Distribution network primary and secondary fusion complete ring main unit bus protection method and device

Abstract

The invention discloses a distribution network primary and secondary fusion complete ring main unit bus protection method and device. The method comprises the following steps: determining a non-tail-end circuit breaker on a main line or a large branch line in the ring main unit as a section switch; and if the power distribution terminal corresponding to the section switch triggers the node fault signal and does not receive the node fault signal of any other interval loop power distribution terminal on the ring main unit bus within the signal collection time, a command is sent out for outlet tripping, and fault removal is completed. Meanwhile, tripping signals are sent to power distribution terminals in other interval units adjacent to the interval unit in a topological mode; and after receiving the tripping signal, the power distribution terminals in other spacing units adjacent to the spacing unit topology send a command to trip off the circuit breakers of the respective spacing units so as to complete fault isolation. According to the scheme, the fault part can be cut off in time under the condition that the 10-kilovolt primary and secondary fusion complete ring main unit bus breaks down, fault diffusion and upgrading are avoided, and operation of the whole 10-kilovolt distribution network system is protected.

Description

Technical Field

[0001] The present invention relates to the technical field of a primary-secondary integrated ring network box for a distribution network, and in particular to a busbar protection method and device for a primary-secondary integrated ring network box for a distribution network. Background Art

[0002] Distribution automation is an important part of power system automation. It uses modern communication technology and computer technology to monitor, manage and control the distribution network in real time. The primary and secondary integrated ring network box is an important device that can integrate primary equipment (such as circuit breakers, disconnectors, etc.) and secondary equipment (such as monitoring systems, protection systems, etc.) into one box to achieve protection and control of the power network. At the same time, the primary and secondary integrated ring network box can also communicate with the remote server through the network communication interface to achieve remote monitoring and automatic control.

[0003] Patent CN201810386606.1 proposes a maintenance method for distributed protection in a smart substation, which is used for the maintenance of the main network busbar protection. No research has been conducted on the busbar protection function and maintenance method of the distribution network. Patent CN201910280740.8 proposes a protection transformation system and method based on the backup power supply of the power system, which transforms the busbar protection in the substation to ensure that when one section of the busbar is repaired, it does not affect the operation of another section of the busbar. No relevant research has been conducted on the busbar protection of the distribution network. CN202320559918.4 proposes a distribution network busbar protection device, which adopts a primary equipment structure design scheme to optimize the busbar operating environment of the distribution network. No relevant research has been conducted on how to quickly locate and isolate the fault when the busbar fails.

[0004] Based on this, there is still much room for improvement in the existing technology regarding the busbar protection of the primary and secondary integrated ring network box of the distribution network. Summary of the invention

[0005] In order to solve the technical problem that the busbar of a distribution network primary and secondary integrated ring network box cannot be cut off in time when a fault occurs, an embodiment of the present invention provides a distribution network primary and secondary integrated ring network box busbar protection method and device.

[0006] The technical solution of the embodiment of the present invention is achieved as follows:

[0007] The embodiment of the present invention provides a busbar protection method for a primary-secondary integrated ring network box of a distribution network, which is applied to a primary-secondary integrated ring network box of a distribution network. The primary-secondary integrated ring network box of the distribution network includes a power supply side incoming line circuit breaker, multiple feeder circuit breakers, a ring network box busbar and multiple distribution terminals; the inflow current of the primary-secondary integrated ring network box of the distribution network flows into the ring network box busbar through the power supply side incoming line circuit breaker, and then flows into the multiple feeder circuit breakers from the ring network box busbar and then flows out; each circuit breaker is respectively connected to a corresponding distribution terminal, and each distribution terminal is used to collect data and control the connected circuit breaker; each circuit breaker and the correspondingly connected distribution terminal form an interval unit, and the distribution terminals are connected to each other. The two units can communicate with each other; the method includes: determining that the non-terminal circuit breaker on the main line or large branch line in the primary and secondary integrated ring network box of the distribution network is a section switch; if the distribution terminal corresponding to the section switch detects a fault-triggered node fault signal, and does not receive a node fault signal from any other interval circuit distribution terminal on the ring network box bus within the signal collection time, a command is issued to control the exit of the interval unit to trip, complete the fault removal, and at the same time send a trip signal to the distribution terminals in other interval units topologically adjacent to the interval unit; after receiving the trip signal, the distribution terminals in other interval units topologically adjacent to the interval unit issue a command to trip the circuit breakers of their respective interval units to complete the fault isolation.

