BMS comprehensive test system with fault diagnosis and balance control functions

Abstract

The application discloses a BMS comprehensive test system with fault diagnosis and balance control functions, and relates to the field of battery management, comprising: a generation module for outputting self-defined voltage, current and temperature simulation signals to a measured BMS; and an acquisition module for capturing voltage balance data, fault response signals and state parameters fed back by the measured BMS in real time, synchronously associating signal generation time sequences with BMS feedback nodes to complete data time sequence alignment and format standardization processing; the application can comprehensively test balance control and fault diagnosis capabilities by constructing differentiated voltage scenarios and multi-grade fault working conditions, quantitatively evaluate diagnosis performance in combination with missed diagnosis rate, misdiagnosis rate and response time, and generate a comprehensive score relying on multi-dimensional weight coefficients and data fluctuation penalty mechanisms to objectively reflect actual performance of the measured BMS.

Description

TECHNICAL FIELD

[0001] The present application relates to the battery management technical field, specifically to a BMS comprehensive test system with fault diagnosis and balance control functions. BACKGROUND

[0002] The battery management system (BMS) test equipment system plays a key role in ensuring the safe and reliable operation of the battery and optimizing the performance of the battery. And the function test is an important means to evaluate whether the BMS test equipment system can accurately and effectively realize its predetermined functions.

[0003] In the prior art, people adaptively provide management services to batteries by customizing different BMS, but for the BMS itself, there is currently no good and comprehensive test system to test its actual performance.

[0004] Therefore, we propose a BMS comprehensive test system with fault diagnosis and balance control functions. SUMMARY

[0005] In view of the above shortcomings of the prior art, the present application provides a BMS comprehensive test system with fault diagnosis and balance control functions, which can effectively solve the problems of the prior art.

[0006] To achieve the above purpose, the present application realizes the following technical solutions;

[0007] The present application discloses a BMS comprehensive test system with fault diagnosis and balance control functions, comprising:

[0008] A generation module is used to output custom voltage, current and temperature simulation signals to the measured BMS; a collection module is used to capture voltage balance data, fault response signals and state parameters fed back by the measured BMS in real time, and to synchronize the generation time sequence with the BMS feedback node to complete data time sequence alignment and format standardization processing; a test module is used to construct a monomer battery voltage differentiation simulation scene, trigger the balance function of the measured BMS, and synchronously collect dynamic data in the balance process; an analog module is used to simulate fault working conditions such as overcharge, overdischarge, short circuit, overheating, monomer voltage imbalance and communication interruption, and output fault trigger signals to the measured BMS; a verification module is used to receive the diagnostic feedback signals output by the measured BMS in response to the simulated fault working conditions, compare the diagnostic results with the simulated fault working condition parameters, and verify the diagnostic accuracy and response timeliness; and a feedback module is used to receive the operation data of the foregoing modules, and construct a quantitative evaluation model of balance control performance and fault diagnosis capability.

[0009] The generation module is interactively connected to the acquisition module via a wireless network. The acquisition module is interactively connected to the test module via a wireless network. The test module is interactively connected to the simulation module and the verification module via a wireless network. The verification module is interactively connected to the feedback module via a wireless network.

[0010] The aforementioned modules of the feedback module are the generation module, the acquisition module, the testing module, the simulation module, and the verification module.

[0011] Furthermore, the custom voltage, current, and temperature analog signals in the generation module are dynamically calculated based on the rated parameters of the BMS under test, the test target, and the real-time load characteristics, wherein the voltage signal output value is:

[0012] ;

[0013] In the formula: To generate a custom voltage signal value output by the module; The rated operating voltage of the BMS under test; These are the weighting coefficients; The load factor is the ratio of the real-time detected equivalent load resistance of the tested BMS to the rated load resistance. For temperature compensation factor, , These represent the measured ambient temperature, the standard test temperature, and the upper and lower limits of the allowable operating temperature of the tested BMS, respectively. For the testing phase coefficient;

[0014] Among them, the current signal output value and the voltage signal output value are related by Ohm's law, and the temperature simulation signal value is dynamically corrected based on the power loss of the voltage and current signals and the ambient temperature.

[0015] Furthermore, the acquisition module follows the following rules when performing data timing alignment:

[0016] When the generator outputs an analog signal, it embeds a clock synchronization mark. After the acquisition module captures the feedback signal, it extracts the mark and calculates the difference with its own reference clock. Based on the difference, it dynamically adjusts the recorded value at the capture time to correct the time deviation, so that the time difference between the signal output and the feedback capture is within a preset threshold.

[0017] The format standardization process includes data type unification, unit normalization, and outlier removal. The logic for determining outliers is as follows:

[0018] If the feedback data exceeds the theoretically reasonable range of the corresponding physical parameters, or if the rate of change of at least 3 consecutive sets of adjacent feedback data exceeds the preset trend threshold and there is no reasonable working condition switching trigger, it is judged as an abnormal value, marked and temporarily stored in the preset abnormal database and associated with the corresponding working condition information.

