Power distribution network fault positioning device based on traveling wave signal analysis

Abstract

The invention provides a power distribution network fault positioning device based on traveling wave signal analysis, and relates to the technical field of power grid monitoring, the power distribution network fault positioning device comprises a main line, a plurality of branches and a fault signal acquisition unit configured at the tail ends of the main line and the branches, the fault signal acquisition unit comprises a fault detection module which comprises an analysis module, a plurality of Rogowski coils and a switch assembly, the switch assembly correspondingly connects a to-be-tested circuit to the analysis module through a wire, and the Rogowski coils are arranged on the wire in a one-to-one correspondence manner; when a fault occurs at a preset position of the power distribution network, traveling waves generated by a fault point are transmitted to each node along a line, and the analysis module receives and analyzes traveling wave information and locates the fault according to an analysis result of each fault signal acquisition unit. Through the setting mode, the distance between the fault point and each fault signal acquisition unit can be calculated in combination with the analysis results of the plurality of fault signal acquisition units, so that the fault point can be accurately positioned.

Description

Technical Field

[0001] This invention relates to the field of electrical fault detection and location technology, and in particular to a power distribution network fault location device based on traveling wave signal analysis. Background Technology

[0002] Given the characteristics of distribution network lines, such as high tripping rate, complex structure, and difficulty in troubleshooting, the state has clearly proposed to strengthen the investigation of defects and hidden dangers in distribution networks, and the requirements for distribution network operation and maintenance have entered a new level; strengthen the application of high-tech, intelligent, and technologically mature monitoring and early warning technologies to improve the level of technical defense.

[0003] Due to its complex structure, numerous branch lines, and varied operating modes, the distribution network is highly susceptible to severe weather events such as strong lightning, torrential rain, and strong winds. Compared to the transmission network, it is more vulnerable and prone to failure. Statistics show that over 90% of power system failures are distribution network failures. Therefore, the safe and reliable operation of the distribution network is a key factor determining the safe and reliable operation of the entire power system.

[0004] Existing power distribution network fault detection and location technologies suffer from three major pain points: Insufficient signal acquisition accuracy makes it difficult to capture weak fault traveling wave signals, resulting in a fault false detection rate exceeding 15%. The positioning algorithm relies on data from a single node, and the segment positioning error generally exceeds 500 meters, which cannot meet the requirements for meter-level positioning. The existing technology has weak fault diagnosis capabilities, only able to identify 1-2 simple fault types, and lacks fault protection mechanisms for the testing equipment itself, resulting in low testing reliability. It is no longer adequate for the complex power distribution network's demand for 'accurate detection, rapid location, and accurate diagnosis' in fault testing, making technological upgrades urgently needed. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of inaccurate signal acquisition, large positioning error, and single fault diagnosis in existing power distribution network fault detection and location technologies. It provides a power distribution network fault detection device based on multi-node traveling wave signal collaborative acquisition and accurate analysis, which realizes efficient capture of fault signals, meter-level positioning and multi-type diagnosis, and has its own overheat fault protection function, thereby improving the reliability and accuracy of power distribution network fault testing and location.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a distribution network fault location device based on traveling wave signal analysis, comprising a main line, multiple branches, and fault signal acquisition units configured at the ends of the main line and branches, wherein the fault signal acquisition unit includes: The fault detection module includes an analysis module, multiple Rogowski coils, and a switching assembly. The switching assembly connects the circuit under test to the analysis module via wires, and the Rogowski coils are arranged one-to-one on the wires. When a fault occurs at a predetermined location in the distribution network, the traveling wave generated at the fault point propagates along the line to each node. The analysis module receives and analyzes the traveling wave information and locates the fault based on the analysis results of each fault signal acquisition unit.

[0007] Furthermore, wireless communication connections are established between the various fault signal acquisition units.

[0008] Furthermore, the fault detection module includes a housing, with an isolation plate horizontally arranged in the middle area of ​​the housing. The switch assembly and the analysis module are both integrated into the housing, and the switch assembly is located below the isolation plate.

[0009] Furthermore, the switching assembly includes: Terminal 1 is located on the enclosure and is connected to the wire; The movable frame, with a vertical guide, is positioned above terminal one; Terminal 2 is mounted on the movable frame, corresponding to terminal 1. The housing is equipped with a fixed plate, and a connecting cylinder is fitted to the outer guide of the fixed plate. The connecting cylinder is connected to the movable frame. A compression spring is provided between the upper surface of the fixed plate and the connecting cylinder. A heat triggering unit is provided on the outer circumferential surface of the connecting cylinder. When the temperature inside the housing is lower than a first threshold, the heat triggering unit locks the connecting cylinder and the fixed plate to the first state of compressing the compression spring. When the temperature reaches the first threshold, the fixed plate is released.

[0010] Furthermore, it also includes a guide rod that is connected to the housing and is vertically arranged, the fixing plate is arranged at the upper end of the guide rod, and the isolation plate and the movable frame are guided and cooperated with the guide rod; The connecting cylinder is connected to the isolation plate, and a power telescopic rod is provided between the isolation plate and the movable frame.

[0011] Furthermore, the guide rods include two spaced apart along the width of the housing, and a closing elastic element is provided between the isolation plate and the movable frame, which can provide a downward closing elastic force to the movable frame.

[0012] Furthermore, the lower end of the power telescopic rod is guided and engaged with the movable frame. A compensation component is provided at the lower end of the power telescopic rod passing through the movable frame. The compensation component includes a rigid ring that is slidably sleeved on the power telescopic rod. The compensation component is configured such that the rigid ring always abuts against the movable frame when the power telescopic rod extends downward.

