Surface charge measuring device and method

Abstract

The invention relates to a surface charge measurement device and method, and the device comprises a potential collection device which is provided with a high-voltage measurement probe and a signal display device; the first supporting frame is used for supporting the large gas insulated switchgear, a shell is arranged on the first supporting frame, and the shell is provided with a closed cavity and an inflation inlet used for inflating the gas insulated switchgear; the first support frame is also used for pressurizing the gas insulated switchgear under the condition that the cavity is inflated, and dismounting the shell after discharging and deflating; the second support frame is provided with a motor group; the motor group comprises a probe driving motor, a horizontal driving motor group and a vertical driving motor group; and the probe driving motor, the horizontal driving motor set and the vertical driving motor set are used for driving the high-voltage measuring probe to approach the surface of the gas insulated switchgear after the shell is detached, so that surface charge measurement is realized. Therefore, the accuracy of the surface charge measurement result of the large-size real-type GIS terminal can be improved.

Description

Technical Field

[0001] This application relates to the field of high voltage insulation measurement technology, and in particular to a surface charge measurement device and method. Background Art

[0002] DC GIS terminals are core components connecting gas-insulated switches (GIS) to cables, possessing advantages such as high reliability and compact structure. Their insulation performance directly affects the safe and stable operation of the entire DC transmission system. Under actual operating conditions, charge easily accumulates on the surface of the epoxy sheath of the GIS terminal, leading to electric field distortion and significantly reducing the surface flashover voltage. Furthermore, the surface charge formed by relaxation polarization after power failure is difficult to dissipate automatically, placing higher demands on insulation design. Accurately understanding the accumulation and distribution characteristics of surface charge is a crucial foundation for optimizing the epoxy sheath insulation structure.

[0003] Currently, the design of surface charge measurement devices faces significant challenges due to the large size and tapered surface of DC GIS terminals, as well as the presence of high-voltage SF6 insulating gas inside their casing. Existing measurement technologies are typically limited to testing small-sized samples or scaled-down models in air environments, making it difficult to accurately reflect the charge distribution under actual operating conditions. In particular, there is a lack of effective means for stable and accurate measurement in an SF6 gas chamber environment.

[0004] Therefore, during implementation, the relevant technologies still have at least one limitation: existing surface charge measurement devices cannot adapt to the structural characteristics of large-size full-size GIS terminals, resulting in significant differences between the measurement results and the actual working conditions. Summary of the Invention

[0005] Based on this, the purpose of this application is to at least solve one of the above-mentioned technical defects, especially the technical defect of low measurement accuracy of large-size gas-insulated switchgear in the prior art. This application provides a surface charge measurement device and method.

[0006] In a first aspect, this application provides a surface charge measuring device for use in large gas-insulated switchgear, the device comprising:

[0007] The potential acquisition device includes a high-voltage measurement probe and a signal display device;

[0008] The first support frame is used to support large gas-insulated switchgear. The first support frame is equipped with a housing, which has a sealed cavity and an inflation port for inflating the gas-insulated switchgear. The first support frame is also used to pressurize the gas-insulated switchgear while the cavity is inflated and to remove the housing after discharge.

[0009] The second support frame is equipped with a motor assembly; the motor assembly includes a probe drive motor, a horizontal drive motor assembly, and a vertical drive motor assembly.

[0010] The probe drive motor, horizontal drive motor assembly, and vertical drive motor assembly are used to drive the high-voltage measurement probe close to the surface of the gas-insulated switchgear after the housing is removed, so as to achieve surface charge measurement.

[0011] In one embodiment, the first support frame is also provided with a high-voltage DC power supply; the high-voltage DC power supply is electrically connected to the large gas-insulated switchgear and is used to pressurize the large gas-insulated switchgear when it is being filled with gas.

[0012] In one embodiment, the first support frame is also provided with a tail tube, through which the high-voltage DC power supply is connected to a large gas-insulated switchgear.

[0013] The tailpipe is used to block the leakage of insulating gas in the cavity while conducting a conductive connection between the high-voltage DC power supply and the equipment, and to prevent interference from the external radiation of the high-voltage electric field.

[0014] In one embodiment, the horizontal drive motor assembly includes a first horizontal servo motor and a second horizontal servo motor;

[0015] The first horizontal servo motor and the second horizontal servo motor are symmetrically arranged at both ends of the horizontal guide rail of the second support frame.

