Large-scale centralized energy storage systems and their insulation testing methods, devices and media

Abstract

This application discloses a large-scale centralized energy storage system and its insulation detection method, device, and medium, relating to the field of insulation detection technology. The method includes: before applying high voltage to the large-scale centralized energy storage system, sequentially controlling each battery cluster management unit to detect the insulation status of its corresponding battery cluster; after applying high voltage to the large-scale centralized energy storage system, sequentially controlling each battery compartment management unit to detect the insulation status of its corresponding battery compartment; and judging and locating insulation anomalies in the large-scale centralized energy storage system based on the insulation status detected by each battery cluster management unit and / or each battery compartment management unit. This application performs insulation detection of the energy storage system entirely through the battery management system, eliminating the need for the energy storage converter to have insulation detection capabilities, thereby reducing insulation detection costs. Furthermore, considering the parallel connection of battery clusters in the battery compartments of large-scale centralized energy storage systems, the insulation detection process is optimized, thereby improving insulation detection efficiency.

Description

Technical Field

[0001] This application relates to the field of insulation testing technology, and in particular to a large-scale centralized energy storage system and its insulation testing method, device and medium. Background Technology

[0002] As the application of energy storage systems expands in the new energy field, their safety has become a critical issue. Insulation failures in energy storage systems can lead to equipment damage or even fires. Currently, in energy storage system architectures, insulation detection is typically achieved jointly by the battery management system (BMS) and the energy storage converter. In related technologies, before the system is powered by high voltage, the BMS and the energy storage converter independently perform insulation detection for their respective circuits. After the system is powered by high voltage, the BMS disables the insulation detection function, and only the energy storage converter continues to perform insulation monitoring. Alternatively, the energy storage converter disables the insulation detection function, and the BMS polls and detects each battery cluster in the energy storage system.

[0003] However, the problem with the related technology is that after the high voltage is applied, the insulation detection module on one side is idle, which wastes hardware resources. Furthermore, the scheme of polling and detecting each battery cluster in the energy storage system through the battery management system is usually suitable for small or distributed energy storage systems with a small number of battery clusters and simple topology, but it is difficult to apply to large centralized energy storage systems with a large number of battery clusters and lack of multi-level topology. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art. Therefore, the purpose of this application is to provide a large-scale centralized energy storage system and its insulation testing method, apparatus, and medium, so as to reduce the insulation testing cost of large-scale centralized energy storage systems and improve the accuracy and efficiency of insulation testing.

[0005] In a first aspect, embodiments of this application propose an insulation detection method for a large-scale centralized energy storage system. The large-scale centralized energy storage system includes at least one battery compartment, each battery compartment having a corresponding battery compartment management unit. Each battery compartment includes at least one battery cluster, each battery cluster having a corresponding battery cluster management unit. The method includes: before applying high voltage to the large-scale centralized energy storage system, sequentially controlling each battery cluster management unit to detect the insulation status of its corresponding battery cluster; after applying high voltage to the large-scale centralized energy storage system, sequentially controlling each battery compartment management unit to detect the insulation status of its corresponding battery compartment; and judging and locating insulation anomalies in the large-scale centralized energy storage system based on the insulation status of the corresponding battery cluster detected by each battery cluster management unit and / or the insulation status of the corresponding battery compartment detected by each battery compartment management unit.

[0006] In some embodiments of this application, the step of sequentially controlling each battery cluster management unit to detect the insulation status of the corresponding battery cluster includes: controlling the current battery cluster management unit to collect the auxiliary voltage of the corresponding battery cluster; obtaining the auxiliary voltage change rate of the battery cluster based on the auxiliary voltage of the battery cluster; if the auxiliary voltage change rate is less than a preset change rate within a preset period, then obtaining the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit based on the auxiliary voltage of the battery cluster; if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a preset insulation resistance value, then determining that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality; after the current battery cluster management unit completes the insulation detection, controlling the next battery cluster management unit to perform insulation detection, until all battery cluster management units complete the insulation detection.

[0007] In some embodiments of this application, the step of sequentially controlling each battery compartment management unit to detect the insulation status of the corresponding battery compartment includes: controlling the Nth battery cluster management unit of the current battery compartment to detect the insulation status of the corresponding battery cluster; if it is determined that the Nth battery cluster has an insulation abnormality, then controlling the (N+1)th battery cluster management unit of the current battery compartment to detect the insulation status of the corresponding battery cluster; if it is determined that the (N+1)th battery cluster has an insulation abnormality, then determining that the current battery compartment has an insulation abnormality; after the current battery compartment management unit completes the insulation detection, switching to the next battery compartment management unit for insulation detection, until all battery compartment management units complete the insulation detection.

[0008] In some embodiments of this application, determining that an insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit when the insulation resistance value is less than a preset insulation resistance value includes: determining that a first-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit when the insulation resistance value is less than a first preset insulation resistance value; determining that a second-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit when the insulation resistance value is less than a second preset insulation resistance value and greater than the first preset insulation resistance value; and determining that a third-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit when the insulation resistance value is less than a third preset insulation resistance value and greater than the second preset insulation resistance value.

