Fault detection method, device and system and storage medium

Abstract

The invention discloses a fault detection method, device and system and a storage medium. The fault detection method comprises the steps of obtaining at least two voltage sampling values; wherein the at least two voltage sampling values are obtained by at least two analog front-end modules in the battery monitoring unit through respective target sampling channels to perform voltage acquisition on the same analog battery cell; determining a voltage difference absolute value between every two voltage sampling values in the at least two voltage sampling values; and when the partial pressure difference absolute value in the at least two obtained pressure difference absolute values is greater than a preset threshold value, determining an abnormal target voltage sampling value according to the partial pressure difference absolute value, and determining that the target sampling channel of the corresponding target analog front-end module has an equalization fault according to the target voltage sampling value. Therefore, the accuracy of equalization fault identification can be improved, and the safety of the battery is further improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a fault detection method, device, system and storage medium. Background Art

[0002] The Cell Supervision Circuit (CSC) plays a vital role in battery balancing. The CSC includes multiple analog front-end modules, each of which has multiple sampling channels connected to different battery cells to monitor the voltage of each single cell in the battery pack in real time.

[0003] In the related art, the voltage sampling values ​​of each sampling channel obtained by the CSC are usually compared with a unique reference value, resulting in inaccurate equalization fault detection; and it is also impossible to accurately detect whether there is a equalization fault between any two sampling channels, thereby reducing the safety of the battery. Summary of the invention

[0004] The present application proposes a fault detection method, device, system and storage medium, which can improve the accuracy of equalization fault identification and thus improve the safety of the battery.

[0005] The technical solution of this application is implemented as follows: In a first aspect, an embodiment of the present application provides a fault detection method, the fault detection method comprising: Acquire at least two voltage sampling values; wherein the at least two voltage sampling values ​​are obtained by at least two analog front-end modules in the battery monitoring unit respectively collecting voltages of the same analog battery cell through their respective target sampling channels; Determine an absolute value of a voltage difference between each two voltage sampling values ​​of at least two voltage sampling values; When some of the at least two pressure difference absolute values ​​obtained are greater than a preset threshold, an abnormal target voltage sampling value is determined based on the partial pressure difference absolute value, and a balancing fault is determined in the target sampling channel of the corresponding target analog front-end module based on the target voltage sampling value.

[0006] Through the above technical means, at least two analog front ends in the battery monitoring unit are obtained by collecting voltages of the same analog cell through their respective target sampling channels, and the absolute value of the voltage difference between each two voltage sampling values ​​in the at least two voltage sampling values ​​is determined, and then the target voltage sampling value with abnormality is determined if there is a part of the absolute value of the voltage difference greater than the preset threshold value in the at least two absolute values ​​of the voltage difference obtained, and finally, according to the target voltage sampling value, it is determined that the target sampling channel of the corresponding target analog front-end module has a balanced fault. In this way, the data collected by the target sampling channels of different analog front-end modules are fault-detected, and the voltage sampling values ​​collected by the target sampling channels of each analog front-end module are compared and analyzed horizontally in pairs, which can not only reduce the threshold value for pressure difference judgment and improve the sensitivity of fault identification; but also determine whether there is a balanced fault in the sampling channels of each analog front-end module, thereby improving the accuracy of balanced fault identification; at the same time, it can also avoid the problem of continuous discharge of the cell due to the pressure difference between the two sampling channels of the battery monitoring unit during actual use, thereby improving the safety of the battery.

[0007] In some embodiments, the fault detection method also includes: determining at least one sampling channel and a corresponding voltage sampling value of each of at least two analog front-end modules; sorting at least one sampling channel and a corresponding voltage sampling value of each of at least two analog front-end modules, and determining the sampling channel serial number and the corresponding voltage sampling value of each of the at least two analog front-end modules; accordingly, determining the absolute value of the voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values, including: comparing each two voltage sampling values ​​of the at least two voltage sampling values ​​according to the sampling channel serial number of each of the at least two analog front-end modules, and obtaining at least two absolute values ​​of the voltage difference.

[0008] Through the above-mentioned technical means, the sampling channels of at least two analog front-end modules and the corresponding voltage sampling values ​​are sorted, so that the corresponding voltage sampling values ​​can be read and compared according to the sampling channel numbers of each analog front-end module after sorting, thereby avoiding the problem of inconsistent system labels in the battery monitoring unit and improving the detection efficiency of equalization faults.

[0009] In some embodiments, determining the target voltage sampling value with an abnormality based on the partial voltage difference absolute value includes: determining the candidate voltage sampling value that appears most times when calculating the partial voltage difference absolute value; and determining the candidate voltage sampling value as the target voltage sampling value with an abnormality.

[0010] Through the above technical means, since the voltage sampling values ​​of the target sampling channels of each analog front-end module are all from the same analog battery cell, ideally, the absolute value of the voltage difference between the voltage sampling values ​​is less than the preset threshold. However, when a balancing fault occurs, there is a large difference between the voltage sampling values ​​obtained by the corresponding sampling channel and the voltage sampling values ​​collected by other sampling channels, so that the absolute value of the voltage difference between the voltage sampling values ​​collected by the abnormal sampling channel and the voltage sampling values ​​collected by other normal sampling channels is greater than the preset threshold. In this way, the voltage sampling values ​​collected by the abnormal sampling channel appear the most in the calculation of the absolute value of the partial voltage difference, and are used as the abnormal target voltage sampling values, so that the sampling channel with the balancing fault can be determined more accurately, and the accuracy of the balancing fault detection can be improved.

[0011] In some embodiments, at least two voltage sampling values ​​include at least a first voltage sampling value, a second voltage sampling value, and a third voltage sampling value; determining a target voltage sampling value with an abnormality based on a partial voltage difference absolute value includes: determining the first voltage sampling value as a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value are both greater than a preset threshold and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value are less than or equal to the preset threshold; determining the second voltage sampling value as a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the second voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value are less than or equal to the preset threshold; determining the third voltage sampling value as a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the third voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the third voltage sampling value and the second voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value is less than or equal to the preset threshold.

[0012] Through the above technical means, when it is determined that the absolute value of the voltage difference between a certain voltage sampling value and other voltage sampling values ​​is greater than a preset threshold and the absolute value of the voltage difference between other voltage sampling values ​​is less than or equal to the preset threshold, it can be determined that the certain voltage sampling value is abnormal, thereby determining the abnormal target voltage sampling value. In this way, when a balancing fault occurs, there is a large difference between the voltage sampling value obtained by the corresponding sampling channel and the voltage sampling value collected by other sampling channels, so that the absolute value of the voltage difference between the voltage sampling value collected by the abnormal sampling channel and the voltage sampling value collected by other normal sampling channels is greater than the preset threshold, so that the voltage sampling value collected by the abnormal sampling channel in the calculation of the absolute value of the partial voltage difference appears the most, and it is used as the abnormal target voltage sampling value, so that the sampling channel with the balancing fault can be more accurately determined, and the accuracy of the balancing fault detection is improved.

[0013] In some embodiments, before determining the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values, the fault detection method also includes: matching each voltage sampling value of the at least two voltage sampling values ​​with a reference voltage range; determining the number of abnormalities in which the voltage sampling values ​​are outside the reference voltage range based on the matching result; and when the number of abnormalities is less than a preset number, executing the step of determining the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values.

[0014] Through the above-mentioned technical means, before obtaining at least two absolute values ​​of the voltage difference, each voltage sampling value can be matched with the reference voltage range to determine the number of abnormal voltage sampling values ​​outside the reference voltage range. When the number of abnormalities is less than the preset number, it indicates that there is no abnormality in the fault detection system. The at least two voltage sampling values ​​collected can be used to execute the aforementioned fault detection method, further improving the accuracy of the equalization fault detection, thereby avoiding the problem of misjudgment of the equalization fault detection due to the abnormality of the fault detection system.

[0015] In some embodiments, the fault detection method further includes: when the number of abnormalities is greater than a preset number, determining that a fault exists in the battery monitoring unit and / or the simulated battery cell.

[0016] Through the above-mentioned technical means, when the number of abnormalities is greater than the preset number, it indicates that there is a problem with the fault detection system, specifically, there is a problem with the battery monitoring unit and / or the simulated battery cell, and the at least two voltage sampling values ​​collected are not used to execute the aforementioned fault detection method, thereby avoiding the problem of misjudgment of equalization fault detection due to abnormalities in the fault detection system.

[0017] In some embodiments, the fault detection method further includes: when the obtained at least two absolute values ​​of the pressure difference are both less than or equal to a preset threshold, determining that there is no equalization fault in the target sampling channels of the at least two analog front-end modules.

[0018] Through the above-mentioned technical means, after determining that there is no balancing fault in each sampling channel of each analog front-end module in the battery monitoring unit, it is determined that there is no fault in the battery monitoring unit; in this way, during actual use, the battery monitoring unit can accurately detect whether there is an imbalance in the battery pack, thereby improving the safety of the battery pack.

[0019] In a second aspect, an embodiment of the present application provides a fault detection device, the fault detection device comprising an acquisition unit and a determination unit, wherein: An acquisition unit is configured to acquire at least two voltage sampling values; wherein the at least two voltage sampling values ​​are obtained by at least two analog front-end modules in the battery monitoring unit respectively acquiring voltages of the same analog battery cell through their respective target sampling channels; A determination unit is configured to determine the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values; and when there are some absolute values ​​of the voltage difference among the at least two absolute values ​​of the voltage difference obtained that are greater than a preset threshold, determine that there is an abnormal target voltage sampling value according to the absolute value of the partial voltage difference, and determine that there is an equalization fault in the target sampling channel of the corresponding target analog front-end module according to the target voltage sampling value.