[0016] One end of the probe drive motor is mounted on a horizontal guide rail, and the other end is equipped with a high-voltage measuring probe.

[0017] The first and second horizontal servo motors are used to synchronously drive the horizontal movement of the probe drive motor, thereby driving the high-voltage measuring probe closer to or away from the surface of the large gas-insulated switchgear.

[0018] In one embodiment, the vertical drive motor assembly includes:

[0019] The first vertical servo motor is mounted on the first vertical guide rail of the second support frame;

[0020] The second vertical servo motor is mounted on the first vertical guide rail of the second support frame;

[0021] The first and second vertical servo motors are used to synchronously drive the vertical movement of both ends of the horizontal guide rail, so as to drive the high voltage measuring probe to move vertically on the surface of the large gas-insulated switchgear.

[0022] In one embodiment, the first support frame is provided with a moving module, which drives the first support frame and the large gas-insulated switchgear to move flexibly on a flat ground.

[0023] In one embodiment, the housing and the first support frame are installed or removed via a flange.

[0024] In one embodiment, the first support frame is further provided with a displacement sensor, which is used to detect the real-time distance between the high-voltage measuring probe and the surface of the gas-insulated switchgear.

[0025] In one embodiment, the bottom of the first support frame is also provided with a grounding terminal; the grounding terminal is connected to the ground grounding grid through a grounding wire, and the grounding wire is covered with an insulating protective tube.

[0026] Secondly, this application provides a surface charge measurement method, applied to the aforementioned surface charge measurement device, for measuring the surface charge of large gas-insulated switchgear, the method comprising:

[0027] Inflate the cavity of the housing provided in the first support frame through the air inlet;

[0028] The gas-insulated switchgear is pressurized while the cavity is filled with gas, and the housing is removed after discharge and gas release.

[0029] After pressurizing for a preset time, the gas-insulated switchgear is discharged and the gas is released.

[0030] After discharging and releasing the gas, remove the casing;

[0031] After the housing is removed, the high-voltage measurement probe of the drive potential acquisition device is brought close to the surface of the gas-insulated switchgear via the probe drive motor, horizontal drive motor group and vertical drive motor group set by the second support frame to realize surface charge measurement.

[0032] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0033] The surface charge measurement device and method provided in this application utilize a potential acquisition device with a high-voltage measurement probe and a signal display device, a first support frame with a housing, and a second support frame equipped with a motor assembly. The motor assembly includes a probe drive motor, a horizontal drive motor assembly, and a vertical drive motor assembly. These motors, after the housing is removed, drive the high-voltage measurement probe close to the surface of the gas-insulated switchgear to achieve surface charge measurement. This structure, through the integrated support structure and automated probe positioning system, enables in-situ, non-contact, automated measurement of surface charge on large GIS equipment. The sealed, gas-filled housing accurately replicates the real operating environment, thereby improving the accuracy of surface charge measurement results for large-size, full-scale GIS terminals. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a surface charge measuring device provided in an embodiment of this application;

[0036] Figure 2 This is a schematic diagram of the structure of a surface charge measuring device under pressurized and inflated conditions, provided in an embodiment of this application.

[0037] Figure 3 This is a schematic diagram of the structure of a surface charge measuring device under surface charge measurement conditions provided in an embodiment of this application;

[0038] Figure 4 This is a schematic flowchart of a surface charge measurement method provided in an embodiment of this application. Attached Figure Description

[0039] 110. Potential acquisition device; 111. High-voltage measurement probe; 112. Signal display device; 120. First support frame; 130. Second support frame; 140. Probe drive motor; 150. Horizontal drive motor assembly; 151. First horizontal servo motor; 152. Second horizontal servo motor; 160. Vertical drive motor assembly; 161. First vertical servo motor; 162. Second vertical servo motor; 170. Housing; 180. High-voltage DC power supply; 190. Tail tube; 210. Observation window; 220. Inflation / discharge port; 230. Pressure gauge; 240. Moving module; 20. Large gas-insulated switchgear. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0042] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0043] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0044] It is understandable that "at least one" can refer to one or more, while "multiple" can refer to two or more. "At least a part of an element" can refer to part or all of an element.

