Voltage measurement and partial discharge detection system for a common capacitive coupled sensing structure

Abstract

The application provides a voltage measurement and partial discharge detection system of a shared capacitive coupling sensing structure, belongs to the technical field of power system control protection signal acquisition and gas insulated metal enclosed power transmission and distribution equipment online monitoring, and comprises a capacitive coupling sensing structure, a voltage measurement channel and a partial discharge detection channel; the capacitive coupling sensing structure is arranged on the side of a high-voltage conductor, the capacitive coupling sensing structure forms a coupling signal based on a capacitive coupling relationship with the high-voltage conductor, and provides the coupling signal to the voltage measurement channel and the partial discharge detection channel through the same coupling signal output end; the voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure, and extract information of respective corresponding target frequency bands from the same coupling signal. The application realizes signal acquisition of voltage measurement and partial discharge detection based on the same capacitive coupling sensing structure and the same coupling signal, does not need to additionally arrange an independent partial discharge sensing structure, and improves the equipment integration.

Description

Technical Field

[0001] This invention relates to the field of power system control and protection signal measurement and online monitoring technology of gas-insulated metal-enclosed power transmission and distribution equipment, specifically to a voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure. Background Technology

[0002] Gas-insulated metal-enclosed power transmission and distribution equipment typically includes a high-voltage conductor, a metal casing, and an insulating gas filling the metal casing. It has advantages such as excellent insulation performance, compact structure, and reliable operation, and is widely used in high-voltage, ultra-high-voltage, and extra-high-voltage power systems.

[0003] During the long-term operation of the aforementioned equipment, factors such as insulation aging, mechanical vibration, internal impurities, process defects, and electric field distortion near the insulators can all trigger partial discharges, seriously threatening equipment safety. Meanwhile, power grid operation and maintenance require real-time monitoring of the equipment's operating voltage. Therefore, voltage measurement and partial discharge detection are crucial aspects of online monitoring for gas-insulated, metal-enclosed power transmission and distribution equipment.

[0004] In existing technologies, voltage measurement and partial discharge detection in gas-insulated, metal-enclosed power transmission and distribution equipment are typically handled by two separate sets of equipment. Voltage acquisition often employs electromagnetic voltage transformers, independent capacitor banks, or other voltage acquisition devices; while partial discharge detection usually involves additional configuration of ultra-high frequency sensors, high-frequency current sensors, small point-type detection elements, or patch-type detection elements.

[0005] Existing solutions have several shortcomings: voltage measurement equipment and partial discharge detection equipment are configured independently, resulting in hardware redundancy, high procurement, installation, and maintenance costs, and poor equipment integration; when different detection devices are wired or installed separately, multiple openings or interfaces may need to be set on the metal casing, increasing the risk of insulation gas leakage; multiple sets of sensing components also occupy the limited internal space of the equipment, which is not conducive to equipment miniaturization, long-distance deployment, and on-site modification; at the same time, the voltage measurement signal and the partial discharge detection signal come from different sensing structures, and there is no natural synchronization relationship between the two, which often requires additional synchronization measures, increasing the system complexity. Summary of the Invention

[0006] The purpose of this invention is to provide a voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure. By using the same capacitive coupling sensing structure to collect voltage signals and high-frequency partial discharge signals, the system integrates voltage measurement and partial discharge detection functions. Furthermore, it eliminates the need for separate partial discharge sensing electrodes or independent partial discharge sensing structures outside the capacitive coupling sensing structure, thereby improving the utilization rate of the sensing structure and the integration of the equipment.

[0007] To achieve the above objectives, this invention provides a voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure, applied to gas-insulated metal-enclosed power transmission and distribution equipment. The gas-insulated metal-enclosed power transmission and distribution equipment includes a high-voltage conductor and a metal casing, comprising: a capacitive coupling sensing structure, a voltage measurement channel, and a partial discharge detection channel. The capacitive coupling sensing structure is disposed around the high-voltage conductor and forms a capacitive coupling relationship with it. Based on the capacitive coupling relationship with the high-voltage conductor, the capacitive coupling sensing structure generates a coupling signal, which is provided to the voltage measurement channel and the partial discharge detection channel respectively through the same coupling signal output terminal. The coupling signal simultaneously includes low-frequency band information reflecting the operating voltage of the high-voltage conductor and high-frequency band information generated by partial discharge. The voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure and extract information corresponding to their respective target frequency bands from the same coupling signal. Specifically, the voltage measurement channel is used to extract low-frequency band information corresponding to the operating voltage of the high-voltage conductor, and the partial discharge detection channel is used to extract high-frequency band information corresponding to partial discharge.