[0013] Furthermore, the compensation component also includes: End plate, installed at the lower end of the power telescopic rod; A compensating compression spring is positioned between the rigid ring and the end plate; The rigid ring is provided with at least one roller, the roller shaft is horizontally arranged, a one-way bearing is provided between the roller and the roller shaft, the roller shaft is in non-rotational engagement with the rigid ring, and the outer peripheral surface of the roller is in rolling engagement with the outer peripheral surface of the power telescopic rod.

[0014] Furthermore, the outer peripheral surface of the fixing plate is provided with a positioning groove, and the thermal triggering unit includes: A locking rod is radially guided and set on the outer circumferential surface of the connecting cylinder. One end is inserted into the positioning groove, and the other end is provided with a plate. A heat-conducting cylinder is positioned along the axial direction of the locking rod; Compression spring two is installed between the plate and the heat-conducting cylinder; An elastic pad is fitted onto the locking rod; The corrugated pipe is located on the side of the elastic pad away from the plate and is filled with a thermal expansion medium.

[0015] Furthermore, a rigid plate is slidably sleeved on the locking rod between the elastic pad and the plate. On the side of the rigid plate near the fixed plate, a permanent magnet is provided on the side wall of the heat-conducting cylinder, and a permanent magnet is provided on the rigid plate to magnetically engage with the permanent magnet.

[0016] The fault location device for power distribution networks based on traveling wave signal analysis disclosed in this invention has the following advantages compared with the prior art: When a fault occurs at a predetermined location in the power distribution network, the fault point will generate a traveling wave signal and propagate rapidly along the line to various nodes. Fault signal acquisition units distributed at the ends of the main line and branches synchronously capture the traveling wave signal through Rogowski coils, effectively reducing the fault missed detection rate; The analysis module accurately analyzes key parameters such as the amplitude, frequency, and propagation time of the traveling wave. Based on the multi-node time difference positioning algorithm and the three-dimensional coordinate calculation model, combined with the collaborative data of multiple fault signal acquisition units, the distance between the fault point and each acquisition unit is calculated, achieving meter-level positioning; At the same time, based on the traveling wave amplitude threshold and frequency characteristics, it automatically identifies more than three types of faults such as short circuit, grounding, and open circuit, achieving a high diagnostic accuracy.

[0017] In conjunction with the thermal trigger protection unit, the acquisition circuit is disconnected when the temperature of the detection circuit exceeds the predetermined value, so as to avoid damage to the detection equipment and affect the accuracy of fault testing, improve the continuous working time of the detection equipment, and reduce the failure rate.

[0018] This device solves the problems of low acquisition accuracy, ambiguous positioning, and limited diagnostic capabilities of existing detection equipment. It can be directly applied to fault testing scenarios in 10kV-35kV urban and rural power distribution networks and new energy access power distribution networks, and has broad engineering application value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a power distribution network fault location device based on traveling wave signal analysis according to the present invention.

[0020] Figure 2 This is a schematic diagram of the connection structure of the conductor, fault detection module and monitoring device in a power distribution network fault location device based on traveling wave signal analysis according to the present invention.

[0021] Figure 3 This is a schematic diagram of the fault detection module in a power distribution network fault location device based on traveling wave signal analysis according to the present invention.

[0022] Figure 4 This is a schematic diagram of the internal structure of the fault detection module in this invention.

[0023] Figure 5 This is a schematic diagram of the internal structure of a power distribution network fault location device based on traveling wave signal analysis according to the present invention. Figure 3 .

[0024] Figure 6 This is a schematic diagram of the structure of the hidden housing of the fault detection module in this invention. Figure 1 .

[0025] Figure 7 This is a schematic diagram of the structure of the fault detection module when the housing is hidden in this invention. Figure 2 .

[0026] Figure 8 This is a side view of the fault detection module in the present invention when the housing is hidden.

[0027] Figure 9 This is a schematic diagram of the switching assembly in this invention.

[0028] Figure 10 This is a side view of the switching assembly in this invention.

[0029] Figure 11 for Figure 10 The diagram shown is a cross-sectional view of the switching assembly at point AA in this invention.

[0030] Figure 12 This is a partial structural diagram of the support frame in this invention.

[0031] Figure 13 This is a partial bottom view of the support frame structure in this invention.

[0032] Figure 14 This is a schematic diagram of the structure of the isolation plate, guide rod and connecting cylinder in this invention.

[0033] Figure 15 This is a schematic diagram of the connection structure of the connecting cylinder, guide rod, and thermal triggering unit in this invention.

[0034] Figure 16 for Figure 11 The diagram shows a partially enlarged structural schematic at point B in this invention.

[0035] Figure 17 for Figure 16 The diagram shows a partially enlarged structural diagram at point C in the first embodiment of the present invention.

[0036] Figure 18 for Figure 16 The diagram shows a partially enlarged structural diagram at point C in the second embodiment of the present invention.

[0037] Figure 19 The diagram shown is a cross-sectional view of the power telescopic rod and the movable frame in this invention.

[0038] Figure 20 for Figure 19 The diagram shows a partially enlarged structural schematic at point D in this invention.