[0045] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0046] As a key component in gas-insulated switches (GIS) and cable connections, DC GIS terminals offer advantages such as high reliability and small size. Their reliability is crucial to the safe and stable operation of the entire power transmission system. Under operating conditions, the charge accumulated on the epoxy sheath of the GIS terminal causes electric field distortion, reduces surface flashover voltage, and the surface charge established by relaxation polarization after power failure is difficult to dissipate. Understanding the characteristics of surface charge accumulation and distribution in GIS terminals is the theoretical basis for stress design of the epoxy sheath.

[0047] However, GIS terminals are characterized by large taper and surface area, and their internal casing is filled with SF6 gas, making it difficult to design a surface charge measurement mechanism. Currently, surface charge measurement mechanisms for GIS terminals are limited to measuring small samples and scaled-down models in air, which cannot reflect the actual service conditions of GIS terminals. Therefore, there is an urgent need to propose a method and device for measuring the surface charge of large-size DC GIS terminals.

[0048] During implementation, the following shortcomings of the relevant technology were discovered:

[0049] Surface charge measurement requires ensuring probe stability, which becomes increasingly difficult to guarantee as the device grows larger. Therefore, existing GIS terminal surface charge measurement devices are limited to measuring small samples (such as discs) and scaled-down models.

[0050] Currently, surface charge measurement of GIS terminals is limited to air environments, while the GIS terminal casing is filled with SF6 gas, and conventional testing methods differ from actual service conditions.

[0051] Based on this, this application provides a surface charge measurement device and method for large-scale gas-insulated switchgear. It can realize the surface charge measurement of full-size GIS terminals; it can realize the measurement of surface charge in an air environment after pressurizing the SF6 sealed gas chamber and removing it; the mechanism has high stability.

[0052] In one exemplary embodiment, Figure 1 This is a schematic diagram of the structure of a surface charge measuring device provided in an embodiment of this application, as shown below. Figure 1 As shown, a surface charge measuring device is provided, applied to a large gas-insulated switchgear 20, the device comprising:

[0053] The potential acquisition device 110 includes a high voltage measurement probe 111 and a signal display device 112;

[0054] The first support frame 120 is used to support the large gas-insulated switchgear 20. The first support frame 120 is provided with a housing 170. The housing 170 has a sealed cavity and an inflation port for inflating the gas-insulated switchgear. The first support frame 120 is also used to pressurize the gas-insulated switchgear when the cavity is inflated, and to remove the housing 170 after discharge.

[0055] The second support frame 130 is equipped with a motor assembly; the motor assembly includes a probe drive motor 140, a horizontal drive motor assembly 150, and a vertical drive motor assembly 160.

[0056] The probe drive motor 140, the horizontal drive motor group 150, and the vertical drive motor group 160 are used to drive the high voltage measurement probe 111 close to the surface of the gas-insulated switchgear after the housing 170 is removed, so as to realize surface charge measurement.

[0057] Among them, the surface charge measuring device refers to a specialized system for quantifying the degree of surface charge accumulation on the insulation of electrical equipment, and its measurement results are of great significance for assessing insulation aging and failure risk. Large gas-insulated switchgear 20 refers to a sealed combined electrical appliance used in high-voltage power transmission and distribution systems for line control and protection, using gases such as SF6 as the insulating medium; the charge distribution on the surface of its internal components directly affects insulation performance. The potential acquisition device 110 is the core component used to sense, convert, and display surface potential values; the high-voltage measuring probe 111 typically refers to a non-contact potential sensor using the principle of electrostatic induction. The first support frame 120 is a load-bearing and sealing structure used to fix the GIS equipment under test and provide pressurization and inflation functions; its housing 170 can refer to a gas chamber designed to create a sealed testing environment. The second support frame 130 is a mechanical motion platform used for precise probe positioning; the motor set can refer to a collection of servo motors providing multi-directional driving force. The horizontal drive motor set 150 and the vertical drive motor set 160 respectively refer to motor systems that control the movement of the probe in a two-dimensional plane, used to achieve precise positioning of the probe relative to the equipment surface.

