Short circuit model determination method and control processing unit

Abstract

This application discloses a short-circuit model determination method and a control processing unit. The short-circuit model determination method is used to determine a short-circuit model applied to multiple devices. The method includes: upon receiving an update request, performing the following steps: updating a reference current sequence so that the detection threshold corresponding to the updated reference current sequence is greater than the detection threshold corresponding to the original reference current sequence; performing a short-circuit test based on a simulated current sequence, real-time current sequences of at least some of the multiple devices, and the updated reference current sequence, and obtaining test results, which are either a pass or a fail; if the test result is a pass, setting the updated reference current sequence as the short-circuit model; if the test result is a fail, setting a historical reference current sequence as the short-circuit model. Through the above method, the reliability of the short-circuit model can be improved from multiple aspects, thereby facilitating effective short-circuit protection.

Description

Technical Field

[0001] This application relates to the field of short-circuit identification technology, and in particular to a short-circuit model determination method and control processing unit. Background Technology

[0002] In electric vehicles, energy storage systems, and various high-power battery applications, short-circuit protection is a core mechanism for ensuring system safety, preventing thermal runaway, and extending battery life. With the increase in battery energy density and the increasing complexity of operating conditions, higher demands are placed on the real-time performance, accuracy, and adaptability of short-circuit detection. Currently, the overload protection schemes widely used in the industry are mainly based on fixed dual-threshold logic, and their specific implementations can be divided into hardware comparison circuit methods and software timer methods.

[0003] However, existing short-circuit protection strategies based on fixed thresholds have poor accuracy and lack adaptive adjustment capabilities, making it difficult to achieve effective short-circuit protection. Summary of the Invention

[0004] This application provides a short-circuit model determination method and control processing unit, which can improve the reliability of the short-circuit model from multiple aspects, thereby facilitating the realization of effective short-circuit protection.

[0005] In a first aspect, embodiments of this application provide a short-circuit model determination method for determining a short-circuit model applied to multiple devices. The method includes: upon receiving an update request, performing the following steps: updating a reference current sequence such that the detection threshold corresponding to the updated reference current sequence is greater than the detection threshold corresponding to the unupdated reference current sequence, wherein the reference current sequence includes multiple reference data, each reference data including a reference current value and its corresponding reference time; performing a short-circuit test based on a simulated current sequence, real-time current sequences of at least some of the multiple devices, and the updated reference current sequence, and obtaining test results, wherein the simulated current sequence includes multiple simulated data, each simulated data packet... The real-time current sequence includes a simulated current value and its corresponding simulated time. Each sampled data includes a current value and its corresponding sampling time from the sampled current. The time interval between two adjacent sampling times is equal to the time interval between two adjacent simulated times and the time interval between two adjacent reference times. The test result is either a pass or a fail. When the test result is a pass, the updated reference current sequence is set as a short-circuit model. When the test result is a fail, the historical reference current sequence is set as a short-circuit model. The historical reference current sequence is the latest reference current sequence used before the updated reference current sequence.

[0006] In one or more embodiments, updating the reference current sequence so that the detection threshold corresponding to the updated reference current sequence is greater than the detection threshold corresponding to the original reference current sequence includes: increasing the reference current value at at least one reference time in the reference current sequence to obtain the updated reference current sequence.

[0007] In one or more embodiments, a short-circuit test is performed based on a simulated current sequence, real-time current sequences of at least some of the multiple devices, and an updated reference current sequence, and a test result is obtained. This includes: performing a short-circuit test based on a test current sequence and an updated reference current sequence, wherein the test current sequence is a simulated current sequence; obtaining test indicators, wherein the test indicators include at least one of test accuracy, test false alarm rate, and test missed detection rate; determining the test result as a test failure when the test indicator meets condition i; and performing a short-circuit test based on the real-time current sequence of at least some of the multiple devices and an updated reference current sequence when the test indicator does not meet condition i, and obtaining a test result; wherein condition i is: the test accuracy is less than the historical accuracy, and / or, within a first preset time period, the difference between the test missed detection rate and the historical missed detection rate is greater than a first preset difference, and / or, the test false alarm rate is greater than K times the historical false alarm rate, wherein K is greater than 1.

[0008] In one or more embodiments, a short-circuit test is performed based on the real-time current sequences of at least some of the multiple devices and an updated reference current sequence, and a test result is obtained. This includes: performing a short-circuit test based on a test current sequence and an updated reference current sequence, wherein the test current sequence is the real-time current sequence of each device in a first target device group, and the first target device group includes at least two devices from a plurality of devices; obtaining test indicators corresponding to each device in the first target device group; determining the test result as a test failure when the test indicator corresponding to any device in the first target device group meets condition i; and performing a short-circuit test based on the real-time current sequences of each device in the plurality of devices and an updated reference current sequence when the test indicators corresponding to none of the devices in the first target device group do not meet condition i, and obtaining a test result.

[0009] In one or more embodiments, a short-circuit test is performed based on the real-time current sequence of each device in a plurality of devices and an updated reference current sequence, and the test result is obtained. This includes: dividing the plurality of devices into N parts, and sequentially designating one part of the N parts as a second target device group; performing a short-circuit test based on the test current sequence and the updated reference current sequence, wherein the test current sequence is the real-time current sequence of each device in the second target device group; obtaining the test index corresponding to each device in the second target device group; determining the test result as a test failure when the test index corresponding to any device in the second target device group meets condition i; and determining the test result as a test pass when the test index corresponding to each device in the plurality of devices does not meet condition i.

