Arc extinguishing method and system of power distribution network passive type voltage-current coordinated injection

Abstract

The application relates to the technical field of power system relay protection, in particular to an arc extinguishing method and system of passive voltage-current coordinated injection of a distribution network. After a single-phase grounding fault occurs in a distribution line, fault phase selection is performed, according to the phase selection information, a passive arc extinguishing transformer generates a reverse voltage of a fault phase and inputs the reverse voltage into a neutral point to clamp the voltage of the fault point; the change amount of a zero sequence voltage is tracked, the capacity of an arc extinguishing coil is adjusted, the residual current of the fault is further reduced, and natural arc extinguishing is realized. The application aims to solve the problem of how to realize the application of the passive arc extinguishing device in multiple fault scenes.

Description

Technical Field

[0001] This application relates to the field of power system relay protection technology, and in particular to a passive voltage-current coordinated injection arc extinguishing method and system for distribution networks. Background Technology

[0002] As the proportion of cable lines in power distribution networks increases, the capacitance to ground increases when a single-phase ground fault occurs. The arc caused by the large ground current generated during the fault is difficult to extinguish on its own. Long-term operation will accelerate the wear and tear of equipment and lines in the system, and may even cause wildfires in extreme cases.

[0003] For arc suppression in single-phase grounding faults, the commonly used solution is to inject compensation current or reduce voltage through active arc suppression devices. However, active arc suppression devices rely on external power sources for control and the control method is relatively complex. Currently, they are mainly configured in new energy power plants (such as photovoltaic / wind power collection lines). For traditional distribution networks with ungrounded neutral points, due to the high configuration and maintenance costs of active arc suppression devices, passive arc suppression devices are mostly used for arc suppression.

[0004] However, one of the drawbacks of traditional passive arc suppression devices is that they are difficult to apply in high-resistance grounding fault scenarios: the compensation current of passive arc suppression devices is determined by the coil inductance and system voltage, while the compensation current required for high-resistance grounding faults is relatively small. However, the compensation current output by traditional passive arc suppression devices cannot be dynamically adjusted with the change of fault resistance, so it is easy to generate excessive compensation current, resulting in overcompensation and failure to extinguish the arc.

[0005] In view of this, this application proposes a passive voltage-current coordinated injection arc extinguishing method and system for power distribution networks, aiming to realize the application of passive arc extinguishing devices in multiple fault scenarios. Summary of the Invention

[0006] The main purpose of this application is to provide a passive voltage-current coordinated injection arc extinguishing method for power distribution networks, aiming to solve the problem of how to realize the application of passive arc extinguishing devices in multiple fault scenarios.

[0007] To achieve the above objectives, this application provides a passive voltage-current coordinated injection arc extinguishing method for distribution networks, the method comprising:

[0008] Step 1: After a single-phase ground fault occurs in the distribution network, the fault phase is selected;

[0009] Step 2: Based on the phase selection results, the passive arc suppression transformer generates a fault-reverse voltage and connects it to the neutral point to clamp the fault point voltage.

[0010] Step 3: Obtain the zero-sequence voltage of the bus and calculate the change in the zero-sequence voltage of the bus;

[0011] Step 4: Track the change in the zero-sequence voltage of the bus and adjust the capacity of the arc suppression coil to further reduce the fault residual current;

[0012] Step 5: The fault phase voltage and the fault point current are both effectively clamped, and the fault point arc is extinguished.

[0013] Optionally, Step 1 includes:

[0014] Collect the phase voltage values ​​of each phase circuit in the distribution network;

[0015] Determine whether the phase voltage value is less than a preset phase voltage threshold;

[0016] If so, it is determined that a single-phase ground fault has occurred in the power distribution network.

[0017] Optionally, the passive arc-suppression transformer includes one main core magnetic circuit, three transformer magnetic circuits, and twelve windings. The first, second, third, fourth, fifth, and sixth windings are wound within the main core magnetic circuit. The first, second, and third windings are arranged concentrically or overlappingly on one core column of the main core magnetic circuit, and the fourth, fifth, and sixth windings are arranged concentrically or overlappingly on another core column of the main core magnetic circuit. The seventh and tenth windings are arranged concentrically or overlappingly symmetrically on two core columns of the first transformer magnetic circuit, the eighth and eleventh windings are arranged concentrically or overlappingly symmetrically on two core columns of the second transformer magnetic circuit, and the ninth and twelfth windings are arranged concentrically or overlappingly symmetrically on two core columns of the third transformer magnetic circuit.

