Single sampling wire harness connection fault diagnosis method and device, battery and electric vehicle

Abstract

The invention discloses a single sampling wire harness connection fault diagnosis method and device, a battery and an electric automobile, and the method comprises the steps: carrying out the statistics of the number of times of irregular ineffectiveness in a set diagnosis time when the irregular ineffectiveness of single voltage sampling occurs, and carrying out the calculation of the number of times of irregular ineffectiveness; if the irregularly invalid times meet the set irregularly invalid criterion, determining that the connection of the single sampling wire harness is unstable, and reporting a fault that the connection of the wire harness is not reliable; and when the single voltage sampling is always effective, monitoring the fluctuation state of the single voltage, and in a set diagnosis time, if the fluctuation state of the single voltage meets a set single voltage fluctuation criterion, considering that the single sampling wire harness connection is unstable, and reporting a fault that the wire harness connection is unreliable. The system has sampling and diagnosis functions at the same time, and faults such as sampling line breakage can be effectively diagnosed.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery diagnosis, and in particular relates to a single-cell sampling harness connection fault diagnosis method, device, battery and electric vehicle. Background Art

[0002] As the energy core of new energy vehicles, lithium batteries have the advantages of high specific energy, low self-discharge rate and long cycle life, so they are widely used in electric vehicles. However, with the large-scale use of lithium-ion batteries, problems related to unreliable wiring harness connection diagnosis have also arisen. For example, when the wiring harness connection is unreliable, the diagnosis time is too long or too short, resulting in false alarms, which in turn leads to the problem of false triggering of fault measures or failure to trigger fault measures, as well as false triggering of full charge calibration. In severe cases, thermal runaway faults may be falsely triggered, which is not friendly to the whole vehicle.

[0003] The existing solution is to determine the virtual connection through the sampling values ​​of the three voltage sampling channels corresponding to two adjacent battery cells. However, when processing with the software, the situation where one of the two adjacent cells is high and the other is low has very strict requirements and must be judged as a virtual connection within the same cycle, which may lead to false alarms. In addition, for the situation where the cell voltage is low or high, the charging and discharging current is not taken into consideration, which may also cause misjudgment. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a single-cell sampling harness connection fault diagnosis method, device, battery and electric vehicle, which have sampling and diagnosis functions and can effectively diagnose faults such as sampling line breakage.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: In a first aspect, a method for diagnosing a fault in a single-cell sampling harness connection is provided, comprising: when single-cell voltage sampling is invalidated irregularly, counting the number of times the invalidation occurs irregularly within a set diagnostic time, if the number of times the invalidation occurs irregularly meets the set criterion for invalidation, it is considered that the single-cell sampling harness connection is unstable, and a harness connection unreliable fault is reported; when single-cell voltage sampling is always valid, monitoring the fluctuation state of the single-cell voltage, within a set diagnostic time, if the fluctuation state of the single-cell voltage meets the set single-cell voltage fluctuation criterion, it is considered that the single-cell sampling harness connection is unstable, and a harness connection unreliable fault is reported.

[0006] The above technical solution can effectively diagnose faults such as sampling line breakage by adopting different judgment methods when the single-cell voltage sampling is invalid from time to time and when the single-cell voltage sampling is always valid, and has the characteristics of accurate diagnosis results and low false alarm rate.

[0007] Furthermore, the number of times that irregular invalidity occurs within the set diagnostic time is counted, including: when the monomer voltage sampling is irregularly invalid, the rising edge state from the valid state to the invalid state is identified and counted once, or the falling edge state from the invalid state to the valid state is identified and counted once.

[0008] The above technical solution provides a specific method for counting the number of irregular invalidations. The statistical solution is implemented based on the data characteristics when irregular invalidations occur, and has the characteristics of convenient statistics and high accuracy.