[0020] Through the above technical means, the data collected by the same analog cell are detected through the target sampling channels of different analog front-end modules, and the voltage sampling values ​​collected by the target sampling channels of each analog front-end module are compared and analyzed horizontally. This can not only reduce the threshold value used for voltage difference judgment and improve the sensitivity of fault identification; it can also determine whether there is a balancing fault in the sampling channels of each analog front-end module, thereby improving the accuracy of balancing fault identification; at the same time, it can also avoid the problem of continuous discharge of the cell due to the voltage difference between the two sampling channels of the battery monitoring unit during actual use, thereby improving the safety of the battery. In addition, the fault detection device can also realize automatic data capture and analysis through plug-ins, further improving the efficiency of fault detection.

[0021] In a third aspect, an embodiment of the present application provides a fault detection system, which includes a battery monitoring unit, a simulated battery cell, a host computer and a data analysis module, wherein the host computer is connected to the data analysis module and the battery monitoring unit, respectively, the battery monitoring unit includes at least two analog front-end modules, and the simulated battery cell includes at least one simulated battery cell, wherein: The target sampling channels of at least two analog front-end modules are respectively connected to the same analog cell in the analog cell device, and the battery monitoring unit is configured to collect voltage of the same analog cell through the target sampling channels of at least two analog front-end modules to obtain at least two voltage sampling values, and transmit the at least two voltage sampling values ​​to the host computer; The host computer is configured to obtain at least two voltage sampling values ​​and send the at least two voltage sampling values ​​to the data analysis module; The data analysis module is configured to obtain at least two voltage sampling values ​​sent by the host computer, determine the absolute value of the voltage difference between each two voltage sampling values ​​among the at least two voltage sampling values; and when there are some absolute values ​​of the voltage difference among the at least two absolute values ​​of the voltage difference obtained that are greater than a preset threshold, determine the existence of an abnormal target voltage sampling value based on the absolute value of the partial voltage difference, and determine the existence of an equalization fault in the target sampling channel of the corresponding target analog front-end module based on the target voltage sampling value.

[0022] Through the above-mentioned technical means, fault detection is performed on the data collected by the same analog battery cell through the target sampling channels of different analog front-end modules, and the voltage sampling values ​​collected by the target sampling channels of each analog front-end module are compared and analyzed horizontally in pairs. This can not only reduce the threshold size for voltage difference judgment and improve the sensitivity of fault identification; it can also determine whether there is a balancing fault in the sampling channels of each analog front-end module, thereby improving the accuracy of balancing fault identification; at the same time, it can also avoid the problem of continuous discharge of the battery cell due to the pressure difference between the two sampling channels of the battery monitoring unit during actual use, thereby improving the safety of the battery.

[0023] In some embodiments, the data analysis module is further configured to determine the candidate voltage sampling value that appears most times when calculating the absolute value of the partial voltage difference; and determine the candidate voltage sampling value as the target voltage sampling value with abnormality.

[0024] Through the above technical means, since the voltage sampling values ​​of the target sampling channels of each analog front-end module are all from the same analog battery cell, ideally, the absolute value of the voltage difference between the voltage sampling values ​​is less than the preset threshold. However, when a balancing fault occurs, there is a large difference between the voltage sampling values ​​obtained by the corresponding sampling channel and the voltage sampling values ​​collected by other sampling channels, so that the absolute value of the voltage difference between the voltage sampling values ​​collected by the abnormal sampling channel and the voltage sampling values ​​collected by other normal sampling channels is greater than the preset threshold. In this way, the voltage sampling values ​​collected by the abnormal sampling channel appear the most in the calculation of the absolute value of the partial voltage difference, and are used as the abnormal target voltage sampling values, so that the sampling channel with the balancing fault can be determined more accurately, and the accuracy of the balancing fault detection can be improved.

[0025] In some embodiments, the data analysis module is further configured to match each of the at least two voltage sampling values ​​with a reference voltage range; determine the number of abnormal voltage sampling values ​​outside the reference voltage range based on the matching results; and when the number of abnormalities is less than a preset number, execute the step of determining the absolute value of the voltage difference between each two of the at least two voltage sampling values.

[0026] Through the above-mentioned technical means, before obtaining at least two absolute values ​​of the voltage difference, each voltage sampling value can be matched with the reference voltage range to determine the number of abnormal voltage sampling values ​​outside the reference voltage range. When the number of abnormalities is less than the preset number, it indicates that there is no abnormality in the fault detection system. The at least two voltage sampling values ​​collected can be used to execute the aforementioned fault detection method, further improving the accuracy of the equalization fault detection, thereby avoiding the problem of misjudgment of the equalization fault detection due to the abnormality of the fault detection system.

[0027] In some embodiments, the fault detection system also includes a display device, which is connected to a host computer; wherein: the data analysis module is also configured to send the output result to the host computer; wherein the output result includes the target sampling channel of the target analog front-end module with the equalization fault and at least one corresponding absolute value of the pressure difference; the host computer is also configured to display the output result through the display device.

[0028] Through the above-mentioned technical means, the output results are displayed on a display device so that the user can determine the target sampling channel of the target analog front-end module with the balancing fault according to the output results, and then eliminate the fault of the target sampling channel of the target analog front-end module with the balancing fault, thereby avoiding safety problems of the battery pack due to the balancing fault of the battery monitoring unit during actual use.

[0029] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by at least one processor, the method as described in any one of the first aspects is implemented.

[0030] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 1 ; Figure 2 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 2 ; Figure 3 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 3 ; Figure 4 A schematic diagram of a connection between an analog cell and an analog front end provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of a simulated battery cell provided in an embodiment of the present application; Figure 6 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 4 ; Figure 7 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 5 ; Figure 8 A schematic diagram of the structure of a fault detection device provided in an embodiment of the present application; Fig. 9 A schematic diagram of the structure of a fault detection system provided in an embodiment of the present application; Fig.10 A schematic diagram of the detailed composition of a fault detection system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present application, the implementation of the embodiments of the present application is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0034] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0035] It should also be pointed out that the terms "first\second\third" involved in the embodiments of the present application are only used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0036] In addition, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] The following is an introduction to the relevant terms and technologies of this application.

[0038] (Battery) balancing: Balancing is the use of power electronics technology to keep the voltage deviation of lithium-ion battery cells or battery packs within the expected range, thereby ensuring that each single cell remains in the same state during normal use to avoid overcharging or over-discharging. Battery balancing is generally divided into active balancing and passive balancing.

[0039] The Battery Supervision Circuit (CSC) is a monitor installed on a battery cell. It is responsible for collecting information about the batteries in the battery string and passing it to the Battery Management Unit (BMU) for processing.

[0040] The remaining power (State Of Charge, SOC) refers to the ratio of the available power in the battery to the nominal capacity. It is an important monitoring data of the battery management system. The battery management system (BMS) controls the battery working state according to the SOC value. The remaining power of the battery also reflects the battery's state of charge.

[0041] End of Line (EOL) testing refers to the functional and performance testing of products after they are offline. In this application, it specifically refers to the balanced fault detection (referred to as "fault detection") performed on CSC's printed circuit board assembly (PCBA) offline.

[0042] The Analog Front End (AFE) module is an integrated circuit. AFE is also the core component of the battery management system in the energy storage system, specifically referring to the "battery sampling chip", which is responsible for real-time collection of accurate information such as battery cell voltage, current, temperature, etc., and feeds this information back to the main controller for monitoring and management of the battery status. In this application, the AFE module refers to a sampling circuit group consisting of an AFE chip and its peripheral components.

[0043] New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in areas such as energy storage.

[0044] At present, new energy batteries are increasingly used in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding. In the embodiments of the present application, the battery may be a battery cell, or may be a battery pack (Pack) composed of multiple battery cells. A battery cell refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and can be used to make a battery pack or a battery pack, so as to supply power to electrical devices. A battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged. The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., which is not limited in the embodiments of the present disclosure.

[0045] In the embodiment of the present application, the battery may also be a single physical module including one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid connection through a busbar component.

[0046] BMS is an indispensable and important component of electric vehicles. It is the hub for managing and monitoring power batteries. It manages, maintains, and monitors various battery modules. It is responsible for preventing overcharge and over discharge of batteries, extending battery life, and helping batteries to operate normally. The architecture of BMS usually includes BMU, CSC, CSU balancing module, high-voltage controller, BTU battery status indicator unit, and GPS communication module. Depending on different application scenarios, BMS can adopt a centralized or distributed architecture. CSC is responsible for monitoring the single cell voltage, single cell temperature and other information of the battery pack, and transmits the information to BMU. It also has battery balancing function.

[0047] Here, the CSC may include multiple AFE modules. The AFE module may include multiple sampling channels, which are responsible for collecting the voltage, current and temperature data of the battery cells and transmitting these data to the corresponding CSC in real time. The CSC is responsible for summarizing the sampling data of each battery cell and uploading the information to the BMU so that the BMU can be used for battery status monitoring, balancing management, protection and fault diagnosis.