[0008] In one embodiment, each of the distribution terminals obtains measurement data within the interval unit, and the measurement data includes voltage, current and power; based on the measurement data, it is determined whether a preset CT line break and busbar protection condition is met; if it is determined that the preset CT line break and busbar protection condition is met, CT line break and busbar protection is performed; the CT line break and busbar protection means that the distribution terminals of each interval unit no longer perform logical analysis and event processing on the busbar protection function.

[0009] In one embodiment, the preset CT break lockout busbar protection condition is: the maximum phase current is greater than 0.02In; and the maximum phase current is greater than 4 times the current of any phase.

[0010] In one embodiment, when it is determined that the preset CT line break busbar protection conditions are met, CT line break busbar protection is performed, including: when it is determined that the preset CT line break busbar protection conditions are met, after a preset delay, a CT line break busbar protection command is triggered to perform CT line break busbar protection.

[0011] In one embodiment, when the GOOSE communication of the power distribution terminal of each of the bay units is abnormal, CT disconnection and busbar locking protection are performed.

[0012] The embodiment of the present invention also provides a distribution network primary and secondary integrated ring network box busbar protection device, the distribution network primary and secondary integrated ring network box busbar protection device includes a power supply side incoming line circuit breaker, multiple feeder circuit breakers, a ring network box busbar and multiple distribution terminals; the inflow current of the distribution network primary and secondary integrated ring network box flows into the ring network box busbar through the power supply side incoming line circuit breaker, and then flows into the multiple feeder circuit breakers from the ring network box busbar and then flows out; each circuit breaker is respectively connected to a corresponding distribution terminal, and each of the distribution terminals is used to collect data and control the connected circuit breaker; each circuit breaker and the correspondingly connected distribution terminal form an interval unit, and the distribution terminals can communicate with each other signal; the non-terminal circuit breaker on the main line or large branch line in the distribution network primary and secondary integrated ring network box is a section switch; the distribution terminal corresponding to the section switch is used to issue a command to control the exit of this interval unit to trip after detecting a fault-triggered node fault signal and not receiving a node fault signal from any other interval circuit distribution terminal on the ring network box bus within the signal collection time, so as to complete the fault removal, and at the same time send a trip signal to the distribution terminals in other interval units topologically adjacent to this interval unit; the distribution terminals in other interval units topologically adjacent to this interval unit are used to issue a command to trip the circuit breakers of their respective interval units after receiving the trip signal to complete the fault isolation.

[0013] In one embodiment, each of the distribution terminals is also used to obtain measurement data within the interval unit, and the measurement data includes voltage, current and power; based on the measurement data, it is determined whether a preset CT line break and busbar protection condition is met; if it is determined that the preset CT line break and busbar protection condition is met, CT line break and busbar protection is performed; the CT line break and busbar protection is that the distribution terminals of each interval unit no longer perform logical analysis and event processing on the busbar protection function.

[0014] In one embodiment, the preset CT break lockout busbar protection condition is: the maximum phase current is greater than 0.02In; and the maximum phase current is greater than 4 times the current of any phase.

[0015] In one embodiment, each of the power distribution terminals is further specifically used to trigger a CT line break busbar protection command after a preset delay time to perform CT line break busbar protection when it is determined that the preset CT line break busbar protection conditions are met.

[0016] In one embodiment, the power distribution terminal of each of the bay units is also used to perform CT disconnection and busbar locking protection when GOOSE communication is abnormal.

[0017] This embodiment has the following beneficial effects:

[0018] This embodiment can, when a 10 kV primary and secondary integrated ring network box bus fails, timely cut off the faulty part through sampling of each interval unit and GOOSE information collected in real time by the distribution terminal, after logical analysis, to avoid the spread and escalation of the fault, prevent the expansion of the fault scope, affect the upstream power grid equipment of the fault, and protect the operation of the entire 10 kV distribution network feeder. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of a method for protecting the busbar of a ring network box in which the primary and secondary components of a distribution network are integrated according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of a ring network box with primary and secondary fusion in a distribution network according to an embodiment of the present invention;

[0021] Figure 3 This is a physical schematic diagram of a set of ring network boxes integrating primary and secondary distribution networks according to an embodiment of the present invention;

[0022] Figure 4 A bus fault clearing logic diagram according to an embodiment of the present invention;