[0010] In one or more embodiments, the test accuracy being less than the historical accuracy includes: the test accuracy being less than the difference between a preset accuracy threshold and twice the standard deviation of the historical accuracy.

[0011] In one or more embodiments, after performing a short-circuit test based on an analog current sequence, real-time current sequences of at least some of the multiple devices, and an updated reference current sequence, and obtaining the test results, the method further includes: generating a version number of the updated reference current sequence according to the test time and a preset sequence number; and storing the version number, the updated reference current sequence, and the test results as a whole.

[0012] In one or more embodiments, short-circuit testing based on a test current sequence and an updated reference current sequence includes: normalizing the test current sequence to obtain a target test current sequence, and normalizing the updated reference current sequence to obtain a target reference current sequence; calculating the distance between the target test current sequence and the target reference current sequence; and determining that a short-circuit event has occurred if the ratio of the distance to the sequence length is less than a preset distance threshold, wherein the sequence length is the sum of the length of the target test current sequence and the length of the target reference current sequence.

[0013] In one or more embodiments, calculating the distance between a target test current sequence and a target reference current sequence includes: generating a local cost matrix based on the Euclidean distance between data in the target test current sequence and data in the corresponding target reference current sequence; determining a cumulative distance matrix based on the local cost matrix; and determining the distance based on the cumulative distance matrix.

[0014] In a second aspect, embodiments of this application provide a control processing unit, including: at least one processor and a memory; the memory is coupled to the processor and is used to store instructions or programs, which, when executed by at least one processor, cause at least one processor to perform the short-circuit model determination method as described in the first aspect.

[0015] The beneficial effects of this application are as follows: The short-circuit model determination method of this application embodiment includes: upon receiving an update request, performing the following steps: updating the reference current sequence so that the detection threshold corresponding to the updated reference current sequence is greater than the detection threshold corresponding to the original reference current sequence, wherein the reference current sequence includes multiple reference data, each reference data including a reference current value and its corresponding reference time; performing a short-circuit test based on the simulated current sequence, the real-time current sequence of at least some of the multiple devices, and the updated reference current sequence, and obtaining the test result, wherein the simulated current sequence includes multiple simulated data, each simulated data including a simulated current value and its corresponding simulated time, the real-time current sequence includes multiple sampled data, each sampled data including a current value in the sampled current and its corresponding sampled time, the time interval between two adjacent sampled times is equal to the time interval between two adjacent simulated times and the time interval between two adjacent reference times, and the test result is either a test pass or a test fail; when the test result is a test pass, setting the updated reference current sequence as the short-circuit model; when the test result is a test fail, setting the historical reference current sequence as the short-circuit model, wherein the historical reference current sequence is the latest reference current sequence used before the update of the reference current sequence. Thus, firstly, the reference current sequence is not fixed but can be updated according to needs, resulting in a reference current sequence applicable to the current operating conditions, thereby improving applicability and enhancing the reliability of the short-circuit model, which is conducive to achieving effective short-circuit protection. Secondly, the detection threshold corresponding to the updated reference current sequence is higher than that corresponding to the original reference current sequence, making it easier to detect smaller short-circuit currents, thereby improving sensitivity and enhancing the reliability of the short-circuit model, which is conducive to achieving effective short-circuit protection. Thirdly, the introduction of a short-circuit testing step ensures that any optimization strategy must be rigorously verified before going live, thereby improving effectiveness and enhancing the reliability of the short-circuit model, which is conducive to achieving effective short-circuit protection. Fourthly, the introduction of a rollback mechanism means that when the test fails, a historical reference current sequence is used as the short-circuit model, ensuring that the final short-circuit model is always a known safe and stable model, thus improving the reliability of the short-circuit model from both safety and stability perspectives, which is conducive to achieving effective short-circuit protection. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0017] Figure 1This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 1 ;

[0018] Figure 2 This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 2 ;

[0019] Figure 3 This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 3 ;

[0020] Figure 4 This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 4 ;

[0021] Figure 5 This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 5 ;

[0022] Figure 6 This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 6 ;

[0023] Figure 7 This is the flowchart of the short-circuit model determination method provided in the embodiments of this application. Figure 7 ;

[0024] Figure 8 This is a schematic diagram of the control processing unit provided in the embodiments of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described clearly and in detail below with reference to the accompanying drawings. Obviously, the embodiments in this application are only some embodiments, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0026] It should be noted that when an element is described as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements between them.

[0027] Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0028] In related technologies, the short-circuit protection schemes are mainly based on fixed dual-threshold logic, and their specific implementation forms can be divided into hardware comparison circuit method and software timer method.

[0029] Hardware Comparison Circuit Method: This scheme uses an analog comparator as the core execution unit. The system compares the voltage drop across the sampling resistor (proportional to the loop current) with a fixed reference voltage (corresponding to the current threshold) in real time. Once the current exceeds the current threshold, a retrievable monostable timer is triggered. If the current fails to fall below another lower fixed threshold within a preset delay time, the system determines that a short circuit event has occurred and performs protective actions (such as disconnecting the loop).

[0030] Software timer method: This scheme relies on the digital processing capabilities of the microcontroller. The microcontroller acquires the battery circuit current signal in real time through an analog-to-digital converter. Its control logic is as follows: when the sampled current value continuously exceeds a preset fixed threshold and the duration reaches a set value, the software algorithm determines that a short circuit event has occurred, and then issues a protection command.