[0018] Optionally, the power distribution network includes phase A, phase B, and phase C, wherein the first ends of the fourth, seventh, and tenth windings are connected to the busbars of phase B, phase C, and phase A, respectively, and the ends are connected together; the first ends of the fifth, eighth, and eleventh windings are connected to the busbars of phase B, phase C, and phase A, respectively, and the ends are connected together; the first ends of the sixth, ninth, and twelfth windings are connected to the busbars of phase B, phase C, and phase A, respectively, and the ends are connected together.

[0019] Optionally, Step 3 includes:

[0020] Collect the zero-sequence voltage of the busbar at at least two consecutive moments in the distribution network;

[0021] Calculate the change in the zero-sequence voltage of the bus.

[0022] Optionally, Step 4 includes:

[0023] When the change in the zero-sequence voltage of the bus is less than a preset change threshold, the capacity of the arc suppression coil is reduced.

[0024] Furthermore, to achieve the above objectives, this application also provides a passive voltage-current coordinated injection arc extinguishing system for power distribution networks, characterized in that the passive voltage-current coordinated injection arc extinguishing system for power distribution networks comprises:

[0025] The fault phase selection module is used to select the fault phase after a single-phase ground fault occurs in the distribution network.

[0026] The voltage arc suppression module is used to generate a fault-opposite voltage from the passive arc suppression transformer based on the phase selection result and connect it to the neutral point to clamp the fault point voltage.

[0027] The arc suppression mode switching discrimination module is used to obtain the bus zero-sequence voltage, calculate the change in the bus zero-sequence voltage, and track the change in the bus zero-sequence voltage.

[0028] The current arc suppression module is used to adjust the capacity of the arc suppression coil to further reduce the residual current in the fault.

[0029] In addition, to achieve the above objectives, this application also provides a computer system comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the passive voltage-current coordinated injection arc extinguishing method for distribution networks as described in any of the preceding claims.

[0030] In addition, to achieve the above objectives, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the passive voltage-current coordinated injection arc extinguishing method for distribution networks as described in any of the preceding claims.

[0031] This application has at least the following beneficial effects:

[0032] 1. The magnitude of the change in the zero-sequence voltage of the bus is used as the criterion for whether to adjust the capacity of the arc suppression coil. When the change is less than the threshold, it is determined that the coil capacity needs to be reduced to reduce the fault residual current. The combination of voltage arc suppression and current arc suppression overcomes the problem of poor arc suppression effect when using single voltage arc suppression or current arc suppression.

[0033] 2. Provide a passive arc suppression transformer with adjustable arc suppression coil capacity to adjust the magnitude of the compensation current, so as to realize the application of passive arc suppression device in multiple scenarios under high resistance / low resistance fault conditions.

[0034] 3. Compared with active arc suppression technology, passive arc suppression transformers do not require power electronic equipment and components, have low cost and high reliability, and do not require an external power supply and are not limited by capacity. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the first embodiment of the passive voltage-current coordinated injection arc extinguishing method for distribution networks in this application.

[0036] Figure 2 This is a schematic diagram of the adjustable arc suppression transformer involved in the embodiments of this application;

[0037] Figure 3 This is a topology diagram of the power distribution network involved in the embodiments of this application;

[0038] Figure 4 This application provides a diagram showing the waveform and effective value of the zero-sequence voltage of the distribution network bus in an embodiment of the present application.

[0039] Figure 5 The present application provides a diagram showing the voltage waveform and effective value of the fault point in the embodiments of this application.

[0040] Figure 6 The present application provides a diagram showing the current waveform and RMS value at the fault point in the embodiments of this application.

[0041] Figure 7 The above is a waveform diagram of the voltage of the passive arc suppression transformer and the voltage of the fault phase involved in the embodiments of this application;

[0042] Figure 8 This is a schematic diagram of the hardware operating environment of the computer system according to an embodiment of this application.

