Digital traveling wave distance measuring switch and its control method and device

Abstract

This application relates to a digital traveling wave ranging switch and its control method and apparatus. The method includes: unidirectional signal acquisition of current, voltage, and remote signaling signals from a three-phase solid-sealed pole assembly; analog-to-digital conversion and synthesis of the current, voltage, and remote signaling signals to obtain telemetry and remote signaling data, which are then transmitted to a secondary terminal control unit; in response to a traveling wave characteristic signal detected by a digital merging unit via a Rogowski coil, the secondary terminal control unit triggers a traveling wave recording function, acquiring traveling wave recording data through the Rogowski coil and the digital merging unit; and calculating traveling wave ranging based on the arrival time of the traveling wave and line parameters in the recorded data to locate the fault point. This application can reduce the structural complexity of the traveling wave ranging switch and improve the signal transmission quality of the traveling wave ranging switch.

Description

Technical Field

[0001] This application relates to the field of power equipment technology, and in particular to a digital traveling wave ranging switch and its control method and device. Background Technology

[0002] The existing primary and secondary integrated pole-mounted switch solid-sealed pole mainly integrates two sets of electromagnetic current transformer coils to sense line phase current signals and zero-sequence current signals. A sampling resistor integrated on the secondary side can convert the electromagnetic current signal into a small electronic current signal, and a digital conversion unit can also be integrated to complete the local digitization of the signal. It is typically installed on 10kV overhead lines to perform line current monitoring and conventional phase-to-phase short-circuit protection and ground fault protection.

[0003] In traveling wave ranging, existing power distribution network traveling wave ranging devices are typically installed independently, requiring additional high-frequency current transformers to collect fault traveling wave current signals. Signal interaction between the device and the switchgear relies on additional communication links and power supply circuits. This results in a complex overall solution with high costs and difficult construction, hindering large-scale deployment. While existing traveling wave ranging devices typically use wideband sensors with a frequency response range of 50Hz to 10MHz, the independent installation method limits their deep integration with the switchgear, and analog signal transmission is susceptible to interference, making signal quality difficult to guarantee. Summary of the Invention

[0004] Therefore, it is necessary to address the above-mentioned technical problems by providing a digital traveling wave ranging switch and its control method and device that can reduce the structural complexity of the traveling wave ranging switch and improve the signal transmission quality of the traveling wave ranging switch.

[0005] In a first aspect, this application provides a control method for a digital traveling wave ranging switch, the digital traveling wave ranging switch comprising: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, the digital merging unit is connected to the three-phase solid-sealed pole assembly, and is also connected to a secondary terminal control unit; the method includes: The digital merging unit performs unidirectional signal acquisition of the current signal, voltage signal and remote signaling signal of the three-phase solid-sealed pole assembly. The analog-to-digital signal conversion unit performs analog-to-digital conversion processing and synthesis on the current signal, the voltage signal, and the remote signaling signal to obtain telemetry data and remote signaling data, which are then transmitted to the secondary terminal control unit. The telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation, and traveling wave ranging analysis, while the remote signaling data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault diagnosis. In response to the digital merging unit detecting a traveling wave characteristic signal through the Rogowski coil, the secondary terminal control unit triggers the traveling wave recording function, acquires traveling wave recording data through the Rogowski coil and the digital merging unit, and performs traveling wave ranging calculation based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location; wherein, the line parameters include the telemetry data and the tele-signaling data.

[0006] In one embodiment, the digital merging unit also integrates a Rogowski coil double integrator; the telemetry data includes three-phase phase current and zero-sequence current; unidirectional signal acquisition of the current signal of the three-phase solid-sealed pole assembly based on the digital merging unit includes: The Rogowski coil of each phase senses the alternating current on the outgoing conductor of each phase and outputs a differential voltage signal that is proportional to the rate of change of the measured alternating current. The analog-to-digital signal conversion unit performs analog-to-digital conversion processing and synthesis on the current signal to obtain telemetry data, including: In response to the digital merging unit receiving the differential voltage signal, the differential voltage signal is integrated by the Rogowski coil double integrator to obtain a linear voltage signal proportional to the alternating current; The linear voltage signal is converted from analog to digital and then digitally synthesized by the analog-to-digital signal conversion unit to obtain the three-phase phase current and zero-sequence current.

[0007] In one embodiment, the telemetry data further includes three-phase phase voltage and zero-sequence voltage; unidirectional signal acquisition of the voltage signal of the three-phase solid-sealed pole assembly based on the digital merging unit includes: The voltage divider voltage sensor, which is composed of the high-voltage arm capacitor and the low-voltage arm capacitor built into the three-phase solid-sealed pole assembly, divides the primary voltage into a secondary low-voltage small signal voltage to obtain the secondary voltage signal. The secondary voltage signal is transmitted through the bottom secondary output terminal of the three-phase solid-sealed pole assembly to the 16-bit AD channel of the analog-to-digital signal conversion unit of the digital merging unit to complete analog-to-digital conversion and digital synthesis, thereby obtaining the three-phase phase voltage and zero-sequence voltage.

[0008] In one embodiment, transmitting the telemetry data to the secondary terminal control unit includes: The digital merging unit packages the telemetry data according to the agreed communication protocol frame format to obtain a packaged telemetry data frame; the communication protocol frame format includes a frame header identifier, device address code, data length, telemetry data field, check code, and frame tail identifier; The packaged telemetry data frames are transmitted uplink to the secondary terminal control unit via the optical fiber communication interface of the digital merging unit through the optical fiber cable. The secondary terminal control unit is then used to verify and decode the telemetry data frames and extract data from each telemetry channel for line monitoring, protection criterion calculation, and traveling wave ranging analysis.

[0009] In one embodiment, the remote signaling signal includes at least remote signaling status signals for the switch's open, closed, and non-energy-storage positions; unidirectional signal acquisition of the remote signaling signal of the three-phase solid-sealed pole assembly is performed based on the digital merging unit, including: The remote signal is transmitted to the optocoupler-isolated digital input channel of the digital merging unit through the switch auxiliary contact and the bottom output terminal of the three-phase solid-sealed pole assembly.

[0010] In one embodiment, the remote signaling signal includes at least digital signals indicating the remote signaling status of the switch at its open, closed, and unstored positions; transmitting the remote signaling data to the secondary terminal control unit includes: The digital merging unit packages the remote signaling signal according to the agreed communication protocol frame format and transmits it uplink to the secondary terminal control unit through the optical fiber communication interface. This enables the secondary terminal control unit to monitor the switch operation status and determine faults based on the remote signaling status contained in the remote signaling signal.

[0011] In one embodiment, in response to the digital merging unit detecting a traveling wave characteristic signal through the Rogowski coil, the secondary terminal control unit triggers the traveling wave recording function to acquire traveling wave recorded data through the Rogowski coil and the digital merging unit, including: In response to the digital merging unit detecting a transient change exceeding a set threshold in the current signal via the Rogowski coil, the secondary terminal control unit instructs the digital merging unit to perform high-speed sampling and waveform recording of the traveling wave current signal at a sampling rate of not less than 5MHz to obtain the traveling wave waveform recording data; the traveling wave waveform recording data includes traveling wave head time markers and raw waveform data; The digital merging unit transmits the traveling wave recording data to the secondary terminal control unit via optical fiber communication.

[0012] In one embodiment, the step of calculating the traveling wave distance based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location includes: The secondary terminal control unit calculates the fault location based on the traveling wave head time marker and the original waveform data, using either the single-end traveling wave ranging method or the double-end traveling wave ranging method.