[0039] In the diagram: 1. Main line; 10. Branch line; 20. Conductor; 2. Fault signal acquisition unit; 21. Incoming line; 3. Fault detection module; 30. Housing; 301. Fixing frame; 33. Analysis module; 35. Isolation plate; 350. Guide cylinder; 351. Positioning surface; 36. Rogowski coil; 360. Signal line; 37. Switch assembly; 370. Terminal 1; 371. Support frame; 3710. Locking frame; 3711. Locking ear plate; 372. Movable frame; 373. Power telescopic rod; 3730. Strip groove; 374. Closing elastic element; 37 5. Terminal 2; 376. Coil bracket; 38. Guide rod; 380. Connecting cylinder; 381. Fixing plate; 382. Compression spring 1; 383. Positioning groove; 39. Thermal trigger unit; 390. Heat-conducting cylinder; 390. Vent hole; 391. Locking rod; 392. Bellows; 393. Elastic pad; 394. Permanent magnet 1; 395. Permanent magnet 2; 396. Rigid plate; 397. Compression spring 2; 4. Compensation assembly; 40. Rigid ring; 41. Compensating compression spring; 42. End plate; 43. Roller; 44. One-way bearing; 9. One-way rotation direction. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the invention in a schematic manner, and therefore only show the components relevant to the invention.

[0041] Please refer to Figure 1-20 This invention provides a power distribution network fault location device based on traveling wave signal analysis. Its specific structure and working principle are described in detail below. Example

[0042] This invention provides a power distribution network fault location device. As one embodiment, referring to Figures 1-8, it includes a main line 1, multiple branch lines 10, and at least three fault signal acquisition units 2 disposed at the ends of the main line 1 and the branch lines 10. The fault signal acquisition units 2 transmit signals synchronously via a wireless communication protocol. Each fault signal acquisition unit 2 includes a fault detection module 3, which includes an analysis module 33, multiple Rogowski coils 36, and a switching assembly 37. The switching assembly 37 connects the line under test to the analysis module 33 via wires 20. The Rogowski coils 36 have a bandwidth of 10kHz-1MHz and an acquisition accuracy of 0.1A, and are correspondingly arranged on the wires 20. When a fault occurs in the distribution network, the traveling wave generated at the fault point propagates along the line to each node. Each fault signal acquisition unit 2 synchronously acquires the traveling wave signal through the Rogowski coil 36 and transmits it to the analysis module 33. The analysis module 33 extracts the amplitude, frequency, and propagation time parameters of the traveling wave signal. Based on the multi-node time difference positioning algorithm and the three-dimensional coordinate calculation model, it calculates the location of the fault point. According to statistics, the positioning error is ≤5 meters. Based on the traveling wave amplitude threshold and frequency characteristics, at least three types of faults, such as short circuit, grounding, and open circuit, are identified.

[0043] Specifically, the structure of the power distribution network fault location device provided in this application is as follows: it includes a main line 1, multiple branches 10, and at least three fault signal acquisition units 2 configured at the ends of the main line 1 and each branch 10. The fault signal acquisition unit 2 includes a fault detection module 3, which consists of an analysis module 33, multiple Rogowski coils 36, and a switching assembly 37. The switching assembly 37 connects the line under test to the analysis module 33 through wires 20, and the Rogowski coils 36 are correspondingly arranged on the wires 20.

[0044] In practical applications, three detection and positioning units are deployed at the end of the main line and the ends of two key branches, with a spacing of 1-3 km. When a fault occurs, each unit synchronously collects traveling wave signals and uploads them to the analysis module via the LoRa protocol. The analysis module is based on the traveling wave propagation speed v=1.8×10⁻⁶. 8m / s, based on the signal reception time differences Δt1 and Δt2 of each unit, the distance to the fault point is calculated using the formula: x=(v×Δt1 + v×Δt2) / 2; Main line 1 serves as the backbone transmission line of the distribution network, undertaking the main power transmission task. Multiple branches 10 extend from main line 1 according to the actual layout of the distribution network, covering different power supply areas. By configuring fault signal acquisition unit 2 at the end of main line 1 and each branch 10, comprehensive coverage of key nodes of the distribution network can be achieved, avoiding missed fault detection due to monitoring blind spots.

[0045] The Rogowski coil 36, as the core signal acquisition element, is installed one-to-one on the wires 20 connecting the switch assembly 37 and the analysis module 33. It can acquire the current signal on each line under test. Compared with traditional current acquisition elements, the Rogowski coil 36 has the advantages of no saturation, wide measurement range, and fast response speed. With a bandwidth of 10kHz-1MHz and an acquisition accuracy of 0.1A, it can quickly capture the weak current changes generated when a fault occurs, effectively reducing the fault missed detection rate. The switch assembly 37 is used to connect the wires 20 and the analysis module 33.

[0046] Analysis module 33 is connected to switch assembly 37 and collects line voltage, current, and power signals through voltage and current transformers. Rogowski coil 36 is mounted on conductor 20 and is used to collect power frequency and traveling wave signals; these signals can be used to determine the fault type. Analysis module 33 acquires the signals collected by Rogowski coil 36, processes and analyzes the signals to determine the fault type, and obtains the signal timing information. Analysis module 33 includes a communication module, which can be a GPRS communication module, for connection to a remote control terminal. When a fault occurs at a predetermined location in the distribution network, the fault point generates a traveling wave signal that propagates rapidly along the line to various nodes. The fault signal acquisition units 2, distributed at the ends of the main line 1 and branch line 10, simultaneously capture this traveling wave information (synchronization error ≤ 1μs). The analysis module 33 performs precise analysis on key parameters such as the amplitude, frequency, and propagation time of the traveling wave. Based on the multi-node time difference positioning algorithm and the three-dimensional coordinate calculation model, combined with the collaborative data of multiple fault signal acquisition units 2, it calculates the distance between the fault point and each acquisition unit (positioning error ≤ 5 meters). Based on the traveling wave amplitude threshold (short circuit fault amplitude ≥ 10kA, ground fault amplitude ≥ 5kA) and frequency characteristics (short circuit fault frequency 50-100kHz, ground fault frequency 20-50kHz), it automatically identifies three or more fault types, including short circuit, ground fault, and open circuit, providing accurate basis for subsequent fault handling, significantly improving the efficiency of distribution network fault investigation, and meeting the needs of rapid and efficient fault handling in the distribution network. Furthermore, as a specific implementation method, each fault signal acquisition unit 2 is wirelessly connected.