[0009] Furthermore, if the number of irregular invalid times meets the set irregular invalid criterion, it is considered that the single-cell sampling harness connection is unstable, and a harness connection unreliable fault is reported, including: within the set diagnostic time T, when the rising edge count is less than the threshold value 1, and the sampling disconnection mark continues to be disconnected and exceeds the set diagnostic time T1, it is prohibited to report the sampling connection unreliable fault, and a sampling disconnection fault is reported; within the set diagnostic time T, when the rising edge count is less than the threshold value 1, and the duration of the sampling disconnection mark does not exceed the set diagnostic time T1, it is prohibited to report the sampling connection unreliable fault and the sampling disconnection fault; within the set diagnostic time T, after the rising edge count is greater than or equal to the threshold value 1, the sampling connection unreliable fault is reported; if during the process, the duration of the single-cell disconnection mark does not exceed the set diagnostic time T1, it is prohibited to report the sampling disconnection fault; if the duration of the single-cell disconnection mark exceeds the set diagnostic time T1, a sampling disconnection fault is reported.

[0010] The above technical solution provides specific irregular invalidity criteria. By combining the statistical irregular invalidity times and the set irregular invalidity criteria, the fault reporting rules under different situations are listed, thereby improving the recognition accuracy of the sampling line break fault when irregular invalidity occurs.

[0011] Furthermore, when the single cell voltage sampling is always valid, the fluctuation state of the single cell voltage is monitored, including: when the charge and discharge current change value is greater than or equal to the set first threshold, the single cell voltage state is not used to judge the fault of unreliable sampling connection; when the charge and discharge current change value is less than the set first threshold: if it is detected that the single cell voltage change is greater than the set second threshold, the corresponding rising edge is counted once, and the fault diagnosis of excessive single cell voltage and unreliable sampling connection is carried out at the same time.

[0012] The above technical solution provides a processing method when the single cell voltage sampling is always valid. By setting the charge and discharge current threshold, the boundary of connection fault diagnosis when the single cell voltage sampling is always valid is distinguished, thereby further improving the recognition accuracy of the sampling line disconnection fault.

[0013] Further, fault diagnosis of single cell voltage being too high and sampling connection being unreliable is carried out, including: when within the set diagnosis time T, the count of rising edges is less than the threshold value 1, it is prohibited to report the sampling connection unreliable fault; when the single cell voltage is higher than the fault threshold value V of single cell voltage being too high and exceeds the set diagnosis time T2, it is prohibited to report the sampling connection unreliable fault and report the single cell voltage being too high fault; when the single cell voltage is higher than the fault threshold value V of single cell voltage being too high and does not exceed the set diagnosis time T2, it is prohibited to report the sampling connection unreliable fault and the single cell voltage being too high fault; when within the set diagnosis time T, the count of rising edges is greater than or equal to the threshold value 1, the sampling connection unreliable fault is reported; if during the process, the single cell voltage is higher than the fault threshold value V of single cell voltage being too high but does not exceed the set diagnosis time T2, it is prohibited to report the single cell voltage being too high fault; if the single cell voltage is higher than the fault threshold value V of single cell voltage being too high and exceeds the set diagnosis time T2, the single cell voltage being too high fault is reported.

[0014] The above technical solution provides a specific fault diagnosis method for excessive single cell voltage and unreliable sampling connection at the rising edge. By setting a specific counting threshold and accurately distinguishing high voltage faults, the recognition accuracy of sampling line break faults is further improved.

[0015] Furthermore, when the charge and discharge current change value is less than the set first threshold value: if it is detected that the cell voltage change is less than the set third threshold value, the corresponding falling edge is counted once, and the fault diagnosis of low cell voltage and unreliable sampling connection is carried out at the same time.

[0016] The above technical solution provides the conditions and method for using falling edge counting, and provides another processing method when the single-cell voltage sampling is always valid, thereby improving the adaptability of the method and further improving the recognition accuracy of the sampling line break fault.