[0031] While the above solutions offer some protection under normal operating conditions, they reveal significant technical bottlenecks when faced with the dynamic changes and complex load characteristics throughout the battery's lifecycle.

[0032] (1) In order to ensure that the real short circuit risk can still be reliably detected throughout the entire battery life cycle (especially after aging leads to an increase in internal resistance), the threshold must be set relatively low. However, in order to avoid false triggering caused by normal instantaneous large currents such as motor start-up and capacitor charging impact, the threshold must be set high enough to leave a safety margin. This contradiction makes it difficult for the system to find the optimal balance between "not missing real short circuits" and "not falsely reporting normal impacts", and often only a compromise solution can be adopted, sacrificing some protection accuracy, thus making it difficult to achieve effective short circuit protection.

[0033] (2) The fixed threshold and delay parameters calibrated at the factory cannot be dynamically adjusted. This leads to performance degradation of the protection system in the later stages of the equipment's life cycle: either it becomes "sluggish" due to the relatively high threshold, failing to intercept risks in the early stages; or it becomes "oversensitive" due to the decreased battery tolerance, affecting system availability. It is evident that the existing short-circuit protection strategy based on fixed thresholds lacks adaptive adjustment capabilities, making it difficult to meet the refined protection requirements of the new generation of high-safety, long-life battery systems, thus making it difficult to achieve effective short-circuit protection.

[0034] Based on this, this application provides a short-circuit model determination method to improve the reliability of the short-circuit model from multiple aspects, thereby achieving effective short-circuit protection.

[0035] Please refer to Figure 1 , Figure 1This is a flowchart illustrating a short-circuit model determination method provided in an embodiment of this application. The method determines a short-circuit model applicable to multiple devices, where any two devices can be the same or different devices. For example, in one specific embodiment, all devices are batteries, each including a cell module and a battery management system. Each cell module includes at least one cell. When a cell module includes multiple cells, these cells can be connected in parallel, series, or a combination thereof, with the latter including both series and parallel connections. The cell module stores and provides electrical energy. The battery management system is electrically connected to the cell module and determines whether a short-circuit event has occurred in the cell module based on the cell module's current and the short-circuit model determined by the method.

[0036] like Figure 1 As shown, the short-circuit model determination method first determines whether an update request has been received. Only when an update request is received are steps S110 to S140 executed. In one specific embodiment, the update request is issued by an operator, for example, by pressing a pre-configured button to output the update request. The update request is a clear control command signal indicating that the update process of the reference current sequence (i.e., the implementation process of the short-circuit model determination method) is carried out in a controlled, non-client environment. That is, the current stage is the test stage before being loaded onto the client, thereby intercepting all potential risks in the update process during the test stage.

[0037] Step S110: Update the reference current sequence so that the detection threshold corresponding to the updated reference current sequence is greater than the detection threshold corresponding to the original reference current sequence. The reference current sequence includes multiple reference data, and each reference data includes a reference current value and its corresponding reference time.

[0038] Specifically, by updating the reference current sequence according to demand, a reference current sequence applicable to the current operating conditions can be obtained, thereby improving applicability. This improved applicability enhances the reliability of the short-circuit model and facilitates effective short-circuit protection.

[0039] The detection threshold corresponding to the updated reference current sequence is greater than that corresponding to the original reference current sequence. This means that the updated reference current sequence is more sensitive to the triggering conditions of short-circuit events, i.e., it is easier to detect short-circuit times with small currents, thereby improving sensitivity. This improved sensitivity enhances the reliability of the short-circuit model and is beneficial for achieving effective short-circuit protection.

[0040] In some embodiments, the specific implementation process of step S110 includes the following steps: increasing the reference current value at at least one reference time in the reference current sequence to obtain an updated reference current sequence.

[0041] Specifically, the reference current sequence So1 is: So1 = [(reference time Ta1, reference current value Ia1), (reference time Ta2, reference current value Ia2), ..., (reference time TaM, reference current value IaM)], where M is an integer greater than 1, meaning the length of the reference current sequence So1 is M. A reference data set includes a reference current value and its corresponding reference time; for example, (reference time Ta1, reference current value Ia1) is a reference data set.

[0042] The updated reference current sequence So2 is: So2 = [(reference time Tb1, reference current value Ib1), (reference time Tb2, reference current value Ib2), ..., (reference time TbM, reference current value IbM)], where the length of the reference current sequence So2 is M. Reference time Ta1 = reference time Tb1, reference time Ta2 = reference time Tb2, ..., reference time TaM = reference time TbM.

[0043] Increasing the reference current value at at least one reference time in the reference current sequence (while keeping the reference current values ​​unchanged) means that reference current value Ib1 ≥ reference current value Ia1, reference current value Ib2 ≥ reference current value Ia2, ..., reference current value IbM ≥ reference current value IaM. For example, taking the case where only the reference current value Ib1 at reference time Ta1 is increased, then reference current value Ib1 > reference current value Ia1, reference current value Ib2 = reference current value Ia2, reference current value Ib3 = reference current value Ia3, ..., reference current value IbM = reference current value IaM.