[0047] Each fault signal acquisition unit 2 is connected to the control terminal via wireless communication. The wireless communication method can utilize protocols such as 5G, LoRa, or Wi-Fi, which are suitable for complex outdoor environments. LoRa is preferred due to its long transmission distance, strong anti-interference capability, and low power consumption, making it suitable for scenarios with dispersed power distribution lines and harsh outdoor environments. Compared to traditional wired connections, wireless communication eliminates the need for extensive cable laying, effectively reducing installation difficulty and construction costs. It is particularly suitable for power distribution networks with numerous branch lines and complex structures, while also reducing the risk of communication failures caused by cable damage and aging, thus improving the operational stability of the device. Multiple fault signal acquisition units 2 achieve real-time data interaction and sharing through wireless communication. When a fault occurs in a certain area, each fault signal acquisition unit 2 can quickly transmit the acquired traveling wave information and preliminary analysis results to the core analysis node, realizing multi-unit data collaborative analysis, further improving the speed and accuracy of fault location, avoiding location errors caused by deviations in data from a single unit, and facilitating maintenance personnel to obtain the operating status and fault data of each fault signal acquisition unit 2 in real time through remote terminals, eliminating the need for on-site inspection, reducing the maintenance burden, and meeting the development needs of intelligent operation and maintenance of distribution networks.

[0048] Furthermore, as a specific implementation method, refer to Figure 2 - Figure 20 The fault detection module 3 includes a housing 30, with an isolation plate 35 horizontally arranged in the middle area inside the housing 30. The switch assembly 37 and the analysis module 33 are both integrated inside the housing 30, and the switch assembly 37 is located below the isolation plate 35.

[0049] Specifically, the fault detection module 3 includes a housing 30, with an isolation plate 35 horizontally arranged in the middle area of ​​the housing 30. The switch assembly 37, the analysis module 33, and the signal conversion module are all integrated and arranged above the isolation plate 35 inside the housing 30. The switch assembly 37 is arranged below the isolation plate 35. The integrated design improves the integration level and reduces the overall size of the device. At the same time, the integrated design can reduce the connection lines between the components, reduce the risk of line failure, and improve the reliability of the device operation. The isolation plate 35 can isolate the switch assembly 37 and the analysis module 33 above it, block the arc, and improve safety.

[0050] In practical applications, a heat dissipation unit (not shown in the figure) will be installed inside the enclosure 30 to dissipate heat from the inside of the enclosure 30. The enclosure 30 is made of high-strength alloy material that is waterproof, dustproof, and corrosion-resistant, providing protection for the internal electrical components, avoiding damage to the components caused by environmental factors, and improving the outdoor adaptability and service life of the device. The isolation plate 35 divides the internal space of the enclosure 30 into upper and lower areas, realizing the partitioned arrangement of the switching assembly 37, analysis module 33, and signal conversion module. This can reduce the impact of electromagnetic interference generated by the switching assembly 37 during operation on the analysis module 33, ensuring the accuracy of the analysis module 33 in analyzing traveling wave signals.

[0051] Furthermore, as a specific implementation, the switch assembly 37 includes: Terminal 370 is mounted on housing 30 and connected to wire 20; The movable frame 372 is vertically guided and positioned above terminal 370; Terminal 2 375 is disposed on the movable frame 372 corresponding to terminal 1 370; The housing 30 is provided with a fixing plate 381, and a connecting cylinder 380 is guided to the outside of the fixing plate 381. The connecting cylinder 380 is connected to the movable frame 372. A compression spring 382 is provided between the upper surface of the fixing plate 381 and the connecting cylinder 380. A heat triggering unit 39 is provided on the outer peripheral surface of the connecting cylinder 380. When the temperature inside the housing 30 is lower than a predetermined value, the heat triggering unit 39 locks the connecting cylinder 380 and the fixing plate 381 to the first state of compressing the compression spring 382. When the temperature reaches the predetermined value, the fixing plate 381 is released.

[0052] Specifically, a mounting bracket 301 is fixedly welded to the side wall of the housing 30. A support bracket 371 is detachably mounted on the upper side of the mounting bracket 301. The support bracket 371 is provided with a slot corresponding to terminal 370. Terminal 370 is snapped into the slot. The support bracket 371 is also detachably and fixedly connected to a locking bracket 3710. The locking bracket 3710 includes a locking ear plate 3711 corresponding to the slot. The lower terminal is snapped into and locked by the locking ear plate 3711 and the slot. The support bracket 371 is also provided with a coil bracket 376 for mounting and fixing the Rogowski coil 36. The Rogowski coil is connected to the analysis module 33 through a signal line 360.

[0053] The switch assembly 37 includes a terminal 370 mounted on a support frame 371 and connected to a wire 20. The other end of the wire 20 is used to connect to the power transmission line under test. A movable frame 372 is horizontally mounted above the support frame 371. A terminal 375 is mounted on the movable frame 372 and can be fixed to the movable frame 372 by a threaded connection. It is connected to the analysis module 33 through an inlet wire 21. A fixing plate 381 is mounted on the housing 30. A connecting cylinder 380 is guided to the outside of the fixing plate 381 and connected to the movable frame 372. A compression spring 382 is mounted between the upper surface of the fixing plate 381 and the connecting cylinder 380. A thermal triggering unit 39 is mounted on the outer circumferential surface of the connecting cylinder 380. When the temperature inside the housing 30 is lower than a first threshold (preferably 85°C-90°C), the thermal triggering unit 39 locks the connecting cylinder 380 and the fixing plate 381 to a first state that compresses the compression spring 382. When the temperature reaches the first threshold, the fixing plate 381 is released.

