Insulation detection method and device for energy storage system

Abstract

The invention relates to the technical field of energy storage system testing, in particular to an insulation detection method and device for an energy storage system. The method comprises the steps that first insulation detection operation is executed before the energy storage system is started, the first insulation detection operation comprises the steps that insulation detection is conducted on battery clusters and an energy storage converter in sequence, whether insulation faults exist in the battery clusters and the energy storage converter or not is judged in sequence according to the detection result, and if yes, starting of the energy storage system is forbidden; in response to startup of the energy storage system, executing a second insulation detection operation, performing one-time polling insulation detection on each battery cluster and the energy storage converter by the second insulation detection operation, judging whether each battery cluster and the energy storage converter have an insulation fault according to a detection result, and if yes, controlling the energy storage system to be shut down; according to the method, insulation detection is carried out twice before and after the energy storage system runs, so that the problem that the safety is reduced in the running process due to the change of the insulation performance when the energy storage system is started is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage system testing, and in particular to an insulation detection method and device for an energy storage system. Background Art

[0002] The energy storage system releases electricity during peak hours of power consumption and stores electricity during low hours of power consumption, which can help the power grid balance the peak-valley difference. The energy storage system has to deal with high-power input or output. Once an insulation failure occurs in an internal component, it is likely to cause significant losses. Therefore, it is necessary to regularly test the insulation performance of the energy storage system and replace components with unqualified insulation performance in a timely manner to prevent insulation accidents.

[0003] At present, insulation testing is usually started when the energy storage system is at rest, so that there is sufficient testing time for insulation testing and accurate insulation test results can be obtained; only after the insulation test is normal, the energy storage system will be controlled to start charging and discharging. However, when the energy storage system is started, it may be affected by the power grid and the insulation performance may change, but the energy storage system cannot be tested again, resulting in reduced safety during the operation of the energy storage system. Summary of the invention

[0004] Based on this, it is necessary to provide an insulation detection method and device for an energy storage system to address the above technical issues.

[0005] In a first aspect, the present application proposes an insulation detection method for an energy storage system, comprising:

[0006] Performing a first insulation detection operation before starting the energy storage system; the first insulation detection operation includes performing insulation detection on each battery cluster and energy storage converter in turn to obtain a first detection result;

[0007] According to the first detection result, it is judged in turn whether each battery cluster and energy storage converter has an insulation fault. If so, the first fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault is output, and the energy storage system is prohibited from starting;

[0008] In response to the energy storage system being powered on, a second insulation detection operation is performed; the second insulation detection operation includes performing a polling insulation detection on each battery cluster and the energy storage converter to obtain a second detection result;

[0009] According to the second detection result, determine whether each battery cluster and energy storage converter has an insulation fault. If so, control the energy storage system to shut down, disconnect each battery cluster and energy storage converter, and output the second fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault.

[0010] In one embodiment, the method further comprises:

[0011] Calculating a first insulation resistance of each battery cluster and a second insulation resistance of the energy storage converter according to the first detection result;

[0012] If any first insulation resistance is less than the first preset value, then the corresponding battery cluster has an insulation fault; if the second insulation resistance is less than the second preset value, then the energy storage converter has an insulation fault;

[0013] Calculating the third insulation resistance of each battery cluster and the fourth insulation resistance of the energy storage converter according to the second detection result;

[0014] If any third insulation resistance is less than the first preset value, the corresponding battery cluster has an insulation fault; if the fourth insulation resistance is less than the second preset value, the energy storage converter has an insulation fault.

[0015] In one embodiment, the method further comprises:

[0016] Before performing the first insulation detection operation, determine the risk index of insulation failure of each battery cluster based on historical data;

[0017] Adjusting the insulation inspection sequence of the battery clusters for the first insulation inspection according to the risk index, the insulation inspection sequence includes: sorting the battery clusters in descending order according to the risk index, and performing insulation inspections in order according to the sorting;

[0018] The polling insulation detection sequence of the battery clusters for the second insulation detection is adjusted according to the risk index. The polling insulation detection sequence includes: sorting the battery clusters in order from high to low according to the risk index, and performing polling insulation detection according to the sorting.

