Insulation fault detection method and related device

Abstract

An insulation fault detection method and related device, the insulation fault detection method comprising: controlling a plurality of transmission branches (12) on an energy storage side of an energy storage system to be connected to a high-voltage bus (S310) through corresponding pre-charging circuits (15), the high-voltage bus being provided with an insulation monitoring module (13); and controlling an insulation monitoring module (13) to perform insulation fault detection on a target loop connected to the high-voltage bus to obtain a first detection result (S320), the target loop comprising a plurality of first loops formed by connecting a plurality of transmission branches (12) with corresponding pre-charging circuits (15) respectively. The insulation fault detection method and the related device can safely and efficiently realize insulation fault detection.

Description

Insulation fault detection method and related device Technical Field

[0001] The present application relates to the field of new energy technologies, and in particular to an insulation fault detection method, system, device, energy storage system, storage medium, and computer program product. Background Art

[0002] In an energy storage system, the main function of the power conversion system (PCS) is to manage the charging and discharging of the energy storage devices in the energy storage system. Before the power conversion system can work, it must first ensure that the impedance of its energy storage side to the ground meets the requirements.

[0003] Summary of the Invention

[0004] The embodiments of the present application provide an insulation fault detection method, system, device, energy storage system, storage medium and computer program product, aiming to provide a safe and efficient insulation fault detection solution.

[0005] In one aspect, the present application provides an insulation fault detection method, which may include:

[0006] The multiple transmission branches on the energy storage side of the control energy storage system are connected to the high-voltage busbar through corresponding pre-charging circuits, and the high-voltage busbar is provided with an insulation monitoring module;

[0007] The insulation monitoring module is controlled to perform insulation fault detection on a target circuit connected to the high-voltage bus to obtain a first detection result. The target circuit may include multiple first circuits formed by connecting multiple transmission branches to corresponding pre-charging circuits respectively.

[0008] In these embodiments, when performing insulation fault detection, insulation fault detection can be directly performed on all target circuits connected to the high-voltage bus, including the first circuit, and the first circuit is formed by connecting multiple transmission branches to corresponding pre-charging circuits, that is, multiple transmission branches are respectively incorporated into the high-voltage bus through corresponding pre-charging circuits. Therefore, the pre-charging circuit can play a protective role, and can avoid the risk of system short circuit or overcharging of energy storage devices caused by failure of multiple transmission branches when each transmission branch is connected to the high-voltage bus at the same time. There is no need to connect the transmission branches one by one to the high-voltage bus for insulation fault detection, thereby saving time for insulation fault detection, thereby providing an efficient and safe insulation fault detection solution.

[0009] Optionally, after obtaining the first detection result, the method may further include:

[0010] When the first detection result indicates that the target circuit connected to the high-voltage bus has an insulation fault, respectively obtaining current values ​​of the plurality of transmission branches;

[0011] According to the current values ​​of the multiple transmission branches, insulation fault determination is performed on the multiple transmission branches to obtain determination results.

[0012] In these embodiments, the current values ​​of multiple transmission branches can be obtained, and then, based on the magnitude of the current values, a multi-branch insulation failure fault judgment can be performed on the multiple transmission branches to obtain a judgment result. Insulation fault location is thereby achieved based on the current value of the transmission branch, and the branch where the fault is located can be quickly located.

[0013] Optionally, performing insulation fault determination on the multiple transmission branches according to the current values ​​of the multiple transmission branches to obtain the determination result may include:

[0014] When the current value of the target transmission branch is not within the first current range, the determination result indicates that the target transmission branch is an insulation fault branch, and the plurality of transmission branches may include the target transmission branch.

[0015] In these embodiments, a method for locating insulation faults based on current values ​​of multiple transmission branches is provided, thereby achieving rapid location of insulation faults to ground.

[0016] Optionally, after obtaining the determination result, the method may further include:

[0017] When the determination result indicates that the target transmission branch is an insulation fault branch, the first loop where the target transmission branch is located is cut off, and the multiple transmission branches may include the target transmission branch.

[0018] In these embodiments, when the insulation fault branch is located according to the determination result, the connection between the target transmission branch and the high-voltage bus can be cut off, thereby reducing the number of transmission branches with insulation faults in the high-voltage system, reducing or even eliminating the number of insulation faults in the target circuit connected to the high-voltage bus, and enabling the normal operation of the power conversion system.