[0058] For example, the working process of the device is as follows: First, the GIS device under test can be fixed to the first support frame 120, the housing 170 is sealed and filled with insulating gas at a specific pressure; then, voltage is applied to the device through the high-voltage DC power supply 180 to simulate the operating conditions and induce surface charge accumulation; after pressurization is completed, the air pressure is released and the housing 170 is removed. At this time, the servo motors on the second support frame 130 work together to drive the high-voltage measurement probe 111 to automatically move to a designated position above the device surface to perform scanning potential measurement, and the data is presented in real time by the signal display device 112.

[0059] In this embodiment, by designing an integrated support structure and an automated probe positioning system, in-situ, non-contact automated operation for surface charge measurement of large GIS equipment is achieved, overcoming the drawbacks of traditional methods that require equipment disassembly, and are characterized by low efficiency and poor safety due to manual measurement. The design of the sealed inflatable shell 170 ensures the consistency between the test conditions and actual operating conditions, improving the authenticity and reliability of the measurement results.

[0060] In one exemplary embodiment, Figure 2 This is a schematic diagram of a surface charge measuring device under pressurized inflation state provided in an embodiment of this application; as shown below. Figure 1 , Figure 2 As shown, the first support frame 120 is also equipped with a high-voltage DC power supply 180; the high-voltage DC power supply 180 is electrically connected to the large gas-insulated switchgear 20 and is used to pressurize the large gas-insulated switchgear 20 when it is being filled with gas.

[0061] Among them, the high-voltage DC power supply 180 can refer to a power supply device that can generate an adjustable DC voltage of thousands to tens of thousands of volts, which can be used to apply a high-voltage electric field to gas-insulated switchgear during experiments.

[0062] For example, the high-voltage DC power supply 180 can be installed in a dedicated compartment of the first support frame 120 and can be connected to the equipment via a high-voltage cable. The power supply is equipped with a voltage regulator, an overcurrent protection device, and a remote control interface, and its housing is shielded to prevent electromagnetic leakage.

[0063] In this embodiment, the high-voltage DC power supply 180 can be integrated into the first support frame 120, which realizes the integration and convenience of the pressurization process, avoids the wiring complexity and electromagnetic interference problems caused by external power supply, and improves the overall integrity and experimental repeatability of the device.

[0064] In an exemplary embodiment, Figure 1 , Figure 2 As shown, the first support frame 120 is also provided with a tail tube 190, and the high voltage DC power supply 180 is connected to the large gas-insulated switchgear 20 through the tail tube 190.

[0065] The tailpipe 190 is used to block the leakage of insulating gas in the cavity and prevent the high voltage electric field from radiating to the outside while the high voltage DC power supply 180 is electrically connected to the equipment.

[0066] The tailpipe 190 can be a structure of a GIS terminal, which is essentially a device connecting a large high-voltage GIS switch and cables. The applied voltage can be applied exactly as in actual operating conditions, without altering the structure of the GIS terminal itself; the tailpipe 190 has no substantial impact on the measurement. The surface charge actually measured is the surface of the epoxy sheath (white) of the GIS terminal.

[0067] Tailpipe 190 can be a special pipe structure that combines conductive connection and sealing isolation functions. Its internal shielding design can effectively suppress the radiation interference of high voltage electric field to the outside world.

[0068] For example, the tailpipe 190 can adopt a double-layer structure design, with the inner layer being a conductive core and the outer layer being an insulating shielding layer. Both ends of the tailpipe 190 can be connected by flanges, with one end connected to the high-voltage power supply output and the other end connected to the large gas-insulated switchgear 20 under test. A corrugated section can be provided in the middle of the pipe body to accommodate equipment installation errors, and O-ring seals can be used at the interfaces to ensure airtightness.

[0069] In this embodiment, the design of the tailpipe 190 achieves the unity of high-voltage electrical connection and cavity airtightness. While ensuring smooth pressurization, it prevents leakage of insulating gas and eliminates the influence of external electromagnetic interference on the measurement results, thus ensuring a high signal-to-noise ratio of experimental data.

[0070] In one exemplary embodiment, Figure 3 This is a schematic diagram of the structure of a surface charge measuring device under surface charge measurement conditions provided in an embodiment of this application, as shown below. Figure 1 , Figure 3 As shown, the horizontal drive motor assembly 150 includes a first horizontal servo motor 151 and a second horizontal servo motor 152.

[0071] The first horizontal servo motor 151 and the second horizontal servo motor 152 are symmetrically arranged at both ends of the horizontal guide rail of the second support frame 130.