[0048] In the related art, before the CSC goes offline, an EOL detection is performed on the CSC, such as a balanced fault detection. Through the detection, potential balanced faults can be discovered and repaired in time, so as to avoid the fact that the balanced fault of the CSC has not been eliminated, such as the voltage difference between the battery cells is too large, which affects the overall performance and life of the product. Specifically, by obtaining the sampling values ​​of the sampling channels corresponding to each AFE module in the CSC, and comparing these multiple sampling values ​​with the theoretical reference value, the absolute value of the voltage difference between the sampling value and the theoretical reference value is obtained, and the absolute value of the voltage difference is compared with the set threshold value to determine whether the sampling channel is faulty. Specifically, each channel is compared with the theoretical reference value, but the theoretical reference value of this method is fixed. The general theoretical reference value is 3200 millivolts (mV), and the reference voltage range is generally the reference value plus or minus 10, that is, the reference voltage range is 3190mV~3210mV. Moreover, this method collects part or all of the voltage sampling values ​​under different balancing states, and compares them with the absolute value and threshold of the voltage difference between the actual measured values ​​of the battery cells. It is impossible to identify and detect the balancing fault between two channels, which reduces the sensitivity of balancing fault identification. In addition, due to the differences in the sampling circuit design in CSC, the voltage values ​​of each sampling channel of the same AFE module are not the same. If the set threshold is reduced blindly, the CSC may make a false alarm, making the balancing fault detection inaccurate. It should be noted that the CSC offline EOL detection device used in the current production line has the detection principle of collecting the voltage message information of each channel of CSC, comparing all of them with the set unique reference value, and alarming after exceeding the judgment threshold (generally ±10mV); but in practice, the balancing fault mode is manifested as one high and one low voltage of adjacent sampling channels, and the abnormal value range is between 3mV and 1500mV; on the other hand, due to the design of the CSC circuit, the sampling values ​​of each sampling channel are not consistent, and the EOL detection method in the related technology has no ability to identify such faults, that is, it is impossible to accurately detect whether there is a balancing fault between two sampling channels.

[0049] In another possible implementation, the device for detecting the sampling function of the cell monitoring unit includes a cell simulator, a main cell monitoring unit and a cell monitoring unit to be tested; wherein the cell simulator includes a voltage source and N resistors connected in series between the positive and negative electrodes of the voltage source; the main cell monitoring unit is connected to the cell simulator to collect the voltage value on each resistor as a standard reference; the cell monitoring unit to be tested is connected to the cell simulator to test its sampling function. When checking the sampling function of the cell monitoring unit to be tested, it is necessary to compare its sampling value with the standard value, and even further data processing is required to determine whether its sampling function is normal. Only when the sampling value is within the set error range can it be judged to be normal, but it is a comparison of the data collected by the two cell monitoring units, and the data collected by the same cell monitoring unit is not compared horizontally between the two sampling channels during the test, and it is also impossible to accurately detect whether there is a balancing fault between the two sampling channels.

[0050] In addition, the energy storage system is a cluster of battery cluster (group) systems. The battery cluster contains multiple CSC balancing components. These CSC components have specific identification numbers in the system. When the upper computer is used to detect balancing faults on these assembled CSCs, affected by the CSC component system numbering, each numbered CSC component needs to be equipped with a separate detection program. The operation steps are complicated and time-consuming, which seriously reduces the detection efficiency of CSC balancing faults.

[0051] In short, CSC plays a vital role in battery balancing. CSC includes multiple analog front-end modules, and the multiple sampling channels corresponding to each of these multiple analog front-end modules are connected to different battery cells respectively to monitor the voltage of each single cell in the battery pack in real time. In related technologies, the voltage sampling values ​​of each sampling channel obtained by CSC are usually compared with a unique reference value, resulting in inaccurate detection of balancing faults; and it is also impossible to accurately detect whether there is a balancing fault between two sampling channels, which reduces the safety of the battery.

[0052] Based on this, the embodiment of the present application provides a fault detection method, which obtains at least two voltage sampling values ​​obtained by respectively collecting voltages of the same analog cell through the respective target sampling channels of at least two analog front-ends in the battery monitoring unit, and determines the absolute value of the voltage difference between each two voltage sampling values ​​in the at least two voltage sampling values, and then determines the target voltage sampling value with abnormalities if there are some absolute values ​​of the voltage difference in the at least two absolute values ​​of the voltage difference that are greater than the preset threshold, and finally determines that the target sampling channel of the corresponding target analog front-end module has a balanced fault according to the target voltage sampling value. In this way, by performing fault detection on the data collected by the target sampling channels of different analog front-end modules on the same analog cell, and performing horizontal pairwise comparison analysis on the voltage sampling values ​​collected by the target sampling channels of each analog front-end module, not only the threshold value for pressure difference judgment can be reduced, and the sensitivity of fault identification can be improved; it can also determine whether there is a balanced fault in the sampling channels of each analog front-end module, thereby improving the accuracy of balanced fault identification; at the same time, it can also avoid the problem of continuous discharge of the cell due to the pressure difference between the two sampling channels of the battery monitoring unit during actual use, thereby improving the safety of the battery.

[0053] The present application is further described in detail below through the accompanying drawings and specific embodiments.

[0054] In one embodiment of the present application, Figure 1 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 1 .like Figure 1 As shown, the method may include: S101, obtaining at least two voltage sampling values.

[0055] In the embodiment of the present application, at least two voltage sampling values ​​are obtained by at least two analog front-end modules in the battery monitoring unit collecting voltages of the same analog battery cell through their respective target sampling channels.

[0056] It should be noted that, for an analog front-end module, it may include at least one sampling channel, and the target sampling channel is any one of the at least one sampling channel. For example, the analog front-end module may include a first sampling channel, a second sampling channel, and a third sampling channel, then the target sampling channel may be the first sampling channel, or the target sampling channel may be the second sampling channel, or the target sampling channel may be the third sampling channel. In addition, the analog cell device includes at least one analog cell (or analog sub-cell), and for each analog front-end module, each target sampling channel may be connected to the corresponding analog cell (i.e., the same analog cell) to obtain the corresponding voltage sampling value.

[0057] Exemplarily, taking the example that each analog front-end module can include a first sampling channel and a second sampling channel, the first sampling channel of each analog front-end module is connected to the first analog battery cell, and the second sampling channel of each analog front-end module is connected to the second analog battery cell. At this time, when the target sampling channel is the first sampling channel, the same analog battery cell corresponding to the target sampling channel is the first analog battery cell; or when the target sampling channel is the second sampling channel, the same analog battery cell corresponding to the target sampling channel is the second analog battery cell. That is to say, in the process of testing the battery monitoring unit, if each analog front-end module has multiple sampling channels, then there are correspondingly multiple analog batteries, and each analog battery cell is connected to a sampling channel of the analog front end.

[0058] Here, the number of analog front-end modules and the number of sampling channels of each analog front-end module are determined according to the battery cell data in the actual process, and the number of battery cells is determined according to the actual situation to determine how many battery cells are included in a battery box in the most economical and efficient way, and there is no specific limitation on this. For example, if a battery box includes 52 battery cells, then the CSC can include four AFE modules, and the number of sampling channels corresponding to these four AFE modules is 14, 12, 14, and 12 respectively, which is the most economical.

[0059] In some embodiments, before acquiring at least two voltage sampling values, the fault detection method may further include: connecting the battery monitoring unit to the fault detection system to acquire data collected by each sampling channel of at least two analog front-end modules.

[0060] In an embodiment of the present application, before obtaining at least two voltage sampling values, CSC access testing is required to obtain the data collected by each sampling channel of each analog front-end module. It should be noted that for these multiple sampling channels, some are used to collect the voltage of the simulated battery cell, and some are used to collect the temperature, current, etc. of the simulated battery cell. Exemplarily, a total of 56 sampling channels are included, of which 52 sampling channels are used to collect the voltage of the battery cell, and the remaining sampling channels are used to collect temperature, current, air pressure and other data. After obtaining the data collected by each sampling channel, the collected data can be placed in a message library. Then, various message data of the battery cell can be obtained from the message library by the host computer, and the analysis data to be performed can be identified and captured from these data, such as capturing multiple voltage sampling values ​​for the next step of data analysis. It should be pointed out that the message data appearing in the embodiment of the present application may specifically refer to voltage sampling data (i.e., at least two voltage sampling values).

[0061] S102: Determine an absolute value of a voltage difference between each two voltage sampling values ​​of at least two voltage sampling values.

[0062] In an embodiment of the present application, after determining at least two voltage sampling values, the absolute value of the voltage difference between each two voltage sampling values ​​is obtained. Exemplarily, the at least two voltage sampling values ​​include a first voltage sampling value U1 and a second voltage sampling value U2, then the absolute value of the voltage difference between the first voltage sampling value U1 and the second voltage difference sampling value U2 |U1-U2| and the absolute value of the voltage difference between the second voltage sampling value U2 and the first voltage sampling value U1 |U2-U1| can be obtained. Exemplarily, the at least two voltage sampling values ​​include a first voltage sampling value U1, a second voltage sampling value U2, and a third voltage sampling value U3, then the absolute value of the voltage difference between the first voltage sampling value U1 and the second voltage sampling value U2 |U1-U2|, the absolute value of the voltage difference between the first voltage sampling value U1 and the third voltage sampling value U3 |U1-U3| and the absolute value of the voltage difference between the second voltage sampling value U2 and the third voltage sampling value U3 |U2-U3| can be obtained.

[0063] In some embodiments, the fault detection method may further include: determining at least one sampling channel of each of at least two analog front-end modules and a corresponding voltage sampling value; sorting at least one sampling channel of each of at least two analog front-end modules and a corresponding voltage sampling value, and determining a sampling channel sequence number of each of at least two analog front-end modules and a corresponding voltage sampling value; Correspondingly, determining the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values ​​includes: comparing each two voltage sampling values ​​of at least two voltage sampling values ​​according to the sampling channel serial numbers of the at least two analog front-end modules respectively to obtain at least two absolute values ​​of the voltage difference.