[0044] This ensures that the detection threshold of the short-circuit model for short-circuit current only increases and never decreases, thereby maintaining or improving sensitivity. This helps prevent the short-circuit model from becoming "sluggish" due to updates, making it particularly suitable for characteristic drift caused by battery aging or environmental changes.

[0045] Step S120: Perform a short-circuit test based on the simulated current sequence, the real-time current sequence of at least some of the multiple devices, and the updated reference current sequence, and obtain the test result. The simulated current sequence includes multiple simulated data, each of which includes a simulated current value and its corresponding simulated time. The real-time current sequence includes multiple sampled data, each of which includes a current value in the sampled current and its corresponding sampled time. The time interval between two adjacent sampled times is equal to the time interval between two adjacent simulated times and the time interval between two adjacent reference times. The test result is either a pass or a fail.

[0046] The simulated current sequence Eo is defined as: Eo = [(simulation time Tc1, simulated current value Ic1), (simulation time Tc2, simulated current value Ic2), ..., (simulation time TcJ, simulated current value IcJ)], where J is an integer greater than 1, indicating that the length of the simulated current sequence Eo is J. A simulated data set includes a simulated current value and its corresponding simulation time; for example, (simulation time Tc1, simulated current value Ic1) is a simulated data set. The simulated current sequence Eo refers to a series of virtual current waveform data synthesized by an algorithm in a simulated environment.

[0047] The real-time current sequence Ro is: Ro = [(sampling time Td1, sampled current value Id1), (sampling time Td2, sampled current value Id2), ..., (sampling time TdL, sampled current value IdL)], where L is an integer greater than 1, meaning the length of the real-time current sequence Ro is L. A sampled data point includes a current value (i.e., the sampled current value) and its corresponding sampling time. For example, (sampling time Ts1, sampled current value Is1) is a sampled data point.

[0048] The sampling method of the real-time current sequence Ro can be set according to the actual application scenario, as long as the final sequence is aligned with the time axis of the reference current sequence So1. For example, in a specific embodiment, the reference current sequence So1 is set as So1=[(0,0),(20,300),…,(20(M-1),300(M-1))], and during sampling, sampling is first performed at a fixed frequency of 1MHz, that is, the current value is sampled once every 1μs to obtain the original sampling sequence. Then, new sequence points are extracted or interpolated at 20μs intervals. For example, an average value is calculated for every 20 points of the original sampling sequence, so that the real-time current sequence Ro can be obtained as: Ro=[(0, sampled current value Id1),(20, sampled current value Id2),…,(20(L-1), sampled current value IrL)].

[0049] The time interval between two adjacent sampling times is equal to the time interval between two adjacent simulation times and the time interval between two adjacent reference times. For example, the time interval between sampling times Td1 and Td2 equals the time interval between simulation times Tc1 and Tc2, which equals the time interval between reference times Ta1 and Ta2. By setting the time interval between two adjacent sampling times to be equal to the time interval between two adjacent simulation times and the time interval between two adjacent reference times, time axis alignment can be achieved, thereby reducing potential distance calculation errors.

[0050] In this embodiment, by introducing a short-circuit testing step, it is ensured that any optimization strategy must be rigorously verified before going live, thereby improving its effectiveness. This improved effectiveness also enhances the reliability of the short-circuit model, which is beneficial for achieving effective short-circuit protection.

[0051] In one specific embodiment, such as Figure 2 As shown, the specific implementation process of step S120 includes the following steps S210 to S240.

[0052] Step S210: Perform a short-circuit test based on the test current sequence and the updated reference current sequence, wherein the test current sequence is a simulated current sequence.

[0053] Short-circuit testing based on the test current sequence and the updated reference current sequence refers to the testing process that determines whether a short-circuit event has occurred based on the test current sequence and the updated reference current sequence.

[0054] In some embodiments, such as Figure 3 As shown, the specific implementation process of step S210 includes the following steps S310 to S330.

[0055] Step S310: Normalize the test current sequence to obtain the target test current sequence, and normalize the updated reference current sequence to obtain the target reference current sequence.

[0056] Specifically, by normalizing the test current sequence and the reference current sequence, the difference in absolute current values ​​can be prevented from dominating the distance calculation.

[0057] In some embodiments, the normalization process includes Z-score normalization or min-max normalization. Taking min-max normalization as an example, for a sequence X = [x1, x2, ...], the formula for min-max normalization is: .

[0058] In this embodiment, the test current sequence is a simulated current sequence Eo. Assuming that in a specific embodiment, the simulated current sequence Eo is: Eo=[(0, 95), (20, 225), (40, 405), (60, 635), (80, 905), (100, 950)], where the minimum current value is 95A and the maximum value is 950A, substituting into the above minimum-maximum normalization formula, the target test current sequence Eo_norm is: Ro_norm=[(0, 000), (20, 0.152), (40, 0.363), (60, 0.632), (80, 0.947), (100, 1.000)]. The updated reference current sequence So2 is: So2=[(0,0),(20,300),(40,600),(60,900),(80,1200),(100,1500)], where the minimum current value is 0A and the maximum value is 1500A. Substituting these values ​​into the minimum-maximum normalization formula, the target reference current sequence So_norm is: So2_norm=[(0,0.000),(20,0.200),(40,0.400),(60,0.600),(80,0.800),(100,1.000)]. Thus, after normalization, all current values ​​fall within the [0,1] interval, which helps to ensure that the distances calculated subsequently better reflect waveform shape differences rather than absolute amplitude magnitude.