[0013] Secondly, this application also proposes a control device for a digital traveling wave ranging switch, the digital traveling wave ranging switch comprising: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, the digital merging unit is connected to the three-phase solid-sealed pole assembly, and is also connected to a secondary terminal control unit; the device comprises: A unidirectional signal acquisition module is used to acquire the current signal, voltage signal and remote signaling signal of the three-phase solid-sealed pole assembly based on the digital merging unit. The signal conversion and synthesis module is used to perform analog-to-digital conversion processing and synthesis of the current signal, the voltage signal and the remote signaling signal through the analog-to-digital signal conversion unit to obtain telemetry data and remote signaling data, and transmit them to the secondary terminal control unit; wherein, the telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation and traveling wave ranging analysis, and the remote signaling data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault judgment; The traveling wave recording and fault location module is used to respond to the digitizing unit detecting a traveling wave characteristic signal through the Rogowski coil, causing the secondary terminal control unit to trigger the traveling wave recording function, acquiring traveling wave recording data through the Rogowski coil and the digitizing unit, and performing traveling wave ranging calculation based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location; wherein, the line parameters include the telemetry data and the tele-signaling data.

[0014] Thirdly, this application also proposes a digital traveling wave ranging switch for implementing the steps of the method described in the first aspect embodiment; the digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, and the digital merging unit is connected to the three-phase solid-sealed pole assembly and also connected to a secondary terminal control unit.

[0015] The aforementioned digital traveling wave ranging switch and its control method and device acquire current, voltage, and remote signaling signals from the three-phase solid-sealed pole assembly using a digital merging unit. The current, voltage, and remote signaling signals are then converted and synthesized using an analog-to-digital conversion unit to obtain telemetry and remote signaling data, which are then transmitted to the secondary terminal control unit. The telemetry data is used by the secondary terminal control unit for line monitoring, protection criterion calculation, and traveling wave ranging analysis, while the remote signaling data is used for switch operation status monitoring and fault diagnosis. In response to the digital merging unit detecting a traveling wave characteristic signal via a Rogowski coil, the secondary terminal control unit triggers a traveling wave recording function. Traveling wave recording data is acquired through the Rogowski coil and the digital merging unit. Based on the traveling wave arrival time and line parameters in the recording data, traveling wave ranging calculation is performed to locate the fault point. The line parameters include both telemetry and remote signaling data, thereby reducing the structural complexity of the traveling wave ranging switch and improving its signal transmission quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a control method for a digital traveling wave ranging switch in one embodiment; Figure 2 This is a schematic diagram of the external structure of a digital traveling wave ranging switch in one embodiment; Figure 3 A front view of a digital traveling wave ranging switch in one embodiment; Figure 4 This is a side cross-sectional view of a digital traveling wave ranging switch in one embodiment; Figure 5 A rear view of a digital traveling wave ranging switch in one embodiment; Figure 6 This is a cross-sectional schematic diagram of a solid-sealed terminal assembly in one embodiment; Figure 7 This is a schematic diagram of the structure of a digital merging unit in one embodiment; Figure 8 This is a block diagram of the module connection of a digital traveling wave ranging switch in one embodiment; Figure 9 This is a structural block diagram of the control device for a digital traveling wave ranging switch in one embodiment.

[0018] Reference numerals: 001 Epoxy resin insulator, 002 Vacuum interrupter, 003 High-voltage arm capacitor on the inlet side, 004 Flexible connection, 005 Insulating pull rod, 006 Shielding mesh, 007 Rogowski coil, 008 Outlet conductive rod, 009 High-voltage arm capacitor on the outlet side, 010 Coil support rod, 011 Low-voltage arm capacitor on the inlet side, 012 Low-voltage arm capacitor on the outlet side, 101 Umbrella skirt, 301 Hard copper wire, 302 Capacitor support rod; 01 Solid-sealed pole assembly, 02 Housing assembly, 03 Magnetically controlled mechanism, 04 Digital merging unit, 401 Housing, 402 Core board, 4021 Disassembly and assembly screw holes. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0021] The existing primary and secondary integrated pole-mounted switch solid-sealed pole mainly integrates two sets of electromagnetic current transformer coils to sense line phase current signals and zero-sequence current signals. A sampling resistor integrated on the secondary side can convert the electromagnetic current signal into a small electronic current signal, and a digital conversion unit can also be integrated to complete the local digitization of the signal. It is typically installed on 10kV overhead lines to perform line current monitoring and conventional phase-to-phase short-circuit protection and ground fault protection.

[0022] In the field of traveling wave ranging, existing traveling wave ranging devices in distribution networks are typically installed independently, requiring additional high-frequency current transformers to collect fault traveling wave current signals. Signal interaction between the device and the switchgear relies on additional communication links and power supply circuits. This results in a complex overall solution with high costs and difficult construction, hindering large-scale deployment. While existing traveling wave ranging devices typically use wideband sensors with a frequency response range of 50Hz to 10MHz, the independent installation method limits their deep integration with the switchgear.

[0023] The existing technical solutions have the following main application defects: (1) Narrow operating bandwidth, unable to meet the requirements of traveling wave ranging. Electromagnetic or electronic current transformers have a small operating bandwidth, with a rated operating frequency of 50Hz. They are mainly used for sampling power frequency current signals and fault current signals below 20kHz, and cannot be adapted to sampling high-frequency traveling wave current signals in the range of 100kHz-1MHz. When a fault occurs in the overhead line of the distribution network, the frequency range of the high-frequency traveling wave signal generated at the fault point is usually between 100kHz and 1MHz. Traditional current transformers have extremely low response sensitivity in this frequency band and cannot effectively collect traveling wave signals, making it difficult to implement the traveling wave ranging function on pole-mounted switches.

[0024] (2) The dual coils are large in size and weight, which is not conducive to miniaturization and lightweighting. Traditional solid-sealed poles need to integrate two sets of electromagnetic current transformer coils (phase current coil and zero-sequence current coil). The dual coil structure is large in size and weight, occupies a lot of space inside the pole, and cannot be adapted to miniaturized and lightweight switch design schemes, resulting in high overall material costs.

[0025] (3) Traveling wave ranging devices are installed independently, which is complex and costly. Existing traveling wave ranging devices need to be installed independently outside the switch, and additional high-frequency current transformers and dedicated communication links are required, which increases the difficulty of on-site construction and the complexity of operation and maintenance. Moreover, the power supply, communication and protection issues of independent devices are difficult to solve in an integrated manner with the switch body, which restricts the large-scale promotion of traveling wave ranging technology on pole-mounted switches in distribution networks.

[0026] (4) The transmission of analog signals is subject to interference, and the signal quality is difficult to guarantee. The current and voltage telemetry signals of existing electromagnetic or electronic pole-mounted switches are transmitted to the terminal in the form of small analog signals. During long-distance transmission, analog signals are easily affected by environmental factors such as electromagnetic interference and changes in line impedance, resulting in signal attenuation and distortion, which affects the measurement accuracy and protection reliability.

[0027] Based on this, this application proposes a solid-encapsulated pole with an integrated Rogowski coil and a digital traveling wave ranging switch. The main feature is that the Rogowski coil is integrated into the solid-encapsulated pole to replace the traditional dual-coil current transformer for current signal acquisition. The switch adopts a digital application scheme, with an integrated digital conversion unit (ADMU) in the enclosure. The ADMU integrates a Rogowski coil double integrator, which can simultaneously complete the sampling and processing of the Rogowski coil current signal, thereby completing the local digital conversion of switch voltage, current telemetry signals and switch status telemetry. Then, lossless signal transmission between the switch and the terminal is achieved through high-speed optical fiber communication.

[0028] Specifically, this application proposes a solid-sealed pole with an integrated Rogowski coil and a digital traveling wave ranging switch. By innovatively integrating a Rogowski coil into the solid-sealed pole, it replaces the traditional electromagnetic current transformer coil for current signal acquisition. Furthermore, by integrating the Rogowski coil secondary integrator with the ADMU (Advanced Digital Mutual Actuator), they share the same power supply, and the ADMU adopts an online hot-swappable design. Through measures such as miniaturized and lightweight pole design, the application of cast aluminum housing, and the use of aluminum profile casing, the overall invention achieves the following beneficial effects: (1) Wideband sampling, supporting traveling wave ranging. The Rogowski coil operates at a frequency much greater than 1MHz, which can effectively complete the accurate sampling of high-frequency traveling wave current signals below 1MHz. Compared with the traditional electromagnetic current transformer (rated operating frequency 50Hz, effective frequency band below 20kHz), the frequency response range is improved by more than 50 times, effectively covering the traveling wave frequency band of distribution network faults (100kHz-1MHz), supporting the application of switch traveling wave ranging protection, and achieving fault location accuracy of hundreds of meters.