[0064] In the embodiment of the present application, it is assumed that there are 56 sampling channels in total, and the data read from the message library is the data collected from the 1st sampling channel to the 56th sampling channel, but not all sampling channels are used to collect voltage. For example, the 1st to 13th data are voltage sampling values, and the 14th data is other data, that is, the multiple voltage sampling values ​​obtained are not sorted according to the sampling channels used to collect voltage. Therefore, the channel sampling number is re-divided according to the acquisition channels used by each analog front-end module to collect voltage. For example, there are n AFE modules and each AFE module has m sampling channels (specifically sampling channels used to collect voltage), then the sampling channel sequence number of the first AFE module (1#AFE) should be: 1~m; the sampling channel sequence number of the second AFE module (2#AFE) should be: m+1~2m; the sampling channel sequence number of the third AFE module (3#AFE) should be: 2m+1~3m; ...; the nth The sampling channel numbers of the AFE module (n#AFE) should be: (n-1)m+1~nm; among them, the sampling channels corresponding to the sampling channel number 1 of 1#AFE, the sampling channel number (m+1) of 2#AFE, ..., and the sampling channel number (n-1) (m+1) of n#AFE are all used to collect the voltage of the same analog battery cell; and so on, the sampling channels corresponding to the sampling channel number m of 1#AFE, the sampling channel number 2m of 2#AFE, ..., and the sampling channel number nm of n#AFE are all used to collect the voltage of the same analog battery cell.

[0065] In an embodiment of the present application, while sorting the sampling channels, the voltage sampling values ​​corresponding to each sampling channel are sorted according to the sampling channel serial number, so that every two voltage sampling values ​​among the multiple voltage sampling values ​​can be conveniently compared according to the sampling channel serial number of each analog front-end module to obtain at least two absolute values ​​of the voltage difference.

[0066] Exemplarily, taking three analog front-end modules and each analog front-end module including two sampling channels as an example, the sampling channel numbers of the first analog front-end module are 1 and 2, the sampling channel numbers of the second analog front-end module are 3 and 4, and the sampling channel numbers of the third analog front-end module are 5 and 6. The voltage sampling values ​​of the sampling channels with numbers 1, 3 and 5 are obtained, where the voltage sampling values ​​of the sampling channels with numbers 1, 3 and 5 are represented by V1, V3 and V5 respectively, then the absolute voltage difference between each two voltage sampling values ​​|V1-V3|, |V1-V5|, |V3-V5| and |V5-V1| can be obtained, and then it is judged whether each voltage difference value is greater than a preset threshold value, so as to determine whether each sampling channel has a balancing fault.

[0067] In this way, in an embodiment of the present application, the sampling channels of at least two analog front-end modules and the corresponding voltage sampling values ​​are sorted, so that the corresponding voltage sampling values ​​can be read and compared according to the sampling channel serial numbers of each analog front-end module after sorting, thereby avoiding the problem of inconsistent system labels in the battery monitoring unit and improving the detection efficiency of equalization faults.

[0068] S103, when some of the at least two pressure difference absolute values ​​obtained are greater than a preset threshold, determining that an abnormal target voltage sampling value exists according to the partial pressure difference absolute value, and determining that a target sampling channel of the corresponding target analog front-end module has a balancing fault according to the target voltage sampling value.

[0069] In the embodiment of the present application, after obtaining at least two absolute values ​​of pressure difference, the at least two absolute values ​​of pressure difference are compared with a preset threshold value, and it can be determined whether there is a balancing fault in the sampling channel of the analog front-end module according to the comparison result.

[0070] In an embodiment of the present application, each analog front-end module collects the voltage of the same analog battery cell through its corresponding target sampling channel. Ideally, the multiple voltage sampling values ​​collected are equal. At this time, the preset threshold value can be 0mV. However, due to errors between the various test lines of the CSC (such as the connecting lines of each sampling channel), each analog resistor or other components, the voltage sampling values ​​of the same analog battery cell collected by the target sampling channels corresponding to each analog front-end module have errors. At this time, the preset threshold value can be 2mV, or the preset threshold value can be 3mV. In other words, the specific value of the preset threshold value can be determined according to the actual situation, and no specific limitation is made to this. In addition, the preset threshold value can be called a determination threshold value, or a judgment threshold value.

[0071] In some embodiments, the fault detection method may further include: when the obtained at least two absolute values ​​of the pressure difference are both less than or equal to a preset threshold, determining that there is no equalization fault in the target sampling channels of the at least two analog front-end modules.

[0072] In an embodiment of the present application, if at least two absolute values ​​of the pressure difference obtained are less than or equal to the preset threshold value, then it means that the target sampling channels corresponding to each analog front-end module have no equalization fault. If each analog front-end module includes only one sampling channel, then this indicates that the sampling channels corresponding to each analog front-end module do not have equalization faults, and at this time, the host computer can display the test pass on the display device. If the analog front-end module includes multiple sampling channels and the current sampling channel does not have an equalization fault, then the next sampling channel is tested until all the sampling channel test results indicate that the sampling channel does not have an equalization fault, then the host computer can display the test pass on the display device, thus completing the test of the battery monitoring unit, thereby improving the accuracy of the equalization detection of the battery monitoring unit during actual use.

[0073] That is to say, after determining that there is no balancing fault in each sampling channel of each analog front-end module in the battery monitoring unit, it is determined that there is no fault in the battery monitoring unit; in this way, during actual use, the battery monitoring unit can accurately detect whether there is an imbalance in the battery pack, thereby improving the safety of the battery pack.

[0074] In some embodiments, after determining that there is an equalization fault in the target sampling channel of the target analog front-end module, the fault detection method may also include: determining the sampling channel serial number corresponding to the target sampling channel of the target analog front-end module, and displaying the sampling channel serial number corresponding to the target sampling channel of the target analog front-end module and at least one corresponding pressure difference absolute value through a display device.

[0075] In some embodiments, after determining that there is no equalization fault in the target sampling channels of at least two analog front-end modules, the fault detection method may further include: displaying through a display device that the target sampling channels of at least two analog front-end modules have passed the test.

[0076] In an embodiment of the present application, the sampling channel with the equalization fault and the corresponding absolute value of the pressure difference are displayed so that the user can process the sampling channel with the equalization fault to avoid the problem of misjudging the equalization fault due to the equalization fault of the CSC itself during actual use, thereby improving the accuracy of equalization fault detection.

[0077] An embodiment of the present application provides a fault detection method, which performs fault detection on data collected from the same analog battery cell through target sampling channels of different analog front-end modules, and performs horizontal pairwise comparative analysis on the voltage sampling values ​​collected by the target sampling channels of each analog front-end module. This method can not only reduce the threshold value for voltage difference judgment and improve the sensitivity of fault identification, but also determine whether there is a balancing fault in the sampling channels of each analog front-end module, thereby improving the accuracy of balancing fault identification. At the same time, it can also avoid the problem of continuous discharge of the battery cell due to the pressure difference between the two sampling channels of the battery monitoring unit during actual use, thereby improving the safety of the battery.

[0078] In another embodiment of the present application, Figure 2 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 2 Before determining the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values, as Figure 2 As shown, the fault detection method may also include: S201, matching each of at least two voltage sampling values ​​with a reference voltage range.

[0079] S202: Determine the number of abnormal voltage sampling values ​​outside the reference voltage range according to the matching result.

[0080] S203, when the number of abnormalities is less than a preset number, executing the step of determining the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values.

[0081] In the embodiment of the present application, the preset number is determined according to the number of voltage sampling values ​​obtained; for example, if the number of voltage sampling values ​​is 100, the preset number may be 98. If the number of voltage sampling values ​​is 10, the preset number may be 8, or 7; that is, if most of the obtained voltage sampling values ​​are outside the reference voltage range, then the fault detection system may be abnormal, and the fault detection system needs to be checked, so as to avoid the problem of misjudgment of equalization fault detection due to the abnormality of the fault detection system.

[0082] In the embodiment of the present application, before determining the absolute value of the voltage difference between each of the at least two voltage sampling values, the fault detection system is first self-checked to avoid the problem of the fault detection system itself being abnormal and affecting the fault detection result, resulting in misjudgment. Specifically, after all the voltage sampling values ​​are obtained, all the voltage sampling values ​​are matched with the reference voltage range, and the number of abnormalities of the voltage sampling values ​​outside the reference voltage range is determined according to the matching results. If the number of abnormalities is less than a preset threshold, it indicates that there is no abnormality in the fault detection system, and then the step of determining the absolute value of the voltage difference between each of the at least two voltage sampling values ​​is performed to perform a horizontal comparison between channels.

[0083] In the embodiment of the present application, when the fault detection system is running for detection, the voltage sampling data read may have batch deviations due to the test bench or system, resulting in the above-mentioned fault detection scheme to make an error in the system abnormality judgment, resulting in "missing" or "over-killing" problems. Therefore, the obtained voltage sampling values ​​(that is, the initial data) are compared with the reference voltage range using a method similar to that in the related art, such as a method similar to EOL detection. When a large number of (batch) abnormal values ​​appear, the use of at least two collected voltage sampling values ​​to execute the above-mentioned fault detection method should be suspended to troubleshoot system problems.

[0084] In some embodiments, the fault detection method may further include: when the number of abnormalities is greater than a preset number, determining that a fault exists in the battery monitoring unit and / or the same simulated battery cell.

