Method and system for identifying failure mode of hybrid direct-current circuit breaker

Abstract

The invention discloses a method and a system for identifying a failure mode of a hybrid direct-current circuit breaker, and belongs to the technical field of electrical equipment. The method comprises the following steps: when the direct current side of the flexible direct current power grid has a fault, identifying the fault of the direct current side through line protection, and sending an action command to a hybrid direct current circuit breaker responsible for removing the fault; based on the action command, after fault current is transferred to an energy consumption branch of the hybrid direct current circuit breaker, a failure coefficient of the hybrid direct current circuit breaker is calculated in real time; and identifying the failure mode of the hybrid DC circuit breaker according to the failure coefficient value calculated in real time and the evaluation model. The operation state of the hybrid direct current circuit breaker can be monitored in real time, the failure coefficient of the hybrid direct current circuit breaker is calculated, and the failure mode of the hybrid direct current circuit breaker is evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment, and more particularly to a method and system for identifying a failure mode of a hybrid DC circuit breaker. Background Art

[0002] Flexible DC transmission system is an important support for the rapid development of new power system forms such as renewable energy, smart grid and energy storage. With the development of power electronic devices and relay protection technology, flexible DC transmission technology based on modular multilevel converter has obvious advantages and has high development potential in flexible DC transmission system. Flexible DC transmission projects are constantly developing in the direction of high voltage and large capacity, which improves the normal operation level of current in flexible DC transmission system, but also increases the difficulty of clearing and isolating fault current in case of DC side fault.

[0003] At present, DC circuit breakers are ideal fault current clearing electrical equipment for flexible DC systems. Hybrid DC circuit breakers have lower normal operating losses, faster fault clearing speed and lower investment costs. They are DC circuit breakers with better overall performance and are deployed in many flexible DC demonstration projects. However, hybrid DC circuit breakers involve multiple devices such as fast mechanical switches, fully controlled power electronic devices, lightning arresters, etc., including multiple branches such as current branches, commutation branches and energy consumption branches. Therefore, there is a risk of some components failing during the operation of hybrid DC circuit breakers or even the entire set of DC circuit breakers refusing to operate. Summary of the invention

[0004] In view of the above problems, the present invention proposes a method for hybrid DC circuit breaker failure mode identification, comprising:

[0005] When a fault occurs on the DC side of the flexible DC grid, the DC side fault is identified through line protection, and an action command is issued to the hybrid DC circuit breaker responsible for clearing the fault.

[0006] Based on the action command, after the fault current is transferred to the energy consumption branch of the hybrid DC circuit breaker, the failure coefficient of the hybrid DC circuit breaker is calculated in real time;

[0007] According to the failure coefficient value calculated in real time and according to the evaluation model, the failure mode of the hybrid DC circuit breaker is identified.

[0008] Optionally, a calculation formula for calculating the failure coefficient of the hybrid DC circuit breaker in real time is as follows:

[0009]

[0010] Among them, K DCCB is the failure coefficient, U DCCB Terminal voltage of hybrid DC circuit breaker, IDCCB is the fault current flowing through the hybrid DC circuit breaker, f DCCB (I DCCB ) is in I DCCB The ideal operating voltage of the lightning arrester reflected by the lightning arrester's volt-ampere characteristic curve under current level.

[0011] Optionally, evaluate the model as follows:

[0012] K DCCB >K, DC circuit breaker operates normally

[0013] Partial failure of DC circuit breaker

[0014] Complete failure of DC circuit breaker

[0015] Among them, K DCCB is the failure coefficient, K is the reliability coefficient, n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

[0016] Optionally, a hybrid DC circuit breaker includes: a current-carrying branch, a current-commutating branch and an energy-consuming branch;

[0017] The flow branch, the commutation branch and the energy consumption branch are connected in parallel;

[0018] The energy consumption branch includes: a plurality of groups of lightning arresters;

[0019] The multiple groups of lightning arresters are connected in series and parallel.

[0020] In another aspect, the present invention provides a hybrid DC circuit breaker failure mode identification system, comprising:

[0021] An initial judgment unit is used to identify the DC side fault through line protection when a fault occurs on the DC side of the flexible DC grid, and issue an action command to the hybrid DC circuit breaker responsible for removing the fault;

[0022] A real-time calculation unit, configured to calculate the failure coefficient of the hybrid DC circuit breaker in real time after transferring the fault current to the energy consumption branch of the hybrid DC circuit breaker based on the action command;

[0023] The identification unit is used to identify the failure mode of the hybrid DC circuit breaker according to the failure coefficient value calculated in real time and according to the evaluation model.