[0019] In one embodiment, the step of determining the risk index of insulation failure of each battery cluster based on historical data includes:

[0020] Obtain the historical insulation resistance of the battery cluster and the risk factor of the battery cluster;

[0021] According to the historical insulation resistance of the battery cluster, the current insulation resistance of the battery cluster is predicted, which is recorded as the predicted insulation resistance;

[0022] The predicted insulation resistance and risk factor are normalized separately;

[0023] The risk index of the battery cluster is calculated based on the normalized predicted insulation resistance and the normalized risk factor.

[0024] In one embodiment, the risk factors of the battery cluster include battery health, number of affected times and number of abnormal times; the number of affected times includes the number of times the battery cluster is affected by grid fluctuations and load mutations; the number of abnormal times includes the number of times overvoltage and overcurrent occur in the battery cluster.

[0025] In one embodiment, the risk index is calculated according to the following formula:

[0026] R = 1 + a × I + b × H + c × A + d × E;

[0027] Among them, R represents the risk index; a represents the coefficient of predicted insulation resistance, a<0, I represents predicted insulation resistance; b represents the coefficient of battery health, b<0, H represents battery health; c represents the coefficient of the number of affected times, c>0, A represents the number of affected times; d represents the coefficient of the number of abnormal times, d>0, E represents the number of abnormal times.

[0028] In one embodiment, the method further comprises:

[0029] When performing the first insulation test, obtain the current internal temperature and internal humidity of the energy storage system;

[0030] Before determining the insulation fault of the battery cluster, according to the insulation correspondence, the internal temperature and the internal humidity, correcting the first insulation resistance of the battery cluster whose risk index is greater than the threshold to the insulation resistance corresponding to the preset internal temperature and the preset internal humidity, and recording the corrected insulation resistance as the corrected insulation resistance;

[0031] It is determined whether the corresponding battery cluster has an insulation fault according to the corrected insulation resistance.

[0032] In one embodiment, the step of determining the insulation correspondence relationship includes:

[0033] Acquire an experimental data set, the data set including historical insulation resistance of the battery cluster and internal temperature and internal humidity of the corresponding energy storage system;

[0034] Construct a BP neural network with internal temperature and internal humidity as input layer and insulation resistance as output layer;

[0035] The data set is divided into a training set and a test set, and the BP neural network is trained to obtain a trained BP neural network model, and the insulation correspondence relationship is the same as that of the BP neural network model.

[0036] In a second aspect, the present application proposes an insulation detection device for an energy storage system, the device comprising:

[0037] A detection module, configured to perform a first insulation detection and obtain a first detection result before the energy storage system is turned on, and perform a second insulation detection and obtain a second detection result in response to the energy storage system being turned on;

[0038] The control module is used to determine whether each battery cluster and energy storage converter has a fault in turn according to the first detection result, and if so, output the first fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault, and prohibit the energy storage system from starting up; and determine whether each battery cluster and energy storage converter has an insulation fault according to the second detection result, and if so, control the energy storage system to shut down, disconnect each battery cluster and energy storage converter, and output the second fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault.

[0039] In a third aspect, the present application proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method provided in the first aspect of the present application are implemented.

[0040] The present application provides an insulation detection method for an energy storage system. Before the energy storage system is started, insulation detection of each battery cluster and energy storage converter is performed in sequence, so that the mutual influence of each battery cluster and energy storage converter during the detection process can be isolated, accurate insulation resistance detection results can be obtained, and the battery cluster with insulation fault can be accurately found; when the energy storage system is started, all battery clusters and energy storage converters are subjected to a polling insulation detection, so that it can be timely detected whether the insulation performance of the battery cluster and the energy storage converter has changed due to the influence of the power grid when the energy storage system is started; when it is detected that the insulation performance of any battery cluster and energy storage converter has a fault, the energy storage system is controlled to shut down immediately, and the battery cluster and the energy storage converter are disconnected, so as to prevent insulation accidents of the energy storage system from occurring during operation; the method provided by the present application can detect the insulation performance of the energy storage system before and after it is started, and effectively avoid the problem of reduced safety caused by changes in the insulation performance of the energy storage system when it is started. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A flowchart of the steps of an insulation detection method for an energy storage system in one embodiment;