[0023] Figure 5 This is a logical diagram of bus fault isolation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0025] The embodiment of the present invention provides a busbar protection method for a primary-secondary integrated ring network box of a distribution network, which is applied to a primary-secondary integrated ring network box of a distribution network, wherein the primary-secondary integrated ring network box of the distribution network comprises an incoming line circuit breaker on the power supply side, multiple feeder circuit breakers, a ring network box busbar and multiple distribution terminals; the inflow current of the primary-secondary integrated ring network box of the distribution network flows into the ring network box busbar through the incoming line circuit breaker on the power supply side, and then flows into the multiple feeder circuit breakers from the ring network box busbar before flowing out; each circuit breaker is respectively connected to a corresponding distribution terminal, and each distribution terminal is used to collect data and control the connected circuit breaker; each circuit breaker and the correspondingly connected distribution terminal form an interval unit, and the distribution terminals can communicate with each other; Figure 1 As shown, the method includes:

[0026] Step 101: Determine that a non-terminal circuit breaker on a trunk line or a large branch line in a primary and secondary integrated ring network box of a distribution network is a section switch;

[0027] Step 102: If the distribution terminal corresponding to the section switch detects a fault-triggered node fault signal, and does not receive a node fault signal from any other bay circuit distribution terminal on the ring network box busbar within the signal collection time, a command is issued to control the outlet of the bay unit to trip, complete the fault removal, and send a trip signal to the distribution terminals in other bay units topologically adjacent to the bay unit;

[0028] Step 103: After receiving the trip signal, the power distribution terminals in other bay units topologically adjacent to the bay unit issue commands to trip the circuit breakers of their respective bay units to complete fault isolation.

[0029] This embodiment is mainly based on the busbar protection of the ring network box of distributed feeder automation. It is mainly to cut off the faulty part in time when the busbar of the 10 kV primary and secondary integrated ring network box fails, avoid the spread and escalation of the fault, and protect the operation of the entire 10 kV distribution network system. Distributed feeder automation refers to the distribution terminal (the protection and measurement and control device of each interval unit in the ring network cabinet) that automatically realizes the functions of fault location, isolation and power supply restoration in non-fault areas through mutual communication, and can report the processing process and results to the distribution automation master station.

[0030] The primary and secondary integrated ring network box is a device in the power distribution system, which is mainly composed of an incoming line cabinet, an outgoing line cabinet and corresponding protection and measurement and control devices. The primary and secondary integrated ring network box integrates the primary and secondary side power distribution, protection and control equipment in one box. Figure 2 and Figure 3 As shown, in the ring network box, 301, 303, 305, 307, 309, 311 are interval circuit breakers, of which 301 is the incoming line circuit breaker on the power supply side, 303, 305, 307, 309, 311 are feeder circuit breakers, and the copper plate connecting the above circuit breakers is the ring network box busbar. The current output by the substation flows into the ring network box from 301, flows through the busbar to 303, 305, 307, 309, 311 feeder circuit breakers, and reaches the downstream user load. Different from the traditional ring network box, each interval circuit of the primary and secondary integrated ring network box is equipped with a distribution terminal (protection and measurement and control device), which can realize the real-time collection and monitoring of data such as voltage, current, switch information, etc. of this circuit. When a short circuit or other fault occurs, the secondary protection device of this circuit can realize the selective, rapid, reliable and sensitive isolation of the fault by the circuit breaker. The device can not only realize the line protection function of this interval unit, but also realize the distributed feeder automation function mentioned above based on the mutual communication of each distribution terminal.

[0031] The specific action logic of this embodiment is as follows:

[0032] Busbar protection logic: In the 10kV distribution network primary and secondary integrated ring network box, each bay unit is equipped with a distributed distribution terminal, which can monitor the measurement data and protection action event signal of the bay unit in real time (the measurement data includes electrical quantity data such as voltage, current, and power. The protection action event signal is the relevant alarm and action information issued by the device after the protection device detects the fault current and voltage data when the power grid fails). The above protection action event signal can be sent to the distribution terminal (protection measurement and control device) of other bay units topologically adjacent to the bay unit based on 61850 GOOSE transmission (topological adjacent refers to the electrical circuit connected to the primary electrical structure). When the section switch (non-end switch on the main line or large branch line, such as Figure 2 The distribution terminal (protection and measurement control device) of which 301 and 303 can be identified as section switches) detects a fault and triggers a "node fault (a switch that detects short-circuit overcurrent or zero-sequence overcurrent triggers a node fault)" signal. During the signal collection time, the distribution terminal (protection and measurement control device) of this interval unit communicates with the protection and measurement control devices of other interval units topologically adjacent to this interval unit. After not receiving the "node fault" signal from any other interval unit circuit distribution terminal (protection and measurement control device) on the ring network cabinet bus, the fault processing unit of the distribution terminal (protection and measurement control device) issues a command output tripping to trip the switch of this interval unit to realize fault removal. The logic is shown in FIG. Figure 4 At the same time, a GOOSE tripping signal is sent to the protection and control devices of other bays topologically adjacent to the bay. After receiving the GOOSE tripping signal, the distribution terminals (protection and control devices) of other bays will issue commands to trip the switches of their respective bays to achieve fault isolation. See the logic for details. Figure 5 .