[0017] Further, fault diagnosis of low cell voltage and unreliable sampling connection is carried out, including: when the count of falling edges is less than the threshold value 1 within the set diagnosis time T, it is prohibited to report the unreliable sampling connection fault; when the cell voltage is lower than the fault threshold value V1 of low cell voltage and exceeds the set diagnosis time T2, it is prohibited to report the unreliable sampling connection fault, and report the cell voltage too low fault; when the cell voltage is lower than the fault threshold value V1 of low cell voltage and does not exceed the set diagnosis time T2, it is prohibited to report the unreliable sampling connection fault and the cell voltage too low fault; when the count of falling edges is greater than or equal to the threshold value 1 within the set diagnosis time T, the unreliable sampling connection fault is reported; if during the process, the cell voltage is lower than the fault threshold value V1 of low cell voltage but does not exceed the set diagnosis time T2, it is prohibited to report the cell voltage too low fault; if the cell voltage is lower than the fault threshold value V1 of low cell voltage and exceeds the set diagnosis time T2, the cell voltage too low fault is reported.

[0018] The above technical solution provides a specific fault diagnosis method for low cell voltage and unreliable sampling connection at the falling edge. By setting a specific counting threshold and accurately distinguishing high voltage faults, the recognition accuracy of the sampling line break fault is further improved.

[0019] In a second aspect, a single cell sampling harness connection fault diagnosis device is provided, including: an irregular diagnosis module, which is used to count the number of irregular invalidities within a set diagnosis time when single cell voltage sampling is irregularly invalid. If the number of irregular invalidities meets the set irregular invalidity criterion, it is considered that the single cell sampling harness connection is unstable, and a harness connection unreliable fault is reported; a fluctuating voltage diagnosis module, which is used to monitor the fluctuation state of the single cell voltage when the single cell voltage sampling is always valid. Within the set diagnosis time, if the fluctuation state of the single cell voltage meets the set single cell voltage fluctuation criterion, it is considered that the single cell sampling harness connection is unstable, and a harness connection unreliable fault is reported.

[0020] The above technical solution can effectively diagnose faults such as sampling line breakage by adopting different judgment methods when the single-cell voltage sampling is invalid from time to time and when the single-cell voltage sampling is always valid, and has the characteristics of accurate diagnosis results and low false alarm rate.

[0021] In a third aspect, a vehicle battery is provided, wherein the vehicle battery is equipped with the single cell sampling harness connection fault diagnosis device according to the second aspect.

[0022] The above technical solution expands the function of the automobile battery and improves the safety of the automobile battery by configuring the single-cell sampling harness connection fault diagnosis device in the automobile battery.

[0023] In a fourth aspect, an electric vehicle is provided, wherein the electric vehicle is equipped with the vehicle battery described in the third aspect.

[0024] The above technical solution, by configuring the automotive battery described in the third aspect onto an electric vehicle, can diagnose the reliability of the single-cell sampling connection, can accurately identify the problem of unreliable wiring harness connection, and the customer can promptly maintain the vehicle according to the fault phenomenon, solving the bigger problem caused by the inability to identify unreliable wiring harness connection.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: when the single cell voltage sampling is irregularly invalid, the present invention counts the number of irregular invalidities within the set diagnosis time. If the number of irregular invalidities meets the set irregular invalidity criterion, it is considered that the single cell sampling harness connection is unstable, and a harness connection unreliable fault is reported; when the single cell voltage sampling is always valid, the fluctuation state of the single cell voltage is monitored. Within the set diagnosis time, if the fluctuation state of the single cell voltage meets the set single cell voltage fluctuation criterion, it is considered that the single cell sampling harness connection is unstable, and a harness connection unreliable fault is reported; it can effectively diagnose faults such as sampling line breakage, and has the characteristics of accurate diagnosis results and low false alarm rate, and customers can timely maintain vehicles according to the fault phenomenon, solving the bigger problem caused by the inability to identify unreliable harness connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an example of a sampling disconnection fault flag; Figure 2 This is an example of abnormally high or low cell voltage; Figure 3 The present invention provides a method for diagnosing a single-cell sampling harness connection fault. Figure 1 ; Figure 4 The present invention provides a method for diagnosing a single-cell sampling harness connection fault. Figure 2 . DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0028] Embodiment 1 A method for diagnosing a fault in a single-cell sampling harness connection comprises: when single-cell voltage sampling is invalidated irregularly, counting the number of times the invalidation occurs irregularly within a set diagnosis time, if the number of times the invalidation occurs irregularly meets the set invalidation criterion, it is considered that the single-cell sampling harness connection is unstable, and an unreliable harness connection fault is reported; when single-cell voltage sampling is always valid, monitoring the fluctuation state of the single-cell voltage, within the set diagnosis time, if the fluctuation state of the single-cell voltage meets the set single-cell voltage fluctuation criterion, it is considered that the single-cell sampling harness connection is unstable, and an unreliable harness connection fault is reported.