[0085] In the embodiment of the present application, if the number of abnormalities is greater than the preset number, then it can be determined that there is an abnormality in the fault detection system. Specifically, there is a fault in the test line of the battery monitoring unit or the target simulated battery. At this time, the step of determining the absolute value of the voltage difference between each of the at least two voltage sampling values ​​is not performed to avoid the fault equalization detection result being affected by the abnormality of the fault detection system. At this time, the fault of the fault detection system can be checked first, and after the fault of the fault detection system is eliminated, the fault detection of the battery monitoring unit can be performed.

[0086] In this way, when the number of abnormalities is greater than the preset number, it indicates that there is a problem with the fault detection system, specifically, there is a problem with the battery monitoring unit and / or the simulated battery cell, and the at least two voltage sampling values ​​collected are not used to execute the aforementioned fault detection method, thereby avoiding the problem of misjudgment of equalization fault detection due to abnormalities in the fault detection system.

[0087] The embodiment of the present application provides a fault detection method. Before obtaining at least two absolute values ​​of voltage differences, each voltage sampling value can be matched with a reference voltage range to determine the number of abnormal voltage sampling values ​​outside the reference voltage range. When the number of abnormalities is less than a preset number, it indicates that there is no abnormality in the fault detection system. The at least two collected voltage sampling values ​​can be used to execute the aforementioned fault detection method, further improving the accuracy of equalization fault detection, thereby avoiding the problem of misjudgment of equalization fault detection due to abnormalities in the fault detection system.

[0088] In yet another embodiment of the present application, Figure 3 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 3 .like Figure 3 As shown, for determining the presence of abnormal target voltage sampling values ​​according to the absolute values ​​of partial voltage differences, the following may be included: S301, determining a candidate voltage sampling value that appears most frequently when calculating the absolute value of a partial voltage difference.

[0089] In an embodiment of the present application, the candidate voltage sampling value that appears most frequently in the partial voltage difference absolute values ​​is determined. For example, the absolute value of the voltage difference between the first voltage sampling value U1 and the second voltage sampling value U2 and the absolute value of the voltage difference between the first voltage sampling value U1 and the second voltage sampling value U3 are both greater than a preset threshold value. At this time, the first voltage sampling value appears most frequently in the partial voltage difference absolute values. At this time, the first voltage sampling value can be determined as the candidate voltage sampling value.

[0090] S302: Determine the candidate voltage sampling value as the target voltage sampling value with an abnormality.

[0091] In the embodiment of the present application, among the absolute values ​​of the partial voltage differences, the candidate voltage sampling values ​​appear the most, so it can be determined that the candidate voltage sampling values ​​are abnormal target voltage sampling values, so that the sampling channel with the equalization fault can be obtained.

[0092] In some embodiments, at least two voltage sampling values ​​include at least a first voltage sampling value, a second voltage sampling value, and a third voltage sampling value; determining a target voltage sampling value with an abnormality based on a partial voltage difference absolute value includes: determining the first voltage sampling value as a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value are both greater than a preset threshold and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value are less than or equal to the preset threshold; determining the second voltage sampling value as a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the second voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value are less than or equal to the preset threshold; determining the third voltage sampling value as a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the third voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the third voltage sampling value and the second voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value is less than or equal to the preset threshold.

[0093] In the embodiment of the present application, assuming that at least two voltage sampling values ​​include three voltage sampling values, then at least two analog front-end modules may also include three analog front-end modules. Through the absolute value of the voltage difference between each two voltage sampling values ​​among the three voltage sampling values, it is possible to determine whether there is a balancing fault in the sampling channel. Specifically, when the absolute value of the voltage difference between the voltage sampling value collected by a certain sampling channel and the voltage sampling value collected by other sampling channels is greater than a preset threshold, and the absolute value of the voltage difference between each two voltage sampling values ​​collected by other sampling channels is less than or equal to the preset threshold, the sampling channel with a balancing fault is determined.

[0094] In this way, when a balancing fault occurs, there is a large difference between the voltage sampling value obtained by the corresponding sampling channel and the voltage sampling values ​​collected by other sampling channels, so that the absolute value of the voltage difference between the voltage sampling value collected by the abnormal sampling channel and the voltage sampling value collected by other normal sampling channels is greater than the preset threshold value. In this way, the voltage sampling value collected by the abnormal sampling channel appears the most in the calculation of the partial voltage difference absolute value, and is used as the abnormal target voltage sampling value, so that the sampling channel with the balancing fault can be determined more accurately, thereby improving the accuracy of balancing fault detection.

[0095] In yet another implementation, the at least two analog front end modules include four analog front end modules.

[0096] In the embodiment of the present application, assuming that the four analog front-end modules include a sampling channel for collecting the voltage of the battery cell, the voltage sampling values ​​collected by the first sampling channels of the four analog front-end modules (the first sampling channel is the target sampling channel in this case) can be represented by X1, X2, X3 and X4, and the absolute value of the voltage difference between every two voltage sampling values ​​between the four voltage sampling values ​​should meet the following conditions: ①、 ; ②、 ; ③、 ; ④、 .

[0097] Here, Z is the preset threshold, and & represents the logical "and", that is, all conditions must be met for it to be true.

[0098] In the embodiment of the present application, the judgment logic for the faulty channel can be as follows: if ①④ are not satisfied, but ②③ are satisfied, then X1 can be determined to be an abnormal target voltage sampling value, so it can be determined that the first sampling channel of the first analog front-end module has a balancing fault; if ①② are not satisfied, but ③④ are satisfied, then X2 can be determined to be an abnormal target voltage sampling value, and it can be determined that the first sampling channel of the second analog front-end module has a balancing fault; if ①②③ are not satisfied, but ④ is satisfied, then X3 can be determined to be an abnormal target voltage sampling value, and it can be determined that the first sampling channel of the third analog front-end module has a balancing fault; if ①②③④ are not satisfied, then X4 can be determined to be an abnormal target voltage sampling value, and it can be determined that the first sampling channel of the fourth analog front-end module has a balancing fault; if ①②③④ are all satisfied, then it can be determined that the sampling of this group of sampling channels of these four analog front-end modules has no balancing fault. It can also be understood that we start from the condition containing the least elements and work backwards, for example, start from condition ④. If condition ④ is met, it is determined that the first sampling channels of the first analog front-end module and the fourth analog front-end module do not have equalization faults; continue to judge condition ③. If condition ③ is not met, it is determined that the first sampling channel of the third analog front-end module has an equalization fault; if condition ③ is still met, it is determined that the first sampling channels of the first analog front-end module, the third analog front-end module and the fourth analog front-end module do not have equalization faults; continue to judge condition ②, and so on, and then determine the sampling channel of the target analog front-end module with equalization faults.

[0099] It should be noted that the above are all for judging whether a single sampling channel has a fault. It can also be used to judge the minimum or maximum voltage sampling value in the form of a ratio among the four voltage sampling values. Except for the absolute value of the voltage difference including the minimum or maximum voltage sampling value, which is not within the absolute value of Z, the absolute values ​​of other voltage differences are within the absolute value of Z. If there are problems with two sampling channels, it is also possible to judge the two largest and two smallest voltage samples in multiple voltage samples to determine the two sampling channels with balanced failures. In other words, when there are two candidate voltage sampling values ​​with the most occurrences, it can be determined that there are problems with the corresponding two sampling channels.

[0100] In another possible implementation, determining the presence of an abnormal target voltage sampling value based on partial pressure difference absolute values ​​may include: determining a common voltage sampling value among the pressure difference absolute values ​​in calculating the partial pressure difference absolute values, and determining the common voltage sampling value as the abnormal target voltage sampling value.

[0101] Exemplarily, it is assumed that some of the absolute values ​​of the pressure difference include the absolute value of the pressure difference between the first voltage sampling value and the second voltage sampling value, the absolute value of the pressure difference between the first voltage sampling value and the second voltage sampling value, and the absolute value of the pressure difference between the first voltage sampling value and the fourth voltage sampling value. In the partial absolute values ​​of the pressure difference, the first voltage sampling value appears in the calculation of each absolute value of the pressure difference, that is, the first voltage sampling value is a common voltage sampling value. At this time, the first voltage sampling value is used as the target sampling value where the abnormality exists.

[0102] The embodiment of the present application provides a fault detection method. Since the voltage sampling values ​​of the respective target sampling channels of each analog front-end module are all from the same analog battery cell, ideally, the absolute value of the voltage difference between the voltage sampling values ​​is less than the preset threshold. However, when a balancing fault occurs, there is a large difference between the voltage sampling values ​​obtained by the corresponding sampling channel and the voltage sampling values ​​collected by other sampling channels, so that the absolute value of the voltage difference between the voltage sampling values ​​collected by the abnormal sampling channel and the voltage sampling values ​​collected by other normal sampling channels is greater than the preset threshold. In this way, the voltage sampling values ​​collected by the abnormal sampling channel appear the most in the calculation of the absolute value of the partial voltage difference, and are used as the abnormal target voltage sampling values, so that the sampling channel with the balancing fault can be more accurately determined, thereby improving the accuracy of the balancing fault detection.