[0024] Optionally, a calculation formula for calculating the failure coefficient of the hybrid DC circuit breaker in real time is as follows:

[0025]

[0026] Among them, KDCCB is the failure coefficient, U DCCB Terminal voltage of hybrid DC circuit breaker, I DCCB is the fault current flowing through the hybrid DC circuit breaker, f DCCB (I DCCB ) is in I DCCB The ideal operating voltage of the lightning arrester reflected by the lightning arrester's volt-ampere characteristic curve under current level.

[0027] Optionally, evaluate the model as follows:

[0028] K DCCB >K, DC circuit breaker operates normally

[0029] Partial failure of DC circuit breaker

[0030] Complete failure of DC circuit breaker

[0031] Among them, K DCCB is the failure coefficient, K is the reliability coefficient, n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

[0032] Optionally, a hybrid DC circuit breaker includes: a current-carrying branch, a current-commutating branch and an energy-consuming branch;

[0033] The flow branch, the commutation branch and the energy consumption branch are connected in parallel;

[0034] The energy consumption branch includes: a plurality of groups of lightning arresters;

[0035] The multiple groups of lightning arresters are connected in series and parallel.

[0036] In yet another aspect, the present invention further provides a computing device, comprising: one or more processors;

[0037] a processor for executing one or more programs;

[0038] When the one or more programs are executed by the one or more processors, the above-described method is implemented.

[0039] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, the method described above is implemented.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention provides a method for identifying a failure mode of a hybrid DC circuit breaker, comprising: when a fault occurs on the DC side of a flexible DC power grid, identifying the DC side fault through line protection, and issuing an action command to a hybrid DC circuit breaker responsible for removing the fault; based on the action command, transferring the fault current to the energy-consuming branch of the hybrid DC circuit breaker, and calculating the failure coefficient of the hybrid DC circuit breaker in real time; and identifying the failure mode of the hybrid DC circuit breaker according to the failure coefficient value calculated in real time and an evaluation model. The present invention can monitor the operating status of a hybrid DC circuit breaker in real time, calculate the failure coefficient of a hybrid DC circuit breaker, and evaluate the failure mode of a hybrid DC circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a flow chart of the method of the present invention;

[0043] Figure 2 A schematic diagram of a flexible DC power grid according to an embodiment of the method of the present invention;

[0044] Figure 3 A schematic diagram of a hybrid DC circuit breaker according to an embodiment of the method of the present invention;

[0045] Figure 4 It is a failure coefficient output result diagram of the hybrid DC circuit breaker failure mode identification method of the method embodiment of the present invention;

[0046] Figure 5 It is a failure mode output result diagram of the hybrid DC circuit breaker failure mode identification method of the method embodiment of the present invention;

[0047] Figure 6 It is a structural diagram of the system of the present invention. DETAILED DESCRIPTION

[0048] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0049] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0050] Embodiment 1:

[0051] The present invention proposes a hybrid DC circuit breaker failure mode identification method, such as Figure 1 As shown, including:

[0052] Step 1: When a fault occurs on the DC side of the flexible DC grid, the DC side fault is identified through line protection, and an action command is issued to the hybrid DC circuit breaker responsible for removing the fault;

[0053] Step 2: after transferring the fault current to the energy consumption branch of the hybrid DC circuit breaker based on the action command, calculating the failure coefficient of the hybrid DC circuit breaker in real time;

[0054] Step 3: According to the failure coefficient value calculated in real time and the evaluation model, the failure mode of the hybrid DC circuit breaker is identified.

[0055] The calculation formula for calculating the failure coefficient of the hybrid DC circuit breaker in real time is as follows:

[0056]

[0057] Among them, K DCCB is the failure coefficient, U DCCB Terminal voltage of hybrid DC circuit breaker, I DCCB is the fault current flowing through the hybrid DC circuit breaker, f DCCB (I DCCB ) is in i DCCB The ideal operating voltage of the lightning arrester reflected by the lightning arrester's volt-ampere characteristic curve under current level.

