Diagnosis Method and Diagnosis System for Potential Defects of BMS Cell Acquisition Circuit

Abstract

An embodiment of the present invention provides a method and a diagnosis system for diagnosing potential defects of a BMS monomer acquisition circuit, belonging to the field of BMS monomer acquisition circuit defect diagnosis. The diagnosis method includes obtaining the acquisition voltage of the BMS and recording the number of times; obtaining the serial number and voltage of each monomer in the BMS according to the acquisition voltage; diagnosing the defective state of the BMS monomer acquisition circuit according to the serial number and voltage of each monomer in the BMS. The method for diagnosing potential defects of the BMS monomer acquisition circuit provided by the present invention can diagnose defective states such as device failure in the BMS monomer acquisition circuit by obtaining the serial number and voltage of each monomer in the BMS, and according to the serial number and voltage of each monomer in the BMS, so as to realize a reliable judgment on the acquisition function of the BMS acquisition circuit, and has a wider defective diagnosis range, more accurate diagnosis and stronger practicability.

Description

Technical Field

[0001] The present invention relates to the technical field of BMS monomer acquisition circuit fault diagnosis, and particularly relates to a method and a system for diagnosing potential faults of a BMS monomer acquisition circuit. Background Art

[0002] With the large-scale use of lithium batteries in the field of electric vehicles, the BMS (Battery Management System), as a core component in the power battery pack, plays an important role in protecting the safety of electric vehicles, charging station equipment, and personnel. The screening of defective products in the battery pack is the core component for controlling the safety and stability of the battery pack.

[0003] Currently, the main strategy for screening BMS acquisition faults is to obtain the BMS monomer acquisition information through communication with the battery pack during the manufacturing process, and judge by comparing the acquisition parameters with the actual parameters. This solution can only obtain obvious acquisition fault phenomena, such as: 1. The acquisition chip fails and cannot collect data; 2. The acquisition voltage has a large error. The scope of fault diagnosis is relatively limited, and it cannot diagnose potential failure faults of some electronic devices. The applicability is relatively narrow and the practicability is not strong.

[0004] The inventors of the present application found in the process of implementing the present invention that the above solution of the prior art has the defect of relatively limited scope of acquisition fault diagnosis. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a method and a system for diagnosing potential faults of a BMS monomer acquisition circuit. The method and the system for diagnosing potential faults of the BMS monomer acquisition circuit have the function of diagnosing various acquisition faults.

[0006] To achieve the above purpose, the embodiments of the present invention provide a method for diagnosing potential faults of a BMS monomer acquisition circuit, including:

[0007] Obtain the acquisition voltage of the BMS and record the number of times;

[0008] Obtain the serial number and voltage of each monomer in the BMS according to the acquisition voltage;

[0009] Diagnose the fault state of the BMS monomer acquisition circuit according to the serial number and voltage of each monomer in the BMS;

[0010] Judge the acquisition function of the BMS according to the fault state of the BMS monomer acquisition circuit.

[0011] Optionally, diagnosing the fault state of the BMS monomer acquisition circuit according to the serial number and voltage of each monomer in the BMS includes:

[0012] Obtain the highest voltage and the lowest voltage among the individual cell voltages of the BMS;

[0013] Judge whether both the highest voltage and the lowest voltage are equal to zero;

[0014] If it is judged that both the highest voltage and the lowest voltage are equal to zero, then it is determined that the power supply of the acquisition chip fails, and a fault record is made;

[0015] If it is judged that the highest voltage and the lowest voltage are not equal to zero, then it is determined that the power supply of the acquisition chip is normal.