[0019] Optionally, after disconnecting the first loop where the target transmission branch is located, the method may further include:

[0020] The insulation monitoring module is controlled to perform insulation fault detection on the target circuit to obtain a second detection result.

[0021] In these embodiments, the insulation fault detection is performed again on the target circuit connected to the high-voltage busbar through the insulation monitoring module, so that it is possible to timely detect whether the insulation fault location based on the current value in the early stage has completely eliminated the insulation fault, thereby realizing the verification of the insulation fault location result.

[0022] Optionally, after obtaining the second detection result, the method may further include:

[0023] When the second detection result indicates that an insulation fault exists in the target circuit connected to the high-voltage bus, cutting off all target circuits connected to the high-voltage bus;

[0024] The transmission branches other than the target transmission branch are controlled to be connected to the high-voltage busbar one by one, and the insulation monitoring module is controlled to perform insulation fault detection on the transmission branches connected to the high-voltage busbar one by one.

[0025] In these embodiments, insulation fault detection is performed one by one only after multiple transmission branches have been excluded from insulation faults to ground. Therefore, in actual use, the number of transmission branches to be detected one by one is reduced, which can reduce the insulation detection time of the energy storage system as a whole.

[0026] Optionally, before controlling the multiple transmission branches on the energy storage side of the energy storage system to be connected to the high-voltage busbar via corresponding pre-charging circuits, the method may further include:

[0027] Obtaining the voltage difference between each transmission branch;

[0028] When the voltage differences between the transmission branches are all less than the voltage threshold, the steps are executed: controlling the multiple transmission branches on the energy storage side of the energy storage system to be connected to the high-voltage busbar via corresponding pre-charging circuits.

[0029] In these embodiments, by obtaining the voltage difference between each transmission branch and comparing it with a voltage threshold, it is possible to immediately detect the presence of circulating current in the transmission branch due to a large voltage difference. When the voltage difference between any two transmission branches is greater than or equal to the voltage threshold, the connection of the multiple transmission branches to the high-voltage bus can be temporarily stopped, and the circuit can be adjusted to eliminate the circulating current, thereby ensuring the safe operation of the high-voltage system.

[0030] Optionally, after obtaining the first detection result, the method may further include:

[0031] When the first detection result indicates that there is no insulation fault in the target circuit connected to the high-voltage bus, the switch module is controlled to be turned on, and the switch module is connected in parallel with the pre-charging circuit;

[0032] After the switch module is turned on for the first time, the pre-charging circuit is cut off.

[0033] In these embodiments, a complete implementation scheme for ground insulation detection on the energy storage side of the energy storage system is provided, which can control the normal operation of the power conversion system or continue to perform ground insulation fault detection based on different first detection results, thereby realizing a complete set of safe and efficient ground insulation fault detection logic.

[0034] Optionally, the transmission branch may include multiple energy storage devices connected in series and / or in parallel.

[0035] In another aspect, the present application provides an insulation fault detection system, which may include:

[0036] A first control module is used to control multiple transmission branches on the energy storage side of the energy storage system to be connected to a high-voltage busbar via corresponding pre-charging circuits, and an insulation monitoring module is provided on the high-voltage busbar;

[0037] The second control module is used to control the insulation monitoring module to perform insulation fault detection on the target circuit connected to the high-voltage bus to obtain a first detection result. The target circuit includes multiple first circuits formed by connecting multiple transmission branches to corresponding pre-charging circuits.

[0038] On the other hand, the present application provides an insulation fault detection device, which may include a processor, a memory, and a program or instruction stored in the memory and executable on the processor. When the program or instruction is executed by the processor, the steps of the insulation fault detection method as described above are implemented.

[0039] In yet another aspect, the present application further provides an insulation fault detection device, which is configured to execute the steps of the insulation fault detection method of the above aspect.

[0040] On the other hand, the present application also provides an energy storage system, which includes the insulation fault detection device of the above aspect.

[0041] On the other hand, the present application also provides a readable storage medium, which stores a program or instruction. When the program or instruction is executed by a processor, the steps of the insulation fault detection method in the above aspect are implemented.

[0042] In yet another aspect, the present application further provides a computer program product, which can be executed by a processor to implement the steps of the insulation fault detection method as described above.

[0043] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. 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 the drawings without creative work.

[0045] FIG1 is a schematic diagram of the architecture of an energy storage system involved in the insulation fault detection method according to an embodiment of the present application.