[0072] One end of the probe drive motor 140 is mounted on a horizontal guide rail, and the other end is equipped with a high-voltage measuring probe 111.

[0073] The first horizontal servo motor 151 and the second horizontal servo motor 152 are used to synchronously drive the horizontal movement of the probe drive motor 140 to drive the high voltage measuring probe 111 to approach or move away from the surface of the large gas-insulated switchgear 20.

[0074] Servo motors refer to electric motors that can precisely control position, speed, and torque, and achieve closed-loop control through encoders.

[0075] For example, two horizontal servo motors can be symmetrically mounted at both ends of a horizontal guide rail, driving the probe bracket to move via a synchronous belt or ball screw. The servo motors can employ absolute encoders and be equipped with brakes to ensure positioning accuracy. The control system can adopt a master-slave mode to ensure synchronous operation of the two motors.

[0076] In this embodiment, a design of dual servo motors symmetrically driving the horizontal guide rail can be adopted, which ensures the stability and high precision of the probe drive motor 140 during horizontal movement, eliminates the stuttering or offset phenomenon that may occur with single motor drive, and provides a stable platform foundation for accurate measurement.

[0077] In an exemplary embodiment, Figure 1 , Figure 3 As shown, the vertical drive motor assembly 160 includes:

[0078] The first vertical servo motor 161 is mounted on the first vertical guide rail of the second support frame 130;

[0079] The second vertical servo motor 162 is mounted on the first vertical guide rail of the second support frame 130;

[0080] The first vertical servo motor 161 and the second vertical servo motor 162 are used to synchronously drive the vertical movement of both ends of the horizontal guide rail, so as to drive the high voltage measuring probe 111 to move vertically on the surface of the large gas-insulated switchgear 20.

[0081] For example, two vertical servo motors can be mounted on vertical guide rails on both sides, driving the horizontal guide rails to move vertically via precision ball screws. The motors can be designed to prevent fall damage and can be equipped with linear encoders for position feedback, forming a fully closed-loop control system. The two motors can be synchronized using electronic axes.

[0082] In this embodiment, the horizontal guide rail can be moved vertically at both ends by synchronous driving of dual servo motors, which ensures that the probe always maintains a horizontal posture in the vertical direction, avoids probe tilting or measurement distance error caused by single-point driving, and realizes precise control of the distance between the probe and the device surface.

[0083] In an exemplary embodiment, Figure 1 , Figure 2 , Figure 3 As shown, the first support frame 120 is equipped with a moving module 240, which drives the first support frame 120 and the large gas-insulated switchgear 20 to move flexibly on the flat ground.

[0084] The moving module 240 may refer to a caster wheel or pulley system with locking function.

[0085] For example, the moving module 240 may include four heavy-duty casters, each equipped with an independent brake. A hydraulic leveling system may be provided at the bottom of the support frame for automatic leveling when in a fixed position. The casters may be made of polyurethane to ensure load-bearing capacity while preventing damage to the ground. In this way, operators can easily move and secure the first support frame 120, which carries heavy GIS equipment, to the experimental location.

[0086] In this embodiment, the addition of the mobile module 240 greatly enhances the flexibility and site adaptability of the device, facilitates assembly line testing of large equipment or testing at different locations, and improves the utilization efficiency of the device.

[0087] I understand. Figure 1 This is a complete structural schematic diagram of the surface charge measuring device provided in the embodiments of this application. Figure 2 This is a schematic diagram of a surface charge measuring device under pressurized and inflated conditions. Figure 3 This is a schematic diagram of the surface charge measuring device under surface charge measurement conditions. Figure 2 In the specified state, the large gas-insulated switchgear 20 is pressurized with gas, and after a preset pressurization time, the large gas-insulated switchgear 20 is de-energized and the gas is released. The outer casing 170 of the large gas-insulated switchgear 20 can then be removed. After removing the casing 170, the first support frame 120 can be moved to the position of the second support frame 130 via the moving module 240, thus obtaining... Figure 3 The measurement states shown are used to measure the surface charge of a large gas-insulated switchgear 20.

[0088] In an exemplary embodiment, Figure 1 , Figure 2 As shown, the housing 170 and the first support frame 120 are installed or removed via flanges.

[0089] Among them, a flange can refer to a connecting device that fastens two flat flanges with sealing grooves together by bolts.

