CN219247471U

CN219247471U - Join in marriage quick protection switch of network overhead line disconnection trouble

Info

Publication number: CN219247471U
Application number: CN202320011503.3U
Authority: CN
Inventors: 杨小鸽
Original assignee: Beijing Chushi Yiyuan Technology Co ltd
Current assignee: Beijing Chushi Yiyuan Technology Co ltd
Priority date: 2023-01-04
Filing date: 2023-01-04
Publication date: 2023-06-23
Anticipated expiration: 2033-01-04

Abstract

The utility model discloses a quick protection switch for a disconnection fault of a network distribution overhead line, which comprises a power end breaker, a zero sequence PT of a power end, a zero sequence CT of the power end, a power end controller, a three-phase PT of a tail end, an A-phase load switch of the tail end, a C-phase load switch of the tail end, a tail end current limiting resistor and a tail end controller, wherein the power end breaker is connected with the power end breaker; the power end controller is respectively connected with the power end breaker, the zero sequence PT of the power end and the secondary wiring terminal of the zero sequence CT of the power end; the terminal controller is respectively connected with secondary wiring terminals of the terminal three-phase PT, the terminal A-phase load switch and the terminal C-phase load switch. When the line breaks, the fault can be reliably detected through the terminal voltage, the judging process is not influenced by the load current, and the generated grounding signal current has obvious characteristics and can be rapidly identified to trigger the rapid switching-off of the switch at the power supply end.

Description

Join in marriage quick protection switch of network overhead line disconnection trouble

Technical Field

The utility model relates to the technical field of power system protection, in particular to a quick protection switch for a disconnection fault of a network distribution overhead line

Background

The domestic 10kV power distribution network adopts a three-phase three-wire system, and belongs to a neutral point non-grounding or small current grounding system. In the fault types of the 10kV distribution line, the line breakage occupies a certain proportion, wherein the fault proportion of the single-phase broken line type is highest. With the development of economy and the improvement of town level, in urban power grid transformation and rural power grid upgrading transformation, in order to improve the insulation level of distribution lines, a large amount of insulated wires are adopted to replace bare wires in a distribution network. Although the insulated wire overcomes the defects of the traditional bare wire, the insulated wire also brings new technical problems, namely the insulated wire is concentrated and ablated due to lightning strike, so that the insulated wire breakage problem is increased. Meanwhile, broken line faults caused by branch scratch and overlarge span in the rural power grid line also occur. Once the broken line fault occurs, the broken line part often causes fire or casualties after falling to the ground, so that proper switching equipment is required to timely handle the fault, and the occurrence of secondary disasters is avoided.

The single-phase broken line fault condition of 10kV distribution lines is various and complex, such as: the front end of the breakpoint is grounded at one end, the rear end of the breakpoint is grounded at one end, the front end and the rear end of the breakpoint are grounded at the same time, metallic grounding, nonmetallic grounding and the like. For the method adopting the phase voltage or phase current characteristics as the judging basis of the single-phase line break fault, the measured phase voltage and phase current data are greatly influenced by factors such as whether single-phase grounding occurs in the system, the size of the line capacitance to ground, the neutral point grounding mode and the like, and the criterion stability is poor.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model aims to provide the rapid protection switch for the disconnection fault of the overhead line of the distribution network, which solves the problem that the occurrence of secondary disasters is caused by the fact that the disconnection fault cannot be rapidly processed at present.

In order to solve the technical problems, the utility model adopts the following technical scheme:

the utility model provides a join in marriage quick protection switch of network overhead line disconnection trouble which characterized in that: the power supply comprises a power supply end breaker, a power supply end zero sequence PT, a power supply end zero sequence CT, a power supply end controller, an end three-phase PT, an end A-phase load switch, an end C-phase load switch, an end current limiting resistor and an end controller; the power end controller is respectively connected with the power end breaker, the zero sequence PT of the power end and the secondary wiring terminal of the zero sequence CT of the power end; the terminal controller is respectively connected with secondary wiring terminals of the terminal three-phase PT, the terminal A-phase load switch and the terminal C-phase load switch; one binding post of the terminal A-phase load switch is connected with an A-phase high-voltage binding post in the terminal three-phase PT, and one binding post of the terminal C-phase load switch is connected with a C-phase high-voltage binding post in the terminal three-phase PT; the other ends of the terminal A-phase load switch and the terminal C-phase load switch are connected with one end of a terminal current limiting resistor, and the other end of the terminal current limiting resistor is connected with the ground.

Preferably, the power end breaker, the power end zero sequence PT, the power end zero sequence CT and the power end controller are arranged on a tower at the power side.