[0029] (2) Miniaturization and weight reduction, cost reduction and efficiency improvement. The Rogowski coil adopts a hollow toroidal structure, which significantly reduces the volume and weight of the coil compared with the traditional electromagnetic current transformer coil, and can support further miniaturization and weight reduction design of the pole.

[0030] (3) Online maintainability solves the lifespan mismatch problem. The Rogowski coil secondary integrator is integrated with the ADMU. The ADMU core board adopts an online hot-swappable design, which can be replaced online in case of board failure, avoiding the need to remove the entire switch and effectively solving the problem of lifespan mismatch between active electronic components and passive switch body. The ADMU housing and enclosure interface meet the IP65 protection requirements, and the core board and housing interface meet the IP55 protection requirements, ensuring the sealing and connection reliability of hot-swappable operation.

[0031] (4) Digital synthesis of zero-sequence signals simplifies the pole structure. Key components such as switch solid-sealed poles, vacuum interrupters, housings, and mechanisms are all miniaturized. Zero-sequence voltage and zero-sequence current sensors are removed. The zero-sequence voltage and zero-sequence current signals are digitally synthesized by ADMU (zero-sequence voltage equals the vector sum of the three-phase voltages, and zero-sequence current equals the vector sum of the three-phase currents). This effectively reduces the complexity of the pole structure, lowers the cost of component materials, and achieves the application effect of cost reduction and efficiency improvement.

[0032] (5) Lossless signal transmission improves measurement accuracy. After the ADMU completes the local digital conversion of voltage and current signals, the signals are transmitted through optical fiber communication. Optical fiber signal transmission is not affected by changes in transmission loop impedance and electromagnetic interference. Compared with the traditional analog signal transmission method, lossless signal transmission is achieved. The telemetry sensing accuracy can meet the accuracy requirements of 0.5 class complete equipment, which is better than the traditional pole-mounted switch 1 class accuracy level.

[0033] (6) Integrated traveling wave ranging, simplifying construction and maintenance. The traveling wave ranging function is integrated with the switch body, eliminating the need for additional independent traveling wave ranging devices and supporting sensors. The acquisition, processing, and transmission of traveling wave signals are all completed by the Rogowski coil and ADMU built into the solid-sealed pole, greatly simplifying the difficulty of on-site construction and the complexity of operation and maintenance, which is conducive to the large-scale promotion and deployment of traveling wave ranging technology on pole-mounted switches in the distribution network.

[0034] It should be noted that the beneficial effects or technical problems solved by the embodiments of this application are not limited to this one, but may also be other implicit or related problems. For details, please refer to the description of the embodiments below.

[0035] Before introducing the specific embodiments of this application, the technical terms involved in this application will be explained: Rogowski Coil: A hollow toroidal current transformer designed based on Faraday's law of electromagnetic induction. It uses a non-magnetic frame, has no magnetic saturation problem, and has advantages such as wide bandwidth, good linearity, and fast response speed. Its operating frequency can be much greater than 1MHz.

[0036] Solid-sealed pole: An insulating structural component that integrates the vacuum interrupter, conductive circuit, insulating support, and other parts into one piece through epoxy resin casting and curing. It is the core component of the pole-mounted switch.

[0037] Digital merging unit (ADMU): An integrated electronic device that performs analog signal acquisition, analog-to-digital conversion, data processing, and communication transmission. In this invention, a Rogowski coil double integrator is integrated.

[0038] Traveling wave ranging: This technology utilizes the propagation characteristics of high-frequency traveling wave signals generated at the fault point on the transmission line to locate the fault point by detecting the arrival time of the traveling wave. The positioning accuracy can reach the level of hundreds of meters.

[0039] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0040] In one exemplary embodiment, such as Figure 1As shown, a control method for a digital traveling wave ranging switch is provided. The digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit. Each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side. The digital merging unit integrates an analog-to-digital signal conversion unit and is connected to the three-phase solid-sealed pole assembly and also to a secondary terminal control unit. The method includes: Step 302: Based on the digital merging unit, unidirectional signal acquisition is performed on the current signal, voltage signal and remote signaling signal of the three-phase solid-sealed pole assembly.

[0041] Among them, unidirectional signal acquisition refers to a unidirectional data flow mode between the ADMU and the solid-state electrode assembly, which uses electrode sensing and ADMU acquisition and processing. Optionally, current signal acquisition refers to: the Rogowski coil 007 induces alternating current on the conductive rod 008, and outputs a differential voltage signal (di / dt signal) that is proportional to the time change rate of the measured current. This differential signal is transmitted to the ADMU through a twisted-pair shielded cable.

[0042] Specifically, the Rogowski coil 007 is bound to the coil support rod 010, and positioned centered through the lead wire conductive rod 008 by the support rod, thus avoiding measurement accuracy errors caused by positional deviations. The Rogowski coil 007 is entirely encased in a buffer layer and a shielding layer. The buffer layer absorbs the stress generated during the epoxy casting process, preventing damage to the coil structure; the shielding layer is grounded via a connection to the support rod 010. The secondary lead wire of the coil uses twisted-pair shielded wire, and the shielding layer of the wire is also grounded via the support rod 010 to prevent interference from strong magnetic fields on the small signal transmission of the coil during switch operation. During signal acquisition: The 007 Rogowski coil built into the solid-sealed pole senses the alternating current on the 008 outgoing conductive rod on the outgoing side, and outputs a differential voltage signal (di / dt signal) that is proportional to the rate of change of the measured current over time. This differential signal is transmitted to the secondary integrator integrated inside the ADMU via a twisted-pair shielded cable; the low-voltage arm capacitors (011, 012) of the voltage sensors on the incoming and outgoing sides transmit the small secondary voltage signal after voltage division by the high-voltage arm capacitor to the ADMU; the remote signaling status signals such as open, closed, and uncharged positions of the switch are transmitted to the digital input channel of the ADMU through the auxiliary contacts of the switch.

[0043] For example, voltage signal acquisition refers to the following: the high-voltage arm capacitor and low-voltage arm capacitor built into the solid-sealed electrode assembly form a voltage divider voltage sensor, which divides the 10kV primary voltage into a low-voltage small-signal voltage on the secondary side. This secondary voltage signal is transmitted to the analog-to-digital signal conversion unit of the ADMU through the secondary output terminal at the bottom of the electrode. Remote signal acquisition refers to the following: remote signaling status signals such as open, closed, and non-energized positions of the switch are transmitted to the optocoupler-isolated switch input channel of the ADMU through the auxiliary contacts of the switch and the output terminal at the bottom of the electrode. The ADMU acquires the remote signaling signals and converts them into digital signals.

[0044] Step 304: The current signal, voltage signal and remote signaling signal are processed and synthesized by analog-to-digital conversion unit to obtain telemetry data and remote signaling data, which are then transmitted to the secondary terminal control unit. The telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation and traveling wave ranging analysis, while the remote signaling data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault diagnosis.

[0045] Among them, telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation and traveling wave ranging analysis, while telemetry data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault diagnosis.

[0046] Optionally, the ADMU packages all processed telemetry digital signals and teleindication digital signals into a data package according to the agreed communication protocol frame format. The frame format includes a frame header identifier, device address code, data length, telemetry data field, checksum, and frame tail identifier.