[0016] Optionally, diagnosing the bad state of the BMS individual cell acquisition circuit according to the serial number and voltage of each individual cell in the BMS further includes:

[0017] Obtain the serial number of the highest voltage and the serial number of the lowest voltage among the individual cell voltages of the BMS;

[0018] Calculate the serial number difference between the serial number of the highest voltage and the serial number of the lowest voltage among the individual cell voltages of the BMS according to formula (1),

[0019] σ = |V max NO - V min NO|, (1)

[0020] where σ is the serial number difference, V max NO is the serial number of the highest voltage among the individual cell voltages of the BMS, V min NO is the serial number of the lowest voltage among the individual cell voltages of the BMS;

[0021] Judge whether the voltages of the nth individual cell and the (n + 1)th individual cell are both equal to zero, whether the highest voltage among the individual cell voltages of the BMS is equal to zero, and whether the serial number difference is one;

[0022] If it is judged that the voltages of the nth individual cell and the (n + 1)th individual cell are both equal to zero and the highest voltage among the individual cell voltages of the BMS is not equal to zero and the serial number difference is one, then it is determined that the acquisition line is broken, and a fault record is made;

[0023] If it is judged that the voltages of the nth individual cell and the (n + 1)th individual cell are not both equal to zero or the highest voltage among the individual cell voltages of the BMS is equal to zero or the serial number difference is not one, then it is determined that the acquisition line is not broken.

[0024] Optionally, diagnosing the bad state of the BMS individual cell acquisition circuit according to the serial number and voltage of each individual cell in the BMS further includes:

[0025] Calculate the average voltage of n individual cells in the BMS according to formula (2),

[0026]

[0027] Among them, A n is the average voltage of each cell in the BMS, and a n is the voltage of the nth cell, where n is the integer number of cells in the BMS;

[0028] Calculate the difference between the mean value of the voltages of two adjacent cells and the average voltage according to formula (3),

[0029]

[0030] Among them, μ1 is the difference between the mean value of the voltages of two adjacent cells and the average voltage;

[0031] Calculate the difference between the voltages of two adjacent cells according to formula (4),

[0032] μ2 = |a n-1 - a n |, (4)

[0033] Among them, μ2 is the difference between the voltages of two adjacent cells;

[0034] Judge whether the difference between the mean value of the voltages of two adjacent cells and the average voltage in the BMS is greater than 5 mV, whether the difference between the voltages of two adjacent cells is greater than 5 mV, and whether the sequence number difference is one;

[0035] When it is judged that the difference between the mean value of the voltages of two adjacent cells and the average voltage in the BMS is greater than 5 mV, the difference between the voltages of two adjacent cells is greater than 5 mV, and the sequence number difference is one, it is determined that the acquisition loop impedance is abnormal, and a fault record is made;

[0036] When it is judged that the difference between the mean value of the voltages of two adjacent cells and the average voltage in the BMS is less than or equal to 5 mV, or the difference between the voltages of two adjacent cells is less than or equal to 5 mV, or the sequence number difference is not one, it is determined that the acquisition loop is normal.

[0037] Optionally, according to the sequence number and voltage of each cell in the BMS, diagnosing the bad state of the BMS cell acquisition circuit further includes:

[0038] Calculate the difference between the mean value of the voltages of three adjacent cells and the average voltage according to formula (5),

[0039]

[0040] Among them, μ3 is the difference between the mean value of the voltages of three adjacent cells and the average voltage;

[0041] Determine whether the difference between the average value of the voltages of three adjacent monomers in the BMS and the average voltage is greater than 5 mV, and whether the difference between the voltages of two adjacent monomers is greater than 5 mV;

[0042] In the case where it is determined that the difference between the average value of the voltages of three adjacent monomers in the BMS and the average voltage is greater than 5 mV and the difference between the voltages of two adjacent monomers is greater than 5 mV, it is determined that there is a leakage in the TVS or a leakage in the capacitor, and a fault record is made;

[0043] In the case where it is determined that the difference between the average value of the voltages of three adjacent monomers in the BMS and the average voltage is less than or equal to 5 mV or the difference between the voltages of two adjacent monomers is less than or equal to 5 mV, it is determined that there is no leakage in the device.

[0044] Optionally, judging the BMS acquisition function according to the bad state of the BMS monomer acquisition circuit includes:

[0045] Determine whether the number of times is greater than or equal to a preset value;

[0046] In the case where it is determined that the number of times is greater than or equal to the preset value, compare the fault records obtained multiple times to determine whether the faults are consistent;

[0047] In the case where it is determined that the multiple faults are consistent, output the fault;

[0048] In the case where it is determined that the number of times is less than the preset value, increment the number of times by one, and return to obtain the acquisition voltage of the BMS, and record the number of times.