[0054] In practical applications, the movable frame 372 is driven by a drive device. The drive device is connected to a control module. The control module controls the drive device to work according to the instructions, so as to realize the up and down movement of the movable frame 372, thereby realizing the opening and closing of the switch assembly 37.

[0055] In some embodiments, a detection unit is also configured inside the enclosure 30. The detection unit is used to detect the operating parameters inside the enclosure 30, such as the operating status of the analysis module 33 inside the enclosure 30 and the temperature inside the enclosure 30. When the analysis module 33 malfunctions and / or the temperature inside the enclosure 30 exceeds a first threshold, the detection unit transmits the detection information to the control module. The control module controls the drive device to drive the movable frame 372 to move, causing terminal 2 375 to separate from terminal 1 370, and the switch assembly 37 to disconnect, thus disconnecting the power supply. This reduces the scope of the fault and avoids further damage to other components inside the enclosure 30 caused by high temperature, thereby improving the fault self-protection capability of the device and the stability of the power distribution network operation.

[0056] However, under certain operating conditions, when the drive device and detection unit also malfunction, the temperature inside the housing 30 becomes too high, and the switch assembly 37 cannot be disconnected in a timely and effective manner. This application addresses this by setting a fixing plate 381, with a connecting cylinder 380 externally guided by the fixing plate 381. The connecting cylinder 380 is connected to the movable frame 372. A compression spring 382 is provided between the upper surface of the fixing plate 381 and the connecting cylinder 380. A thermal triggering unit 39 is provided on the outer circumferential surface of the connecting cylinder 380. The compression spring 382 is compressed in the locked state. In the energy storage state, the drive device is in the closed state, and terminals 370 and 375 are in contact. When the temperature inside the enclosure 30 reaches a predetermined temperature and continues to rise, reaching the first threshold, the thermal trigger unit 39 triggers the release of the fixing plate 381. The compression spring 382 elastically resets and pushes the connecting cylinder 380 upward, thereby driving the drive device to move the movable frame 372 and terminal 375 upward, achieving the separation of terminals 370 and 375, disconnecting the circuit, and ensuring the safety of the switch assembly 37. The thermal trigger unit 39 can set the first threshold according to the temperature environment of the power distribution network, usually set to a critical value exceeding the normal operating temperature range of the component. When the temperature inside the enclosure 30 rises to the predetermined value due to a fault (such as a short circuit or overheating of a component), the thermal trigger unit 39 automatically unlocks, achieving rapid separation of the terminals through the elastic force of the compression spring 382, ​​reducing the scope of the fault impact, and preventing further damage to other components inside the enclosure 30 due to high temperature, thus improving the fault self-protection capability of the device and the stability of the power distribution network operation.

[0057] Furthermore, as a specific implementation, it also includes a guide rod 38 connected to the housing 30 and vertically arranged, the fixing plate 381 is arranged at the upper end of the guide rod 38, and the isolation plate 35 and the movable frame 372 are both guided and cooperated with the guide rod 38; The connecting cylinder 380 is connected to the isolation plate 35, and a power telescopic rod 373 is provided between the isolation plate 35 and the movable frame 372.

[0058] Specifically, a fixed frame 301 is welded to the two side walls of the cabinet 30 near the cabinet door, and a support frame 371 is set on the fixed frame 301. The fixed frame 301 is also provided with a plug-in tube. The lower end of the guide rod 38 is inserted into the plug-in tube, and then the two are locked and positioned by a locking screw. The isolation plate 35 is provided with a guide tube 350, and the movable frame 372 is provided with a guide hole, which guides and cooperates with the guide rod 38. The lower end of the isolation plate 35 and the connecting tube 380 are detachably fixedly connected. As a specific implementation, the driving device is a power telescopic rod 373 set on the isolation plate 35. The telescopic rod of the power telescopic rod 373 is connected to the movable frame 372. The power telescopic rod 373 can be an electric telescopic rod.

[0059] Furthermore, as a preferred embodiment, the guide rod 38 includes two rods spaced apart along the width direction of the housing 30, and a closing elastic element 374 is provided between the isolation plate 35 and the movable frame 372, which can provide a downward closing force to the movable frame 372.

[0060] Two spaced guide rods 38 guide and limit the movement of the isolation plate 35 and the movable frame 372 from both sides. Compared with a single guide rod 38, this effectively prevents the isolation plate 35 and the movable frame 372 from twisting or shifting during movement, further improving the stability and accuracy of the movement of each component and ensuring the precise connection of terminal 1 370 and terminal 2 375. As a specific implementation, the closing elastic element 374 uses two compression springs respectively sleeved on the two guide rods 38, with its two ends abutting against the isolation plate 35 and the movable frame 372 respectively. When the power telescopic rod 373 extends, the elastic force of the closing elastic element 374 can drive the movable frame 372 to move downward, causing terminal 2 375 to abut against terminal 1 370, thereby completing the closing action. In this implementation, the telescopic rod 373 can form a guiding fit with the movable frame 372. Only an end plate 42 needs to be installed at the lower end of the rod passing through the movable frame 372. The telescopic rod 373 only participates in the opening action: during opening, the telescopic rod 373 retracts, applying force to the positioning surface 351 on the movable frame 372 through the end plate 42, thereby pulling the movable frame 372 to compress the opening spring and achieve opening; during closing, the telescopic rod 373 fully extends, completing the closing action under the elastic force of the closing spring. This configuration, using the elastic force of the closing spring to achieve closing, avoids excessive contact between terminal 370 and terminal 375 due to excessive extension of the telescopic rod 373, thus protecting the terminals and improving the reliability and fault tolerance of the device. In addition, if the electric telescopic rod extends at a predetermined speed when the circuit is closed, the movable frame 372 can move synchronously with the extension of the electric telescopic rod under the elastic force of the closing spring, so that the terminals make contact at a uniform speed, avoid the terminals from being worn or damaged by impact, extend the service life of the terminals, and ensure the stability of the line connection.