[0058] Among them, the evaluation model is as follows:

[0059] K DCCB >K, DC circuit breaker operates normally

[0060] Partial failure of DC circuit breaker

[0061] DC circuit breaker complete failure

[0062] Among them, K DCCB is the failure coefficient, K is the reliability coefficient, n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

[0063] Among them, the hybrid DC circuit breaker includes: a current-carrying branch, a current-commutating branch and an energy-consuming branch;

[0064] The flow branch, the commutation branch and the energy consumption branch are connected in parallel;

[0065] The energy consumption branch includes: a plurality of groups of lightning arresters;

[0066] The multiple groups of lightning arresters are connected in series and parallel.

[0067] The present invention is further described below with reference to specific cases:

[0068] During the implementation process, when a DC side fault occurs in the flexible DC grid, the failure mode of the operated hybrid DC circuit breaker responsible for clearing the fault is identified, and the failure coefficient of the DC circuit breaker is calculated in real time to evaluate the failure mode of the hybrid DC circuit breaker. Moreover, the flexible DC grid is a DC grid based on a modular multilevel converter, and the flexible DC grid is equipped with a hybrid DC circuit breaker for clearing and isolating DC faults. The specific implementation steps include:

[0069] S1. When a fault occurs on the DC side of the flexible DC grid, the line protection identifies the fault and sends an action command to the hybrid DC circuit breaker responsible for clearing the fault;

[0070] S2, waiting for the current to transfer to the energy consumption branch, the failure mode recognition method of the hybrid DC circuit breaker takes effect, and the failure coefficient of the hybrid DC circuit breaker is calculated in real time, which is expressed by the following formula:

[0071]

[0072] Where: K DCCB is the failure coefficient of hybrid DC circuit breaker;

[0073] U DCCB is the terminal voltage of the hybrid DC circuit breaker;

[0074] I DCCB is the fault current flowing through the hybrid DC circuit breaker;

[0075] f DCCB (I) is the arrester volt-ampere characteristic curve provided by the manufacturer.

[0076] S3. According to the real-time calculated value of the failure coefficient of the hybrid DC circuit breaker, the failure mode of the hybrid DC circuit breaker is evaluated, which is expressed by the following formula:

[0077] K DCCB >K, DC circuit breaker operates normally

[0078] Partial failure of DC circuit breaker

[0079] Complete failure of DC circuit breaker

[0080] Where: K DCCB is the failure coefficient of hybrid DC circuit breaker;

[0081] K is the reliability coefficient, which is taken as 0.95;

[0082] n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

[0083] Moreover, according to the hybrid DC circuit breaker failure mode identification method of claim 1, it is characterized in that: the hybrid DC circuit breaker is composed of a current-carrying branch, a current-commutating branch and an energy-consuming branch in parallel, wherein the energy-consuming branch is composed of a plurality of groups of lightning arresters connected in series and in parallel.

[0084] like Figure 2 As shown, the flexible DC grid used in the present invention adopts a modular multi-level converter.

[0085] like Figure 3 As shown, the hybrid DC circuit breaker used in the present invention includes a current-carrying branch, a current-converting branch and an energy-consuming branch, wherein the energy-consuming branch is composed of lightning arresters connected in series and in parallel.

[0086] In the example of the present invention, a fault is set to occur at 1.00s in the middle of the line between MMC1 and MMC2, and different failure states of DCCB2 are set.

[0087] In the example of the present invention, the hybrid DC circuit breaker failure mode recognition method is as follows: when a fault occurs on the DC side of the flexible DC grid, the line protection recognizes the fault and sends an action command to the hybrid DC circuit breaker responsible for removing the fault; while waiting for the current to be transferred to the energy-consuming branch, the hybrid DC circuit breaker failure mode recognition method takes effect, and the hybrid DC circuit breaker failure coefficient is calculated in real time, which is represented by the following formula:

[0088]

[0089] Where: K DCCB is the failure coefficient of hybrid DC circuit breaker;

[0090] U DCCB is the terminal voltage of the hybrid DC circuit breaker;

[0091] I DCCB is the fault current flowing through the hybrid DC circuit breaker;

[0092] f DCCB (I) is the arrester volt-ampere characteristic curve provided by the manufacturer.