[0047] Specifically, since the signal has been digitized locally, the fiber optic transmission transmits digital signals rather than analog signals. Digital signal transmission is unaffected by changes in transmission loop impedance and electromagnetic interference, achieving lossless signal transmission. In the signal processing: the ADMU's integrated quadratic integrator integrates the differential voltage signal output from the Rogowski coil, restoring it to a linear voltage signal proportional to the measured current, achieving accurate current signal restoration. The integrated current signal and the secondary voltage signal from the voltage sensor undergo analog-to-digital conversion via the ADMU's 16-bit AD channel, completing the local digitization from analog to digital signals. The remote signaling status signal is acquired by the ADMU's optocoupler isolation circuit and converted into a digital signal. Simultaneously, the ADMU uses software algorithms to digitally synthesize zero-sequence voltage signals based on the three-phase phase voltage digital quantities (zero-sequence voltage equals the vector sum of the three-phase phase voltages) and zero-sequence current signals based on the three-phase phase current digital quantities (zero-sequence current equals the vector sum of the three-phase phase currents), thereby reducing the need for zero-sequence voltage and current sensors on the primary side.

[0048] Step 306: In response to the digital merging unit detecting the traveling wave characteristic signal through the Rogowski coil, the secondary terminal control unit triggers the traveling wave recording function, acquires traveling wave recording data through the Rogowski coil and the digital merging unit, and performs traveling wave ranging calculation based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location; wherein, the line parameters include telemetry data and tele-signaling data.

[0049] The line parameters may include line length and traveling wave propagation speed.

[0050] Optionally, when a fault occurs in the overhead line of the distribution network and generates a high-frequency traveling wave, the Rogowski coil can effectively collect high-frequency traveling wave current signals in the range of 100kHz-1MHz due to its wide bandwidth characteristics (operating frequency much greater than 1MHz). After detecting the traveling wave characteristic signal, the ADMU triggers the traveling wave recording function and collects high-frequency traveling wave data in real time through high-frequency sampling.

[0051] Specifically, in conventional telemetry acquisition mode, the ADMU uses the power frequency sampling rate to acquire steady-state signals of current and voltage. When a transient change characteristic (traveling wave front characteristic) exceeding a set threshold is detected in the current signal, the ADMU switches to a high-sampling-rate traveling wave recording mode, sampling and recording the traveling wave current signal at a sampling rate of no less than 5MHz. The traveling wave recording data includes the traveling wave front time marker and the original waveform data. The ADMU transmits the traveling wave recording data uplink to the secondary terminal control unit via optical fiber communication. The secondary terminal control unit combines parameters such as the arrival time of the traveling wave front, the line length, and the traveling wave propagation speed, and uses either the single-end traveling wave ranging method (calculating the fault distance based on the round-trip time of the traveling wave between the fault point and the bus) or the double-end traveling wave ranging method (calculating the fault distance using the time difference of the traveling wave arriving at both ends of the line) to calculate the fault location accuracy, which can reach the level of hundreds of meters.

[0052] For example, during signal transmission: the ADMU packages all processed telemetry digital signals (three-phase phase voltage, zero-sequence voltage, three-phase phase current, zero-sequence current) and teleindication digital signals (separation, combination, unstored energy, etc.) into a data packet according to the agreed communication protocol frame format, and transmits it to the secondary terminal control unit via a high-speed fiber optic communication interface and fiber optic cable. Since the signal has already undergone local digitization, the fiber optic transmission transmits digital signals rather than small analog signals. Digital signal transmission is unaffected by changes in transmission loop impedance and electromagnetic interference, achieving lossless signal transmission. The ADMU uses a DC 24V power supply, provided by the secondary terminal control unit via a primary-secondary connection cable. The ADMU and the terminal share the same power supply loop and communication link, simplifying the interface relationship between primary and secondary devices.

[0053] The control method for the aforementioned digital traveling wave ranging switch involves unidirectional signal acquisition of current, voltage, and remote signaling signals from the three-phase solid-sealed pole assembly using a digital merging unit. An analog-to-digital conversion unit processes and synthesizes these signals to obtain telemetry and remote signaling data, which are then transmitted to the secondary terminal control unit. The telemetry data enables the secondary terminal control unit to perform line monitoring, protection criterion calculation, and traveling wave ranging analysis, while the remote signaling data enables it to monitor switch operation status and diagnose faults. In response to the digital merging unit detecting a traveling wave characteristic signal via a Rogowski coil, the secondary terminal control unit triggers a traveling wave recording function. Traveling wave recording data is acquired through the Rogowski coil and the digital merging unit. Based on the arrival time of the traveling wave and line parameters in the recording data, traveling wave ranging calculation is performed to locate the fault point. The line parameters include both telemetry and remote signaling data, thereby reducing the structural complexity of the traveling wave ranging switch and improving its signal transmission quality. Furthermore, by integrating a Rogowski coil within the solid-sealed pole to achieve wideband current signal acquisition, and utilizing an ADMU to complete on-site digital conversion and lossless fiber optic transmission, the traveling wave ranging function is integrated with the switch body. This solves the problems of narrow bandwidth of traditional electromagnetic transformers, complex independent installation of traveling wave ranging devices, and susceptibility to interference in analog signal transmission, achieving wideband sampling, miniaturization and lightweight design, lossless signal transmission, and integrated traveling wave ranging.

[0054] Specifically, this application's embodiments leverage the wideband characteristics of Rogowski coils (operating frequency much greater than 1MHz) to effectively extend the operating frequency range of the switching current sensor, effectively covering the high-frequency traveling wave band (100kHz-1MHz) generated after a fault in an overhead power distribution line. This enables wideband sampling, supporting innovative applications of digital switches in traveling wave ranging. Furthermore, by achieving precise acquisition of phase current using a single Rogowski coil and then digitally synthesizing the zero-sequence current and voltage signals within the ADMU, the application of zero-sequence current and voltage sensors on the primary side can be reduced. This significantly reduces the structural complexity of the solid-sealed pole, enabling miniaturized and lightweight pole design, effectively reducing material and production costs.

[0055] In one exemplary embodiment, the digital merging unit also integrates a Rogowski coil double integrator; the telemetry data includes three-phase phase current and zero-sequence current; unidirectional signal acquisition of the current signal of the three-phase solid-sealed pole assembly based on the digital merging unit includes: The alternating current on the outgoing conductor of each phase is induced by the Rogowski coil of each phase, and a differential voltage signal proportional to the rate of change of the measured alternating current is output. The current signal is processed and synthesized through analog-to-digital conversion using an analog-to-digital conversion unit to obtain telemetry data, including: In response to the differential voltage signal received by the digital merging unit, the differential voltage signal is integrated by the Rogowski coil double integrator to obtain a linear voltage signal proportional to the alternating current. The linear voltage signal is converted from analog to digital and then digitally synthesized by the analog-to-digital signal conversion unit to obtain the three-phase current and zero-sequence current.

[0056] In one exemplary embodiment, the telemetry data further includes three-phase phase voltage and zero-sequence voltage; unidirectional signal acquisition of the voltage signal of the three-phase solid-sealed pole assembly based on the digital merging unit includes: The voltage divider voltage sensor, which is composed of the high-voltage arm capacitor and the low-voltage arm capacitor built into the three-phase solid-sealed pole assembly, divides the primary voltage into a secondary low-voltage small signal voltage to obtain the secondary voltage signal. The secondary voltage signal is transmitted through the bottom secondary output terminal of the three-phase solid-sealed pole assembly to the 16-bit AD channel of the analog-to-digital signal conversion unit of the digital merging unit to complete the analog-to-digital conversion and digital synthesis, thereby obtaining the three-phase phase voltage and zero-sequence voltage.

[0057] In one exemplary embodiment, transmitting telemetry data to a secondary terminal control unit includes: The digital merging unit packages the telemetry data according to the agreed communication protocol frame format to obtain the packaged telemetry data frame; the communication protocol frame format includes frame header identifier, device address code, data length, telemetry data field, check code and frame tail identifier; The packaged telemetry data frames are transmitted uplink to the secondary terminal control unit via the fiber optic communication interface of the digital merging unit through the fiber optic cable. The secondary terminal control unit is then used to verify and decode the telemetry data frames and extract data from each telemetry channel for line monitoring, protection criterion calculation, and traveling wave ranging analysis.