[0019] Further, when the test module constructs the monomer battery voltage differentiation simulation scenario, the monomer battery series number and the equalization starting threshold of the measured BMS are acquired first, and then the simulation voltage value of each monomer battery is allocated based on a preset voltage difference gradient;

[0020] The voltage difference gradient is set in an arithmetic sequence, the voltage difference value of adjacent gradients is in a preset interval, and the difference between the maximum monomer voltage and the minimum monomer voltage is not less than 1.2 times the equalization starting threshold.

[0021] The equalization process dynamic data synchronously collected by the test module includes the voltage change curve of each monomer battery, the equalization loop current, the equalization duration, and the power consumption of the BMS control chip. The collection frequency is dynamically adjusted according to the change rate of the equalization current, that is, the dynamic adjustment logic that the greater the current change rate, the higher the collection frequency.

[0022] Further, when the simulation module simulates each fault condition, the fault is divided into three fault levels of mild, moderate and severe based on the harm degree, influence range and recovery difficulty of the fault to the safety of the BMS operation, and each level corresponds to a preset fault level coefficient , wherein is a real number greater than zero, and the severe fault level coefficient is greater than the moderate fault level coefficient, and the moderate fault level coefficient is greater than the mild fault level coefficient.

[0023] The parameters of the fault trigger signal are dynamically set based on the safety threshold of the measured BMS, the fault level and the level coefficient:

[0024] The simulation voltage of the overcharge fault is the product of the overcharge protection threshold of the measured BMS and (1+ ×0.2);

[0025] The simulation voltage of the overdischarge fault is the product of the overdischarge protection threshold and (1- ×0.2);

[0026] The short circuit fault is realized by simulating the sudden change of the loop resistance, and the short circuit resistance value is the product of the normal working loop resistance of the measured BMS and (1 / (1+ ×5)), and it is gradually reduced from mild to severe according to the fault level;

[0027] The simulation temperature of the overheat fault is increased at a linear heating rate, and the heating rate is the product of the preset reference heating rate and (1+ ×3), wherein the reference heating rate is preset based on the heat diffusion characteristics of the measured BMS;

[0028] The voltage deviation value of the monomer voltage imbalance fault is the product of the maximum value of the voltage difference gradient and ;

[0029] The interruption duration of the communication interruption fault is the product of a preset reference interruption duration and (1+2), and the reference interruption duration is set according to the timeout determination criterion of the BMS communication protocol;

[0030] When the simulation module triggers a fault condition, the constraints of single fault priority and composite fault ordered combination are followed, the grade coefficients of each single fault are confirmed to have no conflict before triggering the composite fault, and the comprehensive grade coefficient of the composite fault does not exceed the upper limit of the grade coefficient corresponding to the severe fault.

[0031] Further, when the verification module verifies the diagnostic accuracy and response timeliness, the comprehensive representation of the diagnostic accuracy and response timeliness is quantified as:

[0032] ;

[0033] In the formula: is a diagnostic performance comprehensive evaluation value; is a missed diagnosis rate, that is, the ratio of the number of simulated faults not recognized by the BMS to the total number of simulated faults; is a misdiagnosis rate, that is, the ratio of the number of faults misjudged by the BMS to the total number of diagnostic results; 、 is a weight coefficient of missed diagnosis and misdiagnosis; is a response time influence factor; is an actual response time of the BMS; is a preset optimal response time;

[0034] If D is not less than a preset diagnostic performance threshold, it is determined that the fault diagnosis performance of the measured BMS meets the test requirements, a qualified diagnosis report is generated and is synchronized to the feedback module; if D is less than the preset diagnostic performance threshold, it is determined that the performance does not meet the requirements, the corresponding fault types of missed diagnosis and misdiagnosis and the corresponding working conditions of the response time exceeding the standard are extracted to generate a substandard analysis report.

[0035] Further, the feedback module constructs a quantitative evaluation model, including a balanced control performance evaluation sub-model and a fault diagnosis capability evaluation sub-model, and outputs a comprehensive test score based on the quantitative evaluation model:

[0036] ;

[0037] In the formula: is a comprehensive test score; is a balanced control performance score, which is derived from the balanced control performance evaluation sub-model; is a fault diagnosis capability score, which is derived from the fault diagnosis capability evaluation sub-model; is a weight coefficient; is a data fluctuation penalty coefficient;​ a standard deviation of the comprehensive test score corresponding to the preset repetition number under the same test condition;

[0038] wherein, the greater the value of the measured BMS performance is, the sum is 1, and both are positive numbers, and .

[0039] Further, the data fluctuation penalty coefficient The value is subject to:

[0040] ;

[0041] In the formula: is a confidence level factor; is a preset allowable data fluctuation threshold.

[0042] Further, the fault diagnosis capability score is replaced by the comprehensive representation of diagnosis accuracy and response timeliness;

[0043] The balanced control performance score The expression is:

[0044] ;

[0045] In the formula: is the weight coefficient of the balancing speed, the balancing accuracy and the balancing energy consumption; is the balancing speed; is the preset optimal balancing speed; is the rated voltage of the single battery of the measured BMS; is the maximum voltage deviation value of all single batteries after balancing; is the preset maximum and minimum allowable balancing energy consumption; is the total energy consumption of the balancing process.