[0008] Optionally, it also includes a synchronous sampling control unit, which is electrically connected to the voltage measurement channel and the partial discharge detection channel respectively, and is used to output synchronous sampling control signals to the voltage measurement channel and the partial discharge detection channel, so that the voltage measurement channel and the partial discharge detection channel respectively acquire the voltage signal obtained from the low frequency band information and the partial discharge high frequency signal obtained from the high frequency band information based on the same sampling timing.

[0009] Optionally, it also includes a partial discharge phase acquisition unit, which is electrically connected to the voltage measurement channel and the partial discharge detection channel respectively, and is used to generate a partial discharge phase distribution map by using the voltage signal output by the voltage measurement channel as a phase reference and combining it with the synchronously sampled partial discharge high-frequency signal.

[0010] Optionally, the capacitively coupled sensing structure is arranged circumferentially around the high-voltage conductor.

[0011] Optionally, the capacitively coupled sensing structure extends along the circumferential portion of the high-voltage conductor.

[0012] Optionally, the capacitively coupled sensing structure is connected to a potential constraint network, which is grounded and used to establish the operating potential of the capacitively coupled sensing structure; the potential constraint network is any one of a resistor network, a capacitor network, or a parallel resistor-capacitor network.

[0013] Optionally, the partial discharge detection channel includes a high-frequency coupling network. The partial discharge detection channel extracts the high-frequency band information corresponding to the partial discharge from the coupling signal through the high-frequency coupling network to obtain a high-frequency signal of partial discharge. After high-frequency gating and amplification, the high-frequency signal of partial discharge is sampled at high speed, or it is sampled after at least one of detection processing and envelope extraction processing.

[0014] Optionally, the partial discharge phase acquisition unit uses the synchronously sampled voltage signal as a phase reference and establishes a correspondence between the voltage signal and the partial discharge high-frequency signal according to the synchronous sampling timing to obtain partial discharge phase distribution information.

[0015] Optionally, the voltage measurement channel, the partial discharge detection channel, and the partial discharge phase acquisition unit are integrated into the same electronic device.

[0016] Optionally, the capacitive coupling sensing structure is a planar sensing structure extending circumferentially along the high-voltage conductor, and the planar sensing structure has a capacitive coupling sensing surface disposed opposite to the high-voltage conductor.

[0017] In the above technical solution, the voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure, and the same coupling signal is provided to both channels from the same coupling signal output terminal. The coupling signal simultaneously includes low-frequency band information reflecting the operating voltage of the high-voltage conductor and high-frequency band information generated by partial discharge. Each channel can extract its corresponding target frequency band information from the same coupling signal. Therefore, voltage measurement and partial discharge detection acquire signals based on the same capacitive coupling sensing structure and the same coupling signal, achieving natural phase synchronization using the same source signal, eliminating the need for external synchronization links, simplifying the system structure, and improving monitoring reliability. Furthermore, it eliminates the need for separate partial discharge sensing electrodes or independent partial discharge sensing structures, reducing the number of openings or interfaces on the metal casing and lowering the risk of insulating gas leakage.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a diagram of a complete circumferential capacitively coupled sensing structure.

[0020] Figure 2 This is a diagram of a circumferentially non-closed capacitively coupled sensing structure.

[0021] Figure 3 This is a schematic diagram illustrating the principle of dual-channel target frequency band extraction with the same coupled signal.

[0022] Figure 4 This is a schematic diagram of synchronous phase acquisition between voltage signal and partial discharge high-frequency signal. Detailed Implementation

[0023] The following is in conjunction with the appendix Figure 1 - Appendix Figure 4 The specific implementation methods of the embodiments of the present invention will be described in detail below. It should be understood that the specific implementation methods described herein are only for illustrating and explaining the embodiments of the present invention, and are not intended to limit the embodiments of the present invention.