[0046] FIG2 is a schematic diagram of an optional circuit module structure on the energy storage side of the energy storage system involved in the insulation fault detection method according to an embodiment of the present application.

[0047] FIG3 is a flow chart of an insulation fault detection method according to an embodiment of the present application.

[0048] FIG4 is a flow chart of another embodiment of the insulation fault detection method according to the embodiment of the present application.

[0049] FIG5 is a schematic diagram of a method for detecting an insulation fault according to an embodiment of the present application in which insulation failure occurs in at least two transmission branches to form a loop.

[0050] FIG6 is a flow chart of another embodiment of the insulation fault detection method according to the embodiment of the present application.

[0051] FIG7 is a flow chart of another embodiment of the insulation fault detection method according to the embodiment of the present application.

[0052] FIG8 is a schematic diagram of optional modules of an insulation fault detection system according to an embodiment of the present application.

[0053] FIG9 is a schematic diagram of an optional hardware structure of an insulation fault detection device according to an embodiment of the present application.

[0054] In the drawings, the drawings are not drawn to scale.

[0055] Description of reference numerals:

[0056] 11. Power conversion system; 12. Transmission branch; 13. Insulation monitoring module; 14. Energy storage device; 15. Pre-charging circuit;

[0057] K1, main negative relay; K2, main positive relay; K3, pre-charge relay; R, pre-charge resistor. DETAILED DESCRIPTION

[0058] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0060] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0061] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0062] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0063] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0064] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0065] Please refer to Figure 1, which is a schematic diagram of an optional architecture of an energy storage system in the related art. In this schematic diagram, the energy storage system may include a power conversion system 11 (Power Conversion System, PCS), which may include a DC / AC (Direct Current / Alternating Current) bidirectional converter and a control unit. In some embodiments, the power conversion system 11 may also include a DC-DC (Direct Current-Direct Current) converter. The control unit may also be electrically connected to the control management module of the energy storage device 14 through an interface. Before the power conversion system 11 is put into operation, it must first be ensured that the impedance of its energy storage side to the ground meets the requirements.

[0066] During the process of developing and designing the energy storage system, the inventors of the present application discovered that only one insulation monitoring module 13 is provided on the high-voltage bus in the energy storage system. Therefore, the insulation status of each transmission branch 12 of the energy storage system cannot be detected before it is connected to the high-voltage bus.

[0067] If all transmission branches 12 are connected to the high-voltage busbar at once, there is a risk of insulation failure in multiple transmission branches 12, leading to overcharging of the energy storage devices 14 on the transmission branches 12 or a short circuit in the entire system. Therefore, to detect the insulation status of each transmission branch 12, the related art can only connect each transmission branch 12 to the high-voltage busbar one by one to perform insulation fault detection. This detection method is time-consuming when there are many transmission branches 12.

[0068] In order to solve the above technical problems, avoid the risk of system short circuit or energy storage device overcharging caused by multiple branch insulation failures, and minimize the time of insulation fault detection, the inventors of this application have designed a set of insulation fault detection schemes, and correspondingly provide an insulation fault detection method, system, device, energy storage system, storage medium and computer program product, by controlling multiple transmission branches on the energy storage side of the energy storage system to be connected to the high-voltage bus through corresponding pre-charging circuits, and then controlling the insulation monitoring module set on the high-voltage bus to perform insulation fault detection on the target circuit connected to the high-voltage bus, obtaining a first detection result, and the target circuit can include multiple first circuits formed by connecting multiple transmission branches to the corresponding pre-charging circuits. Among them, multiple transmission branches are incorporated into the high-voltage bus through corresponding pre-charging circuits, and the pre-charging circuit can perform current limiting protection, which can enable multiple transmission branches to be connected to the high-voltage bus together, saving the time of insulation fault detection, and also avoiding the risk of system short circuit or energy storage device overcharging caused by the failure of multiple transmission branches when each transmission branch is connected to the high-voltage bus at the same time, thereby providing a safe and efficient insulation fault detection scheme.

[0069] The following describes the insulation fault detection method, system, device, energy storage system, storage medium and computer program product provided in the embodiments of the present application. First, the insulation fault detection method provided in the embodiments of the present application is introduced.