[0043] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0044] To better understand the above technical solutions, exemplary embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0045] First Embodiment

[0046] Reference Figure 1 This embodiment provides a passive voltage-current coordinated injection arc extinguishing method for power distribution networks, the method comprising the following steps:

[0047] Step 1: After a single-phase ground fault occurs in the distribution network, the fault phase is selected;

[0048] In this step, after a single-phase ground fault occurs in the distribution network, fault phase selection is performed. Based on the phase selection results, the fault phase is determined, and a reverse voltage equal to and opposite to the voltage of the fault phase is generated by a passive arc suppression transformer and connected to the neutral point to clamp the voltage at the fault point.

[0049] Further and optionally, whether a single-phase ground fault has occurred in the distribution network can be determined by collecting the phase voltage values ​​in each phase circuit of the distribution network and judging the magnitude of the phase voltage values ​​with a preset phase voltage threshold. If the value is less than the threshold, it is considered that a single-phase ground fault has been detected in the distribution network.

[0050] Step 2: Based on the phase selection results, the passive arc suppression transformer generates a fault-reverse voltage and connects it to the neutral point to clamp the fault point voltage.

[0051] Step 3: Obtain the zero-sequence voltage of the bus and calculate the change in the zero-sequence voltage of the bus;

[0052] Step 4: Track the change in the zero-sequence voltage of the bus and adjust the capacity of the arc suppression coil to further reduce the fault residual current;

[0053] Step 5: The fault phase voltage and the fault point current are both effectively clamped, and the fault point arc is extinguished.

[0054] In some alternative implementations, the bus zero-sequence voltage can be acquired using a zero-sequence voltage transformer.

[0055] For example, the change in bus zero-sequence voltage The calculation expression is:

[0056]

[0057] When selecting two consecutive moments , Bus zero-sequence voltage , To calculate the change Then:

[0058]

[0059] In this embodiment, when the change in the zero-sequence voltage of the bus is less than the preset change threshold, it means that the compensation current provided by the current arc suppression coil capacity is too large. Therefore, it is necessary to reduce the arc suppression coil capacity to provide a smaller compensation current in order to reduce the fault residual current.

[0060] In some alternative implementations, when it is necessary to reduce the capacity of the arc suppression coil, the number of transformer magnetic circuits connected to the main iron core magnetic circuit is increased or decreased by switching the taps on the winding of the arc suppression coil. When one of the taps is disconnected, the number of transformer magnetic circuits connected to the main iron core magnetic circuit decreases, thereby reducing the capacity of the arc suppression coil; conversely, it increases.

[0061] In the technical solution provided in this embodiment, the magnitude of the change in the zero-sequence voltage of the bus is used as the criterion for whether to adjust the capacity of the arc suppression coil. When the change is less than the threshold, it is determined that the coil capacity needs to be reduced to reduce the fault residual current. In addition, a passive arc suppression transformer with adjustable arc suppression coil capacity is provided to adjust the magnitude of the compensation current, so as to realize the application of the passive arc suppression device in multiple scenarios under high resistance / low resistance fault conditions.

[0062] Second Embodiment

[0063] To achieve an adjustable arc-suppression transformer capacity, this embodiment also provides a structure for an adjustable passive arc-suppression transformer, including:

[0064] The reverse voltage output unit is used to input the reverse voltage of the fault to the neutral point of the distribution network;

[0065] An adjustable arc suppression transformer includes a main core magnetic circuit and multiple transformer magnetic circuits that match the number of phases in the distribution network. The main core magnetic circuit and the transformer magnetic circuits are connected by arc suppression coils wound on their respective core columns, so that the capacity of the arc suppression coil can be reduced by switching the taps on the windings of the arc suppression coils.

[0066] Its working principle is as follows: When it is necessary to reduce the capacity of the arc suppression coil, the number of transformer magnetic circuits connected to the main iron core magnetic circuit is increased / decreased by switching the taps on the winding of the arc suppression coil. When one of the taps is disconnected, the number of transformer magnetic circuits connected to the main iron core magnetic circuit is reduced, thereby reducing the capacity of the arc suppression coil; conversely, it is increased.