[0029] The present invention is based on the current mainstream AFE (Analog Front End) features in the market: it has both sampling and diagnostic functions, and can effectively diagnose faults such as sampling line disconnection. Therefore, it can be judged whether there is an unreliable wiring harness connection problem through the sampling line disconnection fault flag. According to the data observation of unreliable connection in the actual vehicle, when the connection is unreliable, the single sampling line disconnection fault flag has shown irregular connection and disconnection status, such as Figure 1 , Figure 2 shown.

[0030] Obviously, when the sampling disconnection fault flag is disconnected and connected from time to time, it means that the wiring harness connection is unreliable, but because of the short duration, the sampling disconnection fault cannot be reported. In addition, when the single-cell sampling disconnection fault flag is not set, if the single-cell voltage is abnormally high or low from time to time under the premise of low charging or discharging current changes, it can also be considered that the connection is unreliable. If the single-cell voltage continues to be abnormally high or abnormally low, protection can be provided through the single-cell voltage over-high or under-low fault.

[0031] Through the method of the present invention, the problem of unreliable wiring harness connection can be accurately identified, and then the following problems can be solved: 1) accurately identifying the problem of unreliable wiring harness connection and taking fault measures in time: prohibiting charging and reducing power discharge; 2) preventing false triggering of full charge calibration when the charging terminal occurs; 3) preventing false triggering of thermal runaway faults.

[0032] 1) When the single-cell voltage sampling validity mark appears invalid or valid at irregular intervals ("invalid" means that the single-cell voltage sampling is unreliable, and "valid" means that the single-cell voltage sampling is reliable), the count is performed by identifying the rising edge state from the valid to invalid state, or identifying the falling edge state from the invalid to the valid state. Within the diagnostic time, when the count exceeds a certain threshold 1, it is considered that the single-cell sampling harness connection is unstable, and a harness connection unreliable fault is reported.

[0033] The present invention takes the rising edge judgment as an example for explanation (the same applies to the falling edge). First, the single-cell sampling disconnection state diagnosed by the AFE is judged. If it is detected that the single-cell sampling disconnection state diagnosed by the AFE is from normal to disconnection (normal to disconnection is defined as the rising edge, and disconnection to normal is defined as the falling edge), the rising edge is counted once, and the fault diagnosis of the sampling disconnection fault and the unreliable sampling connection is started at the same time, such as Figure 3As shown, first determine whether the single-cell sampling disconnection state is a normal-to-disconnection state or a disconnection state based on the voltage change trend; when it is a normal-to-disconnection state, the sampling disconnection rising edge count is +1, and it is determined whether the sampling disconnection rising edge count is greater than the threshold value 1 within the time T. If it is greater, an unreliable sampling connection fault is reported, otherwise, the sampling disconnection rising edge count is cleared; when it is a disconnection state, determine whether the disconnection duration exceeds the diagnostic time T1. If so, a sampling disconnection fault is reported.

[0034] a) Within the set diagnostic time T, when the count of rising edges is less than the threshold value 1, and the sampling disconnection mark continues to be disconnected and exceeds the set diagnostic time T1, it is prohibited to report the sampling connection unreliable fault, and report the sampling disconnection fault.