[0024] In the process of realizing this invention, the inventors of this application discovered that the voltage measurement and partial discharge detection equipment of existing gas-insulated metal-enclosed power transmission and distribution equipment are usually set up separately, with hardware redundancy, and require additional independent partial discharge sensing structures.

[0025] In this application, the gas-insulated metal-enclosed power transmission and distribution equipment can be any of GIS (Gas Insulated Switchgear), GIL (Gas Insulated Line), gas-insulated busbar, gas-insulated pipeline power transmission equipment, and gas-insulated power transmission and distribution equipment with a metal casing and high-voltage conductors. For ease of explanation, some embodiments are illustrated using GIS equipment, but this does not mean that the scope of protection of this application is limited to GIS equipment.

[0026] Example 1 Reference Figure 1 , Figure 3 , Figure 4 This is the first embodiment of the present invention. This embodiment provides a voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure, which is applied to gas-insulated metal-enclosed power transmission and distribution equipment. The gas-insulated metal-enclosed power transmission and distribution equipment includes a high-voltage conductor and a metal shell.

[0027] like Figure 1 As shown in the embodiments of this application, the voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure includes a capacitive coupling sensing structure, a voltage measurement channel, and a partial discharge detection channel.

[0028] The capacitively coupled sensing structure is placed on the periphery of the high-voltage conductor and forms a capacitive coupling relationship with the high-voltage conductor.

[0029] The capacitively coupled sensing structure is arranged circumferentially around the high-voltage conductor. The capacitively coupled sensing structure is a planar sensing structure extending circumferentially along the high-voltage conductor, and this planar sensing structure has a capacitively coupled sensing surface positioned opposite the high-voltage conductor.

[0030] In one specific embodiment, the gas-insulated metal-enclosed power transmission and distribution equipment can be a 220kV GIS device, with the distance between the metal casing and the high-voltage conductor being approximately 120mm. The capacitive coupling sensing structure is made of a metal material, such as aluminum, aluminum alloy, stainless steel, or other conductive metal materials, and can be the same material as the high-voltage conductor. The capacitive coupling sensing structure is disposed within the annular gap between the metal casing and the high-voltage conductor. For GIL, gas-insulated busbar, or gas-insulated pipeline power transmission devices, the size and installation position of the capacitive coupling sensing structure can be adapted according to the radial gap between the metal casing and the high-voltage conductor to ensure that the insulation clearance between the high-voltage conductor and the capacitive sensing structure meets the insulation requirements of the corresponding voltage level equipment.

[0031] An insulating support structure is provided between the capacitive coupling sensing structure and the metal casing. This insulating support structure is made of insulating material, such as epoxy, ceramic, or other insulating materials that meet the insulation requirements of the corresponding voltage level. The insulating support structure can be bonded to both the metal casing and the capacitive coupling sensing structure using industrial adhesive, allowing the capacitive coupling sensing structure to be suspended and fixed inside the metal casing. The insulating support distance between the capacitive coupling sensing structure and the metal casing can be determined based on the voltage level determined by the potential constraint network and the internal space, for example, it can be from 5mm to 60mm.

[0032] In a preferred embodiment of this application, the capacitively coupled sensing structure is further connected to a potential constraint network, which is grounded and used to establish the operating potential of the capacitively coupled sensing structure. The potential constraint network can be any one of a resistor network, a capacitor network, or a parallel resistor-capacitor network.

[0033] One end of the potential constraint network is connected to the capacitively coupled sensing structure, and the other end is grounded. The parameters of the potential constraint network are determined based on the coupling strength between the capacitively coupled sensing structure and the high-voltage conductor to ensure that the voltage obtained on the capacitively coupled sensing structure is within the processing range of the subsequent electronic circuit, for example, controlled below 10V.

[0034] In one alternative implementation, the potential constraint network can be installed inside a metal housing, in a separate terminal box outside the metal housing, or in an integrated chassis shared by voltage measurement and partial discharge detection, allowing for flexible arrangement based on site space and wiring conditions.