[0059] Step S320: Calculate the distance between the target test current sequence and the target reference current sequence.

[0060] Specifically, by calculating the distance between the target test current sequence and the target reference current sequence, the similarity between the target test current sequence and the target reference current sequence can be determined, thereby determining whether a short circuit event has occurred.

[0061] In some embodiments, such as Figure 4 As shown, the specific implementation process of step S320 includes the following steps S410 to S430.

[0062] Step S410: Generate a local cost matrix based on the Euclidean distance between the data in the target test current sequence and the data in the corresponding target reference current sequence.

[0063] Step S420: Determine the cumulative distance matrix based on the local cost matrix.

[0064] Step S430: Determine the distance based on the cumulative distance matrix.

[0065] Elements in the local cost matrix for: ,in, For the nth data point in the target test current sequence Eo_norm, based on the length J of the simulated current sequence Eo mentioned in the previous embodiment, the length of the target real-time current sequence Eo_norm is J, i.e., n=1, 2, ...J; Let So2_norm be the m-th data in the target reference current sequence. According to the previous embodiment, the length of the updated reference current sequence So2 is M, then the length of the target reference current sequence So2_norm is M, i.e., m=1, 2, ...M.

[0066] Taking Eo_norm=[(0, 000), (20, 0.152), (40, 0.363), (60, 0.632), (80, 0.947), (100, 1.000)] and So2_norm=[(0, 0.000), (20, 0.200), (40, 0.400), (60, 0.600), (80, 0.800), (100, 1.000)] as an example, the calculated values ​​are... As shown in Table 1 below:

[0067] Table 1

[0068]

[0069] Then, based on the local cost matrix, the elements of the following cumulative distance matrix are obtained. :

[0070]

[0071] Based on Table 1, the calculations obtained are as follows: As shown in Table 2 below:

[0072] Table 2

[0073]

[0074] The element D(6, 6) = 0.0264 in the lower right corner of Table 2 represents the distance between the target test current sequence Eo_norm and the target reference current sequence So2_norm, indicating the cumulative difference under optimal time planning. Specifically, the distance between the target test current sequence Eo_norm and the target reference current sequence So2_norm is denoted as D(J, M). The smaller D(J, M), the more similar the waveforms of the target test current sequence Eo_norm and the target reference current sequence So2_norm.

[0075] Step S330: If the ratio of distance to sequence length is less than a preset distance threshold, a short circuit event is determined to have occurred, wherein the sequence length is the sum of the length of the target test current sequence and the length of the target reference current sequence.

[0076] Specifically, firstly, the distance D(J, M) is divided by the sum of the lengths of the target test current sequence Eo_norm (denoted as J according to the aforementioned embodiment) and the target reference current sequence So2_norm (denoted as M according to the aforementioned embodiment) (i.e., the sequence length, which is equal to J+M) to obtain the normalized distance ds, i.e., ds=D(J,M) / (J+M), to eliminate the influence of the sequence length on the absolute value of the distance. Then, the normalized distance ds is compared with a preset distance threshold. If it is less than the preset distance threshold, it is determined that the waveforms of the target test current sequence Eo_norm and the target reference current sequence So2_norm are relatively similar, thus confirming that a short circuit event has occurred; of course, if it is greater than or equal to the preset distance threshold, it is determined that no short circuit event has occurred.

[0077] Step S220: Obtain test metrics, wherein the test metrics include at least one of test accuracy, test false positive rate, and test false negative rate.

[0078] Specifically, the test accuracy rate is the ratio of the number of times a short circuit event is detected to the actual number of short circuit events when monitoring for actual short circuit events. For example, in a specific embodiment, if 1000 actual short circuit events are monitored, and 900 short circuit events are detected by executing step S210, the test accuracy rate is 900 / 1000 = 90%.

[0079] The false alarm rate is the ratio of the number of times a short circuit event is detected to the number of times a real non-short circuit event occurs when monitoring real non-short circuit events. For example, in a specific embodiment, if 1000 real non-short circuit events are monitored, and the number of times a short circuit event is detected by executing step S210 is 8, the false alarm rate is 8 / 1000 = 0.8%.

[0080] The false negative rate is the ratio of the number of short-circuit events that are missed (i.e., short-circuit events actually occurred but were not detected) to the total number of actual short-circuit events when monitoring for actual short-circuit events. For example, in a specific embodiment, if 1000 actual short-circuit events are monitored, and 12 short-circuit events are missed by executing step S210, the false negative rate is 12 / 1000 = 1.2%.

[0081] Step S230: When the test index meets condition i, the test result is determined to be a test failure, wherein condition i is: the test accuracy is less than the historical accuracy, and / or, within the first preset time period, the difference between the test false negative rate and the historical false negative rate is greater than the first preset difference, and / or, the test false positive rate is greater than K times the historical false positive rate, wherein K is greater than 1.

[0082] Specifically, the historical accuracy rate is the accuracy rate of the currently used short-circuit model. This means the current step is still in the testing phase, and the short-circuit model will only be updated after steps S130 to S140 are executed. A test accuracy rate lower than the historical accuracy rate defines a performance degradation state, indicating that the system's current performance has failed to reach its established baseline level, system reliability has decreased, and the current decision is unreliable. Based on this, the test result should be determined as a test failure.

[0083] In one specific embodiment, the specific implementation process of the test accuracy being less than the historical accuracy includes: the test accuracy being less than the difference between a preset accuracy threshold and twice the standard deviation of the historical accuracy.