[0049] Optionally, the preset value includes four times.

[0050] Optionally, the acquisition voltages include 2.4V, 3.0V, 3.7V, and 4.2V.

[0051] On the other hand, the present invention also provides a diagnostic system for potential defects in a BMS monomer acquisition circuit, including:

[0052] The BMS system body;

[0053] A battery simulator, connected to the BMS system body, for executing any one of the above diagnostic methods.

[0054] On yet another aspect, the present invention also provides a computer-readable storage medium, which stores instructions for being read by a machine so that the machine executes any one of the above diagnostic methods.

[0055] Through the above technical solution, the method for diagnosing potential defects of the BMS monomer acquisition circuit provided by the present invention can diagnose defective states such as device failures in the BMS monomer acquisition circuit by obtaining the serial number and voltage of each monomer in the BMS, and based on the serial number and voltage of each monomer in the BMS, so as to realize a reliable judgment of the acquisition function of the BMS acquisition circuit, and the range of defective diagnosis is wider, the diagnosis is more accurate, and the practicability is stronger.

[0056] Other features and advantages of the embodiments of the present invention will be described in detail in the following specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification, and are used to explain the embodiments of the present invention together with the following specific implementation manners, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0058] Figure 1 is a flowchart of a method for diagnosing potential defects of a BMS monomer acquisition circuit according to an embodiment of the present invention;

[0059] Figure 2 is a flowchart of power supply judgment for an acquisition chip in a method for diagnosing potential defects of a BMS monomer acquisition circuit according to an embodiment of the present invention;

[0060] Figure 3 is a flowchart of judgment on disconnection of an acquisition line in a method for diagnosing potential defects of a BMS monomer acquisition circuit according to an embodiment of the present invention;

[0061] Figure 4 is a flowchart of judgment on the impedance of an acquisition loop in a method for diagnosing potential defects of a BMS monomer acquisition circuit according to an embodiment of the present invention;

[0062] Figure 5 is a flowchart of judgment on device leakage in a method for diagnosing potential defects of a BMS monomer acquisition circuit according to an embodiment of the present invention;

[0063] Figure 6 is a flowchart of reducing diagnostic errors in a method for diagnosing potential defects of a BMS monomer acquisition circuit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0064] The following will describe in detail the specific implementation manners of the embodiments of the present invention with reference to the drawings. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention.

[0065] Figure 1It is a flowchart of a method for diagnosing potential defects in the BMS monomer acquisition circuit according to an embodiment of the present invention. In Figure 1 this, the diagnostic method may include:

[0066] In step S10, the acquisition voltage of the BMS is obtained and the number of times is recorded. Among them, in order to avoid certain diagnostic errors in single acquisition voltage data, multiple different acquisition voltages are obtained and diagnosed, and the recording number is defined to start from one synchronously.

[0067] In step S11, the serial number and voltage of each monomer in the BMS are obtained according to the acquisition voltage. Among them, the voltage of each monomer in the BMS is obtained according to the acquisition voltage, and the serial number of each monomer is recorded.

[0068] In step S12, the defective state of the BMS monomer acquisition circuit is diagnosed according to the serial number and voltage of each monomer in the BMS. Among them, after obtaining the serial number and voltage of each monomer, these data can be judged to achieve reliable diagnosis of the BMS monomer acquisition circuit.

[0069] In step S13, the acquisition function of the BMS is judged according to the defective state of the BMS monomer acquisition circuit. Among them, after obtaining the defective state of the BMS monomer acquisition circuit, the acquisition function of the BMS can be determined.

[0070] In steps S10 to S13, first obtain the acquisition voltage of the BMS, and obtain the voltage and corresponding serial number of each monomer in the BMS according to the acquisition voltage. By judging the voltage and serial number of each monomer in the BMS, the diagnosis of the defective state of the BMS monomer acquisition circuit can be realized, and at the same time, combined with the defective state, the quality of the acquisition function of the BMS monomer acquisition circuit can be accurately determined.

