Scaling sleeve multi-interface surface charge measuring device based on three-dimensional probe movement

Abstract

The invention relates to a scaling sleeve multi-interface surface charge measuring device based on three-dimensional probe motion, the scaling sleeve multi-interface surface charge measuring device comprises an airtight cavity, a scaling sleeve, a high-voltage power supply unit and a single detection scanning unit, the scaling sleeve is provided with an open end and a closed end, a guide rod is arranged at the center of the scaling sleeve, and the scaling sleeve is arranged in the airtight cavity in a manner of rotating around the axis of the scaling sleeve; the high-voltage power supply unit is positioned outside the airtight cavity and is electrically connected with the guide rod; each detection scanning unit comprises a signal processing module and an electrostatic detection module, the electrostatic detection module can move axially and is used for scanning and detecting the surface potentials of a plurality of gas-solid interfaces under the rotation of the scaling sleeve and feeding back the measured surface potential data to the signal processing module so as to process the measured surface potential data; and calculating surface charge density distribution. Therefore, by using the single electrostatic probe in combination with three-dimensional motion and rotary scanning, the problem that the surface charges of the multi-layer gas-solid interface in the scaling sleeve are difficult to effectively measure in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of high voltage engineering technology, and in particular to a device for measuring surface charge on multi-interfaces of a scaled-down casing based on three-dimensional probe movement. Background Art

[0002] As a traditional energy power, my country has always had a certain imbalance in the distribution of energy and load centers, and UHV DC transmission technology provides an effective means to solve this problem. In UHV transmission projects, DC bushings play a vital role, including valve-side bushings and wall bushings that connect converter transformers and DC transmission lines. In normal operation, DC bushings need to withstand full voltage and current, and are affected by complex environments such as climate factors, power fluctuations and harmonics, which puts severe tests on their insulation, mechanical, thermal and airtightness performance. Although a large safety margin was reserved for DC bushings during the design stage, and its size is significantly larger than that of AC bushings of the same voltage level, DC bushings still often fail in UHV projects implemented at home and abroad, resulting in equipment loss and power outages, thus affecting the safety and stability of the power system. The root cause of these accidents is still unclear, but it shows that there are some factors that have not been fully considered in the design process of DC bushings, which weaken the design safety margin of its insulation performance, which may lead to safety hazards.

[0003] The gas-solid interface charge problem is considered a typical challenge in the field of DC insulation. Under DC voltage, the device is in an electric field in a fixed direction for a long time, and a large amount of charge will accumulate at the junction of different media, resulting in distortion of the electric field. The overall distribution trend of the charge is related to the conductivity of the material, but due to the characteristics of the gas-solid interface, some charges will be unevenly concentrated at the interface junction, resulting in local electric field anomalies. The non-uniform accumulation of local charge is a complex phenomenon, and this local distortion is often difficult to consider in simulation and insulation design, so it is necessary to verify and obtain relevant data through experimental means.

[0004] At present, the surface charge measurement method is often obtained by inversion algorithm through the measured surface potential value. The real DC bushing has a multi-layer insulation structure, which has multiple gas-solid interfaces from the inside to the outside. The internal gas-solid interface includes the capacitor core-SF6 interface and the SF6-epoxy fiberglass tube interface. These two are in a sealed state and cannot be measured from the outside. The external interface is the interface between the epoxy glass tube outside the bushing and the air, which is the only interface that can be measured in the actual bushing. Since the gas-solid interface potential inside the actual bushing cannot be directly measured, the charge distribution on the interface cannot be confirmed. This data loss makes it impossible to effectively analyze the overall multi-layer interface charge distribution, which needs to be solved urgently. Summary of the invention

[0005] The present application provides a method for measuring the surface charge of multiple interfaces of a scaled-down casing based on three-dimensional probe movement, so as to solve the problem in the prior art that it is difficult to effectively measure the surface charge of multiple layers of gas-solid interfaces inside a scaled-down casing. By using a single electrostatic probe combined with three-dimensional motion and rotational scanning, high-precision scanning of the gas-solid interface can be achieved, thereby ensuring the accuracy and reliability of the measurement results.

[0006] The first aspect of the present application provides a device for measuring surface charge on a multi-interface of a scaled-down casing based on three-dimensional probe movement, comprising:

[0007] An airtight cavity, wherein the airtight cavity is used to store experimental gas;

[0008] A reduced sleeve, the reduced sleeve having an open end and a closed end, the reduced sleeve having a plurality of gas-solid interfaces in a radial direction, the center of the reduced sleeve having an axially extending guide rod, and the reduced sleeve being rotatably arranged around its own axis in the airtight cavity;

[0009] A high-voltage power supply unit, the high-voltage power supply unit is located outside the airtight cavity and is electrically connected to the guide rod;

[0010] A single detection scanning unit, the single detection scanning unit includes a signal processing module located outside the airtight cavity and an electrostatic detection module located inside the airtight cavity, the electrostatic detection module is communicatively connected with the signal processing module; the electrostatic detection module is axially movable, and is used to scan and detect the surface potentials of the multiple gas-solid interfaces under the rotation of the scaled sleeve, and feed back the measured surface potential data to the signal processing module, the signal processing module processes the measured surface potential data, and calculates the surface charge density distribution of each gas-solid interface.

[0011] According to one embodiment of the present application, the scaled-down casing multi-interface surface charge measurement device based on three-dimensional probe movement further includes:

[0012] A rotation drive mechanism is disposed in the airtight cavity and connected to the reduced-size sleeve, and is used for driving the reduced-size sleeve to rotate.

