temperature readings. The wire break fault can be a break in the analog front end or related sampling circuit of the temperature sensor.

[0052] For example, a wire breakage fault can be detected using an AFE (Analog Front-End) chip for temperature sampling. For instance, if the AFE integrates a switchable pull-up / pull-down current source, the operating data is the temperature sensor channel voltage. By sampling twice (once with a pull-up and once with a pull-down), the voltage difference between the two samples is compared to see if it falls within the corresponding preset rated range to determine if a wire breakage has occurred. The specific steps are: First sampling: Enable the pull-up current source and read the temperature sensor channel voltage; Second sampling: Enable the pull-down current source and read the channel voltage again; If the voltage difference exceeds the preset rated range (e.g., 400mV), the temperature sensor is considered to have a wire breakage fault. Alternatively, if a pull-down resistor is connected in series in the sampling channel, and the resistor's connection state is controlled by a switch, the sampling voltage change is compared. With a pull-down resistor connected in series in the AFE's temperature sampling channel, the resistor's connection state is controlled by a switch, and the sampling voltage change is compared. The specific steps are: Close the odd-numbered array switches and read the temperature channel voltage; Open the odd-numbered array switches, close the even-numbered array switches, and read again; If a channel voltage is lower than the preset rated range (e.g., 150mV), a wire breakage is determined.

[0053] This embodiment detects open circuit faults in temperature sensors based on the operating data of each temperature sensor, improving the accuracy and comprehensiveness of fault detection.

[0054] In some embodiments of this application, the battery temperature sensor fault diagnosis method further includes: when the battery's low-voltage power-on time is less than or equal to a preset time, or when each temperature sensor does not have a first outlier failure fault, acquiring the output voltage and / or sampled temperature value of each temperature sensor; and when the output voltage of the temperature sensor exceeds a preset voltage range or the sampled temperature value of the temperature sensor exceeds a preset temperature range, determining that the temperature sensor has a second sampling failure fault.

[0055] Specifically, when the battery's low-voltage charging time is less than or equal to a preset time (i.e., the battery has not yet reached thermal equilibrium), or when it is determined that each temperature sensor does not have a first outlier failure, a second sampling failure is determined for each temperature sensor based on its output voltage and / or sampled temperature value. If the temperature sensor's output voltage exceeds a preset voltage range or its sampled temperature value exceeds a preset temperature range, the temperature sensor's output is considered abnormal, and the temperature sensor is considered to have a second sampling failure. If the temperature sensor's output voltage is less than or equal to a preset voltage range and its sampled temperature value is also less than or equal to a preset temperature range, the temperature sensor's output is determined to be normal, and the temperature sensor is considered not to have a second sampling failure.

[0056] The preset voltage and temperature ranges are determined by the technical parameters of the temperature sensor itself and are set in advance by the temperature sensor manufacturer. Furthermore, the preset voltage and temperature ranges can be further adjusted based on parameters such as the temperature sensor's placement and battery condition. For example, a mapping table between the temperature sensor's placement, battery condition, and adjustment coefficients can be pre-set. During testing, the adjustment coefficients are determined based on this table, thereby adjusting the preset voltage and temperature ranges to their threshold values. The adjusted preset voltage and temperature ranges are then used to assess the second sampling failure.

[0057] This embodiment performs a second sampling failure assessment of the temperature sensor based on a preset voltage range and a preset temperature range, thereby improving the accuracy of the temperature sensor's quality assessment.

[0058] In some embodiments of this application, the battery temperature sensor fault diagnosis method further includes: generating a fault alarm signal based on the fault type of the temperature sensor when it is determined that the temperature sensor is faulty.

[0059] In other words, different fault alarm signals are set for different fault types, thereby improving the accuracy of fault alarm identification, improving the fault feedback effect, and facilitating technicians to accurately identify the fault type of temperature sensing based on the technical fault alarm signals and to set fault handling strategies in a timely manner, thus ensuring the efficiency of fault maintenance.

[0060] For example, the battery management system executes the temperature sensor fault detection method described above, generates corresponding fault alarm signals based on the different fault types identified, and sends them to the vehicle controller. The vehicle controller generates corresponding alarm control commands based on the received fault alarm signals. On the one hand, the fault alarm signals can be transmitted to the vehicle's instrument panel or central control screen for display. On the other hand, the alarm control commands can control the corresponding indicator lights, buzzers, etc. to output corresponding alarms.