[0071] The traditional BMS acquisition defect screening strategy mainly obtains the BMS monomer acquisition information by communicating with the battery pack during the manufacturing process, and judges the comparison between the acquisition parameters and the actual parameters. However, the scope of defective diagnosis of this method is limited, the applicability is narrow and the practicability is not strong. In this embodiment of the present invention, by adopting the method of judging the data related to the voltage and serial number of each monomer in the BMS, the defects of the BMS monomer acquisition circuit can be effectively diagnosed, the diagnostic accuracy is high, and the diagnostic method has wide applicability and stronger practicability. In addition, it can also realize the consistency monitoring during the BMS production process and effectively avoid the potential safety hazards after the BMS is installed in the vehicle.

[0072] In this embodiment of the present invention, in order to obtain the defective state of the BMS monomer acquisition circuit, it is also necessary to discriminate the voltage and serial number of each monomer in the BMS. Specifically, the steps can be as Figure 2 shown. Specifically, inFigure 2 Among them, the diagnostic method may include:

[0073] In step S20, obtain the highest voltage and the lowest voltage among the individual cell voltages of the BMS. Among them, the highest voltage among the individual cell voltages can be denoted as V max , and the lowest voltage among the individual cell voltages can be denoted as V min .

[0074] In step S21, determine whether both the highest voltage and the lowest voltage are equal to zero.

[0075] In step S22, if it is determined that both the highest voltage and the lowest voltage are equal to zero, then it is determined that the power supply of the acquisition chip fails, and a fault record is made. Among them, if the highest voltage V max and the lowest voltage V min are both equal to zero, this indicates that the power supply of the acquisition chip in the acquisition circuit fails, and then the fault needs to be recorded, obtaining the first type of fault.

[0076] In step S23, if it is determined that the highest voltage and the lowest voltage are not equal to zero, then it is determined that the power supply of the acquisition chip is normal. Among them, if the highest voltage V max and the lowest voltage V min are not both equal to zero, that is, the highest voltage V max and the lowest voltage V min are not equal or are both not zero, then it indicates that the power supply of the acquisition chip in the acquisition circuit is normal, and the next test needs to be carried out.

[0077] In steps S20 to S23, first select the highest voltage V max and the lowest voltage V min among the individual cell voltages of the BMS, and judge the values of this highest voltage V max and the lowest voltage V min . If the values of the highest voltage V max and the lowest voltage V min are both equal to zero, then it indicates that the power supply of the acquisition chip in the acquisition circuit is abnormal, that is, there is a power supply failure fault of the acquisition chip, and record this fault; if the values of the highest voltage V max and the lowest voltage V min are not equal or are both not zero, then it indicates that the power supply of the acquisition chip in the acquisition circuit is normal, and continue with the next diagnosis.

[0078] In this embodiment of the present invention, in order to obtain the bad state of the BMS individual acquisition circuit, it is also necessary to discriminate the voltage and serial number of each individual in the BMS. Specifically, the steps can be as Figure 3 shown. Specifically, in Figure 3 , the diagnostic method may further include:

[0079] In step S30, obtain the sequence number of the highest voltage and the sequence number of the lowest voltage among the individual cell voltages of the BMS. Among them, the sequence number of the highest voltage among the individual cell voltages can be expressed as V max NO, and the sequence number of the lowest voltage among the individual cell voltages can be expressed as V min NO.

[0080] In step S31, calculate the sequence number difference between the sequence number of the highest voltage and the sequence number of the lowest voltage among the individual cell voltages of the BMS according to formula (1),

[0081] σ = |V max NO - V min NO|, (1)

[0082] Among them, σ is the sequence number difference, V max NO is the sequence number of the highest voltage among the individual cell voltages of the BMS, and V min NO is the sequence number of the lowest voltage among the individual cell voltages of the BMS.