[0009] In some embodiments of this application, the method further includes: when a first-level insulation abnormality is determined to occur in the battery cluster corresponding to the current battery cluster management unit, sending a first-level alarm to the energy management system and controlling the battery compartment to which the battery cluster to which the current battery cluster management unit belongs to disconnect the main circuit until the energy management system issues a reset command; when a second-level insulation abnormality is determined to occur in the battery cluster corresponding to the current battery cluster management unit, sending a second-level alarm to the energy management system and prohibiting the battery compartment to which the battery cluster to which the current battery cluster management unit belongs from charging and discharging until the energy management system issues a reset command; and when a third-level insulation abnormality is determined to occur in the battery cluster corresponding to the current battery cluster management unit, sending a third-level alarm to the energy management system for early warning.

[0010] In some embodiments of this application, the method further includes: uploading the insulation resistance value of the battery cluster corresponding to each battery cluster management unit to the energy management system in real time, so that the energy management system can obtain the predicted insulation resistance value of the battery cluster corresponding to each battery cluster management unit based on the insulation resistance value of the battery cluster corresponding to each battery cluster management unit, and determine that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality when the predicted insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a preset insulation resistance value.

[0011] In some embodiments of this application, the method further includes: obtaining the total insulation voltage and the actual total voltage of the battery cluster corresponding to the current battery cluster management unit, and performing a self-test on the insulation detection circuit of the current battery cluster management unit based on the total insulation voltage and the actual total voltage.

[0012] Secondly, embodiments of this application propose a computer-readable storage medium storing a computer program thereon, wherein when the computer program is executed by a processor, it implements the insulation detection method for a large-scale centralized energy storage system described in the first aspect embodiment.

[0013] Thirdly, this application provides an insulation detection device for a large-scale centralized energy storage system. The device includes: a first detection module, used to sequentially control each battery cluster management unit to detect the insulation status of the corresponding battery cluster before high voltage is applied to the large-scale centralized energy storage system; a second detection module, used to sequentially control each battery compartment management unit to detect the insulation status of the corresponding battery compartment after high voltage is applied to the large-scale centralized energy storage system; and an insulation detection module, used to determine and locate insulation anomalies in the large-scale centralized energy storage system based on the insulation status of the corresponding battery cluster detected by each battery cluster management unit and / or the insulation status of the corresponding battery compartment detected by each battery compartment management unit.

[0014] Fourthly, this application provides a large-scale centralized energy storage system, wherein the energy storage converter multi-machine parallel system includes a phase alignment device for the energy storage converter multi-machine parallel system as described in the third aspect embodiment.

[0015] The large-scale centralized energy storage system and its insulation testing method, apparatus and medium in this application embodiment perform insulation testing on the energy storage system throughout the entire process through the battery management system, without requiring the energy storage converter to have insulation testing function, thereby reducing the cost of insulation testing. At the same time, considering the characteristics of parallel battery clusters in the battery compartment of the large-scale centralized energy storage system, the insulation testing process is optimized, thereby improving the efficiency of insulation testing.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of an insulation testing method for a large-scale centralized energy storage system according to an embodiment of this application; Figure 2 This is a schematic diagram of a large-scale centralized energy storage system according to an embodiment of this application; Figure 3 This is a schematic diagram illustrating the process of sequentially controlling each battery cluster management unit to detect the insulation state of the corresponding battery cluster according to an embodiment of this application; Figure 4 This is a circuit diagram of an insulation detection circuit according to an embodiment of this application; Figure 5 This is a flowchart illustrating the process of sequentially controlling each battery compartment management unit to detect the insulation status of the corresponding battery compartment according to an embodiment of this application. Figure 6 This is a schematic diagram of the process for handling insulation abnormalities according to an embodiment of this application; Figure 7 This is a block diagram of an insulation detection device for a large-scale centralized energy storage system according to an embodiment of this application. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0019] The following description, with reference to the accompanying drawings, describes a large-scale centralized energy storage system and its insulation testing method, apparatus, and medium according to embodiments of this application.

[0020] Figure 1This is a schematic flowchart of an insulation testing method for a large-scale centralized energy storage system according to an embodiment of this application.

[0021] In some embodiments of this application, reference is made to Figure 1 As shown, the insulation testing methods for large-scale centralized energy storage systems include: S1, before the high voltage is applied to the large centralized energy storage system, sequentially controls each battery cluster management unit to detect the insulation status of the corresponding battery cluster.

[0022] Specifically, refer to Figure 2 As shown in this embodiment of the application, the large-scale centralized energy storage system 100 includes at least one battery compartment 110, each battery compartment 110 is provided with a corresponding battery compartment management unit 120, and each battery compartment 110 includes at least one battery cluster 111, each battery cluster 111 is provided with a corresponding battery cluster management unit 112. Each battery compartment 110 is also connected to the DC side of an energy storage converter 140 to be connected to the power grid 200 through the energy storage converter 140.