[0046] Compared with the known prior art, the technical scheme provided by the present application has the following beneficial effects:

[0047] The application provides a BMS comprehensive test system with fault diagnosis and balance control functions, which generates simulation signals by dynamically adapting the rated parameters of the measured object and real-time working conditions during operation, accurately captures feedback data and completes timing alignment and standardization processing, effectively guarantees data reliability, comprehensively tests balance control and fault diagnosis capabilities by building differentiated voltage scenarios and multi-level fault working conditions, quantitatively evaluates diagnostic performance in combination with missed diagnosis rate, misdiagnosis rate and response time, and generates a comprehensive score based on multi-dimensional weight coefficients and data fluctuation penalty mechanism, objectively reflects the actual performance of the measured BMS, meets the differentiated needs of different test scenarios for dynamic characteristics and stability, provides parameter calibration and horizontal comparison benchmarks for similar product tests, significantly improves test pertinence and comprehensiveness, and reduces test errors. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0049] Figure 1 The structure of the BMS comprehensive test system with fault diagnosis and balance control functions is shown in the figure. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0051] The present application will be further described below in combination with embodiments.

[0052] Embodiment:

[0053] The BMS comprehensive test system with fault diagnosis and balance control functions in the embodiment, as shown in the figure, comprises: Figure 1

[0054] The generating module is used to output self-defined voltage, current and temperature simulation signals to the measured BMS.

[0055] The self-defined voltage, current and temperature simulation signals in the generating module are dynamically calculated based on the rated parameters of the measured BMS, test targets and real-time load characteristics, wherein the voltage signal output value is:​

[0056] ;

[0057] In the formula: is the custom voltage signal value generated by the module output; is the rated operating voltage of the measured BMS; is the weight coefficient; is the load coefficient, which is the ratio of the equivalent load resistance of the measured BMS to the rated load resistance; is the temperature compensation factor, , respectively represent the measured ambient temperature, the standard test temperature, the upper and lower limits of the allowed operating temperature of the measured BMS; is the test phase coefficient;

[0058] The above formula is based on the rated operating voltage of the measured BMS, fully considers the influence of the load coefficient, the temperature compensation factor and the test phase coefficient on the voltage output, dynamically adjusts the weight proportion according to the significant degree of the influence of the load, the ambient temperature and the test phase on the voltage response characteristics, so that the voltage signal dynamically adapts to the BMS rated parameters, the test target and the real-time load characteristics, and ensures that the output voltage can accurately simulate the actual demand under different working conditions;

[0059] The current signal output value and the voltage signal output value are subject to the Ohm's law correlation, and the temperature simulation signal value is dynamically corrected based on the voltage, current signal loss power and ambient temperature;

[0060] wherein, are greater than zero, and the greater the influence of the load on the voltage response characteristics of the measured BMS the greater the load influence is weak the smaller the value is; the more obvious the disturbance of the deviation of the ambient temperature from the standard test temperature on the BMS working state the greater the ambient temperature approaches the standard test temperature the smaller the value is; the higher the demand of the test phase on the dynamic change of the voltage signal the greater the test phase requirement for the stability of the voltage signal the smaller the value is;

[0061] ∈[0.1, 1.5], the higher the requirement of the test phase on the signal dynamic characteristics and fluctuation amplitude the greater the value is, the test phase mainly calibrates the basic parameters and verifies the signal stability the smaller the value is;

[0062] temperature simulation signal value ;

[0063] In the formula: The reference operating temperature of the BMS under test; The weighting coefficient for the influence of ambient temperature and the power loss-temperature conversion coefficient; This refers to the power loss of voltage and current signals; The duration of the current analog signal output; The equivalent density of the tested BMS battery pack; This represents the equivalent volume of the battery pack. The equivalent isobaric specific heat capacity of the battery pack; The thermal response time constant, In this context, e is the natural constant. This is a thermal response hysteresis correction term used to simulate the dynamic characteristics of temperature accumulation over time.

[0064] The above formula takes the reference operating temperature of the tested BMS as the starting point. On the one hand, it adapts the sensitivity of the BMS to changes in ambient temperature by using the influence weighting coefficient of ambient temperature. On the other hand, it combines the power loss of voltage and current signals, the signal continuous output time, and physical parameters such as the equivalent density, volume, and specific heat capacity of the battery pack. The power loss to temperature conversion coefficient realizes the conversion of loss to temperature. At the same time, a thermal response hysteresis correction term is introduced to simulate the dynamic characteristics of temperature accumulation over time. The thermal response time constant and the natural constant work together to the correction term, so that the temperature simulation can not only reflect the immediate impact of the environment and loss, but also restore the hysteresis and cumulative effect of temperature changes in actual operation, thus more closely matching the real temperature change law of the BMS.