[0067] Further and optionally, the two taps extending from one end of the arc suppression coil are respectively wound with the core columns at both ends of the main core magnetic circuit to form two windings, and the other end is wound with one core column of the transformer magnetic circuit to form a winding, and is symmetrically arranged with another winding on the other core column of the transformer magnetic circuit.

[0068] In some alternative implementations, refer to Figure 2The schematic diagram shown illustrates the structure of an adjustable passive arc-suppression transformer. The adjustable passive arc-suppression transformer includes a main core magnetic circuit 1, three transformer magnetic circuits: a first transformer magnetic circuit 2, a second transformer magnetic circuit 3, and a third transformer magnetic circuit 4, and 12 windings. The first winding 5, the second winding 6, the third winding 7, the fourth winding 8, the fifth winding 9, and the sixth winding 10 are wound within the main core magnetic circuit 1. The first winding 5, the second winding 6, and the third winding 7 are arranged concentrically or overlappingly on one core column of the main core magnetic circuit. The fourth winding 8, the fifth winding 9, and the sixth winding 10 are arranged concentrically or overlappingly on another core column of the main core magnetic circuit; the seventh winding 11 and the tenth winding 14 are arranged concentrically or overlappingly symmetrically on two core columns of the first transformer magnetic circuit 2; the eighth winding 12 and the eleventh winding 15 are arranged concentrically or overlappingly symmetrically on two core columns of the second transformer magnetic circuit 3; and the ninth winding 13 and the twelfth winding 16 are arranged concentrically or overlappingly symmetrically on two core columns of the third transformer magnetic circuit 4.

[0069] In some alternative embodiments, the distribution network includes phase A, phase B, and phase C. The first ends of the fourth winding 8, the seventh winding 11, and the tenth winding 14 are connected to the busbars of phase B, phase C, and phase A, respectively, and the ends are connected together. The first ends of the fifth winding 9, the eighth winding 12, and the eleventh winding 15 are connected to the busbars of phase B, phase C, and phase A, respectively, and the ends are connected together. The first ends of the sixth winding 10, the ninth winding 13, and the twelfth winding 16 are connected to the busbars of phase B, phase C, and phase A, respectively, and the ends are connected together.

[0070] Furthermore, as an implementation scheme, this embodiment provides a simulated arc extinguishing example using the adjustable passive arc extinguishing device provided in the embodiments of this application, and establishes a simulation of arc extinguishing using PSCAD / EMTDC. Figure 3The distribution network simulation model shown has five outgoing lines in a 110kV / 10kV substation: three overhead lines (L1=8km, L3=24km, L4=16km) and two cable lines (L2=16km, L5=15km). The positive sequence impedance of the overhead lines is: R1=0.45Ω / km, L1=1.172mH / km, C1=6.1nF / km; the zero sequence impedance is: R0=0.7Ω / km, L0=3.91mH / km, C0=3.8nF / km. The positive sequence impedance of the cable feeders is: R1=0.075Ω / km, L1=0.254mH / km, C1=318nF / km; the zero sequence impedance is: R0=0.102Ω / km, L0=0.892mH / km, C0=212nF / km. The neutral point of the power distribution system is grounded via an arc suppression coil, which is in operation during normal operation. A single-phase arc grounding fault is set in the simulation model, with the fault point located 10km from the first busbar on feeder L3. The arc grounding fault is set to occur on phase B of feeder L3 at 0.2s.

[0071] Based on the phase selection results, the passive arc suppression transformer generates a reverse fault phase voltage, such as... Figure 4 As shown, the voltage at the fault point is clamped after connecting to the neutral point;

[0072] Obtain the zero-sequence voltage of the bus and calculate the change in its effective value. ,like Figure 5 As shown, both the fault phase voltage and the fault point current are effectively clamped, as shown in the figures below. Figure 6 and Figure 7 As shown, the fault phase voltage is 17V, the fault current is 0.015A, and the arc at the fault point is extinguished.