[0013] According to one embodiment of the present application, the rotary drive mechanism includes a drive device, an insulating rod and a rotary bearing, wherein:

[0014] The driving device is arranged on the airtight cavity, the driving device is connected to one end of the guide rod through the insulating rod, one end of the guide rod is located at the open end, the other end of the guide rod is located at the closed end and is electrically connected to the high-voltage power supply unit through an outlet bushing and a high-voltage lead, and the outlet bushing passes through the wall of the airtight cavity;

[0015] The rotary bearing is arranged between the guide rod and the outlet sleeve so that the reduced-ratio sleeve can rotate relative to the outlet sleeve.

[0016] According to one embodiment of the present application, the single detection scanning unit further includes:

[0017] A stepping module, wherein the stepping module is arranged in the airtight cavity and is retractable in the axial direction of the reduced sleeve, the electrostatic detection module is installed at the end of the stepping module, and the electrostatic detection module moves axially from the open end to the closed end as the stepping module is extended, and moves axially from the closed end to the open end as the stepping module is shortened.

[0018] According to one embodiment of the present application, the scaled-down casing comprises a guide rod, an epoxy fiberglass tube and an end cover, wherein:

[0019] The epoxy fiberglass cylinder is coaxially and spaced apart outside the guide rod, one end of the epoxy fiberglass cylinder is open and the other end is closed by the end cover, and the other end of the guide rod passes through the end cover and is fixed to the end cover;

[0020] A scaled capacitor core may or may not be provided on the outer peripheral wall of the guide rod;

[0021] The outer peripheral wall of the epoxy glass fiber reinforced plastic cylinder is provided with or without an umbrella skirt.

[0022] According to one embodiment of the present application, the end cap is a conductive end cap or an insulating end cap.

[0023] According to one embodiment of the present application, a uniform electrode is installed on the end cover.

[0024] According to one embodiment of the present application, an observation window is provided on the airtight cavity.

[0025] According to one embodiment of the present application, the scaled-down casing multi-interface surface charge measurement device with three-dimensional probe motion further includes:

[0026] An ion blower is used to eliminate residual surface charges on the multiple gas-solid interfaces on the scaled-down sleeve at the beginning of the experiment.

[0027] According to the multi-interface surface charge measurement device of the scaled casing based on three-dimensional probe movement of the embodiment of the present application, the position of the electrostatic detection module in the single detection scanning unit is adjusted; a preset DC current is applied to the guide rod of the scaled casing, and the gas-solid interface of the scaled casing is scanned by the electrostatic detection module to obtain the first dynamic change data of the scaled casing; the scaled casing is depolarized to obtain the second dynamic change data of the scaled casing; the surface charge density distribution of the scaled casing is obtained according to the first dynamic change data and the second dynamic change data. Thus, the problem that it is difficult to effectively measure the surface charge of the multi-layer gas-solid interface inside the scaled casing in the prior art is solved. By using a single electrostatic probe combined with three-dimensional motion and rotation scanning, high-precision scanning of the gas-solid interface can be achieved, ensuring the accuracy and reliability of the measurement results.

[0028] A second aspect of the present application provides a method for measuring surface charge on multiple interfaces of a scaled-down casing based on three-dimensional probe movement. The method uses a device for measuring surface charge on multiple interfaces of a scaled-down casing based on three-dimensional probe movement. The method comprises the following steps:

[0029] Adjusting the position of the electrostatic detection module in the single detection scanning unit based on a preset safety distance;

[0030] Using the high-voltage power supply unit to apply a preset direct current to the guide rod of the reduced-ratio bushing, and when the duration of applying the preset direct current to the guide rod is greater than a preset duration, stopping applying the preset direct current to the guide rod and grounding the guide rod;

[0031] Utilize the electrostatic detection module in the single detection scanning unit to scan each gas-solid interface of the scaled-down sleeve to obtain a first set of two-dimensional multi-layer surface potential measurement data, and re-execute the step of adjusting the position of the electrostatic detection module in the single detection scanning unit based on a preset safety distance until a preset end condition is reached to obtain multiple sets of two-dimensional multi-layer surface potential measurement data, and obtain first dynamic change data of the surface potential of each gas-solid interface of the scaled-down sleeve during the polarization process based on the multiple sets of two-dimensional multi-layer surface potential measurement data;

[0032] Performing depolarization measurement on the reduced-scale casing based on a preset time interval to obtain second dynamic change data of the surface potential of each gas-solid interface of the reduced-scale casing during the depolarization process;

[0033] The surface charge density distribution of each gas-solid interface of the scaled-down casing is obtained according to the first dynamic change data and the second dynamic change data.

[0034] According to the multi-interface surface charge measurement method of the scaled casing based on three-dimensional probe movement of the embodiment of the present application, the position of the electrostatic detection module in the single detection scanning unit is adjusted; a preset DC current is applied to the guide rod of the scaled casing, and the gas-solid interface of the scaled casing is scanned by the electrostatic detection module to obtain the first dynamic change data of the scaled casing; the scaled casing is depolarized to obtain the second dynamic change data of the scaled casing; the surface charge density distribution of the scaled casing is obtained according to the first dynamic change data and the second dynamic change data. Thus, the problem that it is difficult to effectively measure the surface charge of the multi-layer gas-solid interface inside the scaled casing in the prior art is solved. By using a single electrostatic probe combined with three-dimensional motion and rotation scanning, high-precision scanning of the gas-solid interface can be achieved, ensuring the accuracy and reliability of the measurement results.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1 It is a cross-sectional schematic diagram of a scaled-down casing multi-interface surface charge measurement device based on three-dimensional probe movement according to one embodiment of the present application;

[0038] Figure 2 It is a three-dimensional schematic diagram of a scaled-down casing multi-interface surface charge measurement device based on three-dimensional probe movement according to one embodiment of the present application;

[0039] Figure 3 This is a schematic structural diagram of a reduced-ratio casing according to an embodiment of the present application;

[0040] Figure 4 is a schematic diagram of a three-axis motor control system according to an embodiment of the present application;

[0041] Figure 5 A flow chart of a method for measuring multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement according to an embodiment of the present application;

[0042] Figure 6 The present invention is a flow chart of a method for measuring multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement according to an embodiment of the present application.