[0023] More specifically, when the battery compartment 110 is not connected to the DC side of the energy storage converter 140 (i.e., before the large centralized energy storage system 100 is connected to high voltage), the battery clusters 111 within the battery compartment 110 are independent of each other, and insulation testing needs to be performed on each battery cluster 111 within the battery compartment 110. Therefore, in this embodiment of the present application, before the large centralized energy storage system 100 is connected to high voltage, the battery compartment management unit 120 sequentially controls each battery cluster management unit 112 to perform insulation testing on the corresponding battery cluster 111, thereby realizing insulation testing of the large centralized energy storage system 100.

[0024] S2, after the high voltage is applied to the large centralized energy storage system, sequentially controls each battery compartment management unit to detect the insulation status of the corresponding battery compartment.

[0025] Specifically, when the battery compartment 110 is connected to the DC side of the energy storage converter 140 (i.e., after the large centralized energy storage system 100 is powered by high voltage), all battery clusters in the battery compartment 110 are connected in parallel to the energy storage converter 140. At this time, since the insulation state of all battery clusters in the battery compartment 110 is consistent, it is not necessary to perform insulation testing on each battery cluster in the battery compartment 110. Therefore, in this embodiment of the present application, after the large centralized energy storage system 100 is powered by high voltage, the insulation testing of the large centralized energy storage system 100 is achieved by sequentially controlling each battery compartment management unit 120 to perform insulation testing on the corresponding battery compartment 110.

[0026] It should be noted that the insulation tests of battery cluster 111 and battery compartment 110 need to be performed sequentially to avoid interference between different battery clusters 111 or battery compartments 110 during insulation testing.

[0027] S3, based on the insulation status of the corresponding battery cluster detected by each battery cluster management unit and / or the insulation status of the corresponding battery compartment detected by each battery compartment management unit, performs insulation anomaly judgment and location for the large centralized energy storage system.

[0028] Specifically, in this embodiment of the application, if any battery cluster management unit 112 detects an insulation abnormality in the corresponding battery cluster 111 before the large centralized energy storage system 100 is powered by high voltage, or if any battery compartment management unit 120 detects an insulation abnormality in the corresponding battery compartment 110 after the large centralized energy storage system 100 is powered by high voltage, then it is determined that the large centralized energy storage system 100 has an insulation abnormality.

[0029] More specifically, in this embodiment of the application, if any battery cluster management unit 112 detects an insulation abnormality in the corresponding battery cluster 111 before the large centralized energy storage system 100 is powered by high voltage, then the battery cluster 111 can be identified as a faulty battery cluster. If any battery compartment management unit 120 detects an insulation abnormality in the corresponding battery compartment 110 after the large centralized energy storage system 100 is powered by high voltage, then the battery compartment 110 needs to be disconnected from the DC side of the energy storage converter 140 to disconnect the main circuit of the battery compartment 110. Then, by controlling each battery cluster management unit 112 in sequence to perform insulation detection on the corresponding battery cluster 111, the faulty battery cluster can be located.

[0030] It should be noted that in this embodiment of the application, after the large-scale centralized energy storage system 100 is connected to high voltage, the battery compartment 110 and the energy storage converter 140 are connected as a whole, and the insulation state of the battery compartment 110 and the energy storage converter 140 remains consistent. Therefore, it is not necessary to perform insulation testing on the energy storage converter 140 separately. However, before the large-scale centralized energy storage system 100 is connected to high voltage, the battery compartment 110 is not connected to the energy storage converter 140, and the insulation state of the battery compartment 110 and the energy storage converter 140 are independent. Therefore, in this embodiment of the application, the insulation of the energy storage converter 140 is also manually tested separately.

[0031] Furthermore, in some embodiments of this application, reference is made to... Figure 3 As shown, each battery cluster management unit is sequentially controlled to detect the insulation status of the corresponding battery cluster, including: S11, control the current battery cluster management unit to collect the auxiliary voltage of the corresponding battery cluster.

[0032] Specifically, in this embodiment of the application, the battery cluster management unit 112 includes an insulation detection circuit. The battery cluster management unit 112 uses its internal insulation detection circuit to calculate the insulation resistance value of the corresponding battery cluster 111 using an unbalanced bridge method. (Reference) Figure 4As shown, the insulation detection circuit includes a first insulation resistance Rp, a second insulation resistance Rn, and an auxiliary resistor r. The resistance values ​​of the first insulation resistance Rp and the second insulation resistance Rn represent the insulation resistance values ​​to ground of the positive and negative terminals of the battery cluster 111, respectively. The voltage u across the auxiliary resistor r is an intermediate variable (i.e., the auxiliary voltage) for calculating the first insulation resistance Rp and the second insulation resistance Rn.

[0033] More specifically, see reference Figure 4 As shown, the insulation detection circuit also includes switches Sa, Sb and Sc. In the unbalanced bridge method, multiple switch opening and closing combinations are designed using switches Sa, Sb and Sc. By collecting the auxiliary voltage u corresponding to multiple switch opening and closing combinations, the auxiliary voltage u is used to solve the equations for solving the first insulation resistance Rp and the second insulation resistance Rn. Finally, the insulation resistance value (including the first insulation resistance Rp and the second insulation resistance Rn) of the current battery cluster management unit 112 corresponding to the battery cluster 111 is obtained.