[0035] like Figure 3As shown in the embodiments of this application, the capacitive coupling sensing structure generates a coupling signal based on the capacitive coupling relationship with the high-voltage conductor, and provides it to the voltage measurement channel and the partial discharge detection channel respectively through the same coupling signal output terminal. The coupling signal is the same coupling signal provided to both the voltage measurement channel and the partial discharge detection channel. The coupling signal simultaneously includes low-frequency band information reflecting the operating voltage of the high-voltage conductor and high-frequency band information generated by partial discharge. The voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure and extract information of their respective target frequency bands from the same coupling signal. Specifically, the voltage measurement channel is used to extract low-frequency band information corresponding to the operating voltage of the high-voltage conductor, and the partial discharge detection channel is used to extract high-frequency band information corresponding to partial discharge.

[0036] It should be noted that both voltage measurement and partial discharge detection are based on the same capacitive coupling process.

[0037] In the embodiments of this application, the voltage measurement channel is used to extract low-frequency band information corresponding to the operating voltage of the high-voltage conductor from the coupled signal, and to obtain a voltage signal based on the low-frequency band information. The signal links within the voltage measurement channel can be sequentially connected to a low-frequency signal gating module, a voltage signal conditioning module, and a voltage measurement module. The low-frequency signal gating module is used to filter low-frequency band information corresponding to the operating voltage of the high-voltage conductor from the coupled signal, the voltage signal conditioning module is used to condition the voltage signal obtained from the low-frequency band information, and the voltage measurement module is used to output the voltage measurement result.

[0038] In one alternative implementation, the voltage measurement channel can perform low-pass filtering and amplification on the low-frequency band information in the coupled signal to obtain a voltage signal reflecting the operating voltage of the high-voltage conductor, and then send the voltage signal to the ADC (Analog-to-Digital Converter).

[0039] In a preferred embodiment of this application, the partial discharge detection channel includes a high-frequency coupling network. This network extracts high-frequency band information corresponding to the partial discharge from the coupled signal to obtain a high-frequency partial discharge signal. The signal links within the partial discharge detection channel can be sequentially connected to a high-frequency signal gating module, a partial discharge signal conditioning module, and a partial discharge measurement module. The high-frequency signal gating module filters high-frequency band information corresponding to the partial discharge from the coupled signal. The partial discharge signal conditioning module conditions the high-frequency partial discharge signal obtained from the high-frequency band information. The partial discharge measurement module outputs the partial discharge detection result.

[0040] In one optional implementation, the partial discharge detection channel includes a high-frequency coupling network. The partial discharge detection channel extracts the high-frequency band information corresponding to the partial discharge from the coupling signal through the high-frequency coupling network to obtain the high-frequency signal of the partial discharge. After high-frequency gating and amplification of the high-frequency signal of the partial discharge, it is sampled at high speed, or it is sampled after at least one of detection processing and envelope extraction processing.

[0041] In a preferred embodiment of this application, to enable the voltage measurement channel and the partial discharge detection channel to process information from their respective target frequency bands, the voltage measurement channel and the partial discharge detection channel can each be equipped with a frequency selection network adapted to their target signal frequency band. The transition frequency band or boundary frequency band of the frequency selection network can be determined based on the structural form of the gas-insulated metal-enclosed power transmission and distribution equipment, the target detection frequency band, and the subsequent sampling method. In a specific example, the transition frequency band or boundary frequency band can be set in the range of several kilohertz to several hundred kilohertz, for example, 10 kHz to 100 kHz.

[0042] It should be noted that the coupling capacitors in the high-frequency coupling network exhibit a large capacitive reactance to low-frequency signals, making it difficult for the power frequency voltage signal corresponding to the low-frequency band information to enter the high-frequency branch. Both the voltage measurement channel and the partial discharge detection channel are located in the subsequent stage of the capacitively coupled sensing structure. They perform signal gating, signal conditioning, and impedance matching with their respective subsequent circuits according to their respective processing frequency bands to reduce mutual interference between the two channels.