[0043] Figure numerals: 1000-scaled sleeve multi-interface surface charge measurement device based on three-dimensional probe movement; 1-airtight cavity; 101-observation window; 2-scaled sleeve; 201-guide rod; 202-scaled capacitor core; 203-epoxy fiberglass cylinder; 204-ground wall; 205-end cover; 3-high-voltage power supply unit; 301-high-voltage lead; 302-outlet sleeve; 4-detection scanning unit; 401-signal processing module; 402-electrostatic detection module; 403-stepping module; 4031-X-axis stepping unit; 4033-Y-axis stepping unit; 4032-Z-axis stepping unit; 404-signal line; 5-rotation drive mechanism; 501-drive device; 502-insulating rod; 503-rotation bearing; 6-ion blower. DETAILED DESCRIPTION

[0044] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0045] It is understandable that the measurement of internal charge is usually performed using multiple electrostatic probes. However, in practice, electrostatic probes are expensive and have few sales channels. It is difficult to use multiple electrostatic probes to measure the potential of multiple interfaces of the casing.

[0046] Based on the problems existing in the prior art, the device for measuring the multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement in the embodiment of the present invention can effectively overcome the problems of complex surface charge accumulation on each interface of the existing casing, the inability to measure the surface charge of each layer of the casing interface through real-type experiments, and the small number of electrostatic probes in actual applications. In particular, only one electrostatic probe is used for the real-type casing to measure the surface potential of the multiple interfaces of the casing. The device and method for measuring the multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement in the embodiment of the present invention can test the surface potential on the multiple interfaces of the scaled-down casing, and use it to infer the distribution of the charges on each interface of the scaled-down casing as a whole, providing a reference for the design theory and structural optimization of the actual engineering casing.

[0047] The following describes a scaled-down casing multi-interface surface charge measurement device based on three-dimensional probe movement according to an embodiment of the present application with reference to the accompanying drawings.

[0048] Specifically, if Figure 1 As shown, a scaled-down sleeve multi-interface surface charge measurement device 1000 based on three-dimensional probe movement according to an embodiment of the present application includes an airtight cavity 1, a scaled-down sleeve 2, a high-voltage power supply unit 3 and a three-axis motor control system detection scanning unit 4.

[0049] Among them, the airtight cavity 1 is used to fill the gas required for the experiment. SF6 insulating gas, other gases required in scientific research, or a mixture of SF6 and other gases can be selected. The gas pressure in the cavity can be set according to the experimental requirements, such as maintaining it at 3 to 4 standard atmospheres. At the same time, the design of the airtight cavity 1 allows experiments to be carried out under high vacuum or higher pressure conditions. To meet different needs, the cavity is equipped with multiple charging and discharging valves, which can withstand a relative pressure of up to 5 atmospheres.

[0050] For ease of observation, Figure 2 As shown, one or more observation windows 101 are provided in the airtight cavity 1 for easy installation and debugging, and a light source can be installed when necessary to improve the internal light. In addition, one end surface of the airtight cavity 1 can be designed to be openable and closable to facilitate the installation and maintenance of the internal device.

[0051] Further, the design of the reduced ratio sleeve 2 follows the structure of the sleeve in the actual project, and is simplified for different situations. One end of the reduced ratio sleeve 2 is open, and the other end is closed, forming an axial structure; radially, the reduced ratio sleeve 2 is provided with multiple gas-solid interfaces from the inside to the outside. The central part is equipped with an axially extending guide rod 201 that can conduct electricity. In addition, the reduced ratio sleeve 2 can rotate freely in the airtight cavity 1 around its own axis. Because the open end of the reduced ratio sleeve 2 enables it to be filled with experimental gas in the airtight cavity 1, therefore, the gas-solid interface inside it (such as between the outer surface of the reduced ratio capacitor core 202 and the inner wall of the epoxy glass fiber reinforced plastic cylinder 203) will also be filled with experimental gas, so that the gas environment inside the reduced ratio sleeve 2 can be guaranteed to be consistent with the gas environment inside the actual engineering sleeve. At the same time, the electrostatic detection module 402 of the detection scanning unit 4 can be extended from the open end to move and measure its surface potential between the gas-solid interface inside the reduced ratio sleeve 2, thereby solving the problem of being difficult to measure the surface potential of the internal gas-solid interface in the actual project. In addition, the reduced-size sleeve 2 will not interfere with the electrostatic detection module 402 of the detection scanning unit 4 extending therein when rotating. Since the reduced-size sleeve 2 has a closed structure, such as being fixed to the epoxy fiberglass cylinder 203 and the guide rod 201 by the end cap 205, the stability of its overall structure is ensured, which helps to achieve smooth rotation.