[0034] For example, in this embodiment of the application, two switch opening and closing combinations are preset, namely the first switch opening and closing combination (closed Sa, open Sb, closed Sc) and the second switch opening and closing combination (open Sa, closed Sb, closed Sc).

[0035] For the first switch opening and closing combination, the collected auxiliary voltage is recorded as u1, combined with... Figure 4 The circuit structure of the insulation detection circuit shown can be represented by the following equations:

[0036] in, This represents the auxiliary voltage collected in the first switch opening and closing combination. Indicates the resistance in the first switch opening and closing combination voltage, Indicates the resistance in the first switch opening and closing combination voltage, This indicates the voltage across the battery cluster in the first switch-on / off combination. , , , , , Representing resistance , , , , , The resistance.

[0037] Similarly, for the second switch opening and closing combination, the collected auxiliary voltage is denoted as u2, combined with... Figure 4 The circuit structure of the insulation detection circuit shown can be represented by the following equations:

[0038] in, This represents the auxiliary voltage collected in the second switch switching combination. Indicates the resistance in the second switch opening and closing combination voltage, Indicates the resistance in the second switch opening and closing combination voltage, This indicates the voltage across the battery cluster in the second switch switching combination. , , , , , Representing resistance , , , , , The resistance.

[0039] Therefore, by solving the above two sets of equations, we can obtain the first insulation resistance Rp and the second insulation resistance Rn, which gives us the insulation resistance value of the battery cluster 111 corresponding to the current battery cluster management unit 112.

[0040] S12, based on the auxiliary voltage of the battery cluster, obtain the auxiliary voltage change rate of the battery cluster.

[0041] Specifically, in this embodiment of the application, when switching between multiple switch opening and closing combinations, the collected auxiliary voltage u is prone to fluctuation. In particular, after the large centralized energy storage system 100 is connected to high voltage, the battery cluster 111 is connected to the DC circuit of the energy storage converter 140, and the Y capacitor of the energy storage converter 140 will form a ground loop, which will interfere with the auxiliary voltage. Therefore, it is necessary to make a reliability judgment on the collected auxiliary voltage u.

[0042] More specifically, in this embodiment of the present application, the reliability of the auxiliary voltage u is determined by the rate of change of the auxiliary voltage u of the battery cluster 111, so as to improve the accuracy of insulation detection.

[0043] S13, if the auxiliary voltage change rate is less than the preset change rate within the preset period, then obtain the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit based on the auxiliary voltage of the battery cluster.

[0044] Specifically, if the auxiliary voltage change rate is less than the preset change rate within the preset period, it indicates that the currently collected auxiliary voltage u is subject to less interference and has high reliability, and can be used to calculate the insulation resistance value of the battery cluster 111 corresponding to the current battery cluster management unit 112.

[0045] Furthermore, in this embodiment of the application, the average value of multiple sets of insulation resistance data is recorded as the insulation resistance value of battery cluster 111 to smooth data fluctuations, reduce noise interference, and improve the accuracy of insulation test results. Specifically, in this embodiment of the application, a rolling update mechanism is adopted, that is, each newly acquired insulation resistance value will replace the oldest resistance value in the calculation of the new average insulation resistance value.

[0046] S14. If the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality.

[0047] Specifically, if the insulation resistance value of the battery cluster 111 corresponding to the current battery cluster management unit 112 is less than the preset insulation resistance value, it is determined that the battery cluster 111 corresponding to the current battery cluster management unit 112 has an insulation abnormality, so as to avoid the battery cluster 111 with insulation abnormality from causing a short circuit in the equipment or even endangering personal safety.

[0048] S15: After the current battery cluster management unit completes the insulation test, control the next battery cluster management unit to perform the insulation test, until all battery cluster management units complete the insulation test.

[0049] Specifically, in this embodiment of the application, after the current battery cluster management unit 112 completes the insulation test, the battery compartment management unit 120 of the battery compartment 110 to which the current battery cluster management unit 112 belongs will control the next battery cluster management unit 112 to perform the insulation test, until all battery cluster management units 112 complete the insulation test.

[0050] Furthermore, in some embodiments of this application, reference is made to... Figure 5 As shown, each battery compartment management unit is sequentially controlled to detect the insulation status of the corresponding battery compartment, including: S21, control the Nth battery cluster management unit of the current battery compartment to detect the insulation status of the corresponding battery cluster.

[0051] Specifically, after high voltage is applied to the large centralized energy storage system 100, since the insulation state of all battery clusters within the battery compartment 110 remains consistent, the insulation state of the entire battery compartment 110 can be determined by performing insulation testing on the Nth (i.e., any) battery cluster within the battery compartment. Optionally, in this embodiment of the application, N is set to 1.

[0052] S22, if it is determined that the Nth battery cluster has an insulation abnormality, then control the N+1th battery cluster management unit in the current battery compartment to detect the insulation status of the corresponding battery cluster.

[0053] Specifically, in this embodiment of the application, if it is determined that the current battery cluster 111 has an insulation abnormality, it is also necessary to control the next battery cluster management unit of the current battery compartment 110 to detect the insulation status of the corresponding battery cluster, so as to avoid misjudgment caused by voltage fluctuations or insulation detection circuit failure, and improve the accuracy of insulation detection.