[0043] Figure 2 A flowchart of the steps of determining whether an insulation detection object has an insulation fault in one embodiment;

[0044] Figure 3 A flowchart of the steps for adjusting the battery cluster insulation detection sequence in one embodiment;

[0045] Figure 4 A flowchart of the steps of calculating the risk index of insulation failure of a battery cluster in one embodiment;

[0046] Figure 5 A flowchart of the steps of a method for determining insulation fault according to corrected insulation resistance in one embodiment;

[0047] Figure 6 A flowchart of steps for constructing a neural network model reflecting insulation correspondence in one embodiment;

[0048] Figure 7 The present invention is a structural block diagram of an insulation detection device for an energy storage system in an embodiment. DETAILED DESCRIPTION

[0049] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0051] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0052] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0053] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0054] In the first aspect, the present application proposes an insulation detection method for an energy storage system, such as Figure 1 As shown, the following steps S102 to S108 are included:

[0055] S102, performing a first insulation detection operation before starting the energy storage system; the first insulation detection operation includes performing insulation detection on each battery cluster and energy storage converter in turn to obtain a first detection result.

[0056] It is understandable that the battery cluster and the energy storage inverter are in a parallel relationship in the insulation detection circuit. If they are tested at the same time, it will lead to a large deviation in the test results or test failure. Therefore, during insulation detection, the battery cluster and the energy storage inverter need to be isolated; each battery cluster is also in a parallel relationship in the insulation detection circuit and needs to be isolated during insulation detection.

[0057] Specifically, according to the operation habits of the energy storage system, the insulation detection start time is preset before the operation time; the insulation detection of the energy storage system includes the first insulation detection before the energy storage system is started and the second insulation detection when the energy storage system is started; the first insulation detection includes performing insulation detection on each battery cluster in turn and insulation detection on the energy storage converter to obtain the first detection result of each detection; the first detection result includes the voltage and current used to calculate the insulation resistance of the detection object.

[0058] Preferably, the insulation resistance is measured using a bridge method, the bridge resistance is known, and the voltage and current of the bridge resistance are measured when the bridge resistance and the insulation resistance reach equilibrium, to obtain the bridge resistance ratio, and then to obtain the insulation resistance value.

[0059] S104, based on the first detection result, determine in turn whether each battery cluster and energy storage converter has an insulation fault, and if so, output first fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault, and prohibit the energy storage system from starting up.

[0060] Specifically, the insulation resistance of the battery cluster and the energy storage inverter can be calculated based on the first detection result; by comparing the insulation resistance of the battery cluster with the insulation alarm threshold of the battery cluster, it can be determined whether the battery cluster has an insulation fault; similarly, by comparing the insulation resistance of the energy storage inverter with the insulation alarm threshold of the energy storage inverter, it can be determined whether the battery cluster has an insulation fault; in response to the existence of an insulation fault in the battery cluster or the energy storage inverter, the battery cluster and the energy storage inverter are prohibited from being closed, the energy storage system is stopped, and a first fault prompt information is issued to notify the staff to repair or replace the battery cluster with the insulation fault or the energy storage inverter with the insulation fault.

[0061] S106, in response to the energy storage system being powered on, executing a second insulation detection operation; the second insulation detection operation includes performing a polling insulation detection on each battery cluster and energy storage converter to obtain a second detection result.