[0093] In the example of the present invention, the failure mode of the hybrid DC circuit breaker is evaluated according to the real-time calculated value of the failure coefficient of the hybrid DC circuit breaker, which is expressed by the following formula:

[0094] K DCCB >K, DC circuit breaker operates normally

[0095] Partial failure of DC circuit breaker

[0096] Complete failure of DC circuit breaker

[0097] Where: K DCCB is the failure coefficient of hybrid DC circuit breaker;

[0098] K is the reliability coefficient, which is taken as 0.95;

[0099] n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

[0100] The hybrid DC circuit breaker failure mode recognition method of the present invention is simulated by using a flexible DC grid. The parameters of the flexible DC grid are set as: rated DC voltage ±500kV, rated active power 1500MW, smoothing reactor 300mH; the parameters of the modular multilevel converter station are set as: submodule capacitance 1500μF, bridge arm inductance 50mH, and the number of submodules 220; the fault setting is: a single-pole metallic grounding fault occurs in the middle of a line with a total length of 100km; the parameters of the hybrid DC circuit breaker DCCB2 are set as: the capacitance in the RC buffer branch is 0.2μF, the resistance is 7.5Ω, and the number of lightning arresters is 10 (n SM =10), the rated voltage of the arrester is 500 kV. The failure modes of the hybrid DC circuit breaker are set as follows: the rated voltage of the arrester in actual normal operation is 500 kV, 450 kV, 400 kV, 250 kV, 100 kV and 50 kV, and the auxiliary commutation switch fails.

[0101] Figure 4 and 5 The output result of the hybrid DC circuit breaker failure mode recognition method provided by the present invention in a specific embodiment is shown. Figure 4 The failure coefficient output result of the hybrid DC circuit breaker failure mode identification method; Figure 5 The failure mode output results of the hybrid DC circuit breaker failure mode identification method are implemented.

[0102] The fault occurred at 1.000s, the hybrid DC circuit breaker operated at 1.003s, and the fault current was transferred to the energy consumption branch at 1.005s. The failure mode recognition method took effect. K DCCB When the rated voltage of the arrester is 500kV, K DCCB When the rated voltage of the arrester is set to 450-50 kV, K DCCB are approximately 0.9, 0.8, 0.5, 0.2 and 0.1 respectively, and the failure mode of the DC circuit breaker is partial failure. In the case of auxiliary commutation switch failure, KDCCB The output is about 0, and the failure mode is complete failure. For arresters with rated voltages of 500kV, 450kV, and 400kV, K DCCB It will jump to a negative value after the fault current decays to 5A, which exceeds the effective detection time and can be ignored.

[0103] The present invention can monitor the operating state of the hybrid DC circuit breaker in real time, calculate the failure coefficient of the hybrid DC circuit breaker, and evaluate the failure mode of the hybrid DC circuit breaker.

[0104] The present invention only needs to obtain the terminal voltage of the hybrid DC circuit breaker, the fault current flowing through the hybrid DC circuit breaker and the arrester volt-ampere characteristic curve data provided by the manufacturer, without the need to install additional electrical measuring equipment.

[0105] The present invention provides reference data for the safe operation and subsequent maintenance of the hybrid DC circuit breaker.

[0106] Embodiment 2:

[0107] The present invention proposes a hybrid DC circuit breaker failure mode recognition system 200, such as Figure 6 As shown, including:

[0108] The initial judgment unit 201 is used to identify the DC side fault through line protection when a fault occurs on the DC side of the flexible DC grid, and issue an action command to the hybrid DC circuit breaker responsible for clearing the fault;

[0109] A real-time calculation unit 202, configured to calculate the failure coefficient of the hybrid DC circuit breaker in real time after transferring the fault current to the energy consumption branch of the hybrid DC circuit breaker based on the action command;

[0110] The identification unit 203 is used to identify the failure mode of the hybrid DC circuit breaker according to the failure coefficient value calculated in real time and according to the evaluation model.

[0111] The calculation formula for calculating the failure coefficient of the hybrid DC circuit breaker in real time is as follows:

[0112]

[0113] Among them, K DCCB is the failure coefficient, U DCCB Terminal voltage of hybrid DC circuit breaker, I DCCB is the fault current flowing through the hybrid DC circuit breaker, f DCCB (I DCCB ) is in I DCCB The ideal operating voltage of the lightning arrester reflected by the lightning arrester's volt-ampere characteristic curve under current level.