[0061] In some embodiments of this application, the battery temperature sensor fault diagnosis method further includes: performing corresponding degradation and power reduction operations on the battery when it is determined that the temperature sensor is faulty.

[0062] Specifically, when a temperature sensor malfunction is confirmed, the battery management system performs corresponding degradation and power reduction operations on the battery. These operations include reducing the battery's input / output power, reducing the battery's charging and discharging current, limiting the battery's peak power, and reducing the battery's available power range. By implementing these degradation and power reduction operations, the heat generated by the battery system is reduced, thereby avoiding the potential risk of thermal runaway caused by temperature monitoring failure and improving vehicle operation safety.

[0063] As a specific embodiment of this application, such as Figure 3 As shown, the method for diagnosing a fault in the battery's temperature sensor may include the following steps: S101, obtain the low-voltage power-down duration of the battery.

[0064] S102, determine whether the low-voltage power-off time is greater than the preset time. If yes, proceed to step S103; otherwise, proceed to steps S106 and S108 respectively.

[0065] S103: After the battery is powered on again, the sampled temperature value of each temperature sensor is acquired.

[0066] S104, determine whether the temperature difference between the sampled temperature value and the average temperature of other temperature sensors exceeds the first preset verification range. If yes, proceed to step S105; otherwise, proceed to steps S106 and S108 respectively.

[0067] S105, It has been determined that the temperature sensor has a first outlier failure. Proceed to step S117.

[0068] S106, determine whether the temperature difference between adjacent temperature sensors exceeds the second preset verification range. If yes, proceed to step S107; otherwise, proceed to steps S111 and S114 respectively.

[0069] S107, It has been determined that the temperature sensor has a second outlier failure. Proceed to step S117.

[0070] S108, acquire the output voltage and / or sampled temperature value of each temperature sensor.

[0071] S109, determine whether the output voltage exceeds the preset voltage range or the temperature value exceeds the preset temperature range. If yes, proceed to step S110; otherwise, proceed to step S108.

[0072] S110, It is determined that the temperature sensor has a second sampling failure fault. Proceed to step S117.

[0073] S111, acquire the operating data of each temperature sensor.

[0074] S112, determine if the working data exceeds the preset rated range. If yes, proceed to step S113; otherwise, proceed to step S111.

[0075] S113, It has been determined that the temperature sensor has a broken wire fault. Proceed to step S117.

[0076] S114, obtain the sampling temperature drop of each temperature sensor within a preset time.

[0077] S115, determine if the sampled temperature drop exceeds the preset temperature drop threshold. If yes, proceed to step S116; otherwise, proceed to step S114.

[0078] S116, It is determined that the temperature sensor has a first sampling failure fault. Proceed to step S117.

[0079] S117 generates a fault alarm signal based on the fault type of the temperature sensor, and simultaneously performs corresponding degradation and power reduction operations on the battery.

[0080] The battery temperature sensor fault diagnosis method provided in this embodiment is based on a battery system where temperature sampling points and temperature sensors are arranged in a one-to-one correspondence. It achieves a temperature acquisition scheme that meets functional safety requirements. The verification logic includes static temperature outlier verification, adjacent temperature point verification, out-of-range verification, abnormal temperature drop strategy, and analog front-end acquisition circuit verification. Through a set of independent verification strategies, such as the diagnosis of adjacent temperature ranges and abnormal characteristics, a diagnostic coverage that meets the highest functional safety level requirements can be achieved. The combined logic more effectively improves the diagnostic coverage. Compared with the battery management system temperature acquisition schemes that meet functional safety requirements in related technologies, this application achieves cost reduction, simplified manufacturing process, and improved system reliability without compromising the functional safety level.

[0081] In summary, the battery temperature sensor fault diagnosis method according to the embodiments of this application involves a temperature sensor located at multiple temperature sampling points within the battery. When the battery is powered on at low voltage for a duration exceeding a preset time, upon re-energizing, the sampled temperature value of each temperature sensor is acquired. If the temperature difference between the sampled temperature value of one temperature sensor and the average temperature of all temperature sensors (excluding the one ...

[0082] Corresponding to the above embodiments, this application also proposes a battery temperature sensor fault diagnosis device.

[0083] In one embodiment of this application, the battery includes multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor.