[0083] In step S32, determine whether the voltages of the nth cell and the (n + 1)th cell are both equal to zero, whether the highest voltage among the individual cell voltages of the BMS is equal to zero, and whether the sequence number difference is one.

[0084] In step S33, when it is determined that the voltages of the nth cell and the (n + 1)th cell are both equal to zero, the highest voltage among the individual cell voltages of the BMS is not equal to zero, and the sequence number difference is one, it is determined that the acquisition line is disconnected and a fault record is made. Among them, if the voltages of the nth cell and the (n + 1)th cell are both equal to zero, that is, the voltages of two adjacent cells are both equal to zero; and the highest voltage V max among the individual cell voltages of the BMS is not zero; at the same time, the sequence number difference σ is one, that is, the highest voltage V max and the lowest voltage V min are adjacent cells, then it indicates that the acquisition line is disconnected, and this fault also needs to be recorded, obtaining the second type of fault.

[0085] In step S34, when it is determined that the voltages of the nth cell and the (n + 1)th cell are not both equal to zero, or the highest voltage among the individual cell voltages of the BMS is equal to zero, or the sequence number difference is not one, it is determined that the acquisition line is not disconnected. Among them, if the voltages of the nth cell and the (n + 1)th cell are not both zero, or the highest voltage V max among the individual cell voltages of the BMS is equal to zero, or the highest voltage V max and the lowest voltage V min are not adjacent cells, then it indicates that the acquisition circuit line is normal, and the next detection can be carried out.

[0086] In steps S30 to S34, first obtain the serial number V of the highest voltage among the monomer voltages max NO and the serial number V of the lowest voltage among the monomer voltages min NO, calculate the corresponding serial number difference, and make a judgment in combination with the voltage of the nth monomer, the voltage of the (n + 1)th monomer, and the value of the highest voltage V among the monomer voltages max . If the voltages of both the nth monomer and the (n + 1)th monomer are zero, and the highest voltage V max is zero, and the serial number difference is equal to one, it indicates that the acquisition line is broken; otherwise, it indicates that the acquisition line is normal and there is no break.

[0087] In this embodiment of the present invention, in order to obtain the bad state of the BMS monomer acquisition circuit, it is also necessary to discriminate the voltage and serial number of each monomer in the BMS. The specific steps can be as Figure 4 shown. Specifically, in Figure 4 , this diagnostic method may further include:

[0088] In step S40, calculate the average voltage of n monomers in the BMS according to formula (2),

[0089]

[0090] where A n is the average voltage of each monomer in the BMS, a n is the voltage of the nth monomer, and n is the integer number of monomers in the BMS.

[0091] In step S41, calculate the difference between the average value of the voltages of two adjacent monomers and the average voltage according to formula (3),

[0092]

[0093] where μ1 is the difference between the average value of the voltages of two adjacent monomers and the average voltage.

[0094] In step S42, calculate the difference between the voltages of two adjacent monomers according to formula (4),

[0095] μ2 = |a n-1 -a n |, (4)

[0096] where μ2 is the difference between the voltages of two adjacent monomers.

[0097] In step S43, judge whether the difference between the average value of the voltages of two adjacent monomers and the average voltage in the BMS is greater than 5 mV, whether the difference between the voltages of two adjacent monomers is greater than 5 mV, and whether the serial number difference is one.

[0098] In step S44, when it is determined that the difference between the average value of the voltages of two adjacent monomers in the BMS and the average voltage is greater than 5 mV, the difference between the voltages of two adjacent monomers is greater than 5 mV, and the sequence number difference is one, it is determined that the acquisition loop impedance is abnormal, and a fault record is made. Among them, if μ1 is greater than 5 mV, μ2 is greater than 5 mV, and the highest voltage V in the monomer voltages of the BMS max and the lowest voltage V min are adjacent monomers, it indicates that the acquisition loop impedance in the acquisition circuit is abnormal, the fault is recorded, and the third type of fault can be obtained.