[0062] Specifically, insulation resistance detection is performed when the energy storage system is powered on, and the polling time of each battery cluster and energy storage converter is set according to the total detection time requirement and the detection time requirement of each detection object, so as to ensure that the charging and discharging circuit of the energy storage system is stable during the insulation detection process, and at the same time avoid the measured current being different from the true value due to the charging and discharging of the capacitor when obtaining the second detection result; the polling time represents the time length from the connection of the battery cluster or energy storage converter to be tested to the acquisition of the second detection result of the insulation detection circuit; at the end of the polling time of the current object under test, the second detection result of the object under test is obtained and the connection between the object under test and the insulation detection circuit is disconnected, and then the next object under test and the insulation detection circuit are connected; the second detection result includes the voltage and current used to calculate the insulation resistance of the detection object when the energy storage system is running.

[0063] S108, based on the second detection result, determine whether each battery cluster and energy storage converter has an insulation fault. If so, control the energy storage system to shut down, disconnect each battery cluster and energy storage converter, and output second fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault.

[0064] Specifically, according to the second detection result, the insulation resistance of the battery cluster and the energy storage inverter after the energy storage system is turned on can be calculated, and the insulation resistance of the battery cluster and the energy storage inverter can be compared with the corresponding insulation alarm threshold, so as to determine whether the battery cluster and the energy storage inverter have insulation faults; when it is determined that any of the battery clusters and the energy storage inverter has an insulation fault, the energy storage system is controlled to shut down, and the connections between the battery clusters and the energy storage inverter are disconnected, and the second fault prompt information is output to notify the staff of the battery cluster with insulation fault and the insulation fault of the energy storage inverter.

[0065] The present application provides an insulation detection method for an energy storage system. Before the energy storage system is started, insulation detection of each battery cluster and energy storage converter is performed in sequence, so that the mutual influence of each battery cluster and energy storage converter during the detection process can be isolated, accurate insulation resistance detection results can be obtained, and the battery cluster with insulation fault can be accurately found; when the energy storage system is started, all battery clusters and energy storage converters are subjected to a polling insulation detection, so that it can be timely detected whether the insulation performance of the battery cluster and the energy storage converter has changed due to the influence of the power grid when the energy storage system is started; when it is detected that there is a fault in the insulation performance of the battery cluster and the energy storage converter, the energy storage system is controlled to shut down immediately, and the battery cluster and the energy storage converter are disconnected, so as to prevent insulation accidents of the energy storage system from occurring during operation; the method provided by the present application can detect the insulation performance of the energy storage system before and after it is started, and effectively avoid the problem of reduced safety caused by changes in the insulation performance of the energy storage system when it is started.

[0066] In an exemplary embodiment, Figure 2 As shown, the method further includes the following steps S202 to S208:

[0067] S202: Calculate the first insulation resistance of each battery cluster and the second insulation resistance of the energy storage converter according to the first detection result.

[0068] Specifically, since the insulation resistance of the battery cluster and the energy storage inverter is composed of multiple dispersed insulating elements, the insulation resistance obtained by the insulation test is the equivalent insulation resistance value composed of these insulating elements; according to the detection method adopted by the insulation detection, the first detection result of each battery cluster is substituted into the formula of the detection method for calculation, and the first insulation resistance of the corresponding detection object can be obtained; the first detection result of the energy storage inverter is substituted into the formula for calculation to obtain the second insulation resistance of the energy storage inverter.

[0069] S204, if any first insulation resistance is less than a first preset value, then an insulation fault occurs in the corresponding battery cluster; if the second insulation resistance is less than a second preset value, then an insulation fault occurs in the energy storage converter.

[0070] Specifically, the first preset value may be the national standard value of the insulation resistance of the battery cluster. When the first insulation resistance of any battery cluster is not less than the first preset value, it is determined that the battery cluster does not have an insulation fault. The second preset value may be the national standard value of the insulation resistance of the energy storage inverter. When the second insulation resistance of the energy storage inverter is not less than the second preset value, it is determined that the energy storage inverter does not have an insulation fault.

[0071] S206, calculating the third insulation resistance of each battery cluster and the fourth insulation resistance of the energy storage converter according to the second detection result.

[0072] Specifically, according to the detection method adopted for insulation detection, the second detection results of each battery cluster and energy storage converter are substituted into the formula of the detection method for calculation, so as to obtain the third insulation resistance of the corresponding battery cluster when the energy storage system is running, and the fourth insulation resistance of the energy storage converter when the energy storage system is running.