[0084] Right now , where A V To test accuracy, A threshold To preset the accuracy threshold, This represents the standard deviation of historical accuracy. For example, in a specific implementation, the standard deviation of historical accuracy... Preset accuracy threshold If the test accuracy ,but In this case, the test result is determined to be a failure.

[0085] The historical missed detection rate is the missed detection rate of the currently used short-circuit model. If, within a first preset time period, the difference between the test missed detection rate and the historical missed detection rate exceeds a first preset difference, it means that, within a specified recent time window or sample batch, the proportion of missed defects in the system has increased significantly and beyond the allowable range compared to its historical baseline. This increase exceeds a preset safety threshold, indicating that the effectiveness of the test system is rapidly declining and there is a serious quality risk. Based on this, the test result should be determined as a test failure.

[0086] For example, in one specific embodiment, the first preset difference is set to 0.1%, and the historical missed detection rate is 0.05%. Within a first preset time period, 1000 real short-circuit events are monitored based on the updated reference current sequence. The result is 12 missed detections, resulting in a test missed detection rate of 1.2%. The difference between the test missed detection rate and the historical missed detection rate is 1.2% - 0.05% = 1.15%, which far exceeds the threshold of 0.1%. In this case, the test result is determined to be a test failure.

[0087] The historical false alarm rate is the false alarm rate of the currently used short-circuit model. A test false alarm rate greater than K times the historical false alarm rate indicates a significant and unexpected deterioration in the system's current operating state. Based on this, the test result should be determined as a failure.

[0088] For example, in one specific embodiment, K is set to 2, and the historical false alarm rate is 0.03%. Based on the updated reference current sequence, 100,000 non-short-circuit events are monitored cumulatively. The result is 800 false alarms, resulting in a test false alarm rate of 0.8%. 0.8% > 0.06% (0.03% × 2), meaning the test false alarm rate is greater than twice the historical false alarm rate. In this case, the test result is determined to be a failure.

[0089] Step S240: When the test index does not meet condition i, perform a short-circuit test based on the real-time current sequence of at least some of the multiple devices and the updated reference current sequence, and obtain the test results.

[0090] Specifically, if the test metric does not meet condition i, it means that the test accuracy is greater than or equal to the historical accuracy, and within a first preset time period, the difference between the test false negative rate and the historical false negative rate is less than or equal to a first preset difference, and the test false alarm rate is less than or equal to K times the historical false alarm rate. In this case, the updated reference current sequence can be tested using at least some of the multiple devices to further determine whether the updated reference current sequence is effective and reliable.

[0091] In some embodiments, such as Figure 5 As shown, the specific implementation process of step S240 includes the following steps S510 to S540.

[0092] Step S510: Perform a short-circuit test based on the test current sequence and the updated reference current sequence, wherein the test current sequence is the real-time current sequence of each device in the first target device group, and the first target device group includes at least two devices from a plurality of devices.

[0093] Step S520: Obtain the test indicators corresponding to each device in the first target device group.

[0094] Step S530: When the test index corresponding to any device in the first target device group meets condition i, the test result is determined to be test failure.

[0095] Step S540: When the test indicators corresponding to each device in the first target device group do not meet condition i, a short-circuit test is performed based on the real-time current sequence of each device in the multiple devices and the updated reference current sequence, and the test results are obtained.

[0096] Specifically, the first target device group includes at least two devices from a plurality of devices, for example, the first target device group includes 10% of the devices from a plurality of devices, in order to enable a small-scale testing process.

[0097] Each device in the first target device group corresponds to a real-time current sequence. A short-circuit test is performed individually based on each real-time current sequence. This yields the test metrics for each device, determining whether each device passes the test. Specifically, if the test metrics of any device in the first target device group meet condition i, the test result for the first target device group is determined to be a failure. Only when the test metrics of all devices in the first target device group fail condition i is the test result for the first target device group determined to be a pass, allowing subsequent steps to be performed: short-circuit testing is conducted based on the real-time current sequences of each device and the updated reference current sequence, and the test results are obtained.

[0098] The specific implementation processes of steps S510 to S540 are similar to those of steps S210 to S240. For example, the specific implementation process of step S510 includes steps S310 to S330, which can be referred to in the description of steps S210 to S240, and are within the scope easily understood by those skilled in the art. The only difference is that in this embodiment, the test current sequence is the real-time current sequence of each device in the first target device group, that is, the analog current sequence in steps S210 to S240 is replaced with the real-time current sequence of each device in the first target device group.

[0099] In some embodiments, such as Figure 6 As shown, the specific implementation process of step S540 includes the following steps S610 to S650.

[0100] Step S610: Divide the multiple devices into N parts, and set one part of the N parts as the second target device group in turn.

[0101] Step S620: Perform a short-circuit test based on the test current sequence and the updated reference current sequence, wherein the test current sequence is the real-time current sequence of each device in the second target device group.

[0102] Step S630: Obtain the test indicators corresponding to each device in the second target device group.

[0103] Step S640: When the test index corresponding to any device in the second target device group meets condition i, the test result is determined to be test failure.

[0104] Step S650: If none of the test indicators for each of the multiple devices meet condition i, the test result is determined to be a pass.