[0099] In step S45, when it is determined that the difference between the average value of the voltages of two adjacent monomers in the BMS and the average voltage is less than or equal to 5 mV, or the difference between the voltages of two adjacent monomers is less than or equal to 5 mV, or the sequence number difference is not one, it is determined that the acquisition loop is normal. Among them, if μ1 or μ2 is less than or equal to 5 mV, or the highest voltage V in the monomer voltages of the BMS max and the lowest voltage V min are not adjacent monomers, it can be explained that the acquisition loop impedance is normal.

[0100] In steps S40 to S45, the average voltage and the difference between the voltages of two adjacent monomers are calculated according to the voltage of each monomer in the BMS. At the same time, the difference between the average value of the voltages of two adjacent monomers and the average voltage is calculated, and the difference between the voltages of two adjacent monomers, the difference between the average value of the voltages of two adjacent monomers and the average voltage, and the value of the sequence number difference σ are judged. If μ1 is greater than 5 mV, μ2 is greater than 5 mV, and the highest voltage V in the monomer voltages of the BMS max and the lowest voltage V min are adjacent monomers, it indicates that the acquisition loop impedance in the acquisition circuit is abnormal, otherwise it indicates that the acquisition loop impedance is normal.

[0101] In this embodiment of the present invention, in order to obtain the bad state of the BMS monomer acquisition circuit, it is also necessary to discriminate the voltage and sequence number of each monomer in the BMS. Specifically, the steps can be as Figure 5 shown. Specifically, in Figure 5 , this diagnostic method may further include:

[0102] In step S50, calculate the difference between the average value of the voltages of three adjacent monomers and the average voltage according to formula (5),

[0103]

[0104] where μ3 is the difference between the average value of the voltages of three adjacent monomers and the average voltage.

[0105] In step S51, it is judged whether the difference between the average value of the voltages of three adjacent monomers in the BMS and the average voltage is greater than 5 mV and whether the difference between the voltages of two adjacent monomers is greater than 5 mV.

[0106] In step S52, when it is judged that the difference between the average value of the voltages of three adjacent monomers in the BMS and the average voltage is greater than 5 mV and the difference between the voltages of two adjacent monomers is greater than 5 mV, it is determined that there is a leakage in the TVS or a leakage in the capacitor, and a fault record is made. Among them, if μ3 is greater than 5 mV and μ2 is greater than 5 mV, it means that there is a leakage in the devices in the acquisition circuit. Specifically, there is a leakage in the TVS or a leakage in the capacitor, and this fault is recorded.

[0107] In step S53, when it is judged that the difference between the average value of the voltages of three adjacent monomers in the BMS and the average voltage is less than or equal to 5 mV or the difference between the voltages of two adjacent monomers is less than or equal to 5 mV, it is determined that there is no leakage in the device. Among them, if μ3 is less than or equal to 5 mV or μ2 is less than or equal to 5 mV, it means that there is no leakage in the devices in the acquisition circuit.

[0108] In steps S50 to S53, the difference μ3 between the average value of the voltages of three adjacent monomers and the average voltage is calculated, and it is judged whether both the difference μ3 between the average value of the voltages of three adjacent monomers and the average voltage and the difference μ2 between the voltages of two adjacent monomers are greater than 5 mV. If both the difference μ3 between the average value of the voltages of three adjacent monomers and the average voltage and the difference μ2 between the voltages of two adjacent monomers are greater than 5 mV, it means that there is a leakage in the TVS or a leakage in the capacitor in the acquisition circuit, otherwise there is no leakage in the device.

[0109] In this embodiment of the present invention, in order to avoid certain diagnostic errors in single - time acquisition of voltage data, multiple different acquisition voltages are obtained and diagnosed. Specifically, the steps can be as shown in 6.

[0110] Specifically, in Figure 6 it, the diagnostic method may include:

[0111] In step S60, it is judged whether the number of times is greater than or equal to a preset value. Among them, the specific value of the preset value includes but is not limited to four times. Specifically, when performing fault simulation, a battery simulator is used to simulate the characteristics of a lithium battery, and the four acquisition voltages are respectively simulated to 2.4 V, 3.0 V, 3.7 V, and 4.2 V.