[0073] S208, if any third insulation resistance is less than the first preset value, then the corresponding battery cluster has an insulation fault; if the fourth insulation resistance is less than the second preset value, then the energy storage converter has an insulation fault.

[0074] Specifically, when the third insulation resistance of any battery cluster is not less than the first preset value, it is determined that the battery cluster has no insulation fault; when the fourth insulation resistance of the energy storage converter is not less than the second preset value, it is determined that the energy storage converter has no insulation fault.

[0075] In an exemplary embodiment, Figure 3 As shown, the method further includes the following steps S302 to S306:

[0076] S302 , before performing the first insulation detection operation, determining the risk index of insulation failure of each battery cluster based on historical data.

[0077] It is understandable that the insulation performance of the insulating elements of a battery cluster will gradually decay during long-term use. Moreover, due to individual differences among battery clusters, some battery clusters with poorer performance are more likely to experience abnormalities, which will damage the insulating elements, leading to a higher risk of insulation failure in the battery cluster. Therefore, in the first insulation test, battery clusters with higher insulation risks can be tested first to confirm that their insulation resistance is at a normal level.

[0078] Specifically, before the first insulation test is performed, the historical insulation resistance of each battery cluster obtained from previous insulation tests is obtained from stored data, and the risk factor of each battery cluster is obtained; the insulation risk index of each battery cluster is calculated based on the historical insulation resistance and the risk factor.

[0079] S304, adjusting the insulation inspection sequence of the battery clusters for the first insulation inspection according to the risk index, the insulation inspection sequence comprising: sorting the battery clusters in order from high to low according to the risk index, and performing insulation inspections in order according to the sorting.

[0080] Specifically, since the first insulation test requires insulation testing of all battery clusters, which takes a long time, and after an insulation fault occurs in a battery cluster, the maintenance operation of the staff is also time-consuming, in order to complete the insulation test before starting the energy storage system more quickly, the insulation test sequence of the battery cluster can be adjusted; priority is given to insulation testing of battery clusters with higher risk indexes, so that battery clusters with insulation faults can be discovered earlier and staff can perform maintenance operations as soon as possible.

[0081] For example, there are ten battery clusters numbered 1 to 10, and insulation tests are performed in ascending order of numbers. The insulation test results of battery clusters 1 to 9 are normal, but the test result of battery cluster 10 shows an insulation fault. The energy storage system needs to wait for the staff to repair or replace battery cluster 10 and then re-test the first insulation. The energy storage system can be started only if there is no insulation fault. If the risk index of battery cluster 10 is higher than that of battery clusters 1 to 9, insulation test is performed on battery cluster 10 first, which can save the test time of battery clusters 1 to 9 before the first insulation fault prompt message is issued.

[0082] S306, adjusting the polling insulation detection sequence of the battery clusters for the second insulation detection according to the risk index, the polling insulation detection sequence comprising: sorting the battery clusters in descending order according to the risk index, and performing polling insulation detection according to the sorting.

[0083] Specifically, after the energy storage system is turned on, battery clusters with higher risk indexes are more likely to experience changes in insulation resistance. Therefore, the battery clusters can be inspected for insulation in a polling order from high to low risk index, which can detect insulation faults faster and shut down the system, thus preventing insulation accidents.

[0084] Furthermore, in the case of the second insulation test, if the insulation test result of any battery cluster and energy storage inverter is an insulation fault, the energy storage system is controlled to shut down and a second fault prompt information is sent to the staff. The second fault prompt information may include the latest risk index report of the battery cluster. The team members can troubleshoot several battery clusters whose risk index is greater than the threshold during maintenance.

[0085] In an exemplary embodiment, Figure 4 As shown, judging the risk index of insulation failure of each battery cluster based on historical data includes the following steps S402 to S408:

[0086] S402, obtaining the historical insulation resistance of the battery cluster and the risk factor of the battery cluster.