Preferably, the terminal three-phase PT, the terminal a-phase load switch, the terminal C-phase load switch, the terminal current limiting resistor and the terminal controller are mounted on one tower at the terminal of the line.

Preferably, the rapid protection switch for the disconnection fault of the overhead line of the distribution network detects the disconnection fault by means of a three-phase PT at the tail end, an A-phase load switch at the tail end, a C-phase load switch at the tail end, a current limiting resistor at the tail end and a tail end controller, and generates a signal for triggering the tripping of a switch at the power supply side.

Preferably, the end A phase load switch, the end C phase load switch and the end current limiting resistor form a tripping signal loop.

The terminal controller rapidly judges whether a broken line fault occurs according to the phase voltage provided by the terminal three-phase PT; the terminal controller controls sound phase switching on in the A-phase load switch of the terminal or the C-phase load switch of the terminal; the tail end current limiting resistor enables a circuit where the broken line fault is located to generate a grounding signal current with a certain width; the power end controller controls the power end breaker to rapidly break after detecting the grounding current signal through the power end zero sequence CT, thereby realizing rapid cutting of broken line faults.

The utility model has the beneficial effects that: the device utilizes the change characteristic of terminal voltage to rapidly judge the occurrence of the disconnection fault, and simultaneously utilizes the rapid load switch to enable the system to generate a current signal, so that the upper switch rapidly acts, the disconnection fault is rapidly removed, and the secondary disaster caused by the disconnection after landing is avoided; when the line breaks, the fault can be reliably detected through the terminal voltage, the judging process is not influenced by the load current, and the generated grounding signal current has obvious characteristics and can be rapidly identified to trigger the rapid switching-off of the switch at the power supply end.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a fast protection switch for disconnection faults of a network distribution overhead line;

FIG. 2 is a schematic diagram of a power end controller;

fig. 3 is a schematic diagram of an end controller.

Reference numerals illustrate:

1. a power supply end breaker; 2. a connecting wire; 3. a power supply end controller; 4. zero sequence CT of the power supply end; 5. a terminal current limiting resistor; 6. terminal three-phase PT;7-A, C phase load switch; 8. an end controller.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

As shown in fig. 1, the fast protection switch for the disconnection fault of the network distribution overhead line comprises a power end breaker 1, a power end zero sequence PT, a power end zero sequence CT4, a power end controller 3, an end three-phase PT6, end a-phase and C-phase load switches 7a and 7b, an end current limiting resistor 5 and an end controller 8; the power end controller 3 is respectively connected with the secondary wiring terminals of the power end breaker 1, the power end zero sequence PT and the power end zero sequence CT4 through connecting wires 2; the tail end controller 8 is respectively connected with the tail end three-phase PT6 and secondary wiring terminals of the tail end A-phase load switch 7a and the tail end C-phase load switch 7 b; one binding post of the terminal A-phase load switch 7a is connected with an A-phase high-voltage binding post in the terminal three-phase PT, and one binding post of the terminal C-phase load switch 7b is connected with a C-phase high-voltage binding post in the terminal three-phase PT; the other ends of the terminal A-phase load switch 7a and the terminal C-phase load switch 7b are connected with one end of the terminal current limiting resistor 5, and the other end of the terminal current limiting resistor 5 is connected with the ground.

Further, the power end breaker 1, the power end zero sequence PT, the power end zero sequence CT4 and the power end controller 3 are installed on a tower at the power side.

Further, the terminal three-phase PT6, the terminal a-phase load switch 7a, the terminal C-phase load switch 7b, the terminal current limiting resistor 5, and the terminal controller 8 are installed on one tower at the end of the line.

Further, the fast protection switch for the disconnection fault of the overhead line of the distribution network detects the disconnection fault by means of the three-phase PT6 at the tail end, the A-phase load switch 7a at the tail end, the C-phase load switch 7b at the tail end, the current limiting resistor 5 at the tail end and the tail end controller 8, and generates a signal for triggering the tripping of the switch at the power supply side.

Further, the phase a load switch 7a at the end, the phase C load switch 7b at the end, and the end current limiting resistor 5 form a trip signal loop.

As shown in fig. 2, CTA, CTC and CTO are a-phase, C-phase and zero-sequence currents, respectively, which are converted by isolation transformers CT1, CT2 and CT3 and then respectively sent to a core control unit U2 for a/D conversion. The phase A and phase C currents are used for judging short circuit faults, the zero sequence current is used for judging whether a grounding current signal generated by the tail end exists or not, if yes, the Q1 is controlled to be conducted through the optical coupler U5, and the quick switching-off of the switch is triggered. E1 is a local wireless communication interface, and information reporting and program upgrading are realized. And U4 and Q2 form a closing loop to realize switch closing.