[0043] In a preferred embodiment of this application, a synchronous sampling control unit is further included. The synchronous sampling control unit is electrically connected to the voltage measurement channel and the partial discharge detection channel, respectively, and is used to output synchronous sampling control signals to the voltage measurement channel and the partial discharge detection channel, so that the voltage measurement channel and the partial discharge detection channel respectively acquire the voltage signal obtained from the low frequency band information and the partial discharge high frequency signal obtained from the high frequency band information based on the same sampling timing.

[0044] It should be noted that since the voltage signal acquired by the voltage measurement channel is obtained from low-frequency band information, and the high-frequency partial discharge signal acquired by the partial discharge detection channel is obtained from high-frequency band information, and the low-frequency band information and the high-frequency band information originate from the same coupling signal, it is beneficial to establish the phase correspondence between the voltage signal and the high-frequency partial discharge signal by synchronously sampling the two channels through the synchronous sampling control unit.

[0045] In one alternative implementation, the synchronous sampling control unit can be implemented by the same controller, synchronous triggering logic, or synchronous clock circuit. The synchronous sampling control unit outputs synchronous sampling control signals to the voltage measurement channel and the partial discharge detection channel, enabling the voltage signal and the partial discharge high-frequency signal to be acquired based on the same sampling timing.

[0046] In one specific approach, the synchronous sampling control unit receives a synchronous sampling pulse from the same controller. The ADCs in the voltage measurement channel and the partial discharge detection channel perform synchronous sampling based on this pulse. The sampling frequency of the voltage signal can be selected from 4kHz, 12.8kHz, 20kHz, 50kHz, and 100kHz. Generally, it is sampled synchronously with the partial discharge signal, and then the signal is down-sampled to obtain voltage signals at these specific frequencies. The sampling frequency of the high-frequency partial discharge signal is higher than that of the voltage signal, for example, greater than 100kHz. Because the synchronous sampling pulse from the same controller is used, the voltage signal and the high-frequency partial discharge signal can be acquired based on a unified sampling timing, which helps to reduce the timing deviation between the two signals.

[0047] like Figure 3 , Figure 4 As shown, in a preferred embodiment of this application, a partial discharge phase acquisition unit is further included. The partial discharge phase acquisition unit is associated with the voltage measurement channel and the partial discharge detection channel, respectively, and is used to generate a partial discharge phase distribution map (PRPD) by using the voltage signal output by the voltage measurement channel as a phase reference and combining it with the synchronously sampled high-frequency partial discharge signal.

[0048] Specifically, the partial discharge phase acquisition unit uses the synchronously sampled voltage signal as a phase reference and establishes a correspondence between the voltage signal and the high-frequency partial discharge signal based on the synchronous sampling timing to obtain partial discharge phase distribution information. The partial discharge phase acquisition unit can use the power frequency sine wave output from the voltage measurement channel as the phase reference and the narrow pulse output from the partial discharge detection channel as the discharge characteristic signal.

[0049] In a preferred embodiment of this application, the zero-crossing point of the voltage signal from negative to positive can be selected as the phase start point of a power frequency cycle. When the partial discharge detection channel outputs a high-frequency pulse in the partial discharge high-frequency signal, the partial discharge phase acquisition unit maps the high-frequency pulse to the phase interval of the power frequency voltage according to the synchronous sampling time corresponding to the high-frequency pulse, completes the partial discharge phase identification, and generates a partial discharge phase distribution map.

[0050] In the embodiments of this application, the voltage measurement channel, the partial discharge detection channel, and the partial discharge phase acquisition unit are integrated into the same electronic device. The electronic device can be an integrated acquisition and processing circuit board, an acquisition and processing module, or an integrated chassis. The electronic device can include a low-frequency signal gating circuit, a voltage signal conditioning circuit, a high-frequency signal gating circuit, a partial discharge signal conditioning circuit, a sampling circuit, and a partial discharge phase acquisition unit to complete voltage signal acquisition, partial discharge high-frequency signal acquisition, and partial discharge phase distribution map generation.

[0051] It should be noted that since the voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure, there is no need to set up a separate partial discharge sensing electrode or a separate partial discharge sensing structure outside of the capacitive coupling sensing structure. Compared with the scheme of setting up a separate point-like or patch-type partial discharge sensing structure, the capacitive coupling sensing structure set around the entire circumference of the high-voltage conductor has a larger effective sensing area, which is beneficial to improving the electric field coupling capability and picking up weak partial discharge signals.