[0035] b) Within the set diagnostic time T, when the count of rising edges is less than the threshold value 1, and the duration of the sampling disconnection mark does not exceed the set diagnostic time T1, it is prohibited to report the sampling connection unreliable fault and the sampling disconnection fault.

[0036] c) Within the set diagnostic time T, when the count of rising edges is greater than or equal to the threshold value 1, a sampling connection unreliable fault is reported; if during the process, the duration of the single-cell disconnection mark does not exceed the set diagnostic time T1, it is prohibited to report the sampling disconnection fault; if the duration of the single-cell disconnection mark exceeds the set diagnostic time T1, a sampling disconnection fault is reported.

[0037] 2) When the cell voltage sampling is always valid, the fluctuation state of the cell voltage is monitored: when the charge or discharge current change is lower than threshold 2 (first threshold), the cell voltage change exceeds threshold 3 (second threshold) or is lower than threshold 4 (third threshold), it is judged that the cell connection is unstable and counted. When the cell connection instability count exceeds the set threshold 5 (fourth threshold) within a unit time, it is considered that the cell sampling harness connection is unstable, and the harness connection is unreliable. Fault.

[0038] If the AFE does not report the sampling disconnection state, the single cell voltage is collected at this time. When the charge and discharge current change value is greater than or equal to threshold 2, the single cell voltage is not used to judge the sampling connection unreliable fault.

[0039] like Figure 4 As shown, when the charge and discharge current change value is less than threshold 2: if it is detected that the single cell voltage change is higher than threshold 3 (the judgment method is the same as that for lower than threshold 4), the rising edge is counted once, and at the same time, the fault diagnosis of single cell voltage being too high (or too low) and sampling connection being unreliable is carried out.

[0040] a) When the count of rising edges is less than the threshold 1 within the set diagnosis time T, it is prohibited to report the sampling connection unreliable fault; when the single cell voltage is higher than the single cell voltage too high fault threshold V and exceeds the set diagnosis time T2, it is prohibited to report the sampling connection unreliable fault and report the single cell voltage too high fault.

[0041] b) When the cell voltage is higher than the cell voltage too high fault threshold V and does not exceed the set diagnosis time T2, it is prohibited to report the sampling connection unreliable fault and the cell voltage too high fault.

[0042] c) When the count of rising edges is greater than or equal to threshold 1 within the set diagnostic time T, an unreliable sampling connection fault is reported; if during the process, the single cell voltage is higher than the single cell voltage too high fault threshold V but does not exceed the set diagnostic time T2, it is prohibited to report the single cell voltage too high fault; if the single cell voltage is higher than the single cell voltage too high fault threshold V for more than the set diagnostic time T2, a single cell voltage too high fault is reported.

[0043] Similarly, when the charge and discharge current change value is less than the set first threshold: if it is detected that the cell voltage change is less than the set third threshold, the corresponding falling edge is counted once, and at the same time, fault diagnosis of low cell voltage and unreliable sampling connection is carried out.

[0044] d) When the count of falling edges is less than the threshold 1 within the set diagnosis time T, it is forbidden to report the sampling connection unreliable fault; when the single cell voltage is lower than the single cell voltage too low fault threshold V1 and exceeds the set diagnosis time T2, it is forbidden to report the sampling connection unreliable fault, and report the single cell voltage too low fault; e) When the cell voltage is lower than the cell voltage too low fault threshold V1 and does not exceed the set diagnosis time T2, it is prohibited to report the sampling connection unreliable fault and the cell voltage too low fault; f) When the count of falling edges is greater than or equal to threshold 1 within the set diagnostic time T, an unreliable sampling connection fault is reported; if during the process, the single cell voltage is lower than the single cell voltage too low fault threshold V1 but does not exceed the set diagnostic time T2, it is prohibited to report a single cell voltage too low fault; if the single cell voltage is lower than the single cell voltage too low fault threshold V1 for more than the set diagnostic time T2, a single cell voltage too low fault is reported.