[0087] Specifically, the historical insulation resistance and risk factor of each battery cluster are acquired from the stored historical data.

[0088] Preferably, the risk factors of the battery cluster include battery health, number of affected times and number of abnormal times; the number of affected times includes the number of times the battery cluster is affected by grid fluctuations and load mutations; the number of abnormal times includes the number of times overvoltage and overcurrent occur in the battery cluster.

[0089] S404, predicting the current insulation resistance of the battery cluster based on the historical insulation resistance of the battery cluster, which is recorded as the predicted insulation resistance.

[0090] Specifically, based on historical insulation resistance and corresponding detection time, an insulation resistance-time curve of each battery cluster is obtained by fitting, and the insulation resistance of the battery cluster during the first insulation detection is predicted.

[0091] S406, normalizing the predicted insulation resistance and risk factor respectively.

[0092] Preferably, for predicting the insulation resistance, maximum and minimum normalization may be adopted, the minimum value may be the battery cluster insulation warning threshold, and the maximum value may be the battery cluster insulation resistance rated value.

[0093] Optionally, for other multiple risk factors, the normalization methods that can be used include maximum and minimum normalization and Z-score normalization.

[0094] S408 , calculating a risk index of the battery cluster according to the normalized predicted insulation resistance and the normalized risk factor.

[0095] Specifically, by assigning corresponding coefficients to the normalized parameters, the risk coefficient of each battery cluster during the first insulation detection is calculated.

[0096] Furthermore, the risk index is calculated as follows:

[0097] R = 1 + a × I + b × H + c × A + d × E;

[0098] Among them, R represents the risk index; a represents the coefficient of predicted insulation resistance, a<0, I represents predicted insulation resistance; b represents the coefficient of battery health, b<0, H represents battery health; c represents the coefficient of the number of affected times, c>0, A represents the number of affected times; d represents the coefficient of the number of abnormal times, d>0, E represents the number of abnormal times.

[0099] It can be understood that the greater the predicted insulation resistance, the smaller the insulation risk; the greater the battery health, the shorter the battery cluster has been in use and the smaller the insulation risk; the greater the number of affected times and abnormal times, the more the insulation elements of the battery cluster may be affected and the greater the insulation risk.

[0100] In an exemplary embodiment, Figure 5As shown, the method further includes the following steps S502 to S506:

[0101] S502, when performing the first insulation test, obtaining the current internal temperature and internal humidity of the energy storage system.

[0102] Specifically, during the first insulation detection process, the internal temperature and internal humidity of the energy storage system where the battery cluster is located are obtained simultaneously.

[0103] S504, before determining the insulation fault of the battery cluster, according to the insulation correspondence, the internal temperature and the internal humidity, correct the first insulation resistance of the battery cluster whose risk index is greater than the threshold value to the insulation resistance corresponding to the preset internal temperature and the preset internal humidity, and record the corrected insulation resistance as the corrected insulation resistance.

[0104] It is understandable that increased temperature will accelerate the polarization process in the insulating element, increase conductivity, and thus reduce insulation performance, while when humidity increases, the insulating element may absorb water, causing its insulation performance to deteriorate. Therefore, temperature and humidity have a significant impact on insulation resistance. During the operation of the energy storage system, the temperature and humidity inside the system are regulated and can be maintained within the set range, but the first insulation test is performed before the energy storage system is started. The judgment of insulation performance may be affected by the internal temperature and humidity before the energy storage system is started, resulting in missed judgments. In particular, battery clusters with a risk index greater than the threshold may have insulation faults during the operation of the energy storage system, but the insulation resistance is affected by temperature and humidity, and the energy storage system is judged to have no insulation faults when it is stationary.

[0105] Specifically, the insulation correspondence reflects the insulation resistance values ​​of battery clusters with the same insulation performance under different temperature and humidity conditions; the preset internal temperature and the preset internal humidity can be the set temperature and humidity when the energy storage system is in operation; if the difference between the internal temperature and humidity during the first insulation test and the set temperature and humidity during the operation of the energy storage system reaches a preset difference, then based on the insulation resistance obtained in the first insulation test of the battery cluster whose risk index is greater than the threshold, the corrected insulation resistance of the battery cluster when the energy storage system is in operation is obtained according to the insulation correspondence.