[0070] Please refer to Figures 1, 2, and 3, wherein Figure 2 shows a schematic diagram of the circuit module structure of the energy storage side of the energy storage system involved in the insulation fault detection method of an embodiment of the present application, and Figure 3 shows a flow chart of an optional embodiment of the insulation fault detection method of the embodiment of the present application. In this embodiment, the insulation fault detection method may include the following steps:

[0071] S310, controlling multiple transmission branches on the energy storage side of the energy storage system to be connected to a high-voltage busbar via corresponding pre-charging circuits, where an insulation monitoring module is provided;

[0072] S320, controlling the insulation monitoring module to perform insulation fault detection on the target circuit connected to the high-voltage bus to obtain a first detection result. The target circuit may include multiple first circuits formed by connecting multiple transmission branches to corresponding pre-charging circuits respectively.

[0073] The above insulation fault detection method can be applied to an insulation fault detection device, which can be a power conversion system 11 or other control modules.

[0074] In addition to the insulation monitoring module 13, the high-voltage system in which the power conversion system 11 is located may also include devices such as a transformer cabinet. The high-voltage system may also be connected to multiple transmission branches 12 through a transmission interface so that the transmission branches 12 are also incorporated into the high-voltage system. The multiple transmission branches 12 may be connected in parallel, and the multiple transmission branches 12 may be respectively arranged in corresponding electrical cabinets. Each transmission branch 12 may include multiple energy storage devices 14 connected in series, multiple energy storage devices 14 connected in parallel, or multiple energy storage devices 14 connected in series and parallel. For example, the energy storage device 14 may be a battery or a large capacitor, thereby realizing the storage of electrical energy.

[0075] Before the power conversion system 11 operates, the insulation monitoring module 13 provided on the high-voltage busbar can be used to perform insulation impedance detection. In this case, multiple transmission branches 12 can be controlled to be connected to the high-voltage busbar via corresponding pre-charging circuits 15, thereby incorporating multiple transmission branches 12 into the high-voltage system. The insulation monitoring module 13 can then be controlled to perform insulation fault detection on the entire high-voltage system (which can be all circuits connected to the high-voltage busbar, i.e., the target circuit).

[0076] Because when performing insulation fault detection, insulation fault detection can be directly performed on all target circuits connected to the high-voltage bus, including the first circuit, and the first circuit is formed by connecting multiple transmission branches 12 with corresponding pre-charging circuits 15, that is, multiple transmission branches 12 are respectively incorporated into the high-voltage bus through the pre-charging circuit 15, so the pre-charging circuit 15 can play a protective role, and can avoid the risk of system short circuit or overcharging of the energy storage device 14 caused by failure of multiple transmission branches 12 when each transmission branch 12 is connected to the high-voltage bus at the same time. There is no need to connect the transmission branches 12 to the high-voltage bus one by one for insulation fault detection, thereby saving the time of insulation fault detection, thereby providing an efficient and safe insulation fault detection solution.

[0077] In some optional examples, the pre-charging circuit 15 may include a pre-charging resistor R and a pre-charging relay K3 , and the pre-charging relay K3 may be connected between the pre-charging resistor R and the high-voltage bus.

[0078] For the purpose of this explanation, the energy storage device 14 on the transmission branch 12 is described as a battery. The transmission branch 12 may also include a main positive relay K2 and a main negative relay K1. The main positive relay K2 is positioned between the high-voltage busbar and the positive electrode of the battery, while the main negative relay K1 is positioned between the high-voltage busbar and the negative electrode of the battery. When insulation fault detection is required, such as when at least one transmission branch 12 needs to be connected to the high-voltage busbar, the main negative relay K1 and the pre-charge relay K3 can be controlled to close.

[0079] It should be noted that when multiple transmission branches 12 are merged into the high-voltage bus, the pre-charge relay K3 and the pre-charge resistor R can form a pre-charge circuit 15, thereby enabling the voltage pre-charge of the main positive relay K2 close to the high-voltage bus, and preventing the main positive relay K2 from being damaged by the instantaneous large current caused by the excessive pressure difference between the inside and outside of the main positive relay K2 at the moment of closing. The conduction of the main negative relay K1 and the pre-charge relay K3 can form a first loop between the transmission branch 12 where the main negative relay K1 is located, the pre-charge circuit 15, and the high-voltage bus. When the insulation monitoring module 13 subsequently performs insulation fault detection, it can achieve insulation fault detection of the target loop including all first loops, thereby improving the efficiency and safety of insulation fault detection.