[0061] Furthermore, the lower end of the power telescopic rod 373 is guided and engaged with the movable frame 372. A compensation component 4 is provided at the lower end of the power telescopic rod 373 passing through the movable frame 372. The compensation component 4 includes a rigid ring 40 that is slidably sleeved on the power telescopic rod 373. The compensation component 4 is configured such that the rigid ring 40 always abuts against the movable frame 372 when the power telescopic rod 373 extends downward.

[0062] Furthermore, under normal conditions, the trigger unit is locked to the fixed plate 381, and the compression spring 382 is compressed.

[0063] It is understandable that when the trigger unit is triggered to release the fixed plate 381, the return force of the compression spring 382 drives the isolation plate 35 to move upward, which in turn moves the power telescopic rod 373. The power telescopic rod 373 drives the movable frame 372 to move, thus achieving the opening of the circuit breaker. At this time, the power telescopic rod 373 is in the fully extended state. If the gap between the end plate 42 and the positioning surface 351 is too large, and the return displacement of the compression spring 382 is limited, it will result in the circuit breaker not being able to open effectively. To solve the above problem, refer to... Figure 19 , Figure 20 The compensation component 4 can apply force to the rigid ring 40 to make the rigid ring 40 contact the positioning surface 351. During the initial installation, the power telescopic rod 373 is in a fully extended state. At this time, under the elastic force of the closing elastic element 374, the terminal 1 370 and the terminal 2 375 contact and close the circuit. Then, the compensation component 4 and the end plate 42 are set at the end of the power telescopic rod 373 that passes through the movable frame 372. At this time, the rigid ring 40 abuts against the positioning surface 351 through the compensation component 4, and the gap between the end plate 42 and the positioning surface 351 is compensated by the compensation component 4.

[0064] Furthermore, as a specific implementation, the compensation component 4 further includes: End plate 42 is installed at the lower end of the power telescopic rod 373; A compensating spring 41 is disposed between the rigid ring 40 and the end plate 42; The rigid ring 40 is provided with at least one roller 43, the roller shaft of the roller 43 is horizontally arranged, a one-way bearing 44 is provided between the roller 43 and the roller shaft, the roller shaft is in non-rotational engagement with the rigid ring 40, and the outer peripheral surface of the roller 43 is in rolling engagement with the outer peripheral surface of the power telescopic rod 373.

[0065] For details, please refer to Figure 19 , Figure 20 The compensating spring 41 is sleeved on the telescopic rod 373, with its two ends abutting against the rigid ring 40 and the end plate 42 respectively. A strip groove 3730 is provided on the outer circumferential surface of the telescopic rod 373. The roller 43 contacts the bottom of the strip groove 3730, and the two are in frictional engagement. By providing a one-way bearing 44, and ensuring that the roller shaft and rigid ring 40 are in non-rotational engagement, the roller 43 can rotate in one direction. (See reference...) Figure 20 In a specific implementation, two rollers 43 are provided, and the unidirectional rotation direction 9 of the two rollers 43 is as follows: Figure 20As shown, the left roller 43 can rotate clockwise in one direction, and the right roller 43 can rotate counterclockwise in one direction. Under the friction between the roller 43 and the bottom of the groove 3730, the rigid ring 40 can move upward in one direction. Under the elastic force of the compensating spring 41, the rigid ring 40 moves upward and abuts against the positioning surface 351, achieving a compensation effect. Furthermore, through the setting of the one-way bearing 44, when the rigid ring 40 wants to move downward, the left roller 43 will rotate counterclockwise under the action of friction, and the right roller 43 will rotate clockwise. The one-way bearing 44 hinders the rotation of the roller 43, thus preventing the rigid ring 40 from moving downward.

[0066] In a preferred embodiment, a rack is provided at the bottom of the groove 3730, and teeth that mesh with the rack are provided on the outer circumferential surface of the roller 43. Through the meshing of the teeth and the rack, a unidirectional limiting force can be better provided to the rigid ring 40. It should be noted that when disassembling the rigid ring 40, the roller shaft of the roller 43 is removed first, and then the rigid ring 40 can be detached downward from the power telescopic rod 373.

[0067] It should be noted that the elastic coefficient of the compensating spring 41 is much smaller than that of the closing elastic element 374.

[0068] Further, refer to Figure 16 , Figure 17 The specific structure of the triggering unit is as follows: the outer peripheral surface of the fixing plate 381 is provided with a positioning groove 383, and the thermal triggering unit 39 includes: The locking rod 391 is radially guided and disposed on the outer circumferential surface of the connecting cylinder 380. One end is inserted into the positioning groove 383, and the other end is provided with a plate. The heat-conducting cylinder 390 is arranged along the axial direction of the locking rod 391; Compression spring 397 is positioned between the plate and the heat-conducting cylinder 390; Elastic pad 393 is fitted onto locking rod 391; The corrugated pipe 392 is located on the side of the elastic pad 393 away from the plate and is filled with a thermal expansion medium.