[0103] In another embodiment of the present application, based on the fault detection method of the above embodiment, Figure 4 A schematic diagram of the connection between an analog cell and an analog front end provided in an embodiment of the present application. Figure 4 As shown, it may include m simulated cells (such as Figure 4 The first simulated battery cell, the second simulated battery cell, ..., the mth simulated battery cell) and n AFE modules (such as Figure 4 As shown in the first AFE module, the second AFE module, ..., the nth AFE module), and each AFE module includes m sampling channels; wherein each analog cell is connected to a sampling channel of each AFE module. Exemplarily, X0101, X0201, ..., X0n01 are respectively obtained by the first analog cell obtained by the first sampling channel corresponding to the first AFE module, the second AFE module, ..., and the nth AFE module; ...; X010m, X020m, ..., X0n0m are respectively obtained by the mth analog cell obtained by the mth sampling channel corresponding to the first AFE module, the second AFE module, ..., and the nth AFE module. Wherein, 0a0b represents the bth sampling channel of the ath AFE module, X0a0b represents the voltage sampling value collected by the bth sampling channel of the ath AFE module, a is any positive integer from 1 to n, and b is any positive integer from 1 to m. Here, these m analog cells constitute a simulated cell device.

[0104] In the embodiment of the present application, the voltage collected by the sampling channel corresponding to the serial number of each AFE module of the CSC actually comes from the same analog battery cell. Ideally, the collected voltage values ​​are equal, that is: (1) in, Indicates the voltage sampling value collected by the first sampling channel of the jth (where 1<j<n) AFE module. However, when a sampling channel has a balancing failure, the voltage sampling value collected by the sampling channel will be higher or lower than the voltage sampling values ​​collected by other sampling channels in the same group.

[0105] in addition, Figure 5 A schematic diagram of the structure of a simulated battery cell provided in an embodiment of the present application. Figure 5 As shown, the simulated battery device may include m simulated batteries (i.e., the first simulated battery cell, the second simulated battery cell, ..., the mth simulated battery cell). Since the voltage of each simulated battery cell is evenly distributed by the power supply voltage of the simulated battery device, ideally, the resistances corresponding to the respective simulated batteries are equal, so that the longitudinal directions in formula (1) are also equal, that is: (2) V1=V2= =Vm(3) Here, V1, V2, ..., Vm correspond to the voltage sampling values ​​of different analog cells collected by each AFE module through their own sampling channels. It should be noted that the EOL detection equipment in the related art is formulated based on this theory, using the reference value as the theoretical average value, and the reference voltage range is obtained by adding or subtracting a voltage threshold from the reference value, which limits the range of positive and negative limits. However, due to the differences in the circuit design of the first sampling channel of each AFE module in the CSC and the inconsistency of the parameter values ​​between the actual circuit components, equations (2) and (3) do not hold. Therefore, it is impossible to implement the EOL detection method in the related art by tightening the reference voltage range.

[0106] In the present application, taking into account the CSC balancing fault detection method in the related art, the embodiment of the present application proposes a fault detection method that can detect balancing faults greater than 2mV, thereby improving the sensitivity and accuracy of fault identification; in addition, the fault detection method proposed in the embodiment of the present application has a higher coverage of the fault detection method in the related art, because the design of the CSC sampling circuit causes the voltage value of each channel to have a certain difference, and the voltage values ​​of some channels are significantly higher than the voltage values ​​of other channels, and the new fault mode (such as ground leakage current, due to the voltage difference between the two sampling channels of the battery monitoring unit, resulting in current generated between the two sampling channels, causing the battery cell to continue to discharge) The abnormal value is smaller than the difference caused by the difference in channel circuit design. Therefore, the fault detection method in the related art cannot identify the balancing fault mode even if the judgment threshold is shrunk. In the embodiment of the present application, based on Figure 5 The structure diagram shown, Figure 6 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 4 .like Figure 6 As shown, the fault detection method may include: S601, accessing the test CSC, at the beginning of detection, obtaining data of all sampling channels of n AFE modules to capture the voltage sampling values ​​therein.

[0107] In the embodiment of the present application, the CSC is connected to obtain the voltage sampling value collected by the CSC. The CSC is connected to the equalization fault detection device, and various message data of the simulated battery cell are obtained through the host computer. The battery cell voltage value to be analyzed is identified and captured in these data for the next step of data analysis.

[0108] S602 , dividing the voltage sampling channels according to the AFE modules, and sorting the sampling channels of each AFE module and the corresponding voltage sampling values ​​in ascending order.

[0109] In the embodiment of the present application, the sampling channels are divided according to the number of sampling channels of each AFE module, and the number of channels of each AFE module and the corresponding voltage values ​​are sorted in sequence.

[0110] S603, according to the sorted sampling channel numbers, compare the voltage sampling values ​​of the sampling channel numbers corresponding to the n AFE modules in pairs. When the absolute value of the difference (voltage drop) between the voltage sampling value of one (or several) sampling channels and the voltage sampling values ​​of other sampling channels exceeds a preset threshold, it can be determined that the sampling channel has a balancing fault.

[0111] In the embodiment of the present application, the voltage sampling values ​​of the corresponding serial numbers of each AFE module are taken as a group of data, and compared with each other. When the absolute value of the difference between the voltage sampling value of a certain (or several) channel and the voltage value of other channels in the group exceeds the set threshold, it is determined that the CSC has a balancing fault. Here, the preset threshold can also be called a judgment threshold.

[0112] S604, outputting the sampling channel sequence number and the voltage drop value corresponding to the sampling channel with the balancing fault.

[0113] In the embodiment of the present application, after the comparison and judgment of all data are completed, the abnormal sampling channel and the corresponding pressure drop value (difference) are output.

[0114] In some embodiments, Figure 7 A schematic diagram of a fault detection method provided in an embodiment of the present application Figure 5 .like Figure 7 As shown, the fault detection method includes: S701, start detection.

[0115] S702, reading the voltage sampling value collected by the CSC.

[0116] In the present application, the CSC includes multiple AFE modules, and each AFE module includes multiple sampling channels, and each sampling channel corresponds to collecting the voltage of the connected analog battery cell.

[0117] S703: Whether the voltage sampling values ​​collected by the sampling channels corresponding to the AFE modules are within the reference voltage range.

[0118] In the embodiment of the present application, if the judgment result of step S703 indicates yes, step S705 is executed; if the judgment result of step S703 indicates no, step S704 is executed.

[0119] S704: Determine whether the fault detection system is abnormal.

[0120] S705 , sequentially reading the voltage sampling values ​​of the sampling channel numbers corresponding to the AFE modules.

[0121] S706 , whether the difference of the sampling channels corresponding to each AFE module exceeds a preset threshold.

[0122] In the embodiment of the present application, if the judgment result of step S706 indicates yes, step S707 is executed; if the judgment result of step S706 indicates no, step S708 is executed.

[0123] S707, determining a balancing failure, identifying an abnormal sampling channel and outputting a corresponding abnormal pressure difference absolute value.

[0124] S708, determine that it is normal.

[0125] In the embodiment of the present application, the determination step of the EOL test method in the related art is added to avoid the problem that the abnormality of the fault detection system affects the detection result and causes misjudgment. Figure 7 The logic adds a system self-check function. After reading the voltage sampling data, first determine whether the voltage sampling values ​​collected by all sampling channels are within the theoretical value, that is, whether they meet the reference voltage range, so as to determine whether the detection system is normal. The reference voltage comes from the theoretical mean value of formula (3). When the following abnormal conditions occur, it can be determined that the system has a fault and the system fault should be checked before testing: (1) The test values ​​of multiple channels deviate significantly from the theoretical values ​​in batches, which may be caused by a fault in the sampling circuit or the simulated battery cell; (2) The voltage values ​​on the same serial number channel of each AFE module are all deviated, and the deviation values ​​are the same. The horizontal comparison method in the embodiment of the present application may not be able to detect the difference, which may be caused by the corresponding simulated battery cell failure.

[0126] In this way, the system self-check function can be realized to ensure that detection can be carried out when other modules of the system are normal, thereby avoiding system abnormal detection for the implementation of production line EOL test.

[0127] In yet another embodiment of the present application, based on the fault detection method provided in the above embodiment, Figure 8 A schematic diagram of the structure of a fault detection device provided in an embodiment of the present application. Figure 8 As shown, the fault detection device 80 includes an acquisition unit 801 and a determination unit 802, wherein: The acquisition unit 801 is configured to acquire at least two voltage sampling values; wherein the at least two voltage sampling values ​​are obtained by at least two analog front-end modules in the battery monitoring unit respectively collecting voltages of the same analog battery cell through their respective target sampling channels; The determination unit 802 is configured to determine the absolute value of the voltage difference between each two voltage sampling values ​​of at least two voltage sampling values; when there are some absolute values ​​of the voltage difference among the at least two absolute values ​​of the voltage difference obtained that are greater than a preset threshold, it is determined that there is an abnormal target voltage sampling value based on the absolute value of the partial voltage difference, and it is determined that there is a balancing fault in the target sampling channel of the corresponding target analog front-end module based on the target voltage sampling value.

[0128] In some embodiments, the determination unit 802 is further configured to determine at least one sampling channel and a corresponding voltage sampling value of each of at least two analog front-end modules; sort at least one sampling channel and a corresponding voltage sampling value of each of at least two analog front-end modules to determine the sampling channel serial numbers and the corresponding voltage sampling values ​​of each of the at least two analog front-end modules; accordingly, the determination unit X01 is further configured to compare each two voltage sampling values ​​of the at least two voltage sampling values ​​according to the sampling channel serial numbers of the at least two analog front-end modules to obtain at least two absolute values ​​of the voltage difference.

[0129] In some embodiments, the determination unit 802 is further configured to determine a candidate voltage sampling value that appears most times when calculating the absolute value of the partial voltage difference; and determine the candidate voltage sampling value as the target voltage sampling value with an abnormality.