[0052] In summary, this embodiment utilizes a planar capacitive coupling sensing structure arranged around the entire circumference of the high-voltage conductor, resulting in a large effective sensing area. The capacitive coupling sensing structure generates a coupling signal based on the capacitive coupling relationship with the high-voltage conductor, and provides this signal to both the voltage measurement channel and the partial discharge detection channel via the same output terminal. The coupling signal simultaneously includes low-frequency information reflecting the operating voltage of the high-voltage conductor and high-frequency information generated by partial discharge. The voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure and extract their respective target frequency band information from the same coupling signal. This allows voltage measurement and partial discharge detection to acquire signals based on the same capacitive coupling sensing structure, and both are completed within the same capacitive coupling process. The voltage measurement channel and the partial discharge detection channel perform signal gating, signal conditioning, and impedance matching according to their respective processing frequency bands, which helps reduce mutual interference between the two channels. The synchronous sampling control unit enables the voltage signal and the high-frequency partial discharge signal to be acquired based on the same sampling timing. The partial discharge phase acquisition unit uses the voltage signal as a phase reference to generate a partial discharge phase distribution map, which helps reduce acquisition timing deviations and phase deviations. Compared to traditional partial discharge detection methods that employ independent sensing structures and require additional synchronization measures, this embodiment uses the same capacitively coupled sensing structure and the same coupling signal for both the voltage signal and the partial discharge high-frequency signal. This facilitates the establishment of a sampling timing and phase correspondence between the two. Compared to solutions that require separate point-like or patch-type partial discharge sensing structures, this embodiment improves the pickup capability of high-frequency partial discharge signals and reduces the possibility of missing weak partial discharge signals. Furthermore, since it eliminates the need for separate partial discharge sensing electrodes or independent partial discharge sensing structures outside the capacitively coupled sensing structure, it reduces the number of openings or interfaces on the metal casing, lowers the complexity of equipment installation, wiring, and maintenance, and reduces the risk of insulating gas leakage.

[0053] Example 2 Reference Figure 2This is a second embodiment of the present invention, providing another voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure. It is applied to gas-insulated, metal-enclosed power transmission and distribution equipment, which includes a high-voltage conductor and a metal casing. This embodiment is similar to Embodiment 1 in system composition, working principle, and beneficial effects, differing only in the circumferential extension method of the capacitive coupling sensing structure. For aspects not mentioned, such as the potential constraint method, dual-channel signal extraction method, synchronous sampling method, partial discharge phase acquisition method, and integrated setting method, please refer to Embodiment 1.

[0054] like Figure 2 As shown, in the embodiments of this application, the capacitively coupled sensing structure is disposed on the periphery of the high-voltage conductor and forms a capacitively coupled relationship with the high-voltage conductor.

[0055] The capacitively coupled sensing structure extends circumferentially along the high-voltage conductor. Specifically, the capacitively coupled sensing structure is a planar sensing structure extending circumferentially along the high-voltage conductor, and this planar sensing structure has a capacitively coupled sensing surface positioned opposite the high-voltage conductor. This capacitively coupled sensing surface extends along a portion of the circumferential region of the high-voltage conductor, forming a circumferentially non-closed sensing region.

[0056] In one specific embodiment, the capacitive coupling sensing structure can be a circumferentially non-closed arc-shaped structure, such as an arc-shaped metal cylinder, an arc-shaped metal plate, or other arc-shaped planar conductive structures. The capacitive coupling sensing structure is made of a metallic material, such as aluminum, aluminum alloy, stainless steel, or other conductive metallic materials, and can be the same as the high-voltage conductor material. The capacitive coupling sensing structure is disposed within the annular gap between the metal casing and the high-voltage conductor, and remains insulated from both the metal casing and the high-voltage conductor.