[0090] For example, the flange can be a weld neck flange design, the sealing surface can be a raised face structure, and a spiral wound gasket can be placed in the middle. Multiple bolt holes can be evenly distributed around the flange circumference, using high-strength bolts for connection. Locating pin holes can be provided on the flange edge to ensure installation accuracy.

[0091] In this embodiment, the flange connection provides excellent sealing performance and mechanical strength, ensuring the safety of the cavity during high-pressure inflation; at the same time, its standardized and modular design makes the installation and removal of the housing 170 quick and easy, greatly improving the efficiency of experimental preparation.

[0092] In one exemplary embodiment, the first support frame 120 is further provided with a displacement sensor, which is used to detect the real-time distance between the high-voltage measuring probe and the surface of the gas-insulated switchgear.

[0093] Among them, displacement sensor refers to a precision device used to detect minute changes in distance between a probe and the surface of a device.

[0094] For example, the displacement sensor employs a non-contact laser ranging principle and is mounted on a probe bracket. For instance, a laser ranging or capacitive displacement sensor can be used to feed real-time distance data back to the control system, enabling precise closed-loop control of the probe's pose. The sensor's measuring head can face the device surface, with the measuring beam parallel to the probe's measuring direction. The sensor's output signal can be connected to the control system to form a closed-loop position control.

[0095] In this embodiment, an integrated displacement sensor is used to construct an active safety protection and precise ranging system. This system can prevent the probe from accidentally colliding with and damaging the surface of the equipment, and ensure that the measurement is carried out at a constant ideal distance, thereby significantly improving the safety and accuracy of the measurement.

[0096] In an exemplary embodiment, the bottom of the first support frame 120 is also provided with a grounding terminal; the grounding terminal is connected to the ground grounding grid through a grounding wire, and the grounding wire is covered with an insulating protective tube.

[0097] For example, the grounding terminal can be made of copper with a silver-plated surface. The terminal may have multiple wiring holes to connect grounding wires of different specifications. The terminals feature an anti-loosening design to ensure reliable connection. The insulating protective tube is made of silicone rubber, which has high voltage resistance and aging resistance.

[0098] In this embodiment, by setting up a dedicated grounding terminal and using an insulating sheath to protect the grounding wire, a reliable and safe grounding path is provided for the experimental system, effectively dissipating residual charge and ensuring the safety of high-voltage test operators and equipment, which complies with the safety specifications for high-voltage testing.

[0099] In one exemplary embodiment, Figure 4 This is a schematic flowchart of a surface charge measurement method provided in an embodiment of this application, as shown below. Figures 1 to 4 As shown, this method is applied to the aforementioned surface charge measuring device for measuring the surface charge of a large gas-insulated switchgear 20. The method includes:

[0100] S401. Inflate the cavity of the housing 170 provided in the first support frame 120 through the air inlet;

[0101] S402. Pressurize the gas-insulated switchgear while the cavity is filled with gas, and remove the housing 170 after discharge and degassing.

[0102] S403. After pressurizing for a preset time, discharge and release the gas-insulated switchgear.

[0103] S404. After discharge and venting, remove the casing 170.

[0104] S405. The probe drive motor 140, the horizontal drive motor group 150 and the vertical drive motor group 160 set by the second support frame 130, after the housing 170 is removed, drive the high voltage measurement probe 111 of the potential acquisition device 110 to approach the surface of the gas-insulated switchgear to realize surface charge measurement.

[0105] The surface charge measurement method refers to an analytical method that quantitatively detects the residual charge on the surface of insulating equipment after high-voltage excitation through a series of standardized procedures. Gas filling refers to filling a sealed cavity with a specific pressure and type of insulating gas (such as SF6) through a gas inlet to simulate the actual operating environment of the equipment. Pressurization refers to applying a high voltage to the gas-insulated switchgear using a high-voltage DC power supply 180, creating a strong electric field between the internal conductors and the housing 170, thereby inducing surface charge accumulation. Discharging refers to disconnecting the high-voltage power supply and grounding the equipment electrodes to release the stored electric field energy; venting refers to releasing the insulating gas in the cavity to ambient pressure. The preset time refers to the pressurization duration set according to experimental requirements, which must ensure sufficient surface charge accumulation and a stable state. Driving the high-voltage measurement probe 111 closer refers to the process of controlling a motor set to precisely move the probe to a specific measurement distance from the equipment surface in a non-contact manner.