[0045] The unreliable sampling connection diagnosed by the above two methods is in an OR relationship. As long as one method reports the unreliable sampling connection, the unreliable sampling connection fault is reported.

[0046] The present invention diagnoses the reliability of the single-cell sampling connection based on the AFE characteristics while taking the charge and discharge current into consideration, thereby being able to accurately identify the problem of unreliable wiring harness connection. Customers can also promptly maintain their vehicles based on the fault phenomenon, thus solving the larger problem caused by the inability to identify unreliable wiring harness connection.

[0047] Embodiment 2 Based on the single-cell sampling harness connection fault diagnosis method described in the first embodiment, this embodiment provides a single-cell sampling harness connection fault diagnosis device, including: The irregular diagnosis module is used to count the number of irregular invalidity within the set diagnosis time when the monomer voltage sampling is irregularly invalid. If the number of irregular invalidity meets the set irregular invalidity criterion, it is considered that the monomer sampling harness connection is unstable and the harness connection is unreliable. Fault; The fluctuating voltage diagnosis module is used to monitor the fluctuation state of the single cell voltage when the single cell voltage sampling is always valid. Within the set diagnosis time, if the fluctuation state of the single cell voltage meets the set single cell voltage fluctuation criterion, it is considered that the single cell sampling harness connection is unstable and a harness connection unreliable fault is reported.

[0048] Embodiment 3 Based on the single cell sampling harness connection fault diagnosis device described in the second embodiment, this embodiment provides a car battery, and the car battery is equipped with the single cell sampling harness connection fault diagnosis device described in the second embodiment.

[0049] Embodiment 4 Based on the automobile battery described in the third embodiment, this embodiment provides an electric vehicle, wherein the electric vehicle is equipped with the automobile battery described in the third embodiment.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A single-unit sampling harness connection fault diagnosis method, characterized in that: include: When the single cell voltage sampling is invalid at irregular intervals, the number of irregular invalidities within the set diagnosis time is counted. If the number of irregular invalidities meets the set irregular invalidity criterion, it is considered that the single cell sampling harness connection is unstable, and the harness connection is unreliable fault is reported; When the single cell voltage sampling is always valid, the fluctuation state of the single cell voltage is monitored. Within the set diagnosis time, if the fluctuation state of the single cell voltage meets the set single cell voltage fluctuation criterion, it is considered that the single cell sampling harness connection is unstable, and a harness connection unreliable fault is reported.

2. The single-cell sampling harness connection fault diagnosis method according to claim 1, characterized in that: Statistics show the number of invalid calls that occur irregularly within the set diagnostic time, including: When the single cell voltage sampling is invalid at irregular intervals, the rising edge state from the valid state to the invalid state is identified and counted once, or the falling edge state from the invalid state to the valid state is identified and counted once.

3. The single-unit sampling harness connection fault diagnosis method according to claim 2, characterized in that: If the number of irregular invalid times meets the set irregular invalid criterion, it is considered that the single sampling harness connection is unstable and the harness connection is unreliable. The fault includes: Within the set diagnosis time T, when the count of rising edges is less than the threshold value 1, and the sampling disconnection mark continues to be disconnected and exceeds the set diagnosis time T1, it is forbidden to report the sampling connection unreliable fault, and report the sampling disconnection fault; Within the set diagnosis time T, when the count of rising edges is less than the threshold 1, and the duration of the sampling disconnection mark does not exceed the set diagnosis time T1, it is prohibited to report the sampling connection unreliable fault and the sampling disconnection fault; Within the set diagnostic time T, when the count of rising edges is greater than or equal to the threshold value 1, an unreliable sampling connection fault is reported; if during the process, the duration of the single-cell disconnection mark does not exceed the set diagnostic time T1, it is prohibited to report the sampling disconnection fault; if the duration of the single-cell disconnection mark exceeds the set diagnostic time T1, a sampling disconnection fault is reported.