[0084] Reference Figure 4 The battery temperature sensor fault diagnosis device 200 of this application embodiment includes: an acquisition module 210 and a fault diagnosis module 220.

[0085] The acquisition module 210 is used to acquire the sampled temperature value of each temperature sensor after the battery is powered on again when the power-on time under low voltage exceeds a preset time. The fault diagnosis module 220 is used to determine that the temperature sensor has a first outlier failure fault when the temperature difference between the sampled temperature value of the temperature sensor and the average temperature value of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range.

[0086] According to one embodiment of this application, the fault diagnosis module 220 is further configured to acquire the sampled temperature value of each temperature sensor when the battery's low-voltage power duration is less than or equal to a preset duration, or when each temperature sensor does not have a first outlier failure fault, and determine that there is a second outlier failure fault in adjacent temperature sensors when it is determined from the sampled temperature value of each temperature sensor that the temperature difference between adjacent temperature sensors exceeds a second preset verification range.

[0087] According to one embodiment of this application, when it is determined that there is no second outlier failure fault in each temperature sensor, the fault diagnosis module 220 is further configured to obtain the sampling temperature drop of each temperature sensor within a preset time. If the sampling temperature drop of the temperature sensor is greater than a preset temperature drop threshold, it is determined that there is a first sampling failure fault in the temperature sensor.

[0088] According to one embodiment of this application, when it is determined that there is no second outlier failure fault in each temperature sensor, the fault diagnosis module 220 is further configured to acquire the operating data of each temperature sensor, and determine that there is a wire breakage fault in the temperature sensor when the operating data of the temperature sensor exceeds the preset rated range.

[0089] According to one embodiment of this application, the fault diagnosis module 220 is further configured to acquire the output voltage and / or sampled temperature value of each temperature sensor when the battery's low-voltage power duration is less than or equal to a preset duration, or when each temperature sensor does not have a first outlier failure fault, and determine that the temperature sensor has a second sampling failure fault when the output voltage of the temperature sensor exceeds a preset voltage range or the sampled temperature value of the temperature sensor exceeds a preset temperature range.

[0090] According to one embodiment of this application, the fault diagnosis module 220 is further configured to generate a fault alarm signal based on the fault type of the temperature sensor when it is determined that the temperature sensor is faulty.

[0091] According to one embodiment of this application, the fault diagnosis module 220 is also used to perform corresponding degradation and power reduction operations on the battery when it is determined that the temperature sensor is faulty.

[0092] It should be noted that the above explanation of the embodiments and beneficial effects of the battery temperature sensor fault diagnosis method also applies to the battery temperature sensor fault diagnosis device of this application. To avoid redundancy, it will not be elaborated in detail here.

[0093] In summary, the battery temperature sensor fault diagnosis device of this application, by acquiring the sampled temperature value of each temperature sensor after the battery is powered on again when the battery is powered on for a period longer than a preset time under low voltage, determines that the temperature sensor has a first outlier failure fault if the temperature difference between the sampled temperature value of the temperature sensor and the average temperature value of all temperature sensors other than the temperature sensor exceeds a first preset verification range. Therefore, this device, based on a system architecture where temperature sampling points and temperature sensors are arranged in a one-to-one correspondence, can achieve diagnostic coverage that meets high functional safety requirements, reducing the fault diagnosis cost of temperature sensors and the complexity of system assembly.

[0094] Corresponding to the above embodiments, this application also proposes a computer-readable storage medium.

[0095] The computer-readable storage medium of this application embodiment stores a battery temperature sensor fault diagnosis program thereon, which, when executed by a processor, implements a battery temperature sensor fault diagnosis method.

[0096] According to the embodiments of this application, a computer-readable storage medium storing a battery temperature sensor fault diagnosis program thereon implements the above-described battery temperature sensor fault diagnosis method when executed by a processor. Based on the above-described battery temperature sensor fault diagnosis method, the fault diagnosis cost of the temperature sensor and the system assembly complexity are reduced.

[0097] Corresponding to the above embodiments, this application also proposes a vehicle.

[0098] Reference Figure 5 The vehicle 300 in this application embodiment includes a battery 310 and a battery management system 320.

[0099] The battery 310 includes multiple battery modules, each of which has multiple temperature sampling points, and each temperature sampling point is equipped with a temperature sensor. The battery management system 320 is used to acquire the sampled temperature value of each temperature sensor after the battery is powered on again when the battery is powered on for a period of time longer than a preset period of time under low voltage. If the temperature difference between the sampled temperature value of the temperature sensor and the average temperature value of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range, the system determines that the temperature sensor has a first outlier failure fault.