[0052] exist Figure 1 and Figure 3In some embodiments shown, the reduced-ratio sleeve 2 is composed of a guide rod 201, an epoxy glass fiber reinforced plastic cylinder 203 and an end cap 205. The epoxy glass fiber reinforced plastic cylinder 203 covers the guide rod 201 and achieves a coaxial effect by being arranged at intervals. One end of the epoxy glass fiber reinforced plastic cylinder 203 is open, and the other end is fixed to an inherent end cap 205. The other end of the guide rod 201 passes through the end cap 205 and is connected thereto. A reduced-ratio capacitor core 202 can be selectively arranged on the outer peripheral wall of the guide rod 201, and the reduced-ratio capacitor core is made of epoxy impregnated paper and aluminum foil. Umbrella skirts can also be selectively arranged on the outer wall of the epoxy glass fiber reinforced plastic cylinder. The end cap 205 can be designed as a conductive end cap or an insulating end cap in different embodiments to regulate the electric field distribution, or by attaching a uniform electrode to the end cap to enhance the uniformity of the electric field.

[0053] In some embodiments, the high-voltage power supply unit 3 is located outside the airtight cavity 1 and is electrically connected to the guide rod 201, and is used to apply a DC voltage to the guide rod 201 and maintain it for the time required for the experiment to complete the polarization process of the surface charge of each gas-solid interface of the scaled-down casing 2.

[0054] In some embodiments, a single detection scanning unit 4 is composed of a signal processing module 401 located outside the airtight cavity 1 and an electrostatic detection module 402 located inside the cavity, and the electrostatic detection module 402 is connected to the signal processing module 401 by communication. The electrostatic detection module 402 of the single detection scanning unit 4 can perform three-axis motion through a three-axis motor control system, so that when the reduced ratio sleeve 2 rotates, only one electrostatic probe is used to perform interpolation motion to scan and detect the surface potential of multiple gas-solid interfaces one by one, and the measured data is fed back to the signal processing module 401, and the signal processing module 401 will process these data to calculate the surface charge density distribution. Before applying a DC voltage to the guide rod 201, it is necessary to first move the electrostatic detection module 402 in three axes to ensure that it is away from the reduced ratio sleeve 2 to maintain a safe distance. In this way, the safety of the electrostatic detection module 402 can be guaranteed when the high-voltage power supply unit 3 applies a DC voltage to the guide rod 201. When the high-voltage power supply unit 3 applies a DC voltage to the guide rod and maintains the required experimental time, the guide rod 201 will remove the DC voltage and be grounded, and a constant electric field will be generated around the reduced sleeve 2. Subsequently, the electrostatic detection module 402 will move axially to the corresponding gas-solid interface for measurement. During the measurement process, the electrostatic detection module 402 will move to the measurement area in three axes in sequence, while ensuring that the same spacing is maintained between the gas-solid interface to be measured, and the reduced sleeve 2 is rotated at the same time. In this way, the electrostatic detection module 402 will operate in a constant electric field, apply a sinusoidal displacement to the gas-solid interface to be measured, thereby inducing a sinusoidally changing charge, forming a current, and feeding it back to the corresponding signal processing module 401. Each signal processing module 401 will process the surface potential data obtained, thereby calculating the surface charge density distribution of each gas-solid interface of the reduced sleeve 2.

[0055] Furthermore, in some embodiments, the single detection and scanning unit 4 further includes a stepping module 403, which is located in the airtight cavity 1 and can perform three-dimensional movement on the reduced-scale sleeve 2 to achieve the entire scanning of the sleeve. The end of the stepping module 403 is equipped with an electrostatic detection module 402, which can move axially from the open end to the closed end as the stepping module 403 is extended, and at the same time, when the stepping module 403 is shortened, it moves from the closed end to the open end.

[0056] Specifically, Figure 1 and Figure 4 As shown, the stepping module 403 is installed in the airtight cavity 1, and can move the entire space around the scaled sleeve 2. The end of the stepping module 403 is connected to the electrostatic detection module 402. When the stepping module 403 is extended, the electrostatic detection module 402 moves toward the closed end; when the stepping module 403 including the Z-axis stepping unit 4032, the X-axis stepping unit 4031 and the Y-axis stepping unit 4033 shrinks, the electrostatic detection module 402 moves toward the open end. During the measurement process, the Z-axis stepping unit 4032 is used to move up and down, the X-axis stepping unit 4031 is axially extended, and the Y-axis stepping unit 4033 is moved in the left and right directions. The signal processing module 401 is located outside the airtight cavity 1 and is connected to the electrostatic detection module 402 through the signal line 404. The stepper module 403 is designed to move with an electrostatic probe in three axes, and can perform three-dimensional measurement on the scaled sleeve 2. One end of the stepper module 403 is mounted on the end wall of the airtight cavity 1, and the end is provided with a mounting slot for fixing the insulating component and installing the electrostatic detection module 402. The electrostatic detection module 402 can select a probe without power supply or with feedback power supply, which is suitable for different surface shapes and potential requirements.

[0057] Specifically, a constant electric field is generated around the reduced-scale casing 2, which enables the electrostatic detection module 402 to operate in the electric field. When the electrostatic detection module 402 undergoes a sinusoidal displacement relative to the gas-solid interface to be measured, the capacitance between the electrostatic detection module 402 and the gas-solid interface will change accordingly, causing the induced charge to change in a sinusoidal form. This process converts the DC charge signal into a sinusoidal current that changes with time, achieving the purpose of measurement.