[0065] ∈ (0,1), the higher the sensitivity of the tested BMS to changes in ambient temperature, the better. The larger the value, the lower the sensitivity. The smaller the value;

[0066] >0 indicates that the higher the thermal conductivity efficiency and the efficiency of heat loss conversion to temperature of the tested BMS battery pack, the better. The larger the value, the lower the heat transfer efficiency and conversion efficiency. The smaller the value;

[0067] The acquisition module is used to capture voltage equalization data, fault response signals and status parameters fed back by the tested BMS in real time, and synchronously associate the signal generation timing with the BMS feedback node to complete data timing alignment and format standardization processing.

[0068] When the acquisition module performs data timing alignment, it follows the following rules:

[0069] The clock synchronization mark is embedded when the generation module outputs the analog signal, the mark is extracted after the acquisition module captures the feedback signal, and a difference value is calculated with the self reference clock, the time deviation is corrected by dynamically adjusting the capture time record value based on the difference value, so that the time difference between the signal output and the feedback capture is within a preset threshold;

[0070] The format standardization processing includes data type unification, dimension normalization and abnormal value elimination, and the abnormal value judgment logic is:

[0071] The feedback data exceeds the theoretically reasonable range of the corresponding physical parameter, or the change rate of at least 3 groups of continuous feedback data exceeds the preset trend threshold without reasonable working condition switching trigger, which is judged as an abnormal value, marked and temporarily stored in the preset abnormal database and associated with the corresponding working condition information;

[0072] The acquisition module synchronously associates the signal generation time sequence with the BMS feedback node through the three-dimensional association index of the signal generation sequence code, feedback data check code and clock compensation value, and based on the sequence code, the analog signal parameters can be traced, the check code verifies the data integrity, and the clock compensation value confirms the time sequence corresponding relationship;

[0073] Among them, the feedback data check code is a fixed length code generated by arranging the voltage balancing data, fault response signal, state parameter and other key fields in the captured feedback data in a preset order, and then performing bit operation and weighted summation operation combined with a preset seed value;

[0074] The test module is used to construct a differentiated analog scene of single battery voltage, trigger the balancing function of the measured BMS, and synchronously collect dynamic data in the balancing process;

[0075] When the test module constructs a differentiated analog scene of single battery voltage, the number of single batteries in series and the balancing start threshold of the measured BMS are obtained first, and then based on the preset voltage difference gradient, the analog voltage value of each single battery is allocated;

[0076] Among them, the voltage difference gradient is set in an arithmetic sequence, the voltage difference value of adjacent gradients is in a preset interval, and the difference value between the maximum single voltage and the minimum single voltage is not less than 1.2 times the balancing start threshold;

[0077] The dynamic data collected by the test module in the balancing process includes the voltage change curve of each single battery, the balancing loop current, the balancing duration, and the power consumption of the BMS control chip, and the collection frequency is dynamically adjusted according to the change rate of the balancing current, that is, the dynamic adjustment logic that the higher the current change rate, the higher the collection frequency;

[0078] The simulation module is used to simulate fault working conditions such as overcharge, overdischarge, short circuit, overheating, single voltage imbalance and communication interruption, and outputs fault trigger signals to the measured BMS;

[0079] The simulation module simulates each fault condition, and based on the harm degree, influence range and recovery difficulty of the fault to the safety of the BMS operation, three fault levels of mild, moderate and severe are divided, and each level corresponds to a preset fault level coefficient , wherein is a real number greater than zero, and the severe fault level coefficient is greater than the moderate fault level coefficient, and the moderate fault level coefficient is greater than the mild fault level coefficient;

[0080] The parameters of the fault trigger signal are dynamically set based on the safety threshold of the measured BMS, the fault level and the level coefficient:

[0081] The simulation voltage of the overcharge fault is the product of the overcharge protection threshold of the measured BMS and (1+ ×0.2);

[0082] The simulation voltage of the over-discharge fault is the product of the over-discharge protection threshold and (1- ×0.2);

[0083] The short circuit fault is realized by simulating a sudden change in loop resistance, and the short circuit resistance value is the product of the normal working loop resistance of the measured BMS and (1 / (1+ ×5)), and decreases gradually from mild to severe according to the fault level;

[0084] The simulation temperature of the overheat fault is increased at a linear heating rate, and the heating rate is the product of the preset reference heating rate and (1+ ×3), wherein the reference heating rate is preset based on the heat diffusion characteristics of the measured BMS;

[0085] The voltage deviation value of the single cell voltage imbalance fault is the product of the maximum voltage difference gradient and ;

[0086] The interruption time of the communication interruption fault is the product of the preset reference interruption time and (1+ ×2), and the reference interruption time is set according to the timeout judgment standard of the BMS communication protocol;

[0087] When the simulation module triggers the fault condition, it is subject to the constraint conditions of single fault priority and ordered combination of composite faults, and before triggering the composite fault, it is confirmed that the level coefficients of each single fault have no conflict, and the comprehensive level coefficient of the composite fault does not exceed the upper limit of the level coefficient corresponding to the severe fault;