[0033] For example: Figure 2 For example: when switch 301 is the power supply line switch, 303, 305, 307, 309, and 311 are all feeder switches, and 301 and 303 are section switches (non-terminal switches on the main line or large branch line). When the busbar of this ring network cabinet fails, switch 301 will detect an overcurrent fault signal, but 303, 305, 307, 309, and 311 cannot detect an overcurrent fault signal. 301 communicates with the topologically adjacent switches of this interval unit and does not receive the corresponding fault signal. Therefore, the protection device of the interval unit 301 trips the interval switch to achieve fault removal. At the same time, a GOOSE trip signal is sent to 303, 305, 307, 309, and 311 to trip switches 303, 305, 307, 309, and 311 to achieve fault isolation.

[0034] Protection interlocking logic: If the CT of any bay unit of the ring main unit is disconnected, the bus protection will be interlocked (the bus protection function of the fault handling unit in the distribution terminal of each bay unit will no longer perform logic analysis and event processing). If the GOOSE communication of each bay distribution terminal is abnormal, the corresponding bus protection will be interlocked.

[0035] CT disconnection logic:

[0036] 1. The maximum phase current is greater than 0.02In;

[0037] 2. The maximum phase current is greater than 4 times the current of any phase.

[0038] If the above two conditions are met, the "CT disconnection alarm" will be reported after a delay of 10 seconds, and the device alarm signal will be issued.

[0039] This embodiment has the following beneficial effects:

[0040] Distributed control: Compared with traditional centralized busbar protection, busbar protection based on distributed feeder automation adopts a distributed control strategy, which disperses the protection function to the distribution terminals (protection and measurement and control devices) of each bay unit, and realizes data sharing and collaborative work of the distribution terminals (protection and measurement and control devices) of each bay unit through optical fiber communication technology. This makes busbar protection more flexible and scalable.

[0041] Fast response: Distributed feeder automation technology can monitor the operation status of the power grid in real time and achieve fast response to bus faults through intelligent control strategies. Once a bus fault is detected, the system can quickly locate the fault point and isolate the fault area, thereby preventing the fault from expanding and causing further damage to the power grid.

[0042] High reliability: Busbar protection based on distributed feeder automation adopts advanced communication technology and intelligent control strategy to ensure the accuracy and reliability of protection action. At the same time, through distributed control strategy, the system can realize multiple detection and verification of busbar faults, further improving the reliability of protection.

[0043] The embodiment of the present invention further provides a busbar protection device for a ring network box with integrated primary and secondary circuits for distribution network, the busbar protection device for a ring network box with integrated primary and secondary circuits for distribution network comprises an incoming line circuit breaker on the power supply side, multiple feeder circuit breakers, a ring network box busbar and multiple distribution terminals; the inflow current of the ring network box with integrated primary and secondary circuits for distribution network flows into the ring network box busbar through the incoming line circuit breaker on the power supply side, and then flows into the multiple feeder circuit breakers from the ring network box busbar before flowing out; each circuit breaker is respectively connected to a corresponding distribution terminal, and each distribution terminal is used to collect data and control the connected circuit breaker; each circuit breaker and the correspondingly connected distribution terminal form an interval unit, and the distribution terminals can communicate with each other; the non-terminal circuit breakers on the main line or large branch line in the ring network box with integrated primary and secondary circuits for distribution network are section switches;

[0044] The distribution terminal corresponding to the section switch is used to issue a command to control the exit of the interval unit to trip after detecting a fault-triggered node fault signal and not receiving a node fault signal from any other interval circuit distribution terminal on the ring network box busbar within the signal collection time, thereby completing the fault removal, and at the same time sending a trip signal to the distribution terminals in other interval units topologically adjacent to the interval unit;

[0045] The power distribution terminals in other bay units topologically adjacent to the bay unit are used to issue commands to trip the circuit breakers of their respective bay units after receiving the trip signal to complete fault isolation.