[0058] In an exemplary embodiment, the remote signaling signal includes at least the remote signaling status signals of the switch's open, closed, and non-energy-storage positions; unidirectional signal acquisition of the remote signaling signal of the three-phase solid-sealed pole assembly is performed based on the digital merging unit, including: The remote signal is transmitted to the optocoupler-isolated digital input channel of the digital merging unit through the auxiliary contact of the switch and the bottom output terminal of the three-phase solid-sealed pole assembly.

[0059] In an exemplary embodiment, the remote signaling signal includes at least digital signals indicating the remote signaling status of the switch's open, closed, and unstored positions; transmitting the remote signaling data to the secondary terminal control unit includes: The digital merging unit packages the remote signaling signals according to the agreed communication protocol frame format and transmits them uplink to the secondary terminal control unit through the optical fiber communication interface. This enables the secondary terminal control unit to monitor the switch operation status and diagnose faults based on the remote signaling status contained in the remote signaling signals.

[0060] In an exemplary embodiment, in response to the digital merging unit detecting a traveling wave characteristic signal via the Rogowski coil, the secondary terminal control unit triggers the traveling wave recording function to acquire traveling wave recorded data via the Rogowski coil and the digital merging unit, including: In response to the digital merging unit detecting a transient change in the current signal exceeding a set threshold via the Rogowski coil, the secondary terminal control unit controls the digital merging unit to perform high-speed sampling and waveform recording of the traveling wave current signal at a sampling rate of not less than 5MHz, thereby obtaining traveling wave waveform recording data; the traveling wave waveform recording data includes traveling wave head time markers and raw waveform data; The digital merging unit transmits the traveling wave recording data to the secondary terminal control unit via fiber optic communication.

[0061] In an exemplary embodiment, traveling wave ranging is calculated based on the arrival time of the traveling wave and line parameters in the traveling wave recording data to obtain the fault location, including: The secondary terminal control unit calculates the fault location based on the traveling wave head time marker and the original waveform data, using either the single-end traveling wave ranging method or the double-end traveling wave ranging method.

[0062] The steps of the above method are described in detail below with a specific embodiment.

[0063] Specifically, the interaction logic and control logic between the ADMU and the poles, as well as between the ADMU and the controller, include: The interaction logic between the ADMU and the terminal block is a unidirectional signal acquisition relationship. The specific interaction logic is as follows: (1) Current signal acquisition and interaction: The 007 Rogowski coil built into the output side of the three-phase solid-sealed pole senses the alternating current on the output conductor and outputs a differential voltage signal (di / dt). This signal is transmitted through a twisted-pair shielded cable to the secondary output terminal at the bottom of the pole to the secondary integrator unit inside the ADMU. The integrator performs integration on the differential signal to restore it to a linear voltage signal proportional to the measured current, and then completes analog-to-digital conversion through a 16-bit AD channel. Only one differential signal is transmitted between the Rogowski coil and the ADMU, and the secondary integration processing is completed inside the ADMU, realizing the separation of signal acquisition and signal processing functions and reducing the number of electronic components inside the pole.

[0064] (2) Voltage signal acquisition and interaction: The high-voltage arm capacitors (003, 009) and low-voltage arm capacitors (011, 012) built into the three-phase solid-sealed pole form a voltage divider voltage sensor, which divides the 10kV primary voltage into a low-voltage small signal voltage on the secondary side. This secondary voltage signal is transmitted to the 16-bit AD channel of the ADMU through the secondary output terminal at the bottom of the pole to complete the analog-to-digital conversion. The voltage signal is acquired passively, and the ADMU does not issue control commands to the pole voltage sensor.

[0065] (3) Power supply signal interaction: The capacitor power supply devices reserved on the A-phase pole incoming side and the C-phase pole outgoing side convert the primary high voltage into DC power output, which is transmitted to the secondary controller unit through the bottom outgoing terminals of the pole and the primary and secondary cables. After processing by the terminal unit power module, it provides DC24V power supply to the ADMU core board. When the switch is in the closed or open state, the dual-side power supply devices can ensure that at least one side of the power supply device works effectively, ensuring the continuity of ADMU power supply. If an external PT power supply scheme is adopted, the PT directly provides AC220V power supply to the secondary controller unit, which is then stepped down by the terminal power module to provide DC24V power supply to the ADMU core board.

[0066] (4) Remote signal acquisition and interaction: The remote signal status signals of the switch, such as open, closed, and uncharged, are transmitted to the optocoupler-isolated switch input channel of the ADMU through the auxiliary contacts of the switch (limit switch, pressure switch, etc.) and the output terminal at the bottom of the pole. After the ADMU acquires the remote signal, it converts it into a digital signal. The remote signal is also acquired passively.

[0067] In summary, the interaction logic between the ADMU and the terminal block is a unidirectional data flow mode from terminal block sensing to ADMU acquisition and processing. The terminal block is only responsible for sensing primary-side voltage and current signals and outputting the power supply voltage, while the ADMU is responsible for processing and digitizing all secondary-side signals. This interaction mode eliminates the need to integrate any active electronic components within the terminal block, maintaining its essential passive device nature and improving its operational reliability.

[0068] The interaction and control logic between the ADMU and the controller (terminal), and the interaction between the ADMU and the secondary terminal control unit (controller) are in a bidirectional data flow mode, including uplink transmission of telemetry / telecommunications data and downlink transmission of control commands. The specific interaction and control logic are as follows: Uplink data transmission logic (ADMU → controller): (1) Telemetry data uplink transmission: The ADMU collects and processes the telemetry digital signals, such as three-phase phase voltage, zero-sequence voltage (digital synthesis), three-phase phase current (integration + AD conversion), and zero-sequence current (digital synthesis), from the 16-bit AD channels, and packages them according to the agreed communication protocol frame format. The frame format includes a frame header identifier, device address code, data length, telemetry data field, check code, and frame tail identifier. The packaged telemetry data frame is transmitted uplink to the secondary terminal control unit via the ADMU's fiber optic communication interface through the fiber optic cable. After receiving the telemetry data frame, the terminal performs verification and decoding, and extracts the data from each telemetry channel for line monitoring, protection criterion calculation, and traveling wave ranging analysis.

[0069] (2) Uplink transmission of remote signaling data: The ADMU packages the digital signals of the switch's remote signaling status, such as open, closed, and no-energy-storage position, according to the agreed communication protocol frame format, and transmits them to the terminal via the fiber optic communication interface. The terminal monitors the switch's operating status and diagnoses faults based on the remote signaling status.

[0070] (3) Traveling wave data uplink transmission: When a fault occurs in the overhead line of the distribution network and generates a high-frequency current traveling wave, the Rogowski coil, with its wideband characteristics (operating frequency much greater than 1MHz), can effectively collect high-frequency traveling wave current signals in the range of 100kHz-1MHz. After detecting the characteristic signal of the traveling wave, the ADMU triggers the traveling wave recording function, collects high-frequency traveling wave data in real time through high-frequency sampling, packages the original high-frequency traveling wave data according to the preset data frame format, and transmits it uplink to the terminal through the fiber optic communication interface. The terminal combines the arrival time of the traveling wave and the line parameters to perform traveling wave ranging calculation, thereby achieving accurate fault location.

[0071] Downlink control transmission logic (controller → ADMU): (1) Power supply control: The secondary terminal control unit provides DC24V power to the ADMU through the primary and secondary connection cables. The ADMU core board adopts an online hot-swappable design. When the board fails and needs to be replaced, the maintenance personnel can replace the board online by using tooling to remove and install the screw holes. After replacement, the ADMU powers on and performs a self-test. It sends a self-test completion confirmation signal to the terminal via RS485. After the terminal confirms that the ADMU has returned to normal working status, it resumes normal reception of telemetry / telecommunication data.

[0072] (2) Communication parameter configuration control: The terminal can send communication parameter configuration commands to the ADMU through the fiber optic communication downlink channel, including communication baud rate setting, telemetry data reporting cycle setting, traveling wave recording trigger threshold setting, zero-sequence signal digital synthesis algorithm parameter setting, ADMU device restart command, etc. After receiving the configuration command, the ADMU updates its internal parameters and replies with a configuration confirmation frame.