[0057] In one optional implementation, the coverage area of ​​the capacitive coupling sensing structure can be determined based on the internal installation space of the gas-insulated metal-enclosed power transmission and distribution equipment. For example, the coverage area of ​​the capacitive coupling sensing structure can be greater than or equal to 1° and less than 360°. When the internal components of the gas-insulated metal-enclosed power transmission and distribution equipment are dense, the installation space is limited, or it is inconvenient to install a complete circumferential closed structure, the circumferential non-closed arc structure of this embodiment can be used. The circumferential non-closed arc structure extends along a portion of the circumferential region of the high-voltage conductor, which can form a planar capacitive coupling sensing surface opposite to the high-voltage conductor while avoiding the internal components of the equipment.

[0058] For GIL, gas-insulated busbars, or gas-insulated pipeline transmission equipment, the circumferential non-closed arc structure can be arranged according to the location of insulators, connection points, or target monitoring sections to adapt to the on-site installation space and monitoring requirements of long-distance tubular equipment.

[0059] It should be noted that although the capacitive coupling sensing structure is not fully enclosed around the high-voltage conductor, it still extends along the circumference of the high-voltage conductor, forming a planar capacitive coupling sensing surface. The capacitive coupling sensing structure generates a coupling signal based on the capacitive coupling relationship with the high-voltage conductor, and provides this signal to both the voltage measurement channel and the partial discharge detection channel through the same output terminal. The coupling signal is the same signal provided to both channels. The coupling signal includes both low-frequency information reflecting the operating voltage of the high-voltage conductor and high-frequency information generated by partial discharge. The voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure and extract information corresponding to their respective target frequency bands from the same coupling signal. Specifically, the voltage measurement channel extracts the low-frequency information corresponding to the operating voltage of the high-voltage conductor, while the partial discharge detection channel extracts the high-frequency information corresponding to partial discharge. Both voltage measurement and partial discharge detection are completed based on the same capacitive coupling process.

[0060] In this embodiment, the voltage measurement channel and the partial discharge detection channel still share the same capacitive coupling sensing structure. Specifically, the capacitive coupling sensing structure provides the same coupling signal to the voltage measurement channel and the partial discharge detection channel respectively through the same coupling signal output terminal. The voltage measurement channel is used to extract low-frequency band information corresponding to the operating voltage of the high-voltage conductor, and the partial discharge detection channel is used to extract high-frequency band information corresponding to partial discharge. The integration method of the synchronous sampling control unit, the partial discharge phase acquisition unit, and the electronic device can adopt the same or adapted settings as in Embodiment 1. The synchronous sampling control unit is used to enable the voltage measurement channel and the partial discharge detection channel to acquire the voltage signal obtained from the low-frequency band information and the partial discharge high-frequency signal obtained from the high-frequency band information respectively based on the same sampling timing. The partial discharge phase acquisition unit is used to generate a partial discharge phase distribution map by using the voltage signal output by the voltage measurement channel as a phase reference and combining it with the synchronously sampled partial discharge high-frequency signal.

[0061] It should be noted that the circumferential non-closed arc structure in this embodiment occupies less internal space and can be applied to working conditions where internal components are dense and installation space is limited. Since the voltage measurement channel and the partial discharge detection channel still share the same capacitive coupling sensing structure, there is no need to set up an independent partial discharge sensing electrode or an independent partial discharge sensing structure outside the capacitive coupling sensing structure.

[0062] In summary, this embodiment sets the capacitive coupling sensing structure as a circumferentially non-closed arc structure, allowing it to flexibly determine the coverage range based on the internal installation space of the gas-insulated, metal-enclosed power transmission and distribution equipment. It can still be arranged around the high-voltage conductor even in situations with dense internal components or limited installation space. This circumferentially non-closed arc structure, while occupying a small space, can still form a planar capacitive coupling sensing surface opposite to the high-voltage conductor, and provide the same coupling signal to both the voltage measurement channel and the partial discharge detection channel through the same coupling signal output terminal. The coupling signal simultaneously includes low-frequency band information reflecting the operating voltage of the high-voltage conductor and high-frequency band information generated by partial discharge. The voltage measurement channel and the partial discharge detection channel extract their respective target frequency band information from the same coupling signal, enabling voltage measurement and partial discharge detection to acquire signals based on the same capacitive coupling sensing structure and the same coupling signal. Both voltage measurement and partial discharge detection are completed based on the same capacitive coupling process, eliminating the need for two independent sensing structures to generate detection signals separately. Compared to traditional partial discharge detection methods that employ independent sensing structures and require additional synchronization measures, this embodiment uses the same capacitively coupled sensing structure and the same coupling signal for both the voltage signal and the partial discharge high-frequency signal. This facilitates the establishment of a sampling timing correspondence and a phase correspondence between the two signals. Furthermore, this embodiment can still establish a phase correspondence between the voltage signal and the partial discharge high-frequency signal through a synchronous sampling control unit and a partial discharge phase acquisition unit, thus meeting the requirements for generating a partial discharge phase distribution map.