[0054] S23, if it is determined that the N+1th battery cluster has an insulation abnormality, then it is determined that the current battery compartment has an insulation abnormality. Specifically, in this embodiment of the application, if it is determined that the N+1th battery cluster has an insulation abnormality, it indicates that two consecutive battery clusters have insulation abnormalities. At this time, the possibility of misjudgment is small, and it can be determined that the current battery compartment 110 has an insulation abnormality.

[0055] S24: After the current battery compartment management unit completes the insulation test, switch to the next battery compartment management unit for insulation test, until all battery compartment management units complete the insulation test.

[0056] Specifically, in this embodiment of the application, all battery compartment management units 120 are connected via CAN communication. After the current battery compartment management unit 120 completes the insulation detection, the current battery compartment management unit 120 will send an insulation monitoring completion signal to the next battery compartment management unit 121 to control the next battery compartment management unit 121 to perform insulation detection, until all battery compartment management units complete the insulation detection.

[0057] It should be noted that in the embodiments of this application, after receiving the completion signal sent by the previous battery compartment management unit 120, the battery compartment management unit 121 actively performs insulation detection (without needing to be controlled by the energy management system 130). This not only realizes cross-compartment battery cluster insulation detection, but also has strong scalability and adaptability to complex topologies (for example, it is not necessary to design battery cluster polling logic for changes in energy storage systems or complex topologies).

[0058] Therefore, in this embodiment of the present application, after high voltage is applied to a large centralized energy storage system, insulation testing is actively performed by the battery compartment management unit to achieve cross-compartment battery cluster insulation testing, so as to adapt to energy storage systems with changing or complex topologies. In view of the parallel connection of battery clusters in the battery compartment of a large centralized energy storage system, only a small number of battery clusters need to be tested for insulation in each battery compartment, thereby simplifying the insulation testing process and effectively improving insulation testing efficiency.

[0059] Furthermore, in some embodiments of this application, if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality, including: if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a first preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has a first-level insulation abnormality; if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a second preset insulation resistance value and greater than a first preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has a second-level insulation abnormality; if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a third preset insulation resistance value and greater than a second preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has a third-level insulation abnormality.

[0060] Specifically, when an insulation abnormality occurs in battery cluster 111, the smaller the insulation resistance value of battery cluster 111, the greater the risk. In this embodiment of the application, the insulation abnormality of battery cluster 111 is divided into three levels according to the relationship between the insulation resistance value of battery cluster 111 and the preset insulation resistance value, so that different countermeasures can be taken when dealing with insulation abnormalities of different risk levels, thereby ensuring the safety of the large-scale centralized energy storage system 100 while maximizing the availability of the system.

[0061] Furthermore, in some embodiments of this application, reference is made to... Figure 6 As shown, the method also includes: S31, when it is determined that a first-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit, a first-level alarm is sent to the energy management system, and the main circuit of the battery compartment to which the battery cluster to which the current battery cluster management unit belongs is disconnected until the energy management system issues a reset command.

[0062] Specifically, when a Level 1 insulation fault occurs in battery cluster 111, it indicates a serious risk of leakage. At this time, a Level 1 alarm is sent to the energy management system 130, and the main circuit of the battery compartment 110 to which battery cluster 111 belongs is immediately disconnected, allowing maintenance personnel to investigate the battery cluster or high-voltage circuit experiencing the insulation fault. After the maintenance personnel complete the repair and issue a reset command through the energy management system 130, it indicates that the Level 1 insulation fault has been repaired, and the Level 1 alarm is deactivated.

[0063] S32, when a secondary insulation abnormality occurs in the battery cluster corresponding to the current battery cluster management unit, a secondary alarm is sent to the energy management system, and the battery compartment to which the battery cluster to which the current battery cluster management unit belongs is prohibited from charging and discharging until the energy management system issues a reset command.

[0064] Specifically, when a secondary insulation anomaly occurs in battery cluster 111, it indicates that the insulation condition of battery cluster 111 has substantially deteriorated, requiring maintenance personnel to perform insulation repairs. At this time, a secondary alarm is sent to the energy management system 130, and charging and discharging of the battery compartment 110 to which battery cluster 111 belongs is prohibited to reduce risks and prevent the battery compartment 110 to which battery cluster 111 belongs from directly disconnecting from the grid, thus avoiding economic losses. Furthermore, after the maintenance personnel complete the repairs and issue a reset command through the energy management system 130, it indicates that the secondary insulation anomaly has been repaired, and the secondary alarm is subsequently lifted.

[0065] S33: When a level 3 insulation abnormality occurs in the battery cluster corresponding to the current battery cluster management unit, a level 3 alarm is sent to the energy management system for early warning.