[0106] S506: Determine whether the corresponding battery cluster has an insulation fault according to the corrected insulation resistance.

[0107] Specifically, the insulation fault of the battery cluster is judged according to the corrected insulation resistance, so that no battery cluster with insulation fault is missed due to low temperature and humidity.

[0108] In an exemplary embodiment, Figure 6 As shown, the method for determining the insulation correspondence relationship includes the following steps S602 to S606:

[0109] S602 , obtaining an experimental data set, where the data set includes the historical insulation resistance of the battery cluster and the internal temperature and internal humidity of the corresponding energy storage system.

[0110] Specifically, a data set of insulation resistance and temperature and humidity measured during various use time periods of the battery cluster is obtained through experiments.

[0111] S604, constructing a BP neural network, with the internal temperature and internal humidity as input layers and the insulation resistance as output layers.

[0112] Specifically, a BP neural network can be constructed, whose input layer includes internal temperature and internal humidity, and whose output layer includes insulation resistance of the battery cluster, and has multiple hidden layers, wherein the activation function of the hidden layer can use ReLU function, and the loss function can be MSE.

[0113] S606, dividing the data set into a training set and a test set, training the BP neural network, and obtaining a trained BP neural network model, wherein the insulation correspondence relationship is the same as that of the BP neural network model.

[0114] Specifically, the BP neural network is trained using experimental data, and the trained BP neural network model can well reflect the insulation correspondence between the insulation resistance of the battery cluster and the temperature and humidity.

[0115] It should be understood that although Figure 1-Figure 6 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1-Figure 6 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0116] Second, as Figure 7 As shown, the present application proposes an insulation detection device 700 for an energy storage system, the device comprising:

[0117] The detection module 701 is used to perform a first insulation detection and obtain a first detection result before the energy storage system is turned on, and to perform a second insulation detection and obtain a second detection result in response to the energy storage system being turned on.

[0118] The control module 702 is used to determine whether each battery cluster and the energy storage converter has a fault in turn according to the first detection result, and if so, output the first fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault, and prohibit the energy storage system from starting up; and determine whether each battery cluster and the energy storage converter has an insulation fault according to the second detection result, and if so, control the energy storage system to shut down, disconnect each battery cluster and the energy storage converter, and output the second fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault.

[0119] For the specific definition of an insulation detection device for an energy storage system, please refer to the definition of an insulation detection method for an energy storage system mentioned above, which will not be repeated here. Each module in the above-mentioned insulation detection device for an energy storage system can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0120] In a third aspect, the present application proposes a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method provided in the first aspect of the present application are implemented.

[0121] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0122] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0123] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. An insulation detection method for an energy storage system, characterized in that: The method comprises: Performing a first insulation detection operation before starting the energy storage system; the first insulation detection operation includes performing insulation detection on each battery cluster and energy storage converter in turn to obtain a first detection result; According to the first detection result, it is judged in turn whether each of the battery clusters and the energy storage converter has an insulation fault, and if so, first fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault is output, and the energy storage system is prohibited from starting; In response to the energy storage system being turned on, performing a second insulation detection operation; the second insulation detection operation includes performing a polling insulation detection on each of the battery clusters and the energy storage converter to obtain a second detection result; According to the second detection result, determine whether each of the battery clusters and the energy storage inverter has an insulation fault. If so, control the energy storage system to shut down, disconnect each of the battery clusters and the energy storage inverter, and output second fault prompt information corresponding to the battery cluster with insulation fault and the energy storage inverter with insulation fault.