[0080] Referring to FIG. 4 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, after obtaining the first detection result in S320 , the method may further include:

[0081] S410, when the first detection result indicates that the target circuit connected to the high-voltage bus has an insulation fault, respectively obtain current values ​​of the plurality of transmission branches;

[0082] S420: Perform insulation fault determination on the multiple transmission branches according to the current values ​​of the multiple transmission branches to obtain a determination result.

[0083] This embodiment considers a solution when the first detection result indicates that the target circuit connected to the high-voltage bus has an insulation fault, and can locate the insulation fault of some transmission branches according to the current value of the transmission branch.

[0084] It should be noted, referring to Figures 2, 4, and 5, that when insulation failure occurs in at least two of the multiple transmission branches, the positive electrodes of the energy storage devices 14 in these transmission branches with insulation failure can be connected via the high-voltage busbar, thereby forming a loop. If the number of energy storage devices 14 on the two transmission branches forming the loop differs significantly, a large voltage differential will be generated. At the same time, since only the wiring impedance, the energy storage device impedance itself, and the main positive relay impedance exist, the resulting loop impedance is very small. At this time, the transmission branch with a larger number of energy storage devices 14 will charge the transmission branch with a relatively smaller number of energy storage devices 14 at a high rate, resulting in a certain current value in the loop formed by the transmission branch insulation failure. It is understandable that the current in the transmission branches with different insulation failures may be either charging current or discharging current.

[0085] Therefore, in this embodiment, the current values ​​of multiple transmission branches can be obtained, and then the insulation failure faults of multiple branches on the multiple transmission branches can be judged according to the magnitude of the current values ​​to obtain a judgment result. Insulation fault location is achieved based on the current value of the transmission branch, and the branch where the fault is located can be quickly located.

[0086] In some embodiments, a current sensor can be provided on the transmission branch to detect and obtain the current value on the transmission branch. For example, the current sensor can be connected between the main positive relay and the positive terminal of the battery. In other embodiments, the current value of the transmission branch can also be measured and converted by other means.

[0087] Referring to FIG. 6 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, in S420 , insulation fault determination is performed on the multiple transmission branches based on the current values ​​of the multiple transmission branches. The determination result may include:

[0088] S610: When the current value of the target transmission branch is not within the first current range, the determination result indicates that the target transmission branch is an insulation fault branch, and the plurality of transmission branches may include the target transmission branch.

[0089] The above-mentioned first current range can be 0, or it can be other current ranges close to 0. Taking the first current range of 0 as an example, when there is a current value on the transmission branch, the transmission branch is the target transmission branch with insulation fault among multiple transmission branches; conversely, when there is no current value on the transmission branch, it indicates that the transmission branch and other transmission branches do not form a loop due to insulation failure, and the transmission branch is not an insulation fault branch caused by multiple branch insulation failure.

[0090] In this embodiment, a method for locating insulation faults based on current values ​​of multiple transmission branches is provided, thereby achieving rapid location of insulation faults to ground.

[0091] 6 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, after obtaining the determination result in S420 , the method may further include:

[0092] S630: When the determination result indicates that the target transmission branch is an insulation fault branch, disconnect the first loop where the target transmission branch is located. The plurality of transmission branches may include the target transmission branch.

[0093] In this embodiment, when the insulation fault branch is located according to the judgment result, the connection between the target transmission branch and the high-voltage bus can be cut off, thereby reducing the transmission branches with insulation faults in the high-voltage system, reducing or even eliminating the number of insulation faults in the target circuit connected to the high-voltage bus, and enabling the normal operation of the power conversion system.

[0094] 6 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, after S630 , the method may further include:

[0095] S640: Control the insulation monitoring module to perform insulation fault detection on the target circuit to obtain a second detection result.

[0096] After locating the fault caused by the failure of insulation of multiple transmission branches to the ground based on the current values ​​of multiple transmission branches, and then cutting off the connection between the target transmission branch and the high-voltage bus, in order to ensure that all insulation fault branches have been found, the insulation monitoring module can also be controlled to perform insulation fault detection on all target circuits connected to the high-voltage bus again to obtain a second detection result.

[0097] It should be noted that current detection based on transmission branch current only detects loop currents caused by insulation between multiple transmission branches and ground. It cannot detect insulation faults in a single transmission branch, or insulation faults between multiple transmission branches and ground without high-rate charging. Therefore, the insulation monitoring module can perform a second insulation fault check to determine whether all insulation faults in the current target loop have been cleared.