4. The single-cell sampling harness connection fault diagnosis method according to claim 1, characterized in that: When the single cell voltage sampling is always valid, the fluctuation state of the single cell voltage is monitored, including: When the charge and discharge current change value is greater than or equal to the set first threshold value, the single cell voltage state is not used to judge the sampling connection unreliable fault; When the charge and discharge current change value is less than the set first threshold: If it is detected that the cell voltage change is greater than the set second threshold, the corresponding rising edge is counted once, and the fault diagnosis of excessive cell voltage and unreliable sampling connection is carried out at the same time.

5. The single-cell sampling harness connection fault diagnosis method according to claim 4, characterized in that: Conduct fault diagnosis of excessive single-cell voltage and unreliable sampling connection, including: When the count of rising edges is less than the threshold 1 within the set diagnosis time T, it is forbidden to report the sampling connection unreliable fault; when the single cell voltage is higher than the single cell voltage too high fault threshold V and exceeds the set diagnosis time T2, it is forbidden to report the sampling connection unreliable fault and report the single cell voltage too high fault; When the cell voltage is higher than the cell voltage too high fault threshold V and does not exceed the set diagnosis time T2, it is forbidden to report the sampling connection unreliable fault and the cell voltage too high fault; When the count of rising edges is greater than or equal to threshold 1 within the set diagnostic time T, an unreliable sampling connection fault is reported; if during the process, the single cell voltage is higher than the single cell voltage too high fault threshold V but does not exceed the set diagnostic time T2, it is prohibited to report the single cell voltage too high fault; if the single cell voltage is higher than the single cell voltage too high fault threshold V for more than the set diagnostic time T2, a single cell voltage too high fault is reported.

6. The single-cell sampling harness connection fault diagnosis method according to claim 4, characterized in that: When the charge and discharge current change value is less than the set first threshold: If it is detected that the cell voltage change is less than the set third threshold, the corresponding falling edge is counted once, and the fault diagnosis of low cell voltage and unreliable sampling connection is carried out at the same time.

7. The single-cell sampling harness connection fault diagnosis method according to claim 6, characterized in that: Conduct fault diagnosis for low cell voltage and unreliable sampling connection, including: When the count of falling edges is less than threshold 1 within the set diagnosis time T, it is forbidden to report the sampling connection unreliable fault; when the single cell voltage is lower than the single cell voltage too low fault threshold V1 and exceeds the set diagnosis time T2, it is forbidden to report the sampling connection unreliable fault and report the single cell voltage too low fault; When the cell voltage is lower than the cell voltage too low fault threshold V1 and does not exceed the set diagnosis time T2, it is forbidden to report the sampling connection unreliable fault and the cell voltage too low fault; When the count of falling edges is greater than or equal to threshold 1 within the set diagnostic time T, an unreliable sampling connection fault is reported; if during the process, the single cell voltage is lower than the single cell voltage too low fault threshold V1 but does not exceed the set diagnostic time T2, it is prohibited to report the single cell voltage too low fault; if the single cell voltage is lower than the single cell voltage too low fault threshold V1 for more than the set diagnostic time T2, a single cell voltage too low fault is reported.

8. A single-unit sampling harness connection fault diagnosis device, characterized in that: include: The irregular diagnosis module is used to count the number of irregular invalidity within the set diagnosis time when the monomer voltage sampling is irregularly invalid. If the number of irregular invalidity meets the set irregular invalidity criterion, it is considered that the monomer sampling harness connection is unstable and the harness connection is unreliable. Fault; The fluctuating voltage diagnosis module is used to monitor the fluctuation state of the single cell voltage when the single cell voltage sampling is always valid. Within the set diagnosis time, if the fluctuation state of the single cell voltage meets the set single cell voltage fluctuation criterion, it is considered that the single cell sampling harness connection is unstable and a harness connection unreliable fault is reported.

9. An automobile battery, characterized in that: The automobile battery is provided with the single cell sampling harness connection fault diagnosis device as claimed in claim 8.

10. An electric vehicle, characterized in that: The electric vehicle is equipped with the vehicle battery according to claim 9.

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