[0063] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0064] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure, applied to gas-insulated metal-enclosed power transmission and distribution equipment, wherein the gas-insulated metal-enclosed power transmission and distribution equipment includes a high-voltage conductor and a metal casing, characterized in that, include: Capacitively coupled sensing structure, voltage measurement channel, and partial discharge detection channel; The capacitively coupled sensing structure is disposed on the periphery of the high-voltage conductor and forms a capacitive coupling relationship with the high-voltage conductor. The capacitive coupling sensing structure generates a coupling signal based on the capacitive coupling relationship with the high-voltage conductor, and provides it to the voltage measurement channel and the partial discharge detection channel respectively through the same coupling signal output terminal; the coupling signal simultaneously includes low-frequency band information reflecting the operating voltage of the high-voltage conductor and high-frequency band information generated by partial discharge; The voltage measurement channel and the partial discharge detection channel share the same capacitive coupling sensing structure and extract information of their respective target frequency bands from the same coupling signal. The voltage measurement channel is used to extract low-frequency band information corresponding to the operating voltage of the high-voltage conductor, and the partial discharge detection channel is used to extract high-frequency band information corresponding to partial discharge.

2. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 1, characterized in that, It also includes a synchronous sampling control unit, which is electrically connected to the voltage measurement channel and the partial discharge detection channel respectively, and is used to output synchronous sampling control signals to the voltage measurement channel and the partial discharge detection channel, so that the voltage measurement channel and the partial discharge detection channel respectively acquire the voltage signal obtained from the low frequency band information and the partial discharge high frequency signal obtained from the high frequency band information based on the same sampling timing.

3. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 2, characterized in that, It also includes a partial discharge phase acquisition unit, which is electrically connected to the voltage measurement channel and the partial discharge detection channel respectively. It is used to generate a partial discharge phase distribution map by using the voltage signal output by the voltage measurement channel as a phase reference and combining it with the synchronously sampled partial discharge high-frequency signal.

4. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 1, characterized in that, The capacitively coupled sensing structure is arranged circumferentially around the high-voltage conductor.

5. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 1, characterized in that, The capacitively coupled sensing structure extends along the circumferential portion of the high-voltage conductor.

6. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 1, characterized in that, The capacitively coupled sensing structure is connected to a potential constraint network, which is grounded and used to establish the operating potential of the capacitively coupled sensing structure. The potential constraint network can be any one of a resistor network, a capacitor network, or a parallel resistor-capacitor network.

7. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 1, characterized in that, The partial discharge detection channel includes a high-frequency coupling network. The partial discharge detection channel extracts the high-frequency band information corresponding to the partial discharge from the coupling signal through the high-frequency coupling network to obtain the high-frequency signal of the partial discharge. After high-frequency gating and amplification, the high-frequency signal of the partial discharge is sampled at high speed, or it is sampled after at least one of detection processing and envelope extraction processing.

8. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 3, characterized in that, The partial discharge phase acquisition unit uses the synchronously sampled voltage signal as a phase reference and establishes a correspondence between the voltage signal and the partial discharge high-frequency signal according to the synchronous sampling timing to obtain partial discharge phase distribution information.

9. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 3, characterized in that, The voltage measurement channel, the partial discharge detection channel, and the partial discharge phase acquisition unit are integrated into the same electronic device.

10. The voltage measurement and partial discharge detection system with a shared capacitive coupling sensing structure according to claim 1, characterized in that, The capacitive coupling sensing structure is a planar sensing structure extending circumferentially along the high-voltage conductor, and the planar sensing structure has a capacitive coupling sensing surface disposed opposite to the high-voltage conductor.

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