[0114] Among them, the evaluation model is as follows:

[0115] K DCCB >K, DC circuit breaker operates normally

[0116] Partial failure of DC circuit breaker

[0117] Complete failure of DC circuit breaker

[0118] Among them, K DCCB is the failure coefficient, K is the reliability coefficient, n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

[0119] Among them, the hybrid DC circuit breaker includes: a current-carrying branch, a current-commutating branch and an energy-consuming branch;

[0120] The flow branch, the commutation branch and the energy consumption branch are connected in parallel;

[0121] The energy consumption branch includes: a plurality of groups of lightning arresters;

[0122] The multiple groups of lightning arresters are connected in series and parallel.

[0123] The present invention can monitor the operating state of the hybrid DC circuit breaker in real time, calculate the failure coefficient of the hybrid DC circuit breaker, and evaluate the failure mode of the hybrid DC circuit breaker.

[0124] Embodiment 3:

[0125] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the method in the above embodiment.

[0126] Embodiment 4:

[0127] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both a built-in storage medium in a computer device and an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiment.

[0128] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0129] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0133] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for identifying failure mode of a hybrid DC circuit breaker, characterized in that: include: When a fault occurs on the DC side of the flexible DC grid, the DC side fault is identified through line protection, and an action command is issued to the hybrid DC circuit breaker responsible for clearing the fault. Based on the action command, after the fault current is transferred to the energy consumption branch of the hybrid DC circuit breaker, the failure coefficient of the hybrid DC circuit breaker is calculated in real time; According to the failure coefficient value calculated in real time and according to the evaluation model, the failure mode of the hybrid DC circuit breaker is identified.

2. The method according to claim 1, characterized in that The calculation formula for calculating the failure coefficient of the hybrid DC circuit breaker in real time is as follows: Among them, k DCCB is the failure coefficient, U DCCB is the terminal voltage of the hybrid DC circuit breaker, I DCCB is the fault current flowing through the hybrid DC circuit breaker, f DCCB (I DCCB ) is in I DCCB The ideal operating voltage of the lightning arrester reflected by the lightning arrester's volt-ampere characteristic curve under current level.

3. The method according to claim 1, characterized in that The evaluation model is as follows: K DCCB >K, DC circuit breaker operates normally Partial failure of DC circuit breaker DC circuit breaker complete failure Among them, K DCCB is the failure coefficient, K is the reliability coefficient, n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

4. The method according to claim 1, characterized in that The hybrid DC circuit breaker comprises: a current-carrying branch, a current-commutating branch and an energy-consuming branch; The flow branch, the commutation branch and the energy consumption branch are connected in parallel; The energy consumption branch includes: a plurality of groups of lightning arresters; The multiple groups of lightning arresters are connected in series and parallel.

5. A hybrid DC circuit breaker failure mode recognition system, characterized in that: include: An initial judgment unit is used to identify the DC side fault through line protection when a fault occurs on the DC side of the flexible DC grid, and issue an action command to the hybrid DC circuit breaker responsible for removing the fault; A real-time calculation unit, configured to calculate the failure coefficient of the hybrid DC circuit breaker in real time after transferring the fault current to the energy consumption branch of the hybrid DC circuit breaker based on the action command; The identification unit is used to identify the failure mode of the hybrid DC circuit breaker according to the failure coefficient value calculated in real time and according to the evaluation model.

6. The system according to claim 5, characterized in that The calculation formula for calculating the failure coefficient of the hybrid DC circuit breaker in real time is as follows: Among them, K DCCB is the failure coefficient, U DCCB Terminal voltage of hybrid DC circuit breaker, I DCCB is the fault current flowing through the hybrid DC circuit breaker, f DCCB (I DCCB ) is in I DCCB The ideal operating voltage of the lightning arrester reflected by the lightning arrester's volt-ampere characteristic curve under current level.

7. The system according to claim 5, characterized in that The evaluation model is as follows: K DCCB >K, DC circuit breaker operates normally Partial failure of DC circuit breaker DC circuit breaker complete failure Among them, K DCCB is the failure coefficient, K is the reliability coefficient, n SM is the number of lightning arresters configured in the hybrid DC circuit breaker.

8. The system according to claim 5, characterized in that The hybrid DC circuit breaker comprises: a current-carrying branch, a current-commutating branch and an energy-consuming branch; The flow branch, the commutation branch and the energy consumption branch are connected in parallel; The energy consumption branch includes: a plurality of groups of lightning arresters; The multiple groups of lightning arresters are connected in series and parallel.

9. A computer device, characterized in that: include: one or more processors; a processor for executing one or more programs; When the one or more programs are executed by the one or more processors, the method according to any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method according to any one of claims 1 to 4 is implemented.

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