[0046] The distribution terminal in the device of this embodiment has a built-in fault processing unit. The fault processing unit is a functional module that can achieve effective protection of the busbar of the existing 10 kV distribution network's primary and secondary integrated ring network box. When a busbar fault occurs, it can quickly isolate the fault, reduce grid losses, and restore normal power supply to non-fault areas.

[0047] Specifically, in one embodiment, each of the distribution terminals is also used to obtain measurement data within the interval unit, and the measurement data includes voltage, current and power; whether a preset CT line break and busbar protection condition is met is determined based on the measurement data; if it is determined that the preset CT line break and busbar protection condition is met, CT line break and busbar protection is performed; the CT line break and busbar protection is that the distribution terminals of each interval unit no longer perform logical analysis and event processing on the busbar protection function.

[0048] Here, the preset CT breakage locking busbar protection condition is: the maximum phase current is greater than 0.02In; and / or the maximum phase current is greater than 4 times of any phase current.

[0049] In addition, each of the power distribution terminals is also specifically used to trigger a CT line break busbar protection command after a preset delay time to perform CT line break busbar protection when it is determined that the preset CT line break busbar protection conditions are met.

[0050] The power distribution terminal of each of the bay units is also used to perform CT disconnection and busbar locking protection when GOOSE communication is abnormal.

[0051] The device of this embodiment mainly uses the interval sampling and GOOSE information collected in real time by the terminal equipment when a fault occurs in the 10 kV primary and secondary integrated ring network box busbar. After logical analysis, it promptly cuts off the faulty part to avoid the spread and escalation of the fault, prevent the expansion of the fault scope, and affect the upstream power grid equipment of the fault, thereby protecting the operation of the entire 10 kV distribution network feeder.

[0052] This embodiment has the following beneficial effects:

[0053] (1) Simplified secondary wiring: Distributed busbar protection technology distributes the functions of a traditional busbar differential protection device to multiple bay units (eL), so that each eL is only connected to the corresponding current transformer (CT). This design greatly simplifies the secondary wiring of the protection and reduces the complexity of on-site operation and maintenance.

[0054] (2) Improve reliability and rapidity: Distributed bus protection technology provides a complete current differential protection function based on the novel CT saturation detection method. The local judgment criteria of the bay unit (BU) provide a guarantee for the reliability of distributed bus protection, ensuring that the fault can be quickly and accurately removed when a bus fault occurs.

[0055] (3) Reduce floor space and cable consumption: Distributed busbar protection technology uses communication technology to achieve data sharing between different interval units, without the need for a dedicated protection screen.

[0056] (4) Enhanced adaptive capability: Distributed bus protection technology provides a PC-based graphical input function for network topology, which is convenient for users to use and ensures the selectivity of bus protection. This design makes the protection highly adaptive and can automatically adjust the protection strategy according to changes in the grid topology.

[0057] (5) Achieve millisecond-level self-healing: In the distributed intelligent feeder automation mode, millisecond-level self-healing of the power grid with multiple backup protection can be achieved, which is of great significance for improving the power supply reliability and stability of the power grid.

[0058] The above-mentioned device provided in this embodiment belongs to the same concept as the above-mentioned method embodiment. The specific implementation process thereof is detailed in the method embodiment and will not be repeated here.

[0059] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0060] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for protecting the busbar of a primary and secondary integrated ring network box in a distribution network, characterized in that: Applied to a primary and secondary integrated ring network box for distribution network, the primary and secondary integrated ring network box for distribution network includes a power supply side incoming line circuit breaker, multiple feeder circuit breakers, a ring network box busbar and multiple distribution terminals; the inflow current of the primary and secondary integrated ring network box for distribution network flows into the ring network box busbar through the power supply side incoming line circuit breaker, and then flows into the multiple feeder circuit breakers from the ring network box busbar and then flows out; each circuit breaker is respectively connected to a corresponding distribution terminal, and each distribution terminal is used to collect data and control the connected circuit breaker; Each circuit breaker and the corresponding connected power distribution terminal form a bay unit, and the power distribution terminals can communicate with each other; the method comprises: Determine that the non-terminal circuit breakers on the main line or large branch line in the primary and secondary integrated ring network box of the distribution network are section switches; If the distribution terminal corresponding to the section switch detects a fault-triggered node fault signal, and does not receive a node fault signal from any other bay circuit distribution terminal on the ring network box bus within the signal collection time, a command is issued to control the exit of this bay unit to trip, complete the fault removal, and at the same time send a trip signal to the distribution terminals in other bay units topologically adjacent to this bay unit; After receiving the trip signal, the power distribution terminals in other bay units topologically adjacent to the bay unit issue commands to trip the circuit breakers of their respective bay units to complete fault isolation.