[0105] Specifically, the multiple devices include a first part of devices, a second part of devices, ..., an Nth part of devices, where N is an integer greater than 1. Each part of devices includes at least one device, that is, the first part of devices includes at least one device, the second part of devices includes at least one device, ..., the Nth part of devices includes at least one device.

[0106] First, designate the first group of devices as the second target device group, and then execute steps S620 and S630. If the test index corresponding to any device in the second target device group meets condition i, the test is directly determined to be unsuccessful. If the test index corresponding to any device in the second target device group does not meet condition i, the test of the first group of devices is determined to be successful.

[0107] Next, the second group of devices is designated as the second target device group, and steps S620 and S630 are executed. If the test index corresponding to any device in the second target device group meets condition i, the test is directly determined to be unsuccessful. If the test index corresponding to any device in the second target device group does not meet condition i, the test of the second group of devices is determined to be successful.

[0108] Next, the third set of devices is designated as the second target device group, and steps S620 and S630 are executed. If the test index corresponding to any device in the second target device group meets condition i, the test is directly determined to be unsuccessful. If the test index corresponding to any device in the second target device group does not meet condition i, the test of the third set of devices is determined to be successful.

[0109] Then, the third part of the equipment is set as the second target equipment group, and then steps S620 and S630 are executed... and so on. If the first part of the equipment, the second part of the equipment, ..., the Nth part of the equipment all pass the test, then the final test result is determined to be a test pass.

[0110] In this way, it is possible to test all devices in multiple devices in a rolling testing manner (i.e., a batch, progressive testing method). This can achieve the testing process of all devices while avoiding the complete paralysis that may be caused by instantaneous switching, thereby effectively reducing the testing risk.

[0111] The specific implementation process of steps S610 to S640 is similar to that of steps S210 to S240. For example, the specific implementation process of step S610 includes steps S310 to S330, which can be referred to in the description of steps S210 to S240, and is within the scope easily understood by those skilled in the art. The only difference is that in this embodiment, the test current sequence is the real-time current sequence of each device in the second target device group, that is, the analog current sequence in steps S210 to S240 is replaced with the real-time current sequence of each device in the second target device group.

[0112] In some embodiments, such as Figure 7 As shown, after performing step S120, the short-circuit model determination method further includes the following steps S710 to S720.

[0113] Step S710: Generate the version number of the updated reference current sequence based on the test time and preset sequence number.

[0114] Step S720: Store the version number, the updated reference current sequence, and the test results as a whole.

[0115] Specifically, the version number consists of a test time and a preset serial number. The test time can be a timestamp accurate to the second, such as January 29, 2026, 15:43:27 (represented as 20260129154327). The preset serial number is a pre-set serial number (such as 001, 002, etc.) to be used for multiple updates within the same second, helping to prevent conflicts. The resulting version number serves as a unique identifier for the short-circuit model, ensuring global uniqueness and temporal sequence, which helps the system quickly identify and compare different versions.

[0116] Subsequently, storing the version number, the updated reference current sequence, and the test results as a whole facilitates quick version lookup, comparison, and rollback in subsequent updates.

[0117] Step S130: When the test result is a pass, set the updated reference current sequence as a short-circuit model.

[0118] Specifically, a test result indicating that the test passed means that the updated reference current sequence is accurate and reliable. In this case, the updated reference current sequence is set as a short-circuit model and applied to actual application scenarios. This allows actual application scenarios to adopt the latest short-circuit model, which is beneficial to improving the adaptability and accuracy of the detection.

[0119] Step S140: When the test result is that the test fails, the historical reference current sequence is set as a short-circuit model, wherein the historical reference current sequence is the latest reference current sequence used before the reference current sequence is updated.

[0120] Specifically, a test failure indicates that the updated reference current sequence is unreliable, inaccurate, or unsafe. In this case, the updated reference current sequence should be replaced by a newer, short-circuit-based historical reference current sequence (i.e., the older version before the update). The historical reference current sequence refers to the latest (most recently effective) reference current sequence used by the system before the generation of the updated reference current sequence. This historical reference current sequence represents a validated, stable sequence from the previous version and serves as a safe backup before the update operation.

[0121] In this way, a version rollback mechanism is implemented to ensure that the system always uses a known and reliable short-circuit model for protection, preventing the protection function from failing due to abnormal short-circuit model updates. This ensures that the short-circuit model used in the end is always a known, safe, and stable model, which helps to improve the reliability of the short-circuit model and achieve effective short-circuit protection.

[0122] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the control processing unit provided in an embodiment of this application. The control processing unit 800 may be a microcontroller unit (MCU) or a digital signal processing (DSP) controller, etc.

[0123] The control processing unit 800 includes at least one processor 810 and a memory 820. The memory 820 can be built into the control processing unit 800 or external to the control processing unit 800. The memory 820 can also be a remotely configured memory connected to the control processing unit 800 via a network.

[0124] Memory 820, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. Memory 820 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on terminal usage, etc. Furthermore, memory 820 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 820 may optionally include memory remotely located relative to processor 810, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0125] The processor 810 performs various functions of the terminal and processes data by running or executing software programs and / or modules stored in the memory 820 and calling data stored in the memory 820, thereby performing overall monitoring of the terminal, such as implementing the short-circuit model determination method described in any embodiment of this application.