[0058] Furthermore, in some embodiments, Figure 1 As shown, the scaled-down sleeve multi-interface surface charge measurement device 1000 based on three-dimensional probe movement also includes a rotation drive mechanism 5, which is installed in the airtight cavity 1 and connected to the scaled-down sleeve 2, and is used to drive the measured object to rotate around the center of the central guide rod, that is, to drive the scaled-down sleeve 2 to perform rotational motion. In other words, the rotation of the scaled-down sleeve 2 is realized by the rotation drive mechanism 5.

[0059] Specifically, if Figure 1As shown, the rotary drive mechanism 5 is composed of a drive device 501, an insulating rod 502 and a rotary bearing 503. The drive device 501 is used as a power source, usually an electric motor, which is installed on the end wall of the airtight cavity 1 and is located on the opposite side of the open end of the cavity to provide rotational power. The drive device 501 is connected to the guide rod 201 located at the open end through the insulating rod 502. The insulating rod 502 is used to isolate the DC voltage between the drive device 501 and the guide rod 201 to ensure safe insulation and guarantee the normal operation of the drive device 501. The other end of the guide rod 201 is connected to the closed end, and is connected to the high-voltage lead 301 through the outlet bushing 302, thereby connecting to the high-voltage power supply unit 3 outside the airtight cavity 1. The outlet bushing 302 is located at the closed end of the airtight cavity 1 and passes through the wall of the airtight cavity 1. It has the function of transmitting DC voltage and maintaining airtight performance. In addition, the rotary bearing 503 is disposed between the guide rod 201 and the outlet sleeve 302, which can ensure electrical connection and realize smooth rotation of the reduced-size sleeve 2 relative to the outlet sleeve 302. Therefore, the driving device 501 can realize rotational driving of the reduced-size sleeve 2.

[0060] In some experimental scenarios, the present application also adds an ion fan 6, such as Figure 1 As shown. The ion blower 6 is located near the scaled sleeve 2 and is used to remove the residual surface charges at multiple gas-solid interfaces on the scaled sleeve 2 before each experiment. A grounding grid and a high-voltage electrode needle tip are provided at the front end of the blower to generate a large number of positive and negative ions; a blower is provided behind the grounding grid and the electrode needle tip to blow the generated ions to the gas-solid interface to neutralize the residual charges thereon.

[0061] Therefore, the scaled-down casing multi-interface surface charge measurement device 1000 based on three-dimensional probe movement proposed in the present application has the following advantages: first, it can measure the surface potential of the gas-solid interface inside and outside the scaled-down casing; second, it can provide basic research for the surface charge of each gas-solid interface of the actual engineering casing corresponding to the scaled-down casing structure; third, through the coordination of the three-dimensional movement of the only electrostatic detection module and the rotational movement of the scaled-down casing, multi-layer two-dimensional measurement data can be obtained, and the surface potential at any position of any gas-solid interface of the scaled-down casing can be measured.

[0062] The following introduces the method for measuring the multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement proposed in this application. The method adopts the above-mentioned device 1000 for measuring the multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement.

[0063] Specifically, Figure 5 A schematic flow chart of a method for measuring multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement provided in an embodiment of the present application.

[0064] like Figure 5As shown, the method for measuring surface charge on multi-interfaces of a scaled-down casing based on three-dimensional probe movement comprises the following steps:

[0065] In step S701 , the position of the static electricity detection module 402 in the single detection scanning unit 4 is adjusted based on a preset safety distance.

[0066] The preset safety distance may be a safety distance pre-set by a person skilled in the art, and is not specifically limited here.

[0067] Specifically, the position of the electrostatic detection module 402 is adjusted to ensure that a preset safety interval is maintained between it and the reduced sleeve 2, thereby preventing the high-voltage power supply unit 3 from damaging the electrostatic detection module 402 when pressurizing the guide rod 201.

[0068] Furthermore, in some embodiments, before adjusting the position of the electrostatic detection module 402 in the detection scanning unit 4 based on the preset safety distance, it also includes: using the ion blower 6 to clear the surface charge of each gas-solid interface of the scaled sleeve 2, and injecting the target gas into the airtight cavity 1 based on the current measurement requirements.

[0069] The target gas may be SF6 insulating gas, other gases, or a mixture of SF6 insulating gas and other gases, which is not specifically limited herein.

[0070] Specifically, before measuring the multi-interface surface charge of the scaled sleeve, it is necessary to eliminate the surface charge of the gas-solid interface of the scaled sleeve 2. The specific operation can be: the surface charge of each gas-solid interface of the scaled sleeve 2 is cleared by the ion blower 6, and then the components of the scaled sleeve multi-interface surface charge measurement device 1000 based on the three-dimensional probe movement are installed, the rotation drive mechanism 5 and the high-voltage power supply unit 3 are connected, and the airtight cavity 1 is closed, the cavity is evacuated to exhaust the air, and the target gas is injected into the airtight cavity 1. It should be noted that the gas in the cavity needs to be kept at the pressure required for the experiment to ensure the stability of the test environment.

[0071] In step S702, a preset DC current is applied to the guide rod 201 of the reduced-size bushing 2 using the high-voltage power supply unit 3, and when the duration of applying the preset DC current to the guide rod 201 is greater than the preset duration, the application of the preset DC current to the guide rod 201 is stopped, and the guide rod 201 is grounded.

[0072] The preset DC current may be a DC current preset by a person skilled in the art, and the preset duration may be a duration preset by a person skilled in the art, which are not specifically limited here.

[0073] Optionally, in the embodiment of the present application, the duration of applying a preset direct current to the guide rod 201 can be obtained by a timer, which is not specifically limited here.