[0066] Specifically, when a Level 3 insulation anomaly occurs in battery cluster 111, it indicates that only a small fluctuation in insulation resistance has occurred. Level 3 insulation anomalies are typically temporary, caused by environmental factors such as temperature and humidity changes or interference from the Y-capacitor in the energy storage converter 140. In this case, a Level 3 alarm is sent to the energy management system 130 so that maintenance personnel can determine whether the anomaly is temporary and perform repairs for non-temporary anomalies. Furthermore, when the insulation resistance of the battery cluster 111 corresponding to the current battery cluster management unit 112 is greater than the third preset insulation resistance value, it indicates that the Level 3 insulation anomaly has been repaired, and the Level 3 alarm is subsequently deactivated.

[0067] Furthermore, in some embodiments of this application, the method further includes: uploading the insulation resistance value of the battery cluster corresponding to each battery cluster management unit to the energy management system in real time, so that the energy management system can obtain the predicted insulation resistance value of the battery cluster corresponding to each battery cluster management unit based on the insulation resistance value of the battery cluster corresponding to each battery cluster management unit, and determine that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality when the predicted insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the preset insulation resistance value.

[0068] Specifically, in this embodiment of the application, the battery compartment management unit 120 is connected to all battery cluster management units within the battery compartment via CAN communication, and the battery compartment management unit 120 is also connected to the energy management system 130 via the Modbus TCP protocol. Furthermore, during insulation testing, the battery cluster management unit 112 uploads the insulation resistance value of the corresponding battery cluster 111 to the energy management system 130 in real time through the battery compartment management unit 120, thereby forming a historical change curve of the insulation resistance value of the battery cluster 111.

[0069] More specifically, the energy management system 130 generates an insulation resistance prediction curve for the battery cluster 111 based on the historical change curve of the insulation resistance value of the battery cluster 111, in order to predict the insulation resistance value of the battery cluster 111 in the next insulation detection cycle. If the predicted insulation resistance value of the battery cluster 111 is less than a preset insulation resistance value, it is determined that the battery cluster 111 has an insulation abnormality. Similarly, in this embodiment of the application, based on the relationship between the predicted insulation resistance value and the preset insulation resistance value of the battery cluster 111, the predicted insulation abnormality of the battery cluster 111 is also subdivided into three levels, so that different countermeasures can be taken when dealing with insulation abnormalities of different risk levels.

[0070] In addition, maintenance personnel can use the battery cluster insulation resistance data and insulation anomaly data collected by the energy management system 130 to assess the insulation performance of the large centralized energy storage system 100 or optimize the operation and maintenance strategy, so as to discover and repair insulation vulnerabilities in the large centralized energy storage system 100 in advance.

[0071] Furthermore, in some embodiments of this application, the method further includes: obtaining the total insulation voltage and the actual total voltage of the battery cluster corresponding to the current battery cluster management unit, and performing a self-test on the insulation detection circuit of the current battery cluster management unit based on the total insulation voltage and the actual total voltage.

[0072] Specifically, the total insulation voltage of battery cluster 111 refers to the voltage across battery cluster 111 measured in the insulation detection circuit of battery cluster management unit 112. The actual total voltage of battery cluster 111 refers to the sum of the voltages of all cells in battery cluster 111, where the voltages of all cells in battery cluster 111 can be read by battery cluster management unit 112. It should be understood that when the insulation detection circuit of battery cluster management unit 112 is working normally, the total insulation voltage of battery cluster 111 should be infinitely close to the actual voltage of battery cluster. Therefore, in this embodiment of the application, when the difference between the total insulation voltage of battery cluster 111 corresponding to the current battery cluster management unit 112 and the actual total voltage is less than a preset difference, it is determined that the insulation detection circuit of battery cluster management unit 112 is working normally.

[0073] More specifically, before and after the start of an insulation detection cycle, the total insulation voltage and actual total voltage of the battery cluster 111 corresponding to the current battery cluster management unit 112 are acquired to perform a self-test on the insulation detection circuit of the current battery cluster management unit 112, thereby ensuring the effectiveness of the insulation detection of the current battery cluster management unit 112.

[0074] In summary, the insulation testing method for large-scale centralized energy storage systems according to the embodiments of this application performs insulation testing on the energy storage system throughout the entire process through the battery management system, eliminating the need for the energy storage converter to have insulation testing capabilities, thereby reducing the cost of insulation testing. Furthermore, after high voltage is applied to the large-scale centralized energy storage system, insulation testing is actively performed by the battery compartment management unit, enabling cross-compartment battery cluster insulation testing to adapt to energy storage systems with varying or complex topologies. Considering the parallel connection of battery clusters in the battery compartments of large-scale centralized energy storage systems, insulation testing is performed on only a small number of battery clusters in each battery compartment, thus simplifying the insulation testing process and effectively improving insulation testing efficiency.

[0075] This application also proposes an insulation testing device for a large-scale centralized energy storage system.

[0076] Figure 7 This is a block diagram of an insulation detection device for a large-scale centralized energy storage system according to an embodiment of this application.

[0077] In some embodiments of this application, reference is made to Figure 7 As shown, the insulation testing device 400 for a large-scale centralized energy storage system includes: a first testing module 410, a second testing module 420, and an insulation testing module 430.