[0112] In step S61, when it is judged that the number of times is greater than or equal to the preset value, the multiple obtained fault records are compared to judge whether the faults are consistent. Among them, if the number of times is greater than or equal to the preset value, it means that the four - time diagnosis is completed, and then the conclusions of the four - time diagnosis are compared.

[0113] In step S62, when it is determined that multiple faults are consistent, the fault is output. Among them, if the fault conclusions are consistent under the diagnosis of the collected voltage four times, it indicates that the fault diagnosis is accurate, and potential defects can be effectively screened out.

[0114] In step S63, when the number of judgments is less than the preset value, the number is incremented by one, and the process returns to obtain the collected voltage of the BMS, and the number is recorded. Among them, if the number is less than the preset value, it means that the number of diagnoses does not meet the requirements, and it is necessary to continue to replace the collected voltage for diagnosis, and the number is incremented by one at the same time.

[0115] In steps S60 to S63, four different collected voltages are preset for simulation diagnosis, the acquisition circuit is diagnosed in sequence according to the four collected voltages, and the corresponding faults are recorded. Finally, the four faults are compared and matched. If the four faults are the same, it means that the fault actually exists, and potential defects can be effectively and accurately screened out.

[0116] On the other hand, the present invention also provides a diagnostic system for potential defects of a BMS monomer acquisition circuit. Specifically, the diagnostic system may include a BMS system body and a battery simulator. Specifically, the battery simulator is connected to the BMS system body and is used to execute any one of the above diagnostic methods.

[0117] On yet another aspect, the present invention also provides a computer-readable storage medium storing instructions for being read by a machine to cause the machine to execute any one of the above diagnostic methods.

[0118] Through the above technical solutions, the diagnostic method for potential defects of the BMS monomer acquisition circuit provided by the present invention can diagnose defective states such as device failures in the BMS monomer acquisition circuit by obtaining the serial number and voltage of each monomer in the BMS, so as to realize a reliable judgment of the acquisition function of the BMS acquisition circuit, and has a wider range of bad diagnosis, more accurate diagnosis, and stronger practicability.

[0119] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0120] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing device generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0121] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0123] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0124] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of computer-readable media.

[0125] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0126] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity 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, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0127] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A diagnostic method for potential defects of a BMS monomer acquisition circuit, characterized in that, Including: Obtain the collected voltage of the BMS and record the number of times; Obtain the serial number and voltage of each cell in the BMS according to the collected voltage; Diagnose the defective state of the cell acquisition circuit in the BMS according to the serial number and voltage of each cell in the BMS; Judge the acquisition function of the BMS according to the defective state of the cell acquisition circuit in the BMS; Diagnosing the defective state of the cell acquisition circuit in the BMS according to the serial number and voltage of each cell in the BMS includes: Calculate the average voltage of n cells in the BMS according to formula (2); Among them, A n is the average voltage of each cell in the BMS, a n is the voltage of the nth cell, and n is the integer number of cells in the BMS; Calculate the difference between the average value of the voltages of two adjacent cells and the average voltage according to formula (3); Wherein, μ1 is the difference between the average value of the voltages of two adjacent cells and the average voltage; Calculate the voltage difference between two adjacent cells according to formula (4); μ2 = |a n-1 -a n |, (4) Wherein, μ2 is the voltage difference between two adjacent cells; Judge whether the difference between the average value of the voltages of two adjacent cells and the average voltage in the BMS is greater than 5mV, whether the voltage difference between two adjacent cells is greater than 5mV, and whether the serial number difference is one; When it is judged that the difference between the average value of the voltages of two adjacent cells and the average voltage in the BMS is greater than 5mV, the voltage difference between two adjacent cells is greater than 5mV, and the serial number difference is one, it is determined that the impedance of the acquisition circuit is abnormal and a fault record is made; When it is judged that the difference between the average value of the voltages of two adjacent cells and the average voltage in the BMS is less than or equal to 5mV, or the voltage difference between two adjacent cells is less than or equal to 5mV, or the serial number difference is not one, it is determined that the acquisition circuit is normal.