[0073] (3) Traveling wave recording trigger control: The terminal can send a traveling wave recording trigger command to the ADMU according to the line operating conditions and configure parameters such as the sampling rate, recording duration, and trigger threshold of the traveling wave recording. The ADMU monitors the traveling wave characteristic components in the Rogowski coil current signal in real time according to the configured parameters. When a traveling wave signal that meets the trigger threshold is detected, the recording is automatically started. After the recording is completed, the traveling wave data frame is transmitted uplink to the terminal.

[0074] (4) Zero-sequence signal synthesis control: The terminal can select the acquisition method of zero-sequence voltage / zero-sequence current through downlink commands. When the "digital synthesis" mode is selected, the ADMU performs digital synthesis of zero-sequence signals based on the digital quantities of three-phase phase voltage / phase current through software algorithms. When the "direct acquisition" mode is selected (when the pole is equipped with an independent zero-sequence sensor), the ADMU directly acquires the signal of the independent zero-sequence sensor. The terminal can flexibly switch the acquisition method of zero-sequence signals according to different protection application scenarios.

[0075] Furthermore, regarding the traveling wave ranging technology implementation scheme of this application embodiment, the traveling wave ranging technology implementation of this application embodiment is based on the wideband sampling characteristics of the Rogowski coil and the high-speed digital processing capability of the ADMU, and the specific implementation scheme is as follows: (1) Traveling wave signal acquisition: When a fault occurs in the overhead line of the distribution network (short circuit, grounding, etc.), a high-frequency traveling wave signal will be generated at the fault point and propagate to both sides. The frequency range of the traveling wave is usually between 100kHz and 1MHz, and the propagation speed is close to the speed of light. The 007 Rogowski coil built into the solid-sealed pole operates at a frequency much greater than 1MHz, which can effectively cover this traveling wave frequency band and realize the accurate acquisition of high-frequency traveling wave current signals. The differential signal output by the Rogowski coil is restored by the integrator inside the ADMU, and the high-frequency characteristic components of the traveling wave signal are retained.

[0076] (2) Digital processing of traveling wave signals: In the conventional telemetry acquisition mode, the ADMU uses the power frequency sampling rate to complete the steady-state signal acquisition of current and voltage; when a transient change feature (traveling wave front feature) exceeding the set threshold is detected in the current signal, the ADMU uses a high sampling rate traveling wave recording mode to sample and record the traveling wave current signal at a sampling rate of not less than 5MHz. The traveling wave recording data includes the traveling wave front time marker and the original waveform data.

[0077] (3) Traveling wave data transmission and ranging analysis: The ADMU transmits the traveling wave recording data to the terminal via fiber optic communication. The terminal combines parameters such as the arrival time of the traveling wave head, the line length, and the propagation speed of the traveling wave to calculate the fault location using either the single-end traveling wave ranging method (which calculates the fault distance based on the round-trip time of the traveling wave between the fault point and the bus) or the double-end traveling wave ranging method (which calculates the fault distance using the time difference between the arrival times of the traveling wave at both ends of the line). The positioning accuracy can reach the level of hundreds of meters.

[0078] It is understood that the embodiments of this application propose a solid-sealed pole with an integrated Rogowski coil and a digital traveling wave ranging switch. By innovatively integrating a Rogowski coil into the solid-sealed pole, it replaces the traditional electromagnetic current transformer coil to complete current signal acquisition. By integrating the Rogowski coil secondary integrator with the ADMU, they share the same power supply, and the ADMU adopts an online hot-swappable design. Through measures such as miniaturized and lightweight pole design, application of cast aluminum housing, and application of aluminum profile shell, the overall invention achieves the following beneficial effects: (1) Wideband sampling, supporting traveling wave ranging. The Rogowski coil operates at a frequency much greater than 1MHz, which can effectively complete the accurate sampling of high-frequency traveling wave current signals below 1MHz. Compared with the traditional electromagnetic current transformer (rated operating frequency 50Hz, effective frequency band below 20kHz), the frequency response range is improved by more than 50 times, effectively covering the traveling wave frequency band of distribution network faults (100kHz-1MHz), supporting the application of switch traveling wave ranging protection, and achieving fault location accuracy of hundreds of meters.

[0079] (2) Miniaturization and weight reduction, cost reduction and efficiency improvement. The Rogowski coil adopts a hollow toroidal structure, which significantly reduces the volume and weight of the coil compared with the traditional electromagnetic current transformer coil, and can support further miniaturization and weight reduction design of the pole.

[0080] (3) Online maintainability solves the lifespan mismatch problem. The Rogowski coil secondary integrator is integrated with the ADMU. The ADMU core board adopts an online hot-swappable design, which can be replaced online in case of board failure, avoiding the need to remove the entire switch and effectively solving the problem of lifespan mismatch between active electronic components and passive switch body. The ADMU housing and enclosure interface meet the IP65 protection requirements, and the core board and housing interface meet the IP55 protection requirements, ensuring the sealing and connection reliability of hot-swappable operation.

[0081] (4) Digital synthesis of zero-sequence signals simplifies the pole structure. Key components such as switch solid-sealed poles, vacuum interrupters, housings, and mechanisms are all miniaturized. Zero-sequence voltage and zero-sequence current sensors are removed. The zero-sequence voltage and zero-sequence current signals are digitally synthesized by ADMU (zero-sequence voltage equals the vector sum of the three-phase voltages, and zero-sequence current equals the vector sum of the three-phase currents). This effectively reduces the complexity of the pole structure, lowers the cost of component materials, and achieves the application effect of cost reduction and efficiency improvement.

[0082] (5) Lossless signal transmission improves measurement accuracy. After the ADMU completes the local digital conversion of voltage and current signals, the signals are transmitted through optical fiber communication. Optical fiber signal transmission is not affected by changes in transmission loop impedance and electromagnetic interference. Compared with the traditional analog signal transmission method, lossless signal transmission is achieved. The telemetry sensing accuracy can meet the accuracy requirements of 0.5 class complete equipment, which is better than the traditional pole-mounted switch 1 class accuracy level.

[0083] (6) Integrated traveling wave ranging, simplifying construction and maintenance. The traveling wave ranging function is integrated with the switch body, eliminating the need for additional independent traveling wave ranging devices and supporting sensors. The acquisition, processing, and transmission of traveling wave signals are all completed by the Rogowski coil and ADMU built into the solid-sealed pole, greatly simplifying the difficulty of on-site construction and the complexity of operation and maintenance, which is conducive to the large-scale promotion and deployment of traveling wave ranging technology on pole-mounted switches in the distribution network.

[0084] Based on the same inventive concept, this application also provides a control device for a digital traveling wave ranging switch used to implement the control method for the digital traveling wave ranging switch described above. The solution provided by this device is similar to the implementation described in the above method. Therefore, the specific limitations in one or more embodiments of the control device for the digital traveling wave ranging switch provided below can be found in the limitations of the control method for the digital traveling wave ranging switch described above, and will not be repeated here.

[0085] In one exemplary embodiment, such as Figure 9 As shown, a control device 900 for a digital traveling wave ranging switch is provided. The digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit. Each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the output side. The digital merging unit integrates an analog-to-digital signal conversion unit and is connected to the three-phase solid-sealed pole assembly and also to a secondary terminal control unit. The device includes: The unidirectional signal acquisition module 901 is used to acquire current signals, voltage signals and remote signaling signals of the three-phase solid-sealed pole assembly based on the digital merging unit. The signal conversion and synthesis module 902 is used to perform analog-to-digital conversion processing and synthesis of current signals, voltage signals and remote signaling signals through the analog-to-digital signal conversion unit to obtain telemetry data and remote signaling data and transmit them to the secondary terminal control unit. Among them, the telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation and traveling wave ranging analysis, and the remote signaling data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault judgment. The traveling wave recording and fault location module 903 is used to respond to the digitization merging unit detecting the traveling wave characteristic signal through the Rogowski coil, causing the secondary terminal control unit to trigger the traveling wave recording function, acquire traveling wave recording data through the Rogowski coil and the digitization merging unit, and perform traveling wave ranging calculation based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location; wherein, the line parameters include telemetry data and tele-signaling data.