[0100] According to the vehicle embodiment of this application, when the battery is powered on at low voltage for a period longer than a preset duration, the battery management system acquires the sampled temperature value of each temperature sensor after the battery is powered on again. If the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range, it determines that the temperature sensor has a first outlier failure fault. This reduces the fault diagnosis cost of the temperature sensor and the system assembly complexity while meeting the diagnostic coverage requirements of a high functional safety level.

[0101] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0102] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0103] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0104] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0105] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0106] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for diagnosing a battery temperature sensor fault, characterized in that, The battery comprises multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor. The method includes: If the battery is powered on at low voltage for a period longer than a preset duration, the sampled temperature value of each temperature sensor is acquired after the battery is powered on again. If the temperature difference between the sampled temperature value of the temperature sensor and the average temperature value of all temperature sensors other than the temperature sensor exceeds a first preset verification range, it is determined that the temperature sensor has a first outlier failure fault.

2. The temperature sensor fault diagnosis method according to claim 1, characterized in that, Also includes: If the battery is powered on at low voltage for a duration less than or equal to the preset duration, or if none of the temperature sensors exhibit the first outlier failure, the sampled temperature value of each temperature sensor is obtained. If, based on the sampled temperature values ​​of each temperature sensor, it is determined that the temperature difference between adjacent temperature sensors exceeds a second preset verification range, then the adjacent temperature sensors are determined to have a second outlier failure.

3. The temperature sensor fault diagnosis method according to claim 2, characterized in that, If it is determined that none of the temperature sensors exhibits the second outlier failure, the method further includes: Obtain the temperature drop rate of each temperature sensor within a preset time period; If the temperature drop of the temperature sensor exceeds a preset temperature drop threshold, the temperature sensor is determined to have a first sampling failure fault.

4. The temperature sensor fault diagnosis method according to claim 2, characterized in that, If it is determined that none of the temperature sensors exhibits the second outlier failure, the method further includes: Acquire the operating data of each temperature sensor; If the operating data of the temperature sensor exceeds the preset rated range, it is determined that the temperature sensor has a broken wire fault.

5. The temperature sensor fault diagnosis method according to claim 1, characterized in that, Also includes: If the battery's low-voltage power-on time is less than or equal to the preset time, or if none of the temperature sensors have the first outlier failure fault, obtain the output voltage and / or sampled temperature value of each temperature sensor. If the output voltage of the temperature sensor exceeds the preset voltage range or the sampled temperature value of the temperature sensor exceeds the preset temperature range, it is determined that the temperature sensor has a second sampling failure fault.

6. The temperature sensor fault diagnosis method according to any one of claims 1-5, characterized in that, Also includes: If a fault is detected in the temperature sensor, a fault alarm signal is generated based on the fault type of the temperature sensor.

7. The temperature sensor fault diagnosis method according to any one of claims 1-5, characterized in that, If a fault is found in the temperature sensor, a corresponding degradation and power reduction operation is performed on the battery.

8. A battery temperature sensor fault diagnosis device, characterized in that, The battery comprises multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor. The device includes: The acquisition module is used to acquire the sampled temperature value of each temperature sensor after the battery is powered on again when the battery is powered on for a period of time that exceeds a preset time under low voltage. The fault diagnosis module is used to determine that the temperature sensor has a first outlier failure fault if the temperature difference between the sampled temperature value of the temperature sensor and the average temperature value of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range.

9. A computer-readable storage medium, characterized in that, It stores a battery temperature sensor fault diagnosis program, which, when executed by a processor, implements the battery temperature sensor fault diagnosis method according to any one of claims 1-7.

10. A vehicle, characterized in that, include: The battery includes multiple battery modules, each battery module having multiple temperature sampling points, and each temperature sampling point having a temperature sensor. The battery management system is configured to, when the battery is powered on for a period of time exceeding a preset duration under low voltage, acquire the sampled temperature value of each temperature sensor after the battery is powered on again, and determine that the temperature sensor has a first outlier failure fault if the temperature difference between the sampled temperature value of the temperature sensor and the average temperature of the sampled temperature values ​​of all temperature sensors other than the temperature sensor exceeds a first preset verification range.

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