[0074] Specifically, the required preset DC voltage is applied to the guide rod 201 through the high-voltage power supply unit 3 and maintained for a preset time to complete the surface charge polarization of the gas-solid interface. After the polarization process is completed, the DC voltage is disconnected and the guide rod 201 is grounded to form a stable DC electric field around the reduced sleeve 2.

[0075] In step S703, the electrostatic detection module 402 in the single detection scanning unit 4 is used to scan each gas-solid interface of the scaled-down sleeve 2 to obtain a first set of two-dimensional multi-layer surface potential measurement data, and the step of adjusting the position of the electrostatic detection module 402 in the single detection scanning unit 4 based on the preset safety distance is re-executed until the preset end condition is reached to obtain multiple sets of two-dimensional multi-layer surface potential measurement data, and the first dynamic change data of the surface potential of each gas-solid interface of the scaled-down sleeve 2 during the polarization process is obtained based on the multiple sets of two-dimensional multi-layer surface potential measurement data.

[0076] Specifically, after stopping applying the preset DC current to the guide rod 201 and grounding the guide rod 201, the electrostatic detection module 402 of the single detection scanning unit 4 is successively moved close to each gas-solid interface of the reduced-scale casing 2. Then, the electrostatic detection module 402 is moved along the first measurement starting area under three-axis control, and the reduced-scale casing 2 is driven to rotate at the same time, so that each electrostatic detection module 402 performs axial and circumferential scanning on the gas-solid interface, and records multi-layer two-dimensional surface potential measurement data. Due to the long depolarization time, the scanning is started immediately after stopping applying the preset DC current to the guide rod 201 and grounding the guide rod 201, and the first set of two-dimensional multi-layer surface potential measurement data after polarization is obtained.

[0077] In detail, the embodiment of the present application enables the electrostatic detection module 402 of the detection scanning unit 4 to first approach the capacitor core 202 of the scaled sleeve 2 for measurement, and then simultaneously enables each electrostatic detection module 402 to move axially and the scaled sleeve 2 to rotate to form an interpolation motion. After the measurement of the capacitor core is completed, the electrostatic detection module 402 is moved out from the inside and moved to the inside of the epoxy fiberglass cylinder 203 to perform surface charge measurement in the same manner as the capacitor core measurement. The measurement method for the outer wall of the epoxy fiberglass cylinder 203 is the same as described above. This measurement enables a single electrostatic detection module 402 to complete axial and circumferential scanning at different gas-solid interfaces to form two-dimensional multi-layer surface potential measurement data.

[0078] Furthermore, steps S701 and S702 are repeatedly executed, as well as the step of using the electrostatic detection module 402 in a single detection scanning unit 4 to scan each gas-solid interface of the scaled-down casing 2, to obtain multiple sets of two-dimensional multi-layer surface potential measurement data, so as to obtain the surface potential change data of each interface of the scaled-down casing 2 over time during the polarization process according to the multiple sets of two-dimensional multi-layer surface potential measurement data, thereby obtaining the two-dimensional surface potential information of multiple polarization processes, i.e., the first dynamic change data.

[0079] Furthermore, in some embodiments, the electrostatic detection module 402 in a single detection scanning unit 4 is used to scan each gas-solid interface of the scaled-down sleeve 2 to obtain multiple two-dimensional multi-layer surface potential measurement data, including: controlling the electrostatic detection module 402 in the single detection scanning unit 4 to move axially to each target measurement area, and controlling the scaled-down sleeve 2 to rotate to scan each gas-solid interface until multiple two-dimensional multi-layer surface potential measurement data are obtained.

[0080] Specifically, the measurement scanning process of the embodiment of the present application is completed by a set of four-axis motion control systems. When it is necessary to measure the surface potential of the inner core of the casing and the inner wall of the epoxy glass tube, the high voltage power supply is disconnected, and then the X-axis and Y-axis motors are moved, and the Y-axis motor carries the electrostatic probe to move to the specified measurement area; the Z-axis adjusts the height to align the probe with the measurement surface; then the probe is moved to the specified measurement area using the software based on labview under the action of the X-axis, and the surface of the capacitor core is measured axially inward; while the probe moves axially, the scaled casing rotates cooperatively under the drive of the T-axis motor to form an interpolation motion, thereby completing the surface potential measurement of the inner core of the casing with a spiral trajectory. After the measurement of the inner core of the casing is completed, the X-axis carries the probe out of the inside of the scaled casing, and the probe is moved under the Y-axis and Z-axis using the software based on labview, and moves to the starting point of measuring the surface potential of the inner wall of the epoxy glass tube. The surface potential measurement method of the inner wall of the epoxy glass tube is the same as the capacitor core measurement method except for the measurement range.

[0081] Furthermore, the rotary drive mechanism 5 performs a specific rotation operation during the scanning process: every time it rotates 360 degrees, the electrostatic detection module 402 moves forward one step, then rotates in the opposite direction, and moves forward again. After the measurement is completed, it moves to the initial position and moves to the next measurement starting area using a set program. In this way, the measurement is continued until the scanning of all gas-solid interfaces is completed, thereby obtaining multiple two-dimensional multi-layer surface potential measurement data.

[0082] In step S704, depolarization measurement is performed on the reduced-scale casing based on a preset time interval to obtain second dynamic change data of the surface potential of each gas-solid interface of the reduced-scale casing during the depolarization process.