[0098] If the second test result indicates no insulation faults in the high-voltage system, the insulation faults found in the first test result have been eliminated and are all caused by insulation faults in multiple transmission branches to ground. If the second test result indicates insulation faults still exist in the high-voltage system, troubleshooting and locating the fault can continue.

[0099] In these embodiments, the insulation fault detection is performed again on the target circuit connected to the high-voltage busbar through the insulation monitoring module, so that it is possible to timely detect whether the insulation fault location based on the current value in the early stage has completely eliminated the insulation fault, thereby realizing the verification of the insulation fault location result.

[0100] 6 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, after obtaining the second detection result, the method may further include:

[0101] S650, when the second detection result indicates that the target circuit connected to the high-voltage bus has an insulation fault, disconnecting all target circuits connected to the high-voltage bus;

[0102] S660: Control the transmission branches other than the target transmission branch to be connected to the high-voltage busbar one by one, and control the insulation monitoring module to perform insulation fault detection on the transmission branches connected to the high-voltage busbar one by one.

[0103] Based on the previous embodiment, this embodiment takes into account the situation where the insulation fault cannot be located based on the current value of the transmission branch. At this time, all the remaining target loops that are still connected to the high-voltage bus can be cut off, and then the multiple transmission branches involved in the remaining target loops can be controlled to be connected to the high-voltage bus one by one, so that the insulation monitoring module can perform insulation detection one by one to continue to locate the insulation fault branch in the remaining transmission branches.

[0104] It can be understood that in this embodiment, insulation fault detection is performed one by one only after multiple transmission branches have been excluded from insulation faults to ground. Therefore, in actual application, the number of transmission branches to be detected one by one is reduced, which can reduce the insulation detection time of the energy storage system as a whole.

[0105] Referring to FIG. 7 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, S310 may include:

[0106] S710, obtaining a voltage difference between each transmission branch;

[0107] S720, when the voltage differences between the transmission branches are all less than the voltage threshold, controlling the multiple transmission branches on the energy storage side of the energy storage system to be connected to the high-voltage busbar via corresponding pre-charging circuits, and the high-voltage busbar is provided with an insulation monitoring module.

[0108] By obtaining the voltage difference between each transmission branch and comparing it to a voltage threshold, it is possible to immediately detect circulating currents in the transmission branches due to large voltage differences. If the voltage difference between any two transmission branches is greater than or equal to the voltage threshold, the connection of multiple transmission branches to the high-voltage busbar can be temporarily stopped, and the circuit can be adjusted to eliminate the circulating currents, thereby ensuring the safe operation of the high-voltage system.

[0109] 2 and 7 , based on the above embodiment, another embodiment of the insulation fault detection method of the present application is proposed. In this embodiment, after S320 , the method may further include:

[0110] S730: When the first detection result indicates that the target circuit connected to the high-voltage busbar has no insulation fault, control the switch module to be turned on, and connect the switch module in parallel with the pre-charging circuit;

[0111] S740: After the switch module is turned on for the first time, the pre-charging circuit is cut off.

[0112] Based on the above embodiments, the embodiment of the present application takes into account the situation where all target circuits directly connected to the high-voltage bus have no insulation faults. In this case, before the power conversion system operates, the impedance of the energy storage system's energy storage side to ground meets the requirements. The switch module between the high-voltage bus and the transmission branch, which is connected in parallel with the pre-charging circuit, can be closed. For example, the switch module can be the main positive relay in Figure 2. After the switch module is turned on for a period of time, it indicates that the main circuit on the energy storage side of the energy storage system is operating normally, and the pre-charging circuit can be disconnected at this time.

[0113] It should be noted that the target circuit may include, for example, a first circuit formed by a plurality of transmission branches and a pre-charging circuit, and may also include a circuit where a substation connected to a high-voltage bus is located.

[0114] In these embodiments, a complete implementation scheme for ground insulation detection on the energy storage side of the energy storage system is provided, which can control the normal operation of the power conversion system or continue to perform ground insulation fault detection based on different first detection results, thereby realizing a complete set of safe and efficient ground insulation fault detection logic.

[0115] 1 to 7 above describe in detail an embodiment of the insulation fault detection method of the present application, and the insulation fault detection system and device of the present application will be described later.