[0073] Furthermore, as an implementation scheme, this embodiment also provides a passive voltage-current coordinated injection arc extinguishing system for power distribution networks, the passive voltage-current coordinated injection arc extinguishing system for power distribution networks comprising:

[0074] Fault phase selection module: used to determine the faulty phase when a single-phase ground fault is detected in the distribution network;

[0075] The voltage arc suppression module is used to control the adjustable passive arc suppression transformer to input reverse voltage to the neutral point of the faulty phase;

[0076] The arc suppression mode switching discrimination module is used to collect the bus zero-sequence voltage at at least two consecutive moments in the distribution network during the input process, calculate the change between the bus zero-sequence voltage, and switch to current arc suppression when the change is less than a preset change threshold.

[0077] The current arc suppression module is used to reduce the arc suppression coil capacity of the adjustable arc suppression transformer in the adjustable passive arc suppression transformer device, so as to reduce the fault residual current.

[0078] The adjustable arc suppression transformer includes a main core magnetic circuit and multiple transformer magnetic circuits that match the number of phases in the distribution network. The main core magnetic circuit and the transformer magnetic circuits are connected by arc suppression coils wound on their respective core columns, so that the capacity of the arc suppression coil can be reduced by switching the taps on the windings of the arc suppression coils.

[0079] As one implementation scheme, Figure 8 This is a schematic diagram of the hardware operating environment of the computer system involved in the embodiments of this application.

[0080] like Figure 8 As shown, the computer system may include: a processor 1001, such as a CPU; a memory 1005; a user interface 1003; a network interface 1004; and a communication bus 1002. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be high-speed RAM or non-volatile memory, such as a disk drive. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0081] Those skilled in the art will understand that Figure 8 The computer system architecture shown does not constitute a limitation on the computer system and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0082] like Figure 8 As shown, the memory 1005, as a storage medium, may include an operating system, a network communication module, a user interface module, and computer programs. The operating system is a program that manages and controls the hardware and software resources of the computer system, as well as the operation of the computer programs and other software or programs.

[0083] exist Figure 8 In the computer system shown, the user interface 1003 is mainly used to connect to the terminal and communicate with the terminal; the network interface 1004 is mainly used to communicate with the backend server; and the processor 1001 can be used to call the computer program stored in the memory 1005.

[0084] In this embodiment, the computer system includes: a memory 1005, a processor 1001, and a computer program stored in the memory and executable on the processor, wherein:

[0085] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0086] Step 1: After a single-phase ground fault occurs in the distribution network, the fault phase is selected;

[0087] Step 2: Based on the phase selection results, the passive arc suppression transformer generates a fault-reverse voltage and connects it to the neutral point to clamp the fault point voltage.

[0088] Step 3: Obtain the zero-sequence voltage of the bus and calculate the change in the zero-sequence voltage of the bus;

[0089] Step 4: Track the change in the zero-sequence voltage of the bus and adjust the capacity of the arc suppression coil to further reduce the fault residual current;

[0090] Step 5: The fault phase voltage and the fault point current are both effectively clamped, and the fault point arc is extinguished.

[0091] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0092] Collect the phase voltage values ​​of each phase circuit in the distribution network;

[0093] Determine whether the phase voltage value is less than a preset phase voltage threshold;

[0094] If so, it is determined that a single-phase ground fault has occurred in the power distribution network.

[0095] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0096] Collect the zero-sequence voltage of the busbar at at least two consecutive moments in the distribution network;

[0097] Calculate the change in the zero-sequence voltage of the bus.

[0098] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0099] When the change in the zero-sequence voltage of the bus is less than a preset change threshold, the capacity of the arc suppression coil is reduced.

[0100] Furthermore, those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program includes program instructions and can be stored in a storage medium, which is a computer-readable storage medium. The program instructions are executed by at least one processor in a computer system to implement the process steps of the embodiments of the above methods.

[0101] Therefore, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the various steps of the passive voltage-current coordinated injection arc extinguishing method for power distribution networks as described in the above embodiments.

[0102] The computer-readable storage medium can be any computer-readable storage medium capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory (ROM), magnetic disk, or optical disk.

[0103] It should be noted that, since the storage medium provided in the embodiments of this application is the storage medium used to implement the methods of the embodiments of this application, those skilled in the art can understand the specific structure and variations of the storage medium based on the methods described in the embodiments of this application, and therefore will not be repeated here. All storage media used in the methods of the embodiments of this application fall within the scope of protection of this application.