[0130] In some embodiments, at least two voltage sampling values ​​include at least a first voltage sampling value, a second voltage sampling value, and a third voltage sampling value; the determining unit 802 is further configured to determine that the first voltage sampling value is a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value are both greater than a preset threshold and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value is less than or equal to the preset threshold; determine that the second voltage sampling value is a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the second voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value is less than or equal to the preset threshold; determine that the third voltage sampling value is a target voltage sampling value with an abnormality when the absolute value of the voltage difference between the third voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the third voltage sampling value and the second voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value is less than or equal to the preset threshold.

[0131] In some embodiments, the determination unit 802 is further configured to match each of the at least two voltage sampling values ​​with a reference voltage range; determine the number of abnormal voltage sampling values ​​outside the reference voltage range based on the matching result; and when the number of abnormalities is less than a preset number, execute the step of determining the absolute value of the voltage difference between each two of the at least two voltage sampling values.

[0132] In some embodiments, the determination unit 802 is further configured to determine that a fault exists in the battery monitoring unit and / or the same simulated battery cell when the number of abnormalities is greater than a preset number.

[0133] In some embodiments, the determination unit 802 is further configured to determine that there is no equalization fault in the target sampling channels of the at least two analog front-end modules when the obtained at least two absolute values ​​of the pressure differences are both less than or equal to a preset threshold.

[0134] In the application embodiment, the detection of equalization faults in the host computer in the related technology mainly relies on human eye readings to identify the faulty channel. If the fault detection is carried out on a large scale, the risk of error is extremely high, and it is not suitable for production line deployment detection. In the embodiment of the present application, the fault detection device can be connected to the automation program plug-in of the data processing module, which can automatically complete the data reading and analysis calculation process, thereby improving the efficiency of CSC equalization fault detection and eliminating the visual fatigue problem caused by human eye readings. In addition, the data processing module directly reads the message data from the message library, and there is no need to load the data display window. The problem of equipping each CSC with a separate data display window due to inconsistent CSC system labels can be avoided; and the message keywords and their values ​​are directly extracted during data processing and analyzed to give results, which can significantly improve the efficiency of batch equalization fault detection.

[0135] It should be noted that the description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

[0136] In yet another embodiment of the present application, Fig. 9 A schematic diagram of the structure of a fault detection system provided in an embodiment of the present application. Fig. 9 As shown, the fault detection system 90 may include a battery monitoring unit 901, a simulated battery cell device 902, a host computer 903 and a data analysis module 904, the host computer 903 is connected to the data analysis module 904 and the battery monitoring unit 901 respectively, the battery monitoring unit 901 includes at least two analog front-end modules, and the simulated battery cell device 902 includes at least one simulated battery cell, wherein: The target sampling channels of at least two analog front-end modules are respectively connected to the same analog cell in the analog cell device 902, and the battery monitoring unit 901 is configured to respectively collect voltages of the same analog cell through the target sampling channels of at least two analog front-end modules to obtain at least two voltage sampling values, and transmit the at least two voltage sampling values ​​to the host computer 903; The host computer 903 is configured to obtain at least two voltage sampling values ​​and send the at least two voltage sampling values ​​to the data analysis module; The data analysis module 904 is configured to obtain at least two voltage sampling values ​​sent by the host computer 903, determine the absolute value of the voltage difference between each two voltage sampling values ​​among the at least two voltage sampling values; and when there are some absolute values ​​of the voltage difference greater than a preset threshold value among the at least two absolute values ​​of the voltage difference obtained, determine that there is an abnormal target voltage sampling value according to the absolute value of the partial pressure difference, and determine that there is an equalization fault in the target sampling channel of the corresponding target analog front-end module according to the target voltage sampling value.

[0137] In the embodiment of the present application, the data analysis module is integrated with the host computer, or the data analysis module and the host computer are two separate modules, which is not limited to this.

[0138] In some embodiments, the data analysis module 904 is further configured to determine the candidate voltage sampling value that appears most times when calculating the absolute value of the partial voltage difference; and determine the candidate voltage sampling value as the target voltage sampling value with abnormality.

[0139] In some embodiments, the data analysis module is further configured to match each of the at least two voltage sampling values ​​with a reference voltage range; determine the number of abnormal voltage sampling values ​​outside the reference voltage range based on the matching results; and when the number of abnormalities is less than a preset number, execute the step of determining the absolute value of the voltage difference between each two of the at least two voltage sampling values.

[0140] In some embodiments, continuing as Fig. 9 As shown, the fault detection system 90 also includes a display device 905, which is connected to the host computer 903; wherein: the data analysis module 904 is also configured to send the output result to the host computer 903; wherein the output result is the target sampling channel of the target analog front-end module and at least one corresponding absolute value of the pressure difference; the host computer 903 is also configured to display the output result through the display device 905.

[0141] In this way, by displaying the output results on a display device, the user can determine the target sampling channel of the target analog front-end module with the balancing fault based on the output results, and then eliminate the fault of the target sampling channel of the target analog front-end module with the balancing fault, thereby avoiding safety problems of the battery pack due to the balancing fault of the battery monitoring unit during actual use.

[0142] In some embodiments, the data analysis module 904 is also configured to send the test pass result to the host computer when there is no equalization fault in the respective sampling channels of at least two analog front ends; the host computer is also configured to display the test pass result through a display device.

[0143] In yet another embodiment of the present application, Fig.10 A detailed schematic diagram of the composition of a fault detection system provided in an embodiment of the present application. Fig.10 As shown, the fault detection system 90 includes a simulated cell device 902, a data analysis module 904, a host computer 903, a display device 905, a battery monitoring unit 901 and a power supply module 906. Among them, the battery monitoring unit 901 includes multiple AFE modules, each AFE module includes multiple sampling channels, the simulated cell device 902 includes multiple simulated cells, and each simulated cell is connected to a sampling channel of each AFE module. Among them, the same simulated cell connected to the target sampling channels of the multiple AFE modules can be any one of the multiple simulated cells included in the simulated cell device 902; the power supply module 906 is connected to the simulated cell device 902 and the battery monitoring unit 901 respectively, and is used to supply power to the simulated cell device and the battery monitoring unit.

[0144] Here, the battery monitoring unit is a test sample, and the battery monitoring unit is tested to avoid false positives of equalization faults, ground leakage current, etc. due to faults in the battery monitoring unit itself during actual use.

[0145] In the embodiment of the present application, the data analysis module is the main implementation tool. The module can independently complete the capture, analysis and judgment of the sampling voltage in the above-mentioned CSC balanced fault detection process, and realize the automatic analysis function of the balanced fault detection data; that is, the data analysis module has the ability to directly read and analyze the voltage sampling values ​​collected by the sampling channel in the message information table, and can avoid the problem of inconsistent system labels of CSC sample parts, thereby improving the detection efficiency. The host computer is a platform for program operation and human-computer interaction. The setting and modification of the judgment threshold can be realized by the host computer. The analog cell device is a tool for providing analog voltage. In the embodiment of the present application, the judgment mechanism is mainly based on the fact that the voltage provided by the analog cell device to the corresponding sampling channel of each AFE module is theoretically consistent. If the voltage value collected by the corresponding sampling channel does not meet the judgment standard, it can be determined that the sampling channel has a balanced fault. The power supply module provides working power for the test samples and other detection system components.

[0146] In the embodiment of the present application, the fault detection of the battery monitoring unit includes: 1. After the system is turned on for testing, the host computer reads the message information of the battery monitoring unit, and the data analysis module identifies and captures the voltage sampling data; 2. The data analysis module reads a group of voltage sampling values ​​according to the sampling channel sequence number of each AFE module, and inputs the analysis module as the judgment data; 3. The data analysis module calculates the absolute value of the voltage difference of the corresponding sampling channel according to the predetermined algorithm for the group of data, and compares it with the judgment threshold; 4. Record the analysis results of the group of data, repeat the above steps 2 and 3 until all sampling channels in a single AFE module are analyzed; 5. Output the results (pass, or all abnormal channels and their voltage drop values). In this way, the fault detection of the battery monitoring unit is completed.

[0147] In some embodiments, based on Fig.10 The fault detection system shown in the figure, the fault detection method provided in the embodiment of the present application may specifically include: Step 1, follow Fig.10 The fault test system shown in the figure sets up the test bench, connects the battery monitoring unit to the fault detection system, and starts the host computer to collect message data after power is turned on. Here, the message data collected by the host computer contains a lot of information, and the data analysis module needs to identify the cell voltage sampling value according to the message name keyword.

[0148] In the embodiment of the present application, assuming that the battery monitoring unit to be tested has n AFE modules, and each AFE module has m voltage sampling channels, the data collected by all sampling channels of the n AFE modules are obtained, which includes n*m data. After the voltage sampling data in the sampling channel is obtained, it is read in sequence according to the sequence number and saved in the data analysis module, ready for the next step of data analysis.

[0149] Step 2: Distinguish and sort the sampling channels according to the AFE modules. Assuming there are n AFE modules and each AFE module has m sampling channels for collecting voltage, the sampling channel numbers of each AFE module should be: 1#AFE: 1 ~ m; 2#AFE: m+1 ~ 2m; 3#AFE: 2m+1 ~ 3m; … n#AFE:(n-1)m+1 ~ nm; Step 3: According to the corresponding serial number of each AFE module, in a group of voltage sampling data (which is the voltage sampling value obtained by multiple AFE modules collecting the same analog battery cell), the absolute value of the voltage difference between the voltage sampling values ​​obtained by the sampling channels is compared horizontally between the two. The absolute value of the voltage difference should be within the judgment threshold ∆V range (i.e., the preset threshold), otherwise it is determined that there is a balancing fault in the sampling channels in the group, and the faulty channel is the sampling channel whose voltage sampling value has a voltage difference with other voltage sampling values.