2. The diagnostic method according to claim 1, characterized in that, Diagnosing the defective state of the cell acquisition circuit in the BMS according to the serial number and voltage of each cell in the BMS further includes: Obtain the highest voltage and the lowest voltage among the cell voltages of the BMS; Judge whether both the highest voltage and the lowest voltage are equal to zero; When it is judged that both the highest voltage and the lowest voltage are equal to zero, it is determined that the power supply of the acquisition chip fails and a fault record is made; When it is judged that the highest voltage and the lowest voltage are not equal to zero, it is determined that the power supply of the acquisition chip is normal.

3. The diagnostic method according to claim 2, wherein Diagnosing the defective state of the cell acquisition circuit in the BMS according to the serial number and voltage of each cell in the BMS further includes: Obtain the serial number of the highest voltage and the serial number of the lowest voltage among the cell voltages of the BMS; Calculate the serial number difference between the serial number of the highest voltage and the serial number of the lowest voltage among the cell voltages of the BMS according to formula (1); σ = |V max NO-V min NO|, (1) wherein, σ is the difference in sequence numbers, V max NO is the sequence number of the highest voltage among the individual cell voltages of the BMS, V min NO is the sequence number of the lowest voltage among the individual cell voltages of the BMS; Judge whether the voltage of the nth cell and the voltage of the (n + 1)th cell are both equal to zero, whether the highest voltage among the cell voltages of the BMS is equal to zero, and whether the serial number difference is one; When it is judged that the voltage of the nth cell and the voltage of the (n + 1)th cell are both equal to zero, the highest voltage among the cell voltages of the BMS is not equal to zero, and the serial number difference is one, it is determined that the acquisition line is broken and a fault record is made; When it is determined that the voltages of the nth cell and the (n + 1)th cell are not both equal to zero, or the highest voltage among the cell voltages of the BMS is equal to zero, or the serial number difference is not one, it is determined that there is no disconnection in the acquisition line.

4. The diagnostic method according to claim 1, wherein Diagnosing the defective state of the BMS cell acquisition circuit according to the serial number and voltage of each cell in the BMS further includes: Calculating the difference between the average value of the voltages of three adjacent cells and the average voltage according to formula (5), where μ3 is the difference between the average value of the voltages of three adjacent cells and the average voltage; Judging whether the difference between the average value of the voltages of three adjacent cells and the average voltage in the BMS is greater than 5 mV and whether the difference between the voltages of two adjacent cells is greater than 5 mV; When it is determined that the difference between the average value of the voltages of three adjacent cells and the average voltage in the BMS is greater than 5 mV and the difference between the voltages of two adjacent cells is greater than 5 mV, it is determined that there is leakage in the TVS or leakage in the capacitor, and a fault record is made; When it is determined that the difference between the average value of the voltages of three adjacent cells and the average voltage in the BMS is less than or equal to 5 mV or the difference between the voltages of two adjacent cells is less than or equal to 5 mV, it is determined that there is no leakage in the device.

5. The diagnostic method according to claim 1, characterized in that, Judging the BMS acquisition function according to the defective state of the BMS cell acquisition circuit includes: Judging whether the number of times is greater than or equal to a preset value; When it is determined that the number of times is greater than or equal to the preset value, comparing the fault records obtained multiple times to judge whether the faults are consistent; When it is determined that the multiple faults are consistent, outputting the fault; When it is determined that the number of times is less than the preset value, incrementing the number of times by one, and returning to obtain the acquisition voltage of the BMS and recording the number of times.

6. The diagnostic method according to claim 5, characterized in that The preset value includes four times.

7. The diagnostic method according to claim 1, characterized in that, The acquisition voltages include 2.4V, 3.0V, 3.7V, and 4.2V.

8. A diagnostic system for potential defects of a BMS single cell acquisition circuit, characterized in that, Including: The BMS system body; A battery simulator, connected to the BMS system body, for performing the diagnostic method according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions for being read by a machine so that the machine performs the diagnostic method according to any one of claims 1 to 7.

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