[0078] The first detection module 410 is used to sequentially control each battery cluster management unit to detect the insulation status of the corresponding battery cluster before the large-scale centralized energy storage system is subjected to high voltage; the second detection module 420 is used to sequentially control each battery compartment management unit to detect the insulation status of the corresponding battery compartment after the large-scale centralized energy storage system is subjected to high voltage; the insulation detection module 430 is used to determine and locate insulation anomalies in the large-scale centralized energy storage system based on the insulation status of the corresponding battery cluster detected by each battery cluster management unit and / or the insulation status of the corresponding battery compartment detected by each battery compartment management unit.

[0079] Further, the first detection module 410 is used to control the current battery cluster management unit to collect the auxiliary voltage of the corresponding battery cluster; obtain the auxiliary voltage change rate of the battery cluster based on the auxiliary voltage of the battery cluster; if the auxiliary voltage change rate is less than a preset change rate within a preset period, then obtain the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit based on the auxiliary voltage of the battery cluster; if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a preset insulation resistance value, then determine that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality; after the current battery cluster management unit completes the insulation detection, control the next battery cluster management unit to perform insulation detection, until all battery cluster management units complete the insulation detection.

[0080] Furthermore, the second detection module 420 is used to control the Nth battery cluster management unit of the current battery compartment to detect the insulation status of the corresponding battery cluster; if it is determined that the Nth battery cluster has an insulation abnormality, then it controls the N+1th battery cluster management unit of the current battery compartment to detect the insulation status of the corresponding battery cluster; if it is determined that the N+1th battery cluster has an insulation abnormality, then it is determined that the current battery compartment has an insulation abnormality; after the current battery compartment management unit completes the insulation detection, it switches to the next battery compartment management unit to perform the insulation detection, until all battery compartment management units complete the insulation detection.

[0081] Furthermore, the first detection module 410 is also used to determine that a first-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a first preset insulation resistance value; to determine that a second-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a second preset insulation resistance value and greater than a first preset insulation resistance value; and to determine that a third-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit if the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than a third preset insulation resistance value and greater than a second preset insulation resistance value.

[0082] Furthermore, the first detection module 410 is also used to send a first-level alarm to the energy management system when it is determined that a first-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit, and control the battery compartment to which the battery cluster to which the current battery cluster management unit belongs to disconnect the main circuit until the energy management system issues a reset command; when a second-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit, it sends a second-level alarm to the energy management system and prohibits the battery compartment to which the battery cluster to which the current battery cluster management unit belongs from charging and discharging until the energy management system issues a reset command; when a third-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit, it sends a third-level alarm to the energy management system for early warning.

[0083] Furthermore, the first detection module 410 is also used to upload the insulation resistance value of the battery cluster corresponding to each battery cluster management unit to the energy management system in real time, so that the energy management system can obtain the predicted insulation resistance value of the battery cluster corresponding to each battery cluster management unit based on the insulation resistance value of the battery cluster corresponding to each battery cluster management unit, and determine that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality when the predicted insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the preset insulation resistance value.

[0084] Furthermore, the first detection module 410 is also used to obtain the total insulation voltage and the actual total voltage of the battery cluster corresponding to the current battery cluster management unit, and to perform a self-test on the insulation detection circuit of the current battery cluster management unit based on the total insulation voltage and the actual total voltage.

[0085] It should be understood that the specific implementation of the insulation testing device 400 for the large-scale centralized energy storage system of this application can be found in the specific implementation of the insulation testing method for the large-scale centralized energy storage system described in the foregoing embodiments of this application. To reduce redundancy, it will not be repeated here.

[0086] Based on the insulation testing method for large-scale centralized energy storage systems in the foregoing embodiments of this application, this application also proposes a computer-readable storage medium storing an insulation testing program for a large-scale centralized energy storage system, which, when executed by a processor, implements the insulation testing method for large-scale centralized energy storage systems in the foregoing embodiments of this application.

[0087] It should be understood that the specific implementation of the computer-readable storage medium of this application can be found in the specific implementation of the insulation detection method for the large centralized energy storage system described in the foregoing embodiments of this application. To reduce redundancy, it will not be repeated here.

[0088] This application also proposes a large-scale centralized energy storage system.

[0089] Figure 2 This is a structural diagram of a large-scale centralized energy storage system according to an embodiment of this application.

[0090] In some embodiments of this application, reference is made to Figure 2 As shown, the large-scale centralized energy storage system 100 includes the insulation detection device 400 of the large-scale centralized energy storage system described in the above-described embodiments of this application.

[0091] It should be understood that the specific implementation of the large-scale centralized energy storage system 100 of this application can be referred to the specific implementation of the insulation detection device 400 of the large-scale centralized energy storage system in the aforementioned embodiments of this application. To reduce redundancy, it will not be described again here.

[0092] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0093] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0096] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0097] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0098] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0099] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An insulation testing method for a large-scale centralized energy storage system, characterized in that, The large-scale centralized energy storage system includes at least one battery compartment, each battery compartment being equipped with a corresponding battery compartment management unit. Each battery compartment includes at least one battery cluster, each battery cluster being equipped with a corresponding battery cluster management unit. The method includes: Before the high voltage is applied to the large centralized energy storage system, each battery cluster management unit is sequentially controlled to detect the insulation status of the corresponding battery cluster. After the large-scale centralized energy storage system is powered by high voltage, each battery compartment management unit is sequentially controlled to detect the insulation status of the corresponding battery compartment. Based on the insulation status of the corresponding battery cluster detected by each battery cluster management unit and / or the insulation status of the corresponding battery compartment detected by each battery compartment management unit, insulation anomalies are identified and located in the large-scale centralized energy storage system.