[0150] In the embodiment of the present application, the battery monitoring unit includes 4 AFE modules, and each AFE module includes m voltage sampling channels. The voltage value of the first sampling channel of each AFE module is used as an example. The voltage value of the first sampling channel of each AFE module is X1, X(m+1), X(2m+1), and X(3m+1). The voltage difference (absolute value) between them should satisfy: ①、 ; ②、 ; ③、 ; ④、 .

[0151] Here, Z is the judgment threshold (i.e., the preset threshold), and & represents the logical "and", that is, it is true only when all conditions are met.

[0152] In the embodiment of the present application, the judgment logic for the fault channel can be as follows: if ①④ are not satisfied, but ②③ are satisfied, then X1 can be determined to be an abnormal target voltage sampling value, so it can be determined that the first sampling channel of the first analog front-end module 1#AFE has a balanced fault; if ①② are not satisfied, but ③④ are satisfied, then it can be determined that For an abnormal target voltage sampling value, it can be determined that there is a balance fault in the first sampling channel of the second analog front-end module 2#AFE; if ①②③ are not satisfied, but ④ is satisfied, then it can be determined that For an abnormal target voltage sampling value, it can be determined that the first sampling channel of the third analog front-end module 3#AFE has a balanced fault; if ①②③④ are not satisfied, it can be determined that For an abnormal target voltage sampling value, it can be determined that the first sampling channel of the fourth analog front-end module 4#AFE has a balancing fault; if ①②③④ are all satisfied, it can be determined that the four analog front-end modules have no balancing faults in the corresponding sampling channels of this group.

[0153] In the embodiment of the present application, the above four steps are repeated for other sampling channel numbers to compare and determine the voltage sampling values, and are performed m times in total. If the absolute value of the voltage difference exceeds the determination threshold, the sampling channel group is determined to be abnormal, that is, there is a balancing fault in the CSC.

[0154] Step 4: Analyze and judge according to the above steps. If there is no fault, output the qualified conclusion; if there is a faulty channel, output the sampling channel with fault and the corresponding absolute value of pressure difference in sequence.

[0155] It should be noted that the description of the above system embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the system embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

[0156] It can be understood that in this embodiment, a "unit" can be a part of a circuit, a part of a processor, a part of a program or software, etc., and of course it can also be a module, or it can be non-modular. Moreover, the components in this embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional module.

[0157] In this embodiment, if the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor to perform all or part of the steps of the method described in this embodiment. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0158] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by at least one processor, the steps of the method described in any one of the aforementioned embodiments are implemented.

[0159] An embodiment of the present application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements the steps of the method described in any of the aforementioned embodiments.

[0160] It should be noted here that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0161] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices, equipment, or computer program products. Therefore, the present application may take the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program codes.

[0162] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0163] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0164] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0165] It should be noted that, in this application, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, product or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, product or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, product or device including the element.

[0166] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0167] The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0168] The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0169] The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0170] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A fault detection method, characterized in that: The fault detection method comprises: Acquire at least two voltage sampling values; wherein the at least two voltage sampling values ​​are obtained by at least two analog front-end modules in the battery monitoring unit respectively collecting voltages of the same analog battery cell through their respective target sampling channels; Determine an absolute value of a voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values; When some of the at least two pressure difference absolute values ​​obtained are greater than a preset threshold, an abnormal target voltage sampling value is determined based on the partial pressure difference absolute value, and a balancing fault is determined in the target sampling channel of the corresponding target analog front-end module based on the target voltage sampling value.

2. The fault detection method according to claim 1, characterized in that: The fault detection method further comprises: Determine at least one sampling channel and a corresponding voltage sampling value of each of the at least two analog front-end modules; Sorting at least one sampling channel of each of the at least two analog front-end modules and the corresponding voltage sampling value, and determining the sampling channel sequence number of each of the at least two analog front-end modules and the corresponding voltage sampling value; Accordingly, determining the absolute value of the voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values ​​includes: Each two voltage sampling values ​​of the at least two voltage sampling values ​​are compared according to the sampling channel serial numbers of the at least two analog front-end modules to obtain the at least two voltage difference absolute values.

3. The fault detection method according to claim 1, characterized in that: The step of determining the target voltage sampling value having an abnormality according to the absolute value of the partial voltage difference comprises: Determine the candidate voltage sampling value that appears most times when calculating the absolute value of the partial voltage difference; The candidate voltage sampling value is determined as the target voltage sampling value having an abnormality.

4. The fault detection method according to claim 3, characterized in that: The at least two voltage sampling values ​​at least include a first voltage sampling value, a second voltage sampling value and a third voltage sampling value; the determining of the target voltage sampling value having an abnormality according to the absolute value of the partial voltage difference includes: When the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value are both greater than a preset threshold value and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value is less than or equal to the preset threshold value, determining that the first voltage sampling value is the target voltage sampling value with an abnormality; When the absolute value of the voltage difference between the second voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the second voltage sampling value and the third voltage sampling value are both greater than a preset threshold value and the absolute value of the voltage difference between the first voltage sampling value and the third voltage sampling value is less than or equal to the preset threshold value, determining that the second voltage sampling value is the target voltage sampling value with an abnormality; When the absolute value of the voltage difference between the third voltage sampling value and the first voltage sampling value and the absolute value of the voltage difference between the third voltage sampling value and the second voltage sampling value are both greater than the preset threshold and the absolute value of the voltage difference between the first voltage sampling value and the second voltage sampling value is less than or equal to the preset threshold, the third voltage sampling value is determined to be the target voltage sampling value with an abnormality.

5. The fault detection method according to any one of claims 1 to 4, characterized in that: Before determining the absolute value of the voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values, the fault detection method further includes: Matching each of the at least two voltage sampling values ​​with a reference voltage range; Determine the number of abnormalities of the voltage sampling values ​​being outside the reference voltage range according to the matching result; When the number of abnormalities is less than a preset number, a step of determining an absolute value of a voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values ​​is performed.

6. The fault detection method according to claim 5, characterized in that: The fault detection method further comprises: When the number of abnormalities is greater than a preset number, it is determined that the battery monitoring unit and / or the simulated battery cell has a fault.

7. The fault detection method according to any one of claims 1 to 4, characterized in that: The fault detection method further comprises: When the obtained at least two absolute values ​​of the pressure differences are both smaller than or equal to the preset threshold, it is determined that there is no equalization fault in the target sampling channels of the at least two analog front-end modules.

8. A fault detection device, characterized in that: The fault detection device comprises an acquisition unit and a determination unit, wherein: The acquisition unit is configured to acquire at least two voltage sampling values; wherein the at least two voltage sampling values ​​are obtained by at least two analog front-end modules in the battery monitoring unit respectively acquiring voltages of the same analog battery cell through their respective target sampling channels; The determination unit is configured to determine the absolute value of the voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values; and when there are some voltage difference absolute values ​​greater than a preset threshold value among the at least two voltage difference absolute values ​​obtained, determine that there is an abnormal target voltage sampling value according to the partial voltage difference absolute value, and determine that there is an equalization fault in the target sampling channel of the corresponding target analog front-end module according to the target voltage sampling value.

9. A fault detection system, characterized in that: The fault detection system includes a battery monitoring unit, a simulated battery cell device, a host computer and a data analysis module, wherein the host computer is connected to the data analysis module and the battery monitoring unit respectively, the battery monitoring unit includes at least two simulated front-end modules, and the simulated battery cell device includes at least one simulated battery cell, wherein: The target sampling channels of the at least two analog front-end modules are respectively connected to the same analog cell in the analog cell device, and the battery monitoring unit is configured to respectively collect voltage from the same analog cell through the target sampling channels of the at least two analog front-end modules to obtain at least two voltage sampling values, and transmit the at least two voltage sampling values ​​to the host computer; The host computer is configured to obtain the at least two voltage sampling values ​​and send the at least two voltage sampling values ​​to the data analysis module; The data analysis module is configured to obtain at least two voltage sampling values ​​sent by the host computer, determine the absolute value of the voltage difference between each two voltage sampling values ​​among the at least two voltage sampling values; and when there are some absolute values ​​of the pressure difference among the at least two absolute values ​​of the pressure difference obtained that are greater than a preset threshold, determine the existence of an abnormal target voltage sampling value based on the absolute value of the partial pressure difference, and determine the existence of an equalization fault in the target sampling channel of the corresponding target analog front-end module based on the target voltage sampling value.

10. The fault detection system according to claim 9, characterized in that: The data analysis module is further configured to determine a candidate voltage sampling value that appears most times when calculating the absolute value of the partial voltage difference; and determine the candidate voltage sampling value as the target voltage sampling value with an abnormality.

11. The fault detection system according to claim 9, characterized in that: The data analysis module is further configured to match each of the at least two voltage sampling values ​​with a reference voltage range; and determine the number of abnormalities of the voltage sampling values ​​being outside the reference voltage range according to the matching result; And when the number of abnormalities is less than a preset number, a step of determining an absolute value of a voltage difference between each two voltage sampling values ​​of the at least two voltage sampling values ​​is performed.

12. The fault detection system according to any one of claims 9 to 11, characterized in that: The fault detection system further includes a display device, which is connected to the host computer; wherein: The data analysis module is further configured to send an output result to the host computer; wherein the output result includes a target sampling channel of the target analog front-end module with a balancing fault and at least one corresponding absolute value of a pressure difference; The host computer is also configured to display the output result through the display device.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

Images