[0106] For example, the method can perform the following key operations in sequence: First, the device under test is sealed in the housing 170 and filled with insulating gas to establish the experimental environment; then, the high-voltage DC power supply 180 is turned on to pressurize the device for a certain period of time to stabilize the surface charge distribution; after pressurization, a safe discharge and venting process is performed; then, the housing 170 is removed to expose the device surface; finally, through the coordinated control of the multi-axis servo motor system, the measuring probe is automatically and accurately positioned to the predetermined measurement point to perform scanning or fixed-point potential measurement, thereby achieving non-destructive and accurate measurement of the surface charge distribution.

[0107] In this embodiment, by standardizing and automating the measurement process and strictly distinguishing between the pressurization, discharge, and measurement stages, the method effectively ensures the safety of the experimental operation and the repeatability of the results. The scheme of first pressurizing and then depressurizing ensures that charge accumulation occurs under real-world conditions, avoiding interference from external environmental factors. Using a motor-driven probe instead of manual operation not only eliminates personal safety risks but also greatly improves the positioning accuracy and efficiency of the measurement, providing reliable data support for accurately assessing the insulation status of large gas-insulated equipment.

[0108] In some exemplary embodiments, such as Figure 1 , Figure 3 As shown, the above-mentioned device also includes:

[0109] The observation window 210 is used to observe the condition inside the cavity; the inflation / deflation port 220 is used to perform inflation / deflation; and the pressure gauge 230 is used to measure the inflation pressure.

[0110] In some exemplary embodiments, the testing process includes:

[0111] The probe drive motor 140 is connected to the ball screw controlled by the first horizontal servo motor 151. When the first horizontal servo motor 151 is started, the probe drive motor 140 is moved to the edge of the measuring mechanism (the entire mechanism is outside the GIS terminal housing 170).

[0112] SF6 gas at 0.5 MPa is injected into the GIS terminal housing 170 through the inflation port.

[0113] Apply a high-voltage DC voltage (GIS terminal service voltage) to the end of the cable, and then disconnect the power after 2 hours. Discharge the GIS terminal housing 170 and recover SF6 gas.

[0114] Remove the connecting bolts between the flange and the GIS terminal housing 170, and then remove the GIS terminal housing 170.

[0115] The remaining components of the GIS terminal after removing the GIS terminal housing 170 are moved to the position of the second support frame via the moving module 240.

[0116] By controlling the first horizontal servo motor 151, the second horizontal servo motor 152 and the probe drive motor 140, the high-voltage measurement probe 111 is moved to the vicinity of the epoxy sheath of the GIS terminal (close to the contact side). The probe can be controlled to be perpendicular to the surface of the epoxy sheath of the GIS terminal, such as at a distance of 3mm.

[0117] Turn on the electrometer and oscilloscope to collect the surface potential signal of the GIS terminal.

[0118] The first vertical servo motor 161, the second vertical servo motor 162, the first horizontal servo motor 151, and the second horizontal servo motor 152 can be started simultaneously. The first vertical servo motor 161 and the second vertical servo motor 162 drive the first horizontal servo motor 151 and the second horizontal servo motor 152 downwards. The first horizontal servo motor 151 drives the probe drive motor 140 to move to one side (i.e., towards the surface of the GIS epoxy terminal sheath; moving to one side can mean moving diagonally downwards along the surface of the GIS epoxy terminal sheath, or diagonally upwards, which is essentially the same), ensuring the probe is vertical and approximately 3mm away from the surface of the GIS terminal epoxy sheath. This continues until the high-voltage measurement probe 111 has collected the potential distribution information along the entire edge of the GIS terminal.

[0119] The collected potential distribution is converted into a charge distribution form:

[0120] ;

[0121] In the formula, U is the surface potential matrix, which is determined by the output of the electrostatic probe; σ is the surface charge density matrix.

[0122] The above embodiments of this application propose a surface charge measurement device and method for large-size DC GIS terminals. This device and method can measure the surface charge of the epoxy sheath of large-size, large-tapered full-size GIS terminals (existing technologies are limited to samples and scaled-down models). This application can use SF6 gas pressurization and air environment for surface charge attenuation, which is consistent with the actual charge accumulation and distribution characteristics. Furthermore, this application adopts a dual-motor control method to ensure high stability of the mechanism, ensuring that the probe does not shake during motor control of the probe.