[0083] Further, in some embodiments, depolarization measurement is performed on the scaled-down casing 2 based on a preset time interval to obtain second dynamic change data of the surface potential of each gas-solid interface of the scaled-down casing 2 during the depolarization process, including: based on the preset time interval, using the electrostatic detection module 402 in a single detection scanning unit 4 to scan each gas-solid interface of the scaled-down casing 2 to obtain second dynamic change data of the surface potential of each gas-solid interface of the scaled-down casing 2 during the depolarization process.

[0084] It can be understood that the embodiments of the present application take into account the long depolarization time and need to gradually obtain the surface potential change information of each interface during the depolarization process through timed measurement, wherein the preset time interval can be a time interval pre-set by a technician in the field and is not specifically limited here.

[0085] It should be noted that after the polarization process data collection is completed, the surface potential change data during the depolarization process is obtained periodically according to the method of step S703 based on a preset time interval.

[0086] Specifically, after the polarization process data collection is completed, the electrostatic detection module 402 of the detection scanning unit 4 is successively moved close to each gas-solid interface of the reduced-scale casing 2. Then, the electrostatic detection module 402 is moved along the first measurement starting area under three-axis control, and the reduced-scale casing 2 is driven to rotate at the same time, so that each electrostatic detection module 402 performs axial and circumferential scanning on the gas-solid interface, and obtains the second dynamic change data of the surface potential of each gas-solid interface of the reduced-scale casing 2 during the depolarization process.

[0087] In step S705, the surface charge density distribution of each gas-solid interface of the scaled-down casing is obtained according to the first dynamic change data and the second dynamic change data.

[0088] Specifically, the embodiment of the present application can infer the change of the surface charge of each interface of the scaled-down casing 2 based on the first dynamic change data and the second dynamic change data obtained, and further obtain the surface charge density distribution of the gas-solid interface.

[0089] Therefore, according to the multi-interface surface charge measurement method of the scaled-down casing based on three-dimensional probe movement of the embodiment of the present application, the surface charge of each gas-solid interface of the scaled-down casing 2 is measured by applying the multi-interface surface charge measurement device 1000 of the scaled-down casing based on three-dimensional probe movement, which has the following advantages: First, this method can effectively measure the surface charge of the gas-solid interface inside and outside the scaled-down casing 2 through four-axis movement with only one electrostatic probe, thereby realizing all-round data collection and solving the problem of shortage of electrostatic probes; secondly, this measurement method can provide a powerful basic research tool for the surface charge measurement of each gas-solid interface of the engineering casing with a structure similar to the scaled-down casing 2 in actual engineering; in addition, through the axial movement of the electrostatic detection module 402 and the rotation of the scaled-down casing 2, multiple layers of two-dimensional measurement data can be generated, so that the surface potential information can be obtained at any gas-solid interface position of the scaled-down casing 2.

[0090] In order to facilitate those skilled in the art to more clearly and intuitively understand the multi-interface surface charge measurement method of the scaled-down casing based on three-dimensional probe movement in the embodiment of the present application, the following is combined with Figure 6 Provide detailed explanation.

[0091] like Figure 6 As shown, the method for measuring multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement comprises the following steps:

[0092] S801, after eliminating the surface charges of each gas-solid interface of the scaled-down casing 2, various components of the scaled-down casing multi-interface surface charge measuring device 1000 based on three-dimensional probe movement of the scaled-down casing are installed.

[0093] S802, filling the airtight cavity 1 with the required experimental gas.

[0094] S803, move and adjust the position of the electrostatic detection module 402 so that an appropriate safety distance is maintained between the electrostatic detection module 402 and the reduced-size sleeve 2.

[0095] S804, adjusting the high-voltage power supply unit 3, applying a DC voltage to the guide rod 201 using the high-voltage power supply unit 3 and maintaining it for a required time, then removing the DC voltage and grounding the guide rod 201.

[0096] S805, after completing step S804, the electrostatic detection module 402 is sequentially approached to and measures each gas-solid interface of the reduced-scale casing 2. The measurement process is that the electrostatic detection module 402 moves axially while rotating the reduced-scale casing 2, so that the electrostatic detection module 402 completes the axial and circumferential scanning of the gas-solid interface, and finally generates two-dimensional multi-layer surface potential measurement data.

[0097] S806, repeating steps S803 to S805, to obtain dynamic change data of surface potentials of each interface of the reduced-scale casing 2 during the polarization process.

[0098] S807, after the polarization data collection is completed, repeat step S805 at intervals to perform depolarization measurement to obtain data on the surface potential changes of each interface of the reduced-scale casing during the depolarization process.

[0099] S808, invert and calculate the surface charge change of each interface of the scaled-down casing according to the acquired data.

[0100] According to the multi-interface surface charge measurement method of the scaled casing based on three-dimensional probe movement of the embodiment of the present application, the position of the electrostatic detection module in the single detection scanning unit is adjusted; a preset DC current is applied to the guide rod of the scaled casing, and the gas-solid interface of the scaled casing is scanned by the electrostatic detection module to obtain the first dynamic change data of the scaled casing; the scaled casing is depolarized to obtain the second dynamic change data of the scaled casing; the surface charge density distribution of the scaled casing is obtained according to the first dynamic change data and the second dynamic change data. Thus, the problem that it is difficult to effectively measure the surface charge of the multi-layer gas-solid interface inside the scaled casing in the prior art is solved. By using a single electrostatic probe combined with three-dimensional motion and rotation scanning, high-precision scanning of the gas-solid interface can be achieved, ensuring the accuracy and reliability of the measurement results.