[0088] Wherein, when it is confirmed that the level coefficients of each single fault have no conflict: based on the physical property classification of the fault condition, including voltage related, resistance related, temperature related and communication related, only one single fault of the same physical property category is allowed to be selected into the composite fault, and single faults of different physical property categories can be combined, so as to confirm that the level coefficients of each single fault have no conflict;

[0089] When the comprehensive level coefficient of the composite fault is confirmed to be not more than the upper limit of the level coefficient corresponding to the severe fault:

[0090] the comprehensive level coefficient of the composite fault , denotes the comprehensive level coefficient of the composite fault, denotes the number of single faults contained in the composite fault, denotes the level coefficient of the i-th single fault, denotes the weight coefficient of the i-th single fault;

[0091] wherein, , and the weight coefficient of each single fault is preset based on the harm degree of the fault, and it is determined after calculation ≤ , if it exceeds, the value of each is reduced in proportion to the weight proportion, until is within the preset upper limit range of the level coefficient of the severe fault;

[0092] The verification module is configured to receive the diagnostic feedback signal output by the BMS under the simulated fault working condition, compare the diagnostic result with the simulated fault working condition parameter, and verify the diagnostic accuracy and response timeliness.

[0093] When the verification module verifies the diagnostic accuracy and response timeliness, the comprehensive representation of the diagnostic accuracy and response timeliness is quantified as:

[0094] ;

[0095] In the formula: is the comprehensive evaluation value of the diagnostic performance; is the missed diagnosis rate, i.e. the ratio of the number of simulated faults not recognized by the BMS to the total number of simulated faults; is the misdiagnosis rate, i.e. the ratio of the number of faults misjudged by the BMS to the total number of diagnostic results; is the weight coefficient of missed diagnosis and misdiagnosis; is the response time influence factor; is the actual response time of the BMS; is the preset optimal response time;

[0096] The above formula comprehensively considers the accuracy and response timeliness of fault diagnosis, quantifies the missed diagnosis rate and misdiagnosis rate as accuracy influence factors through corresponding weight coefficients, introduces a response time influence factor, combines an exponential function to amplify the negative impact of exceeding the response time, and finally integrates the accuracy and timeliness into a single quantitative index. Based on this, it can not only flexibly adapt to different scenarios and pay different attention to missed diagnosis and misdiagnosis, but also highlight the influence of fault harm degree on response timeliness.​

[0097] wherein, , are all greater than zero, and , the sum of which is 1, and , the value of which is customized by the system end user, , initially set to 0.5, 0.5, positively correlated with the fault type, and the higher the fault hazard degree, the greater the value of λ;

[0098] If D is not less than the preset diagnosis performance threshold, it is determined that the fault diagnosis performance of the measured BMS meets the test requirements, a qualified diagnosis report is generated and synchronized to the feedback module; if D is less than the preset diagnosis performance threshold, it is determined that it does not meet the requirements, the corresponding fault types and response time exceeding the corresponding working conditions of missed diagnosis and misdiagnosis are extracted to generate a substandard analysis report;

[0099] D and the corresponding , , data are associated with the unique identifier of the measured BMS and stored in the preset test database in the system as the parameter calibration basis and performance horizontal comparison benchmark for subsequent testing of the same type of BMS;

[0100] The feedback module is used to receive the running data of the foregoing modules and construct a quantitative evaluation model for balanced control performance and fault diagnosis capability;

[0101] The quantitative evaluation model constructed by the feedback module includes a balanced control performance evaluation sub-model and a fault diagnosis capability evaluation sub-model, and outputs a comprehensive test score based on the quantitative evaluation model:

[0102] ;

[0103] In the formula: is the comprehensive test score; is the balanced control performance score, which is derived from the balanced control performance evaluation sub-model; is the fault diagnosis capability score, which is derived from the fault diagnosis capability evaluation sub-model; is the weight coefficient; is the data fluctuation penalty coefficient; is the standard deviation of the comprehensive test score corresponding to the preset repetition number under the same test working condition;

[0104] The above formula takes into account the two core test dimensions of balanced control performance and fault diagnosis capability, and by introducing a data fluctuation penalty coefficient and the standard deviation of repeated test scores under the same test condition, a penalty mechanism is constructed, so that the BMS with poorer test data reliability and repeatability faces higher score penalty, avoiding the accidental influence of single test result. The final comprehensive score can not only reflect the pros and cons of the core performance of the BMS, but also reflect the stability of the test data;

[0105] wherein, The greater the value of the measured BMS performance is better, The sum is 1, and both are positive, and ;

[0106] Data fluctuation penalty coefficient The value is subject to:

[0107] ;

[0108] In the formula, is a confidence level factor; is a preset allowed data fluctuation threshold;

[0109] wherein, The value range is preset to [1, 5], and is subject to: the higher the confidence of the test data (the better the data reliability and repeatability), the smaller the value, and the lower the confidence of the test data (the worse the data reliability and repeatability), the greater the value;

[0110] Fault diagnosis capability score The results are replaced by the comprehensive representation of diagnostic accuracy and response timeliness;

[0111] Balanced control performance score The expression is:

[0112] ;