As shown in fig. 3, PTA, PTB and PTC are voltages to ground of A, B, C phases, respectively, and are sent to isolation transformers T1, T2 and T3 to be transformed after passing through current limiting resistors R1, R7 and R8, respectively, and then sent to a core control unit U2 to be a/D converted, respectively. When the line fault occurs, the phase voltage of the fault phase at the end of the line is obviously reduced, and the voltage change of the other two phases is weak, and the core control unit U2 rapidly researches and judges the line phase according to the principle. When the phase A or the phase B is broken, the U2 controls the end C phase load switch to be switched on for a period of time through a switching-on loop formed by the optocoupler U4 and the high-voltage triode Q2, at the moment, the C phase current can flow to the ground through the end current limiting flow, the power end zero sequence CT detects the signal and then rapidly switches off, and the broken line fault is isolated. When the C phase breaks, the U2 controls the end A phase load switch to close for a period of time through a closing loop formed by the optocoupler U5 and the high-voltage triode Q1, at the moment, the A phase current can flow to the ground through the end current limiting flow, the power end zero sequence CT detects the signal and then rapidly breaks the gate, and the broken line fault is isolated.

The principle of the utility model is as follows: when a line breaks, the end controller 8 rapidly judges whether a line break occurs or not and whether the line break is located according to the phase voltage change characteristics provided by the end three-phase PT 6; the end controller 8 controls one sound phase of the A, C phase load switches 7a and 7b to be closed, and at the moment, the end current limiting resistor 5 enables a circuit where the disconnection fault is located to generate a grounding signal current with a certain width; the power end controller 3 controls the power end breaker 1 to rapidly break after detecting the grounding current signal through the power end zero sequence CT4, thereby realizing rapid cutting of broken line faults.

When the line breaks, the rapid protection switch can reliably detect the line break through the change characteristics of the three-phase voltage at the tail end, the judging process is not influenced by the load current, and the generated grounding signal current has obvious characteristics and can be rapidly identified to trigger the rapid switch-off of the switch at the power supply side, so that the power supply is cut off before the line breaks and falls to the ground, and further expansion of accident hazard is prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present utility model without departing from the spirit or scope of the utility model. Thus, it is intended that the present utility model also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. The utility model provides a join in marriage quick protection switch of network overhead line disconnection trouble which characterized in that: the power supply comprises a power supply end breaker, a power supply end zero sequence PT, a power supply end zero sequence CT, a power supply end controller, an end three-phase PT, an end A-phase load switch, an end C-phase load switch, an end current limiting resistor and an end controller; the power end controller is respectively connected with the power end breaker, the zero sequence PT of the power end and the secondary wiring terminal of the zero sequence CT of the power end; the terminal controller is respectively connected with secondary wiring terminals of the terminal three-phase PT, the terminal A-phase load switch and the terminal C-phase load switch; one binding post of the terminal A-phase load switch is connected with an A-phase high-voltage binding post in the terminal three-phase PT, and one binding post of the terminal C-phase load switch is connected with a C-phase high-voltage binding post in the terminal three-phase PT; the other ends of the terminal A-phase load switch and the terminal C-phase load switch are connected with one end of a terminal current limiting resistor, and the other end of the terminal current limiting resistor is connected with the ground.

2. The rapid protection switch for disconnection fault of network distribution overhead line according to claim 1, wherein: the power end breaker, the power end zero sequence PT, the power end zero sequence CT and the power end controller are arranged on a tower at the power side.

3. The rapid protection switch for disconnection fault of network distribution overhead line according to claim 1, wherein: the three-phase PT at the tail end, the A-phase load switch at the tail end, the C-phase load switch at the tail end, the terminal current limiting resistor and the terminal controller are arranged on a pole tower at the tail end of the circuit.

4. The rapid protection switch for disconnection fault of network distribution overhead line according to claim 1, wherein: the rapid protection switch for the disconnection fault of the overhead line of the distribution network detects the disconnection fault by means of a terminal three-phase PT, a terminal A-phase load switch, a terminal C-phase load switch, a terminal current-limiting resistor and a terminal controller, and generates a signal for triggering the tripping of a power supply side switch.

5. The rapid protection switch for disconnection fault of network distribution overhead line according to claim 1, wherein: the A phase load switch at the tail end, the C phase load switch at the tail end and the tail end current limiting resistor form a tripping signal loop.