[0101] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0102] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0103] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A scaled-down casing multi-interface surface charge measurement device based on three-dimensional probe movement, characterized in that: include: An airtight cavity, wherein the airtight cavity is used to store experimental gas; A reduced sleeve, the reduced sleeve having an open end and a closed end, the reduced sleeve having a plurality of gas-solid interfaces in a radial direction, the center of the reduced sleeve having an axially extending guide rod, and the reduced sleeve being rotatably arranged around its own axis in the airtight cavity; A high-voltage power supply unit, the high-voltage power supply unit is located outside the airtight cavity and is electrically connected to the guide rod; A single detection scanning unit, the single detection scanning unit comprising a signal processing module located outside the airtight cavity and an electrostatic detection module located inside the airtight cavity, the electrostatic detection module being communicatively connected with the signal processing module; The electrostatic detection module can move axially to scan and detect the surface potentials of the multiple gas-solid interfaces as the reduced sleeve rotates, and feeds the measured surface potential data back to the signal processing module. The signal processing module processes the measured surface potential data to calculate the surface charge density distribution of each gas-solid interface.

2. The device for measuring surface charge on a multi-interface of a scaled-down casing based on three-dimensional probe movement according to claim 1 is characterized in that: Also includes: A rotation drive mechanism is disposed in the airtight cavity and connected to the reduced-size sleeve, and is used for driving the reduced-size sleeve to rotate.

3. The device for measuring surface charge on a multi-interface of a scaled-down casing based on three-dimensional probe movement according to claim 2 is characterized in that: The rotary drive mechanism comprises a drive device, an insulating rod and a rotary bearing, wherein: The driving device is arranged on the airtight cavity, the driving device is connected to one end of the guide rod through the insulating rod, one end of the guide rod is located at the open end, the other end of the guide rod is located at the closed end and is electrically connected to the high-voltage power supply unit through an outlet bushing and a high-voltage lead, and the outlet bushing passes through the wall of the airtight cavity; The rotary bearing is arranged between the guide rod and the outlet sleeve so that the reduced-ratio sleeve can rotate relative to the outlet sleeve.

4. The device for measuring surface charge on a multi-interface of a scaled-down casing based on three-dimensional probe movement according to claim 1 is characterized in that: The single detection scanning unit further includes: A stepping module, wherein the stepping module is arranged in the airtight cavity and is retractable in the axial direction of the reduced sleeve, the electrostatic detection module is installed at the end of the stepping module, and the electrostatic detection module moves axially from the open end to the closed end as the stepping module is extended, and moves axially from the closed end to the open end as the stepping module is shortened.

5. The device for measuring surface charge on a multi-interface of a scaled-down casing based on three-dimensional probe movement according to claim 1, characterized in that: The reduced-ratio casing comprises a guide rod, an epoxy glass fiber reinforced plastic cylinder and an end cover, wherein: The epoxy fiberglass cylinder is coaxially and spaced apart outside the guide rod, one end of the epoxy fiberglass cylinder is open and the other end is closed by the end cover, and the other end of the guide rod passes through the end cover and is fixed to the end cover; A scaled capacitor core may or may not be provided on the outer peripheral wall of the guide rod; The outer peripheral wall of the epoxy glass fiber reinforced plastic cylinder is provided with or without an umbrella skirt.

6. The device for measuring surface charge on multi-interfaces of a scaled-down casing based on three-dimensional probe movement according to claim 5 is characterized in that: The end cap is a conductive end cap or an insulating end cap.

7. The device for measuring surface charge on multi-interfaces of a scaled-down casing based on three-dimensional probe movement according to claim 5 is characterized in that: The end cover is additionally provided with a uniform electrode.

8. The device for measuring surface charge on multi-interfaces of a scaled-down casing based on three-dimensional probe movement according to any one of claims 1 to 7, characterized in that: An observation window is arranged on the airtight cavity.

9. The device for measuring surface charge on multi-interfaces of a scaled-down casing based on three-dimensional probe movement according to any one of claims 1 to 7, characterized in that: Also includes: An ion blower is used to eliminate residual surface charges on the multiple gas-solid interfaces on the scaled-down sleeve at the beginning of the experiment.

10. A method for measuring multi-interface surface charge of a scaled-down casing based on three-dimensional probe movement, characterized in that: Using the multi-interface surface charge measurement device for a reduced-ratio casing as claimed in any one of claims 1 to 9, the method comprises the following steps: Adjusting the position of the electrostatic detection module in the single detection scanning unit based on a preset safety distance; Using the high-voltage power supply unit to apply a preset direct current to the guide rod of the reduced-ratio bushing, and when the duration of applying the preset direct current to the guide rod is greater than a preset duration, stopping applying the preset direct current to the guide rod and grounding the guide rod; Utilize the electrostatic detection module in the single detection scanning unit to scan each gas-solid interface of the scaled-down sleeve to obtain a first set of two-dimensional multi-layer surface potential measurement data, and re-execute the step of adjusting the position of the electrostatic detection module in the single detection scanning unit based on a preset safety distance until a preset end condition is reached to obtain multiple sets of two-dimensional multi-layer surface potential measurement data, and obtain first dynamic change data of the surface potential of each gas-solid interface of the scaled-down sleeve during the polarization process based on the multiple sets of two-dimensional multi-layer surface potential measurement data; Performing depolarization measurement on the reduced-scale casing based on a preset time interval to obtain second dynamic change data of the surface potential of each gas-solid interface of the reduced-scale casing during the depolarization process; The surface charge density distribution of each gas-solid interface of the scaled-down casing is obtained according to the first dynamic change data and the second dynamic change data.

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