[0069] Specifically, the heat-conducting cylinder 390 and the connecting cylinder 380 are integrated. The thermal expansion medium can be any of the existing technologies such as paraffin or kerosene, and the elastic pad 393 can be any of the existing technologies such as rubber or spring pads. In the initial state, the temperature is low and the volume of the thermal expansion medium is small. Under the elastic force of the second compression spring 397, the plate is pushed and the bellows 392 is squeezed, so that the end of the locking rod 391 extends into the plate, thus reliably locking the connecting cylinder 380 and the fixed plate 381. At this time, the first compression spring 382 is stably maintained in the compressed energy storage state in the first state, and the second compression spring 397 provides continuous axial elastic force for the locking rod 391, so that the locking rod 391 is always tightly inserted into the positioning groove 383. The heat-conducting cylinder 390 is made of a material with high thermal conductivity and has vent holes 3900 on its side wall to ensure that the bellows 392 can fully exchange heat with the inside of the housing 30, making the thermal triggering unit 39 more sensitive to temperature changes.

[0070] When the temperature inside the housing 30 rises, the thermal expansion medium expands in volume due to heat. The elastic coefficient of the elastic pad 393 is less than that of the compression spring 397. During this process, the elastic pad 393 is compressed first. At this time, the locking rod 391 remains locked. As the temperature inside the housing 30 continues to rise, the amount of compression of the elastic pad 393 increases, and the elastic force increases. When the temperature inside the housing 30 continues to rise to the first threshold, the thermal expansion medium continues to expand due to heat. At this time, the bellows 392 extends and pushes the plate through the elastic pad 393 to compress the compression spring 397, causing the locking rod 391 to separate from the positioning groove 383. This disengages the locking rod 391 from the positioning groove 383, thereby unlocking the connecting cylinder 380 from the fixing plate 381 and achieving the effect of opening the circuit breaker.

[0071] Furthermore, the aforementioned implementation method can immediately disconnect the switch assembly 37 and disconnect the circuit when the fault detection module 3 malfunctions, thereby avoiding continued power supply to the fault analysis and location module 3. On the one hand, it can prevent the accumulation of heat caused by continued power supply and thus avoid a larger quality accident. On the other hand, it can also reduce the waste of electrical energy and achieve the effect of energy saving. Example

[0072] This invention provides a distribution network fault location device based on traveling wave signal analysis. As one implementation method, refer to... Figure 18 As a further improvement, a rigid plate 396 is slidably sleeved on the locking rod 391 between the elastic pad 393 and the plate. On the side of the rigid plate 396 near the fixed plate 381, a permanent magnet 394 is provided on the side wall of the heat-conducting cylinder 390, and a permanent magnet 395 is provided on the rigid plate 396 to magnetically engage with the permanent magnet 394.

[0073] Specifically, in this embodiment, the elastic coefficient of the elastic pad 393 is equal to or greater than the elastic coefficient of the compression spring 397. The permanent magnet 394 is fixed on the heat-conducting cylinder 390. The rigid plate 396 is guided and slidably engaged with the locking rod 391. The permanent magnet 395 is fixedly connected to the rigid plate 396. In the initial state, under the elastic force of the compression spring 397, the plate abuts against the rigid plate 396, causing the permanent magnets 394 and 395 on the rigid plate 396 to be magnetically connected. When the temperature inside the housing 30 rises, the thermal expansion medium expands due to heat, the bellows 392 elongates, and the elastic pad 393 is compressed. At this time, the compression of the elastic pad 393 is small, and the elastic force of the elastic pad 393 is less than that of the permanent magnets 394 and 395. The magnetic attraction of permanent magnet 395, at this time, the magnetic attraction of permanent magnet 394 and permanent magnet 395 keeps the rigid plate 396 in position. When the temperature inside the box 30 continues to rise to the first threshold, the thermal expansion medium continues to expand due to heat, and the length of the bellows 392 continues to lengthen. The greater the amount of compression of the elastic pad 393, the greater the elastic force. At this time, the elastic force of the elastic pad 393 is equal to the magnetic attraction of permanent magnet 394 and permanent magnet 395. When the temperature inside the box 30 continues to rise, the bellows 392 continues to lengthen. At this time, permanent magnet 394 and permanent magnet 395 separate, and under the action of the elastic force of the elastic pad 393, the plate moves rapidly, and the locking rod 391 is quickly separated from the positioning groove 383.

[0074] The fault detection and location performance of this device was verified through a 10kV distribution network simulation experiment. The experiment constructed a distribution network simulation platform containing one main line and three branches. Twenty simulated fault points (totaling 20) were set up in the middle section of the main line and at the ends of each branch. Different types of faults were generated using a short-circuit generator and a grounding simulator. Each fault signal acquisition unit synchronously acquired traveling wave signals, and the analysis module ran a multi-node time difference algorithm. Test results showed that the average location error of the 20 fault points was 3.2 meters, with a maximum error not exceeding 5 meters, and the fault type diagnosis accuracy reached 99.7%. The Rogowski coil's acquisition error within the fault signal amplitude range of 0.5A-20kA was ≤0.05A, meeting the requirements for accurate acquisition of distribution network fault signals.