2. The method for protecting the busbar of the primary and secondary integrated ring network box of the distribution network according to claim 1 is characterized in that: Each of the power distribution terminals obtains measurement data within the interval unit, and the measurement data includes voltage, current and power; Determine whether the preset CT disconnection blocking busbar protection condition is met according to the measured data; When it is determined that the preset CT line break busbar protection conditions are met, the CT line break busbar protection is performed; the CT line break busbar protection is that the distribution terminals of each bay unit no longer perform logical analysis and event processing on the busbar protection function.

3. The method for protecting the busbar of the primary and secondary integrated ring network box of the distribution network according to claim 2 is characterized in that: The preset CT break blocking busbar protection condition is: The maximum phase current is greater than 0.02In; and the maximum phase current is greater than 4 times the current of any phase.

4. The method for protecting the busbar of the primary and secondary integrated ring network box of the distribution network according to claim 2 is characterized in that: When it is determined that the preset CT disconnection busbar protection conditions are met, CT disconnection busbar protection is performed, including: When it is determined that the preset CT line break busbar protection conditions are met, the CT line break busbar protection command is triggered after a preset delay time to perform CT line break busbar protection.

5. The method for protecting the busbar of the primary and secondary integrated ring network box of the distribution network according to claim 2 is characterized in that: When the GOOSE communication of the power distribution terminal of each of the interval units is abnormal, CT disconnection and busbar locking protection are performed.

6. A primary and secondary integrated ring network box busbar protection device for distribution network, characterized in that: The distribution network primary and secondary integrated ring network box busbar protection device comprises a power supply side incoming line circuit breaker, multiple feeder circuit breakers, a ring network box busbar and multiple distribution terminals; the inflow current of the distribution network primary and secondary integrated ring network box flows into the ring network box busbar through the power supply side incoming line circuit breaker, and then flows into the multiple feeder circuit breakers from the ring network box busbar and then flows out; each circuit breaker is respectively connected to a corresponding distribution terminal, and each distribution terminal is used to collect data and control the connected circuit breaker; each circuit breaker and the correspondingly connected distribution terminal form an interval unit, and the distribution terminals can communicate with each other; the non-terminal circuit breakers on the main line or large branch line in the distribution network primary and secondary integrated ring network box are section switches; The distribution terminal corresponding to the section switch is used to issue a command to control the exit of the interval unit to trip after detecting a fault-triggered node fault signal and not receiving a node fault signal from any other interval circuit distribution terminal on the ring network box busbar within the signal collection time, thereby completing the fault removal, and at the same time sending a trip signal to the distribution terminals in other interval units topologically adjacent to the interval unit; The power distribution terminals in other bay units topologically adjacent to the bay unit are used to issue commands to trip the circuit breakers of their respective bay units after receiving the trip signal to complete fault isolation.

7. The primary and secondary integrated ring network box busbar protection device of the distribution network according to claim 6 is characterized in that: Each of the distribution terminals is also used to obtain measurement data within the interval unit, the measurement data including voltage, current and power; determine whether a preset CT line break and busbar protection condition is met based on the measurement data; if it is determined that the preset CT line break and busbar protection condition is met, perform CT line break and busbar protection; the CT line break and busbar protection means that the distribution terminals of each interval unit no longer perform logical analysis and event processing on the busbar protection function.

8. The primary and secondary integrated ring network box busbar protection device of the distribution network according to claim 7 is characterized in that: The preset CT break blocking busbar protection condition is: The maximum phase current is greater than 0.02In; and the maximum phase current is greater than 4 times the current of any phase.

9. The primary and secondary integrated ring network box busbar protection device of distribution network according to claim 7 is characterized in that: Each of the power distribution terminals is also specifically used to trigger a CT line break busbar protection command after a preset delay time to perform CT line break busbar protection when it is determined that the preset CT line break busbar protection conditions are met.

10. The primary and secondary integrated ring network box busbar protection device of distribution network according to claim 7 is characterized in that: The power distribution terminal of each of the bay units is also used to perform CT disconnection and busbar locking protection when GOOSE communication is abnormal.

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