[0126] There can be one or more processors 810. Figure 8 The example provided uses a processor 810. The processor 810 and memory 820 can be connected via a bus or other means. The processor 810 may include a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field-programmable gate array (FPGA) device, etc. The processor 810 can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0127] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0128] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for determining a short-circuit model, characterized in that, The method for determining a short-circuit model applicable to multiple devices includes: Upon receiving an update request, perform the following steps: The reference current sequence is updated so that the detection threshold corresponding to the updated reference current sequence is greater than the detection threshold corresponding to the unupdated reference current sequence. The reference current sequence includes multiple reference data, and each reference data includes a reference current value and its corresponding reference time. A short-circuit test is performed based on a simulated current sequence, a real-time current sequence of at least some of the plurality of devices, and an updated reference current sequence, and a test result is obtained. The simulated current sequence includes multiple simulated data, each of which includes a simulated current value and its corresponding simulated time. The real-time current sequence includes multiple sampled data, each of which includes a current value in the sampled current and its corresponding sampled time. The time interval between two adjacent sampled times is equal to the time interval between two adjacent simulated times and the time interval between two adjacent reference times. The test result is either a pass or a fail. When the test result is a pass, the updated reference current sequence is set as the short-circuit model; When the test result is a test failure, the historical reference current sequence is set as the short-circuit model, wherein the historical reference current sequence is the latest reference current sequence used before updating the reference current sequence; The step of updating the reference current sequence to make the detection threshold corresponding to the updated reference current sequence greater than the detection threshold corresponding to the unupdated reference current sequence includes: The reference current value at at least one reference moment in the reference current sequence is increased to obtain the updated reference current sequence, thereby ensuring that the detection threshold of the short-circuit model for short-circuit current only increases and does not decrease. The short-circuit test is performed based on the simulated current sequence, the real-time current sequences of at least some of the plurality of devices, and the updated reference current sequence, and the test results are obtained, including: A short-circuit test is performed based on the test current sequence and the updated reference current sequence, wherein the test current sequence is the simulated current sequence; Obtain test metrics, wherein the test metrics include at least one of test accuracy, test false positive rate, and test false negative rate; When the test metric meets condition i, the test result is determined to be a test failure; When the test index does not meet condition i, a short-circuit test is performed based on the real-time current sequence of at least some of the multiple devices and the updated reference current sequence, and the test result is obtained. Wherein, condition i is: the test accuracy rate is less than the historical accuracy rate, and / or, within a first preset time period, the difference between the test false negative rate and the historical false negative rate is greater than a first preset difference, and / or, the test false positive rate is greater than K times the historical false positive rate, where K is greater than 1.

2. The method of claim 1, wherein, The short-circuit test is performed based on the real-time current sequence of at least some of the plurality of devices and the updated reference current sequence, and the test results are obtained, including: A short-circuit test is performed based on the test current sequence and the updated reference current sequence, wherein the test current sequence is the real-time current sequence of each device in the first target device group, and the first target device group includes at least two devices among the plurality of devices; Obtain the test indicators corresponding to each device in the first target device group; When the test index corresponding to any device in the first target device group meets condition i, the test result is determined to be a test failure. When the test indicators corresponding to each device in the first target device group do not meet condition i, a short-circuit test is performed based on the real-time current sequence of each device and the updated reference current sequence, and the test result is obtained.

3. The method of claim 2, wherein, The short-circuit test is performed based on the real-time current sequence of each of the plurality of devices and the updated reference current sequence, and the test results are obtained, including: The multiple devices are divided into N parts, and one part of each of the N parts is set as the second target device group. A short-circuit test is performed based on the test current sequence and the updated reference current sequence, wherein the test current sequence is the real-time current sequence of each device in the second target device group; Obtain the test indicators corresponding to each device in the second target device group; When the test index corresponding to any device in the second target device group meets condition i, the test result is determined to be a test failure. If none of the test indicators for any of the multiple devices meet condition i, the test result is determined to be a pass.

4. The method according to any one of claims 1 to 3, characterized in that, The test accuracy being less than the historical accuracy includes: the test accuracy being less than the difference between a preset accuracy threshold and twice the standard deviation of the historical accuracy.

5. The method according to claim 1, characterized in that, After performing a short-circuit test based on the simulated current sequence, the real-time current sequences of at least some of the plurality of devices, and the updated reference current sequence, and obtaining the test results, the method further includes: Based on the test time and preset sequence number, an updated version number of the reference current sequence is generated; The version number, the updated reference current sequence, and the test results are stored as a whole.

6. The method according to any one of claims 1-3, characterized in that, The short-circuit test based on the test current sequence and the updated reference current sequence includes: The test current sequence is normalized to obtain a target test current sequence, and the updated reference current sequence is normalized to obtain a target reference current sequence. Calculate the distance between the target test current sequence and the target reference current sequence; If the ratio of the distance to the sequence length is less than a preset distance threshold, a short circuit event is determined to have occurred, wherein the sequence length is the sum of the length of the target test current sequence and the length of the target reference current sequence.

7. The method of claim 6, wherein, The calculation of the distance between the target test current sequence and the target reference current sequence includes: A local cost matrix is ​​generated based on the Euclidean distance between the data in the target test current sequence and the corresponding data in the target reference current sequence; Based on the local cost matrix, determine the cumulative distance matrix; The distance is determined based on the cumulative distance matrix.

8. A control processing unit, characterized by include: At least one processor and memory; The memory is coupled to the processor and is used to store instructions or programs that, when executed by the at least one processor, cause the at least one processor to perform the short-circuit model determination method as described in any one of claims 1-7.

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