[0113] In the formula, is the weight coefficient of balanced speed, balanced accuracy and balanced energy consumption; is the balanced speed; is the preset optimal balanced speed; is the rated voltage of the single battery of the measured BMS; is the maximum voltage deviation value of all single batteries after balancing; is the preset maximum and minimum allowed balanced energy consumption; is the total energy consumption of the balancing process;

[0114] The formula above evaluates the balancing control performance from three core dimensions of balancing speed, balancing accuracy and balancing energy consumption. The importance proportion of each dimension is adjusted by the corresponding weight coefficient, so as to dynamically adjust according to the different requirements of timeliness, consistency and energy saving of the test scene, realize multi-dimensional and personalized quantitative evaluation of balancing performance, and comprehensively reflect the actual performance of BMS balancing control.

[0115] wherein, are positive numbers and the sum is 1, when the test scene has high requirement on the response timeliness of voltage difference elimination The greater the value, when there is no strict constraint on the balancing response speed The smaller the value, when the test scene has strict requirement on the consistency of single battery voltage The greater the value, when moderate deviation of single battery voltage is allowed The smaller the value, when the test scene has strict constraint on the energy consumption of balancing process The greater the value, when the energy loss has negligible effect on system performance The smaller the value;

[0116] Among them, the aforementioned modules of the feedback module are the generation module, the collection module, the test module, the simulation module and the verification module.

[0117] The generation module is connected to the collection module through wireless network interaction, the collection module is connected to the test module through wireless network interaction, the test module is connected to the simulation module and the verification module through wireless network interaction, and the verification module is connected to the feedback module through wireless network interaction.

[0118] In this embodiment, the generation module outputs custom voltage, current and temperature simulation signals to the measured BMS, the collection module runs in the back to capture the voltage balancing data, fault response signals and state parameters fed back by the measured BMS in real time, synchronously associates the signal generation time sequence with the BMS feedback node, to complete the data time sequence alignment and format standardization processing, then the test module constructs a single battery voltage differentiation simulation scene, triggers the balancing function of the measured BMS, synchronously collects the dynamic data in the balancing process, the simulation module further simulates fault working conditions such as overcharge, overdischarge, short circuit, overheating, single battery voltage imbalance and communication interruption, outputs fault trigger signals to the measured BMS, receives the diagnostic feedback signals output by the measured BMS in response to the simulated fault working conditions through the verification module, compares the diagnostic results with the simulated fault working condition parameters, verifies the diagnostic accuracy and response timeliness, and finally receives the running data of the aforementioned modules through the feedback module, constructs a quantitative evaluation model of balancing control performance and fault diagnosis capability.

[0119] The system in the above embodiment can be applied to the BMS comprehensive test scene, can accurately simulate various working scenes and fault working conditions, can capture key data in real time and process it in a standardized manner, can accurately verify the accuracy and response timeliness of BMS fault diagnosis, can quantitatively evaluate the balanced control performance, can provide reliable data support for BMS optimization, can greatly improve the test efficiency and accuracy, and can effectively guarantee the safety, stability and reliability of the battery system in operation.

[0120] Referring to the system in the above embodiment, an application example of the system is shown:

[0121] XX car enterprise carries out fault diagnosis and balanced control function test on a BMS for an electric vehicle, and uses the system in the above embodiment to carry out practical operation verification:

[0122] The generation module dynamically calculates the custom voltage signal output value as 3.72V according to the rated working voltage 3.7V of the BMS, the real-time load characteristics and the test target, the current signal is obtained based on Ohm's law as 0.85A, and the temperature simulation signal is dynamically corrected as 25.3℃. When the acquisition module captures the voltage balancing data, fault response signals and state parameters fed back by the BMS, the time deviation is corrected by embedding a clock synchronization marker, so that the time difference between the signal output and the feedback capture is within the preset threshold. At the same time, the data type is unified, the dimension is normalized, the feedback data of a group of parameters beyond the reasonable range is judged as an abnormal value, and after being marked, it is temporarily stored in the abnormal database and associated with the working condition information;

[0123] The test module first confirms that the number of BMS monomer batteries in series is 16, the equalization starting threshold is 0.05V, the voltage difference gradient is set in an arithmetic sequence, the simulation voltage value of each monomer battery is allocated, and the maximum and minimum monomer voltage difference is ensured to be 0.06V. Synchronously collect the voltage change curve of each monomer battery in the equalization process, the equalization loop current 0.3A, the equalization duration 2.5 minutes and the BMS control chip power consumption, and dynamically adjust the acquisition frequency according to the current change rate. The simulation module divides the overcharge and short circuit faults into light faults, and the corresponding fault level coefficient is 0.3. The calculation gives the overcharge fault simulation voltage as 4.3V, and the short circuit fault simulation resistance as 0.2Ω. According to the single fault priority principle, the fault working condition is triggered;

[0124] After the verification module receives the BMS fault diagnosis feedback signal, the leakage diagnosis rate is calculated as 0, the misdiagnosis rate is 0, the actual response time is 0.2 seconds, the comprehensive evaluation value of the diagnosis performance is 98.6 points, which is higher than the threshold value, and it is determined that the fault diagnosis performance meets the requirements and generates a qualified report. The feedback module constructs a quantitative evaluation model, in which the balanced control performance score is 88 points, the fault diagnosis ability score is 98.6 points, the weight coefficient is set to 0.4, 0.6, the data fluctuation penalty coefficient is 1.2, the standard deviation of the repeated test score of the same working condition is 1.5, and the final comprehensive test score is calculated as 92.3 points, indicating that the balanced control and fault diagnosis comprehensive performance of the measured BMS is good.