2. The method according to claim 1, characterized in that The method further comprises: Calculating a first insulation resistance of each battery cluster and a second insulation resistance of the energy storage converter according to the first detection result; If any of the first insulation resistances is less than a first preset value, then the corresponding battery cluster has an insulation fault; if the second insulation resistance is less than a second preset value, then the energy storage converter has an insulation fault; Calculating the third insulation resistance of each battery cluster and the fourth insulation resistance of the energy storage converter according to the second detection result; If any of the third insulation resistances is less than the first preset value, then the corresponding battery cluster has an insulation fault; if the fourth insulation resistance is less than the second preset value, then the energy storage converter has an insulation fault.

3. The method according to claim 2, characterized in that The method further comprises: Before performing the first insulation detection operation, determining the risk index of insulation failure of each battery cluster based on historical data; Adjusting the insulation inspection sequence of the battery clusters for the first insulation inspection according to the risk index, the insulation inspection sequence comprising: sorting the battery clusters in descending order according to the risk index, and performing insulation inspections in order according to the sorting; The polling insulation detection sequence of the battery clusters for the second insulation detection is adjusted according to the risk index, and the polling insulation detection sequence includes: sorting the battery clusters in order from high to low according to the risk index, and performing polling insulation detection according to the sorting.

4. The method according to claim 3, characterized in that The step of determining the risk index of insulation failure of each battery cluster based on historical data includes: obtaining a historical insulation resistance of the battery cluster and a risk factor of the battery cluster; Predicting a current insulation resistance of the battery cluster according to the historical insulation resistance of the battery cluster, recorded as predicted insulation resistance; Normalizing the predicted insulation resistance and the risk factor respectively; The risk index of the battery cluster is calculated according to the normalized predicted insulation resistance and the normalized risk factor.

5. The method according to claim 4, characterized in that The risk factors of the battery cluster include battery health, number of affected times and number of abnormal times; the number of affected times includes the number of times the battery cluster is affected by grid fluctuations and load mutations; the number of abnormal times includes the number of times overvoltage and overcurrent occur in the battery cluster.

6. The method according to claim 5, characterized in that The risk index is calculated according to the following formula: R = 1 + a × I + b × H + c × A + d × E; Among them, R represents the risk index; a represents the coefficient of the predicted insulation resistance, a<0, I represents the predicted insulation resistance; b represents the coefficient of the battery health, b<0, H represents the battery health; c represents the coefficient of the number of affected times, c>0, A represents the number of affected times; d represents the coefficient of the number of abnormal times, d>0, E represents the number of abnormal times.

7. The method according to claim 6, characterized in that The method also includes: When performing the first insulation detection, obtaining the current internal temperature and internal humidity of the energy storage system; Before determining the insulation fault of the battery cluster, according to the insulation correspondence, the internal temperature and the internal humidity, correcting the first insulation resistance of the battery cluster whose risk index is greater than the threshold to the insulation resistance corresponding to the preset internal temperature and the preset internal humidity, and recording the corrected insulation resistance as the corrected insulation resistance; It is determined whether the corresponding battery cluster has an insulation fault according to the corrected insulation resistance.

8. The method according to claim 7, characterized in that The step of determining the insulation correspondence relationship comprises: Acquire an experimental data set, the data set including historical insulation resistance of the battery cluster and internal temperature and internal humidity of the corresponding energy storage system; Constructing a BP neural network, with the internal temperature and the internal humidity as input layers, and the insulation resistance as output layers; The data set is divided into a training set and a test set, and the BP neural network is trained to obtain a trained BP neural network model, and the insulation corresponding relationship is the same as the BP neural network model.

9. An insulation detection device for an energy storage system, characterized in that: The device comprises: A detection module, configured to perform a first insulation detection and obtain a first detection result before the energy storage system is turned on, and perform a second insulation detection and obtain a second detection result in response to the energy storage system being turned on; A control module is used to determine whether each battery cluster and energy storage converter has a fault in turn according to the first detection result, and if so, output first fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault, and prohibit the energy storage system from starting up; and determine whether each battery cluster and the energy storage converter has an insulation fault according to the second detection result, and if so, control the energy storage system to shut down, disconnect each battery cluster and the energy storage converter, and output second fault prompt information corresponding to the battery cluster with insulation fault and the energy storage converter with insulation fault.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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