[0116] 8 , in one embodiment of the insulation fault detection system of the present application, the system includes:

[0117] A first control module 810 is used to control multiple transmission branches on the energy storage side of the energy storage system to be connected to a high-voltage busbar via corresponding pre-charging circuits. The high-voltage busbar is provided with an insulation monitoring module.

[0118] The second control module 820 is used to control the insulation monitoring module to perform insulation fault detection on the target circuit connected to the high-voltage bus to obtain a first detection result. The target circuit includes multiple first circuits formed by connecting multiple transmission branches to corresponding pre-charging circuits.

[0119] In some embodiments, the above system may further include:

[0120] an acquisition module, configured to respectively acquire current values ​​of the plurality of transmission branches when the first detection result indicates that an insulation fault exists in a target circuit connected to the high-voltage busbar;

[0121] The determination module is used to determine insulation faults of the plurality of transmission branches according to current values ​​of the plurality of transmission branches to obtain a determination result.

[0122] In other embodiments, the determination module is configured to, when the current value of the target transmission branch is not within the first current range, determine that the target transmission branch is an insulation fault branch, and the plurality of transmission branches include the target transmission branch.

[0123] In some further embodiments, the system may further include:

[0124] The cutting module is used to cut off the first loop where the target transmission branch is located when the determination result indicates that the target transmission branch is an insulation fault branch, and the multiple transmission branches include the target transmission branch.

[0125] In some further embodiments, the system may further include:

[0126] The third control module is used to control the insulation monitoring module to perform insulation fault detection on the target circuit to obtain a second detection result.

[0127] In some further embodiments, the above-mentioned disconnection module may also be configured to disconnect all target circuits connected to the high-voltage bus when the second detection result indicates that an insulation fault exists in the target circuit connected to the high-voltage bus;

[0128] The third control module can also be used to control the transmission branches other than the target transmission branch to be connected to the high-voltage bus one by one, and control the insulation monitoring module to perform insulation fault detection on the transmission branches connected to the high-voltage bus one by one.

[0129] In some other embodiments, the first control module 810 can also be used to obtain the voltage difference between each transmission branch; when the voltage difference between each transmission branch is less than the voltage threshold, the multiple transmission branches on the energy storage side of the energy storage system are controlled to be connected to the high-voltage bus through the corresponding pre-charging circuit.

[0130] In some other embodiments, the above-mentioned cut-off module can also be used to control the switch module to be turned on when the first detection result indicates that there is no insulation fault in the target circuit connected to the high-voltage bus, and the switch module is connected in parallel with the pre-charging circuit; after the switch module is turned on for the first time, the pre-charging circuit is cut off.

[0131] In some further embodiments, the transmission branch includes a plurality of energy storage devices connected in series and / or in parallel.

[0132] 9 shows a schematic diagram of the hardware structure of an insulation fault detection device provided in an embodiment of the present application. The insulation fault detection device may include a processor 901 and a memory 902 storing computer program instructions.

[0133] Specifically, the processor 901 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0134] The memory 902 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 902 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 902 may include removable or non-removable (or fixed) media. Where appropriate, the memory 902 may be internal or external to the device. In a specific embodiment, the memory 902 is a non-volatile solid-state memory.

[0135] In certain embodiments, the memory may include read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0136] The processor 901 implements any one of the insulation fault detection methods in the above embodiments by reading and executing computer program instructions stored in the memory 902 .

[0137] In one example, the insulation fault detection device may further include a communication interface 903 and a bus 909. As shown in FIG9 , the processor 901, the memory 902, and the communication interface 903 are connected via the bus 909 and communicate with each other.

[0138] The communication interface 903 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0139] Bus 909 comprises hardware, software or both, couples the parts of equipment to each other.For example, and not limitation, bus can comprise accelerated graphics port (AGP) or other graphics buses, enhanced industry standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industry standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations.In suitable cases, bus 909 can comprise one or more buses.Although the present application embodiment describes and shows specific bus, the application considers any suitable bus or interconnection.

[0140] The insulation fault detection device can execute the insulation fault detection method in the embodiment of the present application, thereby realizing the insulation fault detection method described in combination with the above embodiment.

[0141] In addition, in conjunction with the insulation fault detection method in the above embodiments, embodiments of the present application may provide a computer storage medium or a readable storage medium for implementation. The computer storage medium or the readable storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any of the insulation fault detection methods in the above embodiments is implemented.