2. The insulation testing method for a large-scale centralized energy storage system according to claim 1, characterized in that, The step of sequentially controlling each battery cluster management unit to detect the insulation status of the corresponding battery cluster includes: Control the current battery cluster management unit to collect the auxiliary voltage of the corresponding battery cluster; Based on the auxiliary voltage of the battery cluster, obtain the rate of change of the auxiliary voltage of the battery cluster; If the rate of change of the auxiliary voltage is less than the preset rate of change within the preset period, then the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is obtained based on the auxiliary voltage of the battery cluster. If the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality. After the current battery cluster management unit completes the insulation test, the next battery cluster management unit is controlled to perform the insulation test, until all battery cluster management units have completed the insulation test.

3. The insulation testing method for a large-scale centralized energy storage system according to claim 2, characterized in that, The step of sequentially controlling each battery compartment management unit to detect the insulation status of the corresponding battery compartment includes: Control the Nth battery cluster management unit in the current battery compartment to detect the insulation status of the corresponding battery cluster; If it is determined that the Nth battery cluster has an insulation abnormality, then the N+1th battery cluster management unit of the current battery compartment is controlled to detect the insulation status of the corresponding battery cluster. If it is determined that the N+1th battery cluster has an insulation abnormality, then it is determined that the current battery compartment has an insulation abnormality. After the current battery compartment management unit completes the insulation test, the process switches to the next battery compartment management unit for insulation testing, until all battery compartment management units have completed the insulation test.

4. The insulation testing method for a large-scale centralized energy storage system according to claim 3, characterized in that, If the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality, including: If the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the first preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has experienced a first-level insulation abnormality. If the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the second preset insulation resistance value and greater than the first preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has experienced a secondary insulation abnormality. If the insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the third preset insulation resistance value and greater than the second preset insulation resistance value, then it is determined that the battery cluster corresponding to the current battery cluster management unit has experienced a level three insulation abnormality.

5. The insulation testing method for a large-scale centralized energy storage system according to claim 4, characterized in that, The method further includes: When it is determined that a first-level insulation abnormality has occurred in the battery cluster corresponding to the current battery cluster management unit, a first-level alarm is sent to the energy management system, and the main circuit of the battery compartment to which the battery cluster to which the current battery cluster management unit belongs is disconnected until the energy management system issues a reset command. When a secondary insulation abnormality occurs in the battery cluster corresponding to the current battery cluster management unit, a secondary alarm is sent to the energy management system, and the battery compartment to which the battery cluster to which the current battery cluster management unit belongs is prohibited from charging and discharging until the energy management system issues a reset command; When a level 3 insulation abnormality occurs in the battery cluster corresponding to the current battery cluster management unit, a level 3 alarm is sent to the energy management system for early warning.

6. The insulation testing method for an energy storage system according to claim 3, characterized in that, The method further includes: The insulation resistance value of the battery cluster corresponding to each battery cluster management unit is uploaded to the energy management system in real time. The energy management system obtains the predicted insulation resistance value of the battery cluster corresponding to each battery cluster management unit based on the insulation resistance value of the battery cluster corresponding to each battery cluster management unit. When the predicted insulation resistance value of the battery cluster corresponding to the current battery cluster management unit is less than the preset insulation resistance value, it is determined that the battery cluster corresponding to the current battery cluster management unit has an insulation abnormality.

7. The insulation testing method for a large-scale centralized energy storage system according to claim 3, characterized in that, The method further includes: The insulation total voltage and actual total voltage of the battery cluster corresponding to the current battery cluster management unit are obtained, and the insulation detection circuit of the current battery cluster management unit is self-tested based on the insulation total voltage and the actual total voltage.

8. A computer-readable storage medium, characterized in that, It stores an insulation testing program for a large centralized energy storage system, which, when executed by a processor, implements the insulation testing method for a large centralized energy storage system as described in any one of claims 1-7.

9. An insulation testing device for a large-scale centralized energy storage system, characterized in that, The device includes: The first detection module is used to sequentially control each battery cluster management unit to detect the insulation status of the corresponding battery cluster before the high voltage is applied to the large centralized energy storage system. The second detection module is used to sequentially control each battery compartment management unit to detect the insulation status of the corresponding battery compartment after the large-scale centralized energy storage system is subjected to high voltage. An insulation detection module is used to determine and locate insulation anomalies in the large-scale centralized energy storage system based on the insulation status of the corresponding battery cluster detected by each battery cluster management unit and / or the insulation status of the corresponding battery compartment detected by each battery compartment management unit.

10. A large-scale centralized energy storage system, characterized in that, The large-scale centralized energy storage system includes the insulation detection device for the large-scale centralized energy storage system as described in claim 9.

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