[0075] The performance comparison between this device and existing fault detection equipment is as follows:

[0076] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A distribution network fault location device based on traveling wave signal analysis, characterized in that, It includes a main line (1), multiple branches (10), and fault signal acquisition units (2) configured at the ends of the main line (1) and branches (10). The fault signal acquisition units (2) transmit signals synchronously with each other through a wireless communication protocol. The fault signal acquisition unit (2) includes: The fault detection module (3) includes an analysis module (33), multiple Rogowski coils (36) and a switch assembly (37). The switch assembly (37) connects the circuit under test to the analysis module (33) via wires (20). The Rogowski coils (36) are arranged one-to-one on the wires (20). When a fault occurs in the power distribution network, the traveling wave generated at the fault point is transmitted to each node along the line. Each fault signal acquisition unit synchronously acquires the traveling wave signal through the Rogowski coil (36) and transmits it to the analysis module (33). The analysis module (33) extracts the amplitude, frequency and propagation time parameters of the traveling wave signal, calculates the location of the fault point based on the multi-node time difference positioning algorithm and the three-dimensional coordinate calculation model, and identifies at least the short circuit, grounding and open circuit fault types according to the traveling wave amplitude threshold and frequency characteristics.

2. The power distribution network fault location device based on traveling wave signal analysis according to claim 1, characterized in that, Wireless communication connection between each fault signal acquisition unit (2).

3. The distribution network fault location device based on traveling wave signal analysis according to claim 1, characterized in that, The fault detection module (3) includes a housing (30), with an isolation plate (35) horizontally arranged in the middle area of ​​the housing (30). The switch assembly (37) and the analysis module (33) are both integrated in the housing (30), and the switch assembly (37) is located below the isolation plate (35).

4. A power distribution network fault location device based on traveling wave signal analysis according to claim 3, characterized in that, The switching assembly (37) includes: Terminal 1 (370) is located on the housing (30) and connected to the wire (20); The movable frame (372) is vertically guided and positioned above terminal one (370); Terminal 2 (375) is disposed on the movable frame (372) corresponding to terminal 1 (370); The housing (30) is provided with a fixing plate (381), and a connecting cylinder (380) is guided to the outside of the fixing plate (381). The connecting cylinder (380) is connected to the movable frame (372). A compression spring (382) is provided between the upper surface of the fixing plate (381) and the connecting cylinder (380). A heat triggering unit (39) is provided on the outer circumferential surface of the connecting cylinder (380). When the temperature inside the housing (30) is lower than the first threshold, the heat triggering unit (39) locks the connecting cylinder (380) and the fixing plate (381) to the first state of compressing the compression spring (382). When the temperature reaches the first threshold, the fixing plate (381) is released.

5. A distribution network fault location device based on traveling wave signal analysis according to claim 4, characterized in that, It also includes a guide rod (38) that is connected to the housing (30) and is vertically arranged. The fixing plate (381) is arranged at the upper end of the guide rod (38). The isolation plate (35) and the movable frame (372) are both guided and cooperated with the guide rod (38). The connecting cylinder (380) is connected to the isolation plate (35), and a power telescopic rod (373) is provided between the isolation plate (35) and the movable frame (372).

6. A power distribution network fault location device based on traveling wave signal analysis according to claim 5, characterized in that, The guide rod (38) includes two rods spaced apart along the width direction of the housing (30). A closing elastic element (374) is provided between the isolation plate (35) and the movable frame (372). The closing elastic element (374) can provide a downward closing force to the movable frame (372).

7. A distribution network fault location device based on traveling wave signal analysis according to claim 6, characterized in that, The lower end of the telescopic rod (373) is guided and engaged with the movable frame (372). The lower end of the telescopic rod (373) passing through the movable frame (372) is provided with a compensation component (4). The compensation component (4) includes a rigid ring (40) slidably sleeved on the telescopic rod (373). The compensation component (4) is configured such that the rigid ring (40) always abuts against the movable frame (372) when the telescopic rod (373) extends downward.

8. A distribution network fault location device based on traveling wave signal analysis according to claim 7, characterized in that, The compensation component (4) further includes: End plate (42) is provided at the lower end of the power telescopic rod (373); A compensating spring (41) is disposed between the rigid ring (40) and the end plate (42); The rigid ring (40) is provided with at least one roller (43), the roller shaft of the roller (43) is horizontally arranged, a one-way bearing (44) is provided between the roller (43) and the roller shaft, the roller shaft is in non-rotational engagement with the rigid ring (40), and the outer peripheral surface of the roller (43) is in rolling engagement with the outer peripheral surface of the power telescopic rod (373).

9. A distribution network fault location device based on traveling wave signal analysis according to claim 4 or 6, characterized in that, The outer peripheral surface of the fixing plate (381) is provided with a positioning groove (383), and the thermal triggering unit (39) includes: The locking rod (391) is arranged on the outer circumferential surface of the connecting cylinder (380) along the radial guide of the connecting cylinder (380), with one end inserted into the positioning groove (383) and the other end provided with a plate. A heat-conducting cylinder (390) is arranged along the axial direction of the locking rod (391); Compression spring 2 (397) is disposed between the plate and the heat-conducting cylinder (390); An elastic pad (393) is fitted onto a locking rod (391); A corrugated pipe (392) is located on the side of the elastic pad (393) away from the plate and is filled with a thermal expansion medium.

10. A power distribution network fault location device based on traveling wave signal analysis according to claim 9, characterized in that, Between the elastic pad (393) and the plate, a rigid plate (396) is slidably sleeved on the locking rod (391). On the side of the rigid plate (396) close to the fixed plate (381), a permanent magnet (394) is provided on the side wall of the heat-conducting cylinder (390), and a permanent magnet (395) is provided on the rigid plate (396) to magnetically engage with the permanent magnet (394).

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