[0086] The various modules in the control device of the aforementioned digital traveling wave ranging switch can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0087] In an exemplary embodiment, this application also proposes a digital traveling wave ranging switch for implementing the steps of the method in the above embodiments; the digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, and the digital merging unit is connected to the three-phase solid-sealed pole assembly and also connected to a secondary terminal control unit.

[0088] Specifically, refer to Figure 2 This is a schematic diagram of the external structure of a digital traveling wave ranging switch; refer to... Figure 3 A front view of a digital traveling wave ranging switch in one embodiment, including: 01 solid-sealed pole assembly, 02 housing assembly; Figure 4 A side cross-sectional view of a digital traveling wave ranging switch in one embodiment, including: 03 magnetic control mechanism; Figure 5 A rear view of a digital traveling wave ranging switch in one embodiment, including: 04 digital merging unit; Figure 6 This is a cross-sectional schematic diagram of a solid-sealed pole assembly in one embodiment, including: 001 epoxy resin insulator, 002 vacuum interrupter, 003 high-voltage arm capacitor on the inlet side, 004 flexible connection, 005 insulating pull rod, 006 shielding mesh, 007 Rogowski coil, 008 outlet conductive rod, 009 high-voltage arm capacitor on the outlet side, 010 coil support rod, 011 low-voltage arm capacitor on the inlet side, 012 low-voltage arm capacitor on the outlet side, 101 umbrella skirt, 301 hard copper wire, and 302 capacitor support rod; Figure 7 This is a schematic diagram of the structure of a digital merging unit in one embodiment, including: 401 housing, 402 core board, and 4021 mounting and disassembly screw holes; Figure 8This is a block diagram of the module connection of a digital traveling wave ranging switch in one embodiment. The switch body refers to the switch body of the digital traveling wave ranging switch, including an arc-extinguishing chamber and a magnetic control mechanism, a remote signaling module, a capacitor power supply module, a voltage sensor, and a Rogowski coil connected thereto. The ADMU includes an integration module and an AD conversion module, i.e., an analog-to-digital signal conversion unit. The controller refers to the secondary terminal control unit, including a control module, a power supply module, a decoding module, and a CPU. The control module controls the magnetic control mechanism via DC380V, the power supply module draws power from the capacitor power supply module via AC24V and also supplies power to the ADMU via DC24V, and the decoding module communicates bidirectionally with the ADMU via optical fiber.

[0089] Specifically, the solid-sealed pole structure, such as Figure 6 As shown, the specific technical solution is as follows: (1) The solid-sealed pole adopts a conventional top-in and bottom-out structure, which is suitable for the installation and application habits of pole-mounted circuit breakers on overhead lines; the 001 epoxy resin insulator is designed with 101 umbrella skirt structure at the inlet end, outlet end, bottom end and inner cavity to increase the internal and external insulation creepage distance, so as to realize the miniaturization design of the pole while meeting the internal and external insulation creepage distance requirements of 10kV pole-mounted circuit breakers; a low-voltage arm capacitor cavity is reserved at the bottom for potting and installing the low-voltage arm capacitor of the voltage sensor.

[0090] (2) The upper end of the 003 incoming high-voltage arm capacitor is connected to the stationary end of the 002 arc-extinguishing chamber via a 301 hard copper wire, and the lower end is connected to the 011 incoming low-voltage arm capacitor via a 302 capacitor support rod; while the upper end of the 009 outgoing high-voltage arm capacitor is directly connected to the 008 outgoing conductive rod via a screw, and the lower end is connected to the 012 outgoing low-voltage arm capacitor via a wire. The high-voltage arm capacitor and the low-voltage arm capacitor constitute a voltage divider voltage sensor, which converts the 10kV primary voltage into a low-voltage small signal voltage on the secondary side according to the transformation ratio, for acquisition and processing by the ADMU.

[0091] (3) The pole adopts a miniaturized vacuum interrupter with a 002. The moving end of the interrupter is connected to one side of the 004 U-shaped flexible connection and is locked by the thread of the 005 insulating pull rod. The other side of the flexible connection is connected to the 008 outgoing conductive rod by an internal hex bolt. The flexible connection has a reserved through hole in the middle through which the insulating pull rod passes, so as to realize that the moving end of the interrupter moves up and down in conjunction with the insulating pull rod without causing motion interference, thus avoiding affecting the stability of the mechanical characteristics of the switch.

[0092] (4) A Rogowski coil (007) is integrated on the pole output side. The Rogowski coil is designed based on Faraday's law of electromagnetic induction and Ampere's circuital law. It adopts a hollow ring structure and is uniformly wound on a non-magnetic frame. When the current-carrying conductor being measured (008 output conductor rod) passes through the center of the coil, the alternating current generates an alternating magnetic field around the conductor. The coil generates an induced electromotive force (i.e., differential signal di / dt) that is proportional to the rate of change of the measured current through electromagnetic induction. To improve the accuracy of current acquisition, the Rogowski coil is tied to the 010 coil support rod. The support rod is used for positioning to keep the Rogowski coil centered and pass through the 008 output conductor rod, thereby avoiding measurement accuracy errors caused by position deviation. The Rogowski coil is wrapped with a buffer layer and a shielding layer. The buffer layer is mainly used to absorb the stress generated during the epoxy casting process to avoid damage to the coil structure. The shielding layer is grounded by connecting to the support rod. At the same time, the secondary output of the coil uses twisted-pair shielded wire. The shielding layer of the shielding wire is also grounded by the support rod to avoid interference from the strong magnetic field on the small signal transmission of the coil during the operation of the switch.

[0093] (5) A 006 shielding mesh is added between the flexible connector and the Rogowski coil to uniformize the electric field and improve the stability of partial discharge of the pole. The shielding mesh adopts a metal mesh structure and is installed in the space between the flexible connector and the Rogowski coil. It can effectively improve the electric field distortion problem caused by irregular conductors in this area and reduce the risk of partial discharge.

[0094] Digital traveling wave ranging switch structure as follows Figures 2 to 8 As shown, the specific technical solution is as follows: (1) The digital traveling wave ranging switch adopts a three-phase discrete pillar structure. Among them, the 01 solid-sealed pole assembly adopts three structural schemes: the A-phase pole has a reserved capacitor power supply structure on the incoming side, the C-phase pole has a reserved capacitor power supply structure on the outgoing side, and the B-phase pole has no power supply structure. This realizes the power supply device on both sides of the arc-extinguishing chamber break, supporting the switch to be powered in both closed and open states. The pole adopts three configuration structures, which can flexibly configure the application scheme of built-in capacitor power supply or external PT power supply according to user needs. At the same time, it is also conducive to the miniaturization and weight reduction of the product.

[0095] (2) The 01 solid-sealed pole assembly is installed on the 02 cast aluminum housing assembly and is integrated through the built-in 03 magnetic control mechanism. The integrated cast aluminum housing has no welding points, has better sealing performance than the sheet metal housing, is lighter in weight, and has a compact overall structure, meeting the IP67 protection requirements.

[0096] (3) The 04 Digital Integration Unit (ADMU) is installed on the back of the enclosure and adopts an external integration solution. The overall structure of the ADMU also adopts a miniaturized and lightweight design. The 401 housing is made of aluminum profile in one piece. The 402 core board unit and the housing adopt an online hot-swappable design. When the switch fails during operation, the core board can be replaced online by using a tool to apply it to the 4021 mounting and dismounting screw hole. The connection interface between the ADMU housing and the enclosure meets the IP65 protection requirement to prevent moisture from entering the switch enclosure. The electrical interface between the housing and the core board meets the IP55 protection requirement to ensure that moisture cannot enter the interface in the outdoor environment.