[0142] In addition, an embodiment of the present application further provides a computer program product, including a computer program, which can implement the steps and corresponding contents of the aforementioned method embodiment when executed by a processor.

[0143] In addition, an embodiment of the present application further provides an energy storage system, which includes the insulation fault detection device or control system of the above embodiment, or the energy storage system can also execute the above insulation fault detection method.

[0144] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A method for detecting an insulation fault, the method comprising: Controlling multiple transmission branches on the energy storage side of the energy storage system to be connected to a high-voltage busbar via corresponding pre-charging circuits, wherein an insulation monitoring module is provided on the high-voltage busbar; The insulation monitoring module is controlled to perform insulation fault detection on the target circuit connected to the high-voltage bus to obtain a first detection result, where the target circuit includes multiple first circuits formed by connecting multiple transmission branches to corresponding pre-charging circuits.

2. The method according to claim 1, wherein After obtaining the first detection result, the method further includes: When the first detection result indicates that the target circuit connected to the high-voltage bus has an insulation fault, respectively obtaining current values ​​of the plurality of transmission branches; According to the current values ​​of the multiple transmission branches, insulation fault determination is performed on the multiple transmission branches to obtain determination results.

3. The method according to claim 2, wherein: The step of performing insulation fault determination on the plurality of transmission branches according to the current values ​​of the plurality of transmission branches to obtain a determination result includes: When the current value of the target transmission branch is not within the first current range, the determination result indicates that the target transmission branch is an insulation fault branch, and the plurality of transmission branches include the target transmission branch.

4. The method according to claim 2, wherein: After obtaining the determination result, the method further includes: When the determination result indicates that the target transmission branch is an insulation fault branch, the first loop where the target transmission branch is located is cut off, and the plurality of transmission branches include the target transmission branch.

5. The method according to claim 4, wherein After cutting off the first loop where the target transmission branch is located, the method further includes: The insulation monitoring module is controlled to perform insulation fault detection on the target circuit to obtain a second detection result.

6. The method according to claim 5, wherein: After obtaining the second detection result, the method further includes: When the second detection result indicates that the target circuit connected to the high-voltage bus has an insulation fault, cutting off all the target circuits connected to the high-voltage bus; The transmission branches other than the target transmission branch are controlled to be connected to the high-voltage bus one by one, and the insulation monitoring module is controlled to perform insulation fault detection on the transmission branches connected to the high-voltage bus one by one.

7. The method according to claim 1, wherein Before the plurality of transmission branches on the energy storage side of the control energy storage system are connected to the high-voltage busbar via corresponding pre-charging circuits, the method further includes: Obtaining a voltage difference between the transmission branches; When the voltage difference between each of the transmission branches is less than the voltage threshold, the step of controlling the multiple transmission branches on the energy storage side of the energy storage system to be connected to the high-voltage bus through the corresponding pre-charging circuit is executed.

8. The method according to claim 1, wherein After obtaining the first detection result, the method further includes: When the first detection result indicates that the target circuit connected to the high-voltage bus has no insulation fault, controlling the switch module to be turned on, and the switch module is connected in parallel with the pre-charging circuit; After the switch module is turned on for a first time, the pre-charging circuit is cut off.

9. The method according to claim 1, wherein: The transmission branch includes a plurality of energy storage devices connected in series and / or in parallel.

10. An insulation fault detection system, comprising: A first control module is used to control multiple transmission branches on the energy storage side of the energy storage system to be connected to a high-voltage busbar via corresponding pre-charging circuits, and an insulation monitoring module is provided on the high-voltage busbar; The second control module is used to control the insulation monitoring module to perform insulation fault detection on the target circuit connected to the high-voltage bus to obtain a first detection result. The target circuit includes multiple first circuits formed by connecting multiple transmission branches to the corresponding pre-charging circuits.

11. An insulation fault detection device, comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the insulation fault detection method according to any one of claims 1 to 9. 12 . An insulation fault detection device, configured to execute the steps of the insulation fault detection method according to claim 1 .

13. An energy storage system, comprising the insulation fault detection device according to claim 11 or 12.

14. A readable storage medium storing a program or instruction, wherein the program or instruction, when executed by a processor, implements the steps of the insulation fault detection method according to any one of claims 1 to 9. 15 . A computer program product, wherein the computer program product can be executed by a processor to implement the steps of the insulation fault detection method according to claim 1 .

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