[0104] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0105] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] It should be noted that any reference signs placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. This application can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0109] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0110] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for arc extinguishing by passive voltage-current coordinated injection in a power distribution network, characterized in that, The method comprises the following steps: Step 1: after a single-phase ground fault occurs in the power distribution network, fault phase selection is performed; Step 2: according to the phase selection result, a passive arc extinguishing transformer generates a fault phase reverse voltage to be connected to the neutral point to clamp the fault point voltage; Step 3: the bus zero sequence voltage is obtained, and the change amount of the bus zero sequence voltage is calculated; Step 4: the change amount of the bus zero sequence voltage is tracked, and the capacity of the arc suppression coil is adjusted to further reduce the fault residual current; Step 5: the fault phase voltage and the fault point current are effectively clamped, and the arc at the fault point is extinguished; The passive arc extinguishing transformer comprises one main core magnetic circuit, three variable magnetic circuits and twelve windings, wherein the first winding, the second winding, the third winding, the fourth winding, the fifth winding and the sixth winding are wound in the main core magnetic circuit, the first winding, the second winding and the third winding are arranged in a concentric or overlapping manner on one core column of the main core magnetic circuit, the fourth winding, the fifth winding and the sixth winding are arranged in a concentric or overlapping manner on the other core column of the main core magnetic circuit; the seventh winding and the tenth winding are arranged in a concentric or overlapping manner on two core columns of the first variable magnetic circuit, the eighth winding and the eleventh winding are arranged in a concentric or overlapping manner on two core columns of the second variable magnetic circuit, and the ninth winding and the twelfth winding are arranged in a concentric or overlapping manner on two core columns of the third variable magnetic circuit; The power distribution network comprises A phase, B phase and C phase, wherein the first ends of the fourth winding, the seventh winding and the tenth winding are connected to the B phase bus, the C phase bus and the A phase bus respectively, and the ends are connected; the first ends of the fifth winding, the eighth winding and the eleventh winding are connected to the B phase bus, the C phase bus and the A phase bus respectively, and the ends are connected; the first ends of the sixth winding, the ninth winding and the twelfth winding are connected to the B phase bus, the C phase bus and the A phase bus respectively, and the ends are connected.

2. The method of claim 1, wherein, The Step 1 comprises: Collecting phase voltage values in each phase circuit in the power distribution network; Determining whether the phase voltage values are less than a preset phase voltage threshold value; If yes, it is determined that a single-phase ground fault occurs in the power distribution network.

3. The method of claim 1, wherein, The Step 3 comprises: Collecting bus zero sequence voltages at at least two continuous time points in the power distribution network; Calculating the change amount between the bus zero sequence voltages.

4. The method of claim 1, wherein, The Step 4 comprises: When the change amount between the bus zero sequence voltages is less than a preset change amount threshold value, the capacity of the arc suppression coil is reduced.

5. A system for implementing the arc extinguishing method of passive type voltage-current coordinated injection of power distribution network as claimed in claim 1, characterized by, The system comprises: A fault phase selection module for performing fault phase selection after a single-phase ground fault occurs in the power distribution network; A voltage arc extinguishing module for generating a fault phase reverse voltage by a passive arc extinguishing transformer to be connected to the neutral point to clamp the fault point voltage according to the phase selection result; An arc extinguishing mode switching discrimination module for obtaining a bus zero sequence voltage and calculating the change amount of the bus zero sequence voltage, and tracking the change amount of the bus zero sequence voltage; A current arc extinguishing module for adjusting the capacity of the arc suppression coil to further reduce the fault residual current.

6. A computer system, characterized by The computer system comprises a memory, a processor, and a computer program stored on the memory and capable of running on the processor, and the computer program, when executed by the processor, implements the steps of the arc extinguishing method of passive voltage-current coordinated injection of a power distribution network according to any one of claims 1 to 4.

7. A computer readable storage medium characterized in that, The computer readable storage medium stores a computer program, and the computer program, when executed by a processor, implements the steps of the arc extinguishing method of passive voltage-current coordinated injection of a power distribution network according to any one of claims 1 to 4.

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