[0097] (4) The Rogowski coil secondary integrator unit is innovatively integrated inside the ADMU. The secondary small signal of the Rogowski coil is directly transmitted to the ADMU through a shielded cable. The ADMU performs the integration processing of the current signal and simultaneously completes the synthesis of the zero-current signal and the AD conversion of the signal. The parameters of the integrator and the Rogowski coil are perfectly matched to ensure that the differential signal is accurately restored to a linear signal proportional to the measured current.

[0098] (5) The ADMU adopts a 16-bit high-speed AD channel design, which can complete the acquisition of telemetry signals of phase voltage, zero voltage, phase current, and zero current on both sides of the switch, as well as remote signaling status signals such as switch open, closed, and no energy storage position. It can also digitally synthesize zero voltage and zero current signals based on phase voltage and phase current through software algorithms.

[0099] (6) The ADMU uses a DC24V power supply, which is provided by the secondary terminal control unit through the primary and secondary connection cables.

[0100] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0101] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0102] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for a digital traveling wave ranging switch, characterized in that, The digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, and is connected to the three-phase solid-sealed pole assembly and also to a secondary terminal control unit; the method includes: The digital merging unit performs unidirectional signal acquisition of the current signal, voltage signal and remote signaling signal of the three-phase solid-sealed pole assembly. The analog-to-digital signal conversion unit performs analog-to-digital conversion processing and synthesis on the current signal, the voltage signal, and the remote signaling signal to obtain telemetry data and remote signaling data, which are then transmitted to the secondary terminal control unit. The telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation, and traveling wave ranging analysis, while the remote signaling data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault diagnosis. In response to the digital merging unit detecting a traveling wave characteristic signal through the Rogowski coil, the secondary terminal control unit triggers the traveling wave recording function, acquires traveling wave recording data through the Rogowski coil and the digital merging unit, and performs traveling wave ranging calculation based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location; wherein, the line parameters include the telemetry data and the tele-signaling data.

2. The method according to claim 1, characterized in that, The digital merging unit also integrates a Rogowski coil double integrator; the telemetry data includes three-phase phase current and zero-sequence current; based on the digital merging unit, unidirectional signal acquisition of the current signal of the three-phase solid-sealed pole assembly is performed, including: The Rogowski coil of each phase senses the alternating current on the outgoing conductor of each phase and outputs a differential voltage signal that is proportional to the rate of change of the measured alternating current. The analog-to-digital signal conversion unit performs analog-to-digital conversion processing and synthesis on the current signal to obtain telemetry data, including: In response to the digital merging unit receiving the differential voltage signal, the differential voltage signal is integrated by the Rogowski coil double integrator to obtain a linear voltage signal proportional to the alternating current; The linear voltage signal is converted from analog to digital and then digitally synthesized by the analog-to-digital signal conversion unit to obtain the three-phase phase current and zero-sequence current.

3. The method according to claim 2, characterized in that, The telemetry data also includes three-phase phase voltage and zero-sequence voltage; unidirectional signal acquisition of the voltage signal of the three-phase solid-sealed pole assembly based on the digital merging unit includes: The voltage divider voltage sensor, which is composed of the high-voltage arm capacitor and the low-voltage arm capacitor built into the three-phase solid-sealed pole assembly, divides the primary voltage into a secondary low-voltage small signal voltage to obtain the secondary voltage signal. The secondary voltage signal is transmitted through the bottom secondary output terminal of the three-phase solid-sealed pole assembly to the 16-bit AD channel of the analog-to-digital signal conversion unit of the digital merging unit to complete analog-to-digital conversion and digital synthesis, thereby obtaining the three-phase phase voltage and zero-sequence voltage.

4. The method according to claim 3, characterized in that, Transmitting the telemetry data to the secondary terminal control unit includes: The digital merging unit packages the telemetry data according to the agreed communication protocol frame format to obtain a packaged telemetry data frame; the communication protocol frame format includes a frame header identifier, device address code, data length, telemetry data field, check code, and frame tail identifier; The packaged telemetry data frames are transmitted uplink to the secondary terminal control unit via the optical fiber communication interface of the digital merging unit through the optical fiber cable. The secondary terminal control unit is then used to verify and decode the telemetry data frames and extract data from each telemetry channel for line monitoring, protection criterion calculation, and traveling wave ranging analysis.

5. The method according to claim 1, characterized in that, The remote signaling signals include at least the remote signaling status signals of the switch's open, closed, and non-energy-storage positions; unidirectional signal acquisition of the remote signaling signals of the three-phase solid-sealed pole assembly is performed based on the digital merging unit, including: The remote signal is transmitted to the optocoupler-isolated digital input channel of the digital merging unit through the switch auxiliary contact and the bottom output terminal of the three-phase solid-sealed pole assembly.

6. The method according to claim 5, characterized in that, The remote signaling signal includes at least digital signals indicating the remote signaling status of the switch's open, closed, and unstored positions; transmitting the remote signaling data to the secondary terminal control unit includes: The digital merging unit packages the remote signaling signal according to the agreed communication protocol frame format and transmits it uplink to the secondary terminal control unit through the optical fiber communication interface. This enables the secondary terminal control unit to monitor the switch operation status and determine faults based on the remote signaling status contained in the remote signaling signal.

7. The method according to claim 1, characterized in that, The response of the digital merging unit detecting a traveling wave characteristic signal through the Rogowski coil triggers the secondary terminal control unit to activate the traveling wave recording function, acquiring traveling wave recording data through the Rogowski coil and the digital merging unit, including: In response to the digital merging unit detecting a transient change exceeding a set threshold in the current signal via the Rogowski coil, the secondary terminal control unit instructs the digital merging unit to perform high-speed sampling and waveform recording of the traveling wave current signal at a sampling rate of not less than 5MHz to obtain the traveling wave waveform recording data; the traveling wave waveform recording data includes traveling wave head time markers and raw waveform data; The digital merging unit transmits the traveling wave recording data to the secondary terminal control unit via optical fiber communication.

8. The method according to claim 7, characterized in that, The step of calculating the traveling wave distance based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location includes: The secondary terminal control unit calculates the fault location based on the traveling wave head time marker and the original waveform data, using either the single-end traveling wave ranging method or the double-end traveling wave ranging method.

9. A control device for a digital traveling wave ranging switch, characterized in that, The digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, and is connected to the three-phase solid-sealed pole assembly and also to a secondary terminal control unit; the device includes: A unidirectional signal acquisition module is used to acquire the current signal, voltage signal and remote signaling signal of the three-phase solid-sealed pole assembly based on the digital merging unit. The signal conversion and synthesis module is used to perform analog-to-digital conversion processing and synthesis of the current signal, the voltage signal and the remote signaling signal through the analog-to-digital signal conversion unit to obtain telemetry data and remote signaling data, and transmit them to the secondary terminal control unit; wherein, the telemetry data is used to enable the secondary terminal control unit to perform line monitoring, protection criterion calculation and traveling wave ranging analysis, and the remote signaling data is used to enable the secondary terminal control unit to perform switch operation status monitoring and fault judgment; The traveling wave recording and fault location module is used to respond to the digitizing unit detecting a traveling wave characteristic signal through the Rogowski coil, causing the secondary terminal control unit to trigger the traveling wave recording function, acquiring traveling wave recording data through the Rogowski coil and the digitizing unit, and performing traveling wave ranging calculation based on the traveling wave arrival time and line parameters in the traveling wave recording data to obtain the fault location; wherein, the line parameters include the telemetry data and the tele-signaling data.

10. A digital traveling wave ranging switch, characterized in that, The steps for implementing the method according to any one of claims 1 to 8; the digital traveling wave ranging switch includes: a three-phase solid-sealed pole assembly and a digital merging unit, wherein each phase of the three-phase solid-sealed pole assembly includes a Rogowski coil disposed on the outgoing line side; the digital merging unit integrates an analog-to-digital signal conversion unit, the digital merging unit is connected to the three-phase solid-sealed pole assembly, and is also connected to a secondary terminal control unit.

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