[0125] In summary, in the above-mentioned embodiments, during the operation of the system, the rated parameters of the measured object and the real-time working conditions are dynamically adapted to generate simulation signals, feedback data is accurately captured and time alignment and standardization processing are completed, the data reliability is effectively guaranteed, the differentiated voltage scenarios and multi-level fault working conditions are constructed, the balanced control and fault diagnosis capabilities are comprehensively tested, the diagnosis performance is quantitatively evaluated in combination with the leakage diagnosis rate, the misdiagnosis rate and the response time, and the comprehensive score is generated relying on the multi-dimensional weight coefficient and the data fluctuation penalty mechanism, which objectively reflects the actual performance of the measured BMS, meets the differentiated needs of different test scenarios for dynamic characteristics and stability, and provides parameter calibration and horizontal comparison benchmark for similar product testing, significantly improves the test pertinence and comprehensiveness, and reduces the test error.

[0126] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A BMS comprehensive test system with fault diagnosis and balance control functions, characterized in that, The method comprises the following steps: A generating module is used to output custom voltage, current, and temperature simulation signals to the BMS under test; A collecting module is used to capture voltage balancing data, fault response signals, and state parameters fed back by the BMS under test in real time, and to synchronize the generation timing of signals with the feedback nodes of the BMS to complete data timing alignment and format standardization processing; A testing module is used to construct a monomer battery voltage differentiation simulation scenario, trigger the balancing function of the BMS under test, and synchronously collect dynamic data in the balancing process; An analog module is used to simulate fault working conditions such as overcharging, over-discharging, short circuit, overheating, monomer voltage imbalance, and communication interruption, and output fault trigger signals to the BMS under test; A verification module is used to receive diagnostic feedback signals output by the BMS under test in response to the simulated fault working conditions, compare the diagnostic results with the parameters of the simulated fault working conditions, and verify the diagnostic accuracy and response timeliness thereof; A feedback module is used to receive the operation data of the aforementioned modules, and construct a quantitative evaluation model of the balancing control performance and fault diagnosis capability; The aforementioned modules of the feedback module are the generating module, the collecting module, the testing module, the analog module, and the verification module; The custom voltage, current, and temperature simulation signals in the generating module are dynamically calculated based on the rated parameters, test targets, and real-time load characteristics of the BMS under test, wherein the output value of the voltage signal is: ； In the formula: is a custom voltage signal value generated by the module output; is the rated operating voltage of the measured BMS; is a weight coefficient; is a load coefficient, which is the ratio of the equivalent load resistance of the measured BMS to the rated load resistance; is a temperature compensation factor, , respectively represent the measured ambient temperature, the standard test temperature, the upper and lower limits of the allowable operating temperature of the measured BMS; is a test phase coefficient; The output value of the current signal and the output value of the voltage signal are subject to an Ohm's law correlation, and the value of the temperature simulation signal is dynamically corrected based on the power loss of the voltage and current signals and the environmental temperature; When the testing module constructs a monomer battery voltage differentiation simulation scenario, the number of monomer batteries connected in series and the balancing start threshold of the BMS under test are first obtained, and then the simulation voltage values of each monomer battery are allocated based on a preset voltage difference gradient; The voltage difference gradient is set in an arithmetic sequence, the voltage difference between adjacent gradients is within a preset interval, and the difference between the maximum monomer voltage and the minimum monomer voltage is not less than 1.2 times the balancing start threshold; The dynamic data collected by the testing module in the balancing process includes the voltage change curve of each monomer battery, the balancing loop current, the balancing duration, and the power consumption of the BMS control chip, and the collection frequency is dynamically adjusted according to the change rate of the balancing current, i.e., the greater the current change rate, the higher the collection frequency. 2.The BMS comprehensive test system with fault diagnosis and balance control functions according to claim 1, wherein, When the collecting module performs data timing alignment, the following is performed: When the generating module outputs simulation signals, a clock synchronization marker is embedded, and after the collecting module captures the feedback signals, the marker is extracted and the difference with the reference clock of the collecting module is calculated, the capture time record value is dynamically adjusted based on the difference to correct the time deviation, so that the time difference between the signal output and the feedback capture is within a preset threshold; The format standardization processing includes data type unification, dimension normalization, and abnormal value elimination, and the abnormal value determination logic is as follows: If the feedback data exceeds the theoretically reasonable range of the corresponding physical parameter, or the change rate of at least 3 groups of consecutive feedback data exceeds the preset trend threshold without a reasonable working condition trigger, it is determined as an abnormal value, which is temporarily stored in a preset abnormal database after being marked and associated with the corresponding working condition information. 3.The BMS comprehensive test system with fault diagnosis and balance control functions according to claim 1, characterized in that, The simulation module simulates each fault condition, and based on the harm degree, influence range and recovery difficulty of the fault on the operation safety of the BMS, divides three fault levels of mild, moderate and severe, and each level corresponds to a preset fault level coefficient wherein is a real number greater than zero, and the severe fault level coefficient is greater than the moderate fault level coefficient, and the moderate fault level coefficient is greater than the mild fault level coefficient; The parameters of the fault trigger signal are dynamically set based on the safety threshold, fault level, and level coefficient of the BMS under test: The simulation voltage of overcharge fault is the product of the overcharge protection threshold of the measured BMS and (1+ ×0.2); The analog voltage of over-discharge fault is the product of over-discharge protection threshold and (1- ×0.2); The short-circuit fault is realized by simulating a sudden change in loop resistance, and the short-circuit resistance value is the product of the normal working loop resistance of the measured BMS and (1 / (1+ ×5)); The simulated temperature for overheating faults increases at a linear rate, which is the sum of the preset baseline rate and (1 + ... The product of (×3), where the reference heating rate is preset based on the thermal diffusion characteristics of the measured BMS; The voltage deviation value of the single-cell voltage imbalance fault is the product of the voltage difference gradient maximum value and the voltage difference gradient minimum value. The interruption duration for communication interruption faults is the preset baseline interruption duration multiplied by (1+). The product of (×2) is used, and the baseline interruption duration is set according to the timeout judgment standard of the BMS communication protocol. The simulation module triggers the fault condition, subject to single fault priority, composite fault ordered combination constraint condition, composite fault triggers before confirming the level coefficient of each single fault without conflict, and the comprehensive level coefficient of the composite fault does not exceed the upper limit of the level coefficient corresponding to the severe fault. 4.The BMS comprehensive test system with fault diagnosis and balance control functions according to claim 1, wherein, When the verification module verifies the diagnostic accuracy and response timeliness, the comprehensive representation of diagnostic accuracy and response timeliness is quantified as: ； In the formula: is a diagnostic performance comprehensive evaluation value; is a missed diagnosis rate, i.e., a ratio of the number of simulated faults not recognized by the BMS to the total number of simulated faults; is a misdiagnosis rate, i.e., a ratio of the number of faults misjudged by the BMS to the total number of diagnostic results; , is a weight coefficient of missed diagnosis and misdiagnosis; is a response time influence factor; is an actual response time of the BMS; is a preset optimal response time; If D is not less than the preset diagnosis performance threshold, it is determined that the fault diagnosis performance of the measured BMS meets the test requirements, a qualified diagnosis report is generated and is synchronized to the feedback module; If D is less than the preset diagnosis performance threshold, it is determined that it does not meet the standard, and the corresponding fault type of missed diagnosis, misdiagnosis and the corresponding working condition of response time exceeding the standard are extracted to generate a substandard analysis report.