[0123] It should be understood that although the steps in the flowcharts of the embodiments described above 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 embodiments described above 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 of other steps.

[0124] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, apparatus, article, or device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or device that includes said element.

[0125] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0126] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surface charge measuring device, characterized in that, The device, used in large gas-insulated switchgear, comprises: The potential acquisition device includes a high-voltage measurement probe and a signal display device; A first support frame is used to support the large gas-insulated switchgear. The first support frame is provided with a housing. The housing has a sealed cavity and an inflation port for inflating the gas-insulated switchgear. The first support frame is also used to pressurize the gas-insulated switchgear when the cavity is inflated and to remove the housing after discharge. The second support frame is equipped with a motor assembly; the motor assembly includes a probe drive motor, a horizontal drive motor assembly, and a vertical drive motor assembly. The probe drive motor, the horizontal drive motor group, and the vertical drive motor group are used to drive the high-voltage measurement probe close to the surface of the gas-insulated switchgear after the housing is removed, so as to realize surface charge measurement.

2. The apparatus according to claim 1, characterized in that, The first support frame is also equipped with a high-voltage DC power supply; the high-voltage DC power supply is electrically connected to the large gas-insulated switchgear and is used to pressurize the large gas-insulated switchgear when it is being filled with gas.

3. The apparatus according to claim 2, characterized in that, The first support frame is also provided with a tail tube, through which the high-voltage DC power supply is connected to the large gas-insulated switchgear; The tailpipe is used to block the leakage of insulating gas in the cavity and prevent the high-voltage electric field from radiating and interfering with the external environment while the high-voltage DC power supply is electrically connected to the device.

4. The apparatus according to claim 1, characterized in that, The horizontal drive motor assembly includes a first horizontal servo motor and a second horizontal servo motor. The first horizontal servo motor and the second horizontal servo motor are symmetrically arranged at both ends of the horizontal guide rail of the two support frames; One end of the probe drive motor is located on the horizontal guide rail, and the other end is equipped with a high-voltage measuring probe; The first horizontal servo motor and the second horizontal servo motor are used to synchronously drive the horizontal movement of the probe drive motor, so as to drive the high voltage measuring probe closer to or away from the surface of the large gas-insulated switchgear.

5. The apparatus according to claim 1, characterized in that, The vertical drive motor assembly includes: The first vertical servo motor is mounted on the first vertical guide rail of the second support frame; The second vertical servo motor is mounted on the first vertical guide rail of the second support frame; The first vertical servo motor and the second vertical servo motor are used to synchronously drive the vertical movement of both ends of the horizontal guide rail, so as to drive the high voltage measuring probe to move vertically on the surface of the large gas-insulated switchgear.

6. The apparatus according to claim 1, characterized in that, The first support frame is equipped with a moving module, which drives the first support frame and the large gas-insulated switchgear to move flexibly on a flat ground.

7. The apparatus according to claim 1, characterized in that, The housing and the first support frame are installed or removed via flanges.

8. The apparatus according to claim 1, characterized in that, The first support frame is also equipped with a displacement sensor, which is used to detect the real-time distance between the high-voltage measuring probe and the surface of the gas-insulated switchgear.

9. The apparatus according to claim 1, characterized in that, The bottom of the first support frame is also provided with a grounding terminal; the grounding terminal is connected to the ground grounding grid through a grounding wire, and the grounding wire is covered with an insulating protective tube.

10. A method for measuring surface charge, characterized in that, The surface charge measuring device according to any one of claims 1-9 is used for measuring the surface charge of large gas-insulated switchgear, the method comprising: Inflate the cavity of the housing provided in the first support frame through the air inlet; The gas-insulated switchgear is pressurized while the cavity is filled with gas, and the housing is removed after discharge and degassing. After pressurizing for a preset time, the gas-insulated switchgear is discharged and the gas is released. After discharging and releasing the gas, the housing is removed; The probe drive motor, horizontal drive motor group, and vertical drive motor group, which are set by the second support frame, allow the high voltage measurement probe of the drive potential acquisition device to approach the surface of the gas-insulated switchgear after the housing is removed, so as to realize surface charge measurement.

Images