5. The BMS comprehensive test system with fault diagnosis and equalization control functions according to claim 1, characterized in that, The feedback module constructs a quantitative evaluation model, including an equalization control performance evaluation sub-model and a fault diagnosis capability evaluation sub-model, and outputs a comprehensive test score based on the quantitative evaluation model: ； In the formula: is a comprehensive test score; is a balanced control performance score, derived from a balanced control performance evaluation sub-model; is a fault diagnosis capability score, derived from a fault diagnosis capability evaluation sub-model; is a weight coefficient; is a data fluctuation penalty coefficient; is a standard deviation of the comprehensive test scores corresponding to a preset number of repetitions under the same test working condition. wherein, The greater the value of the measured BMS performance is better, The sum of the values of a and b is 1, and both are positive numbers, and . 6.The BMS comprehensive test system with fault diagnosis and balance control functions according to claim 5, wherein, The data fluctuation penalty coefficient The value is subject to: ； In the formula: is a confidence level factor; is a preset allowable data fluctuation threshold.

7. The BMS comprehensive test system with fault diagnosis and equalization control functions according to claim 5, characterized in that, the failure diagnostic capability score quantifying results in terms of a composite representation of diagnostic accuracy and response timeliness; the balanced control performance score The expression for the balanced control performance score is: ； In the formula: is a weight coefficient of balancing speed, balancing accuracy, and balancing energy consumption; is the balancing speed; is a preset optimal balancing speed; is a rated voltage of a single battery of the measured BMS; is a maximum voltage deviation value of all single batteries after balancing is completed; is a preset maximum and minimum allowed balancing energy consumption; is the total energy consumption of the balancing process. 8.The BMS comprehensive test system with fault diagnosis and balance control functions of claim 1, wherein, The generation module is connected with the acquisition module through wireless network interaction, the acquisition module is connected with the test module through wireless network interaction, the test module is connected with the simulation module and the verification module through wireless network interaction, and the verification module is connected with the feedback module through wireless network interaction.

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