Non-contact wire icicle corona wind and leakage current measuring device and method

Abstract

The invention discloses a non-contact wire ice edge corona wind and leakage current measuring device and method, and relates to the field of corona wind and leakage current measurement. An icicle is fixed at the geometric center of the wire; the measuring assembly is used for detecting corona wind and leakage current generated by the wire; the automatic lifting platform is used for controlling the vertical distance between the measuring assembly and the icicle; the invention provides the non-contact comprehensive measuring device for the first time, the corona wind speed and the leakage current can be synchronously measured, the discharge phenomenon can be observed in real time, the technical blank is filled, and the measuring device is high in practicability and high in practicability. Through the transparent acrylic shell, the tip discharge phenomenon of the icicle can be directly observed, real-time recording of the discharge form in the experiment process is facilitated, the shell fixes a wire at the geometric center, it is ensured that the icicle is vertically downward, uneven field intensity distribution is avoided, and a stable electric field environment is provided for measurement.

Description

Technical Field

[0001] The invention relates to the field of corona wind and leakage current measurement, in particular to a non-contact conductor ice spike corona wind and leakage current measurement device and method. Background Art

[0002] my country's ultra-high and ultra-high voltage (UHV) power grids have entered a new phase of large-scale construction. These UHV transmission lines, many of which traverse high-altitude regions, are subject to severe conductor icing, threatening their safe and reliable operation. UHV transmission lines have high surface field strengths, and icing on live conductors is influenced by a variety of factors, including the corona wind generated by ice spikes at the conductor tips, which is a significant factor.

[0003] On ultra-high voltage transmission lines, the corona wind generated by the charged tips of icicles can affect the subsequent icing process. To more accurately characterize and study the wet growth rime icing process on conductors, it is necessary to measure the wind speed and leakage current of the icicle corona wind. However, currently, there is no dedicated device for measuring the icicle corona wind and leakage current on conductors.

[0004] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means to solve them. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is: by simulating the electric field strength of the actual conductor ice spike surface, experimentally measuring the corona wind and leakage current of the conductor ice spike under different field strengths and being able to observe the discharge phenomenon at the tip of the ice spike in real time, the parameters such as the corona wind and leakage current of the ice spike under different conditions are obtained. Based on this, the shape and growth law of ice coverage are predicted, further providing a scientific basis and technical support for the anti-icing design of transmission lines, ice coverage status prediction, and line operation and maintenance.

[0006] The above technical problem is solved by the following technical solution: The present invention provides a non-contact conductor ice spike corona wind and leakage current measuring device and method, which includes a housing;

[0007] A conductor, the geometric center of which is fixed with an ice ridge;

[0008] A measuring component, used for detecting corona wind and leakage current generated by the conductor;

[0009] An automatic lifting platform, used to control the vertical distance between the measuring assembly and the ice ridge;

[0010] The housing fixes the conductor, the automatic lifting platform adjusts the distance between the measuring component and the conductor, and the measuring component measures the corona wind and leakage current generated by the conductor.

[0011] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method of the present invention: the housing is composed of six plates spliced ​​together, which includes:

[0012] Removable upper cover;

[0013] Side panels with concave support plates.

[0014] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method of the present invention: the concave support plate is provided with a central groove structure for keeping the ice spike extending vertically downward, and the conductor axis coincides with the central axis of the shell.

[0015] In a preferred embodiment of the non-contact wire ice spike corona wind and leakage current measuring device and method of the present invention: the length of the wire is greater than the width of the shell and is fixed at the geometric center by a groove.

[0016] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method of the present invention: the measuring component includes:

[0017] A shielding net is fixedly connected to the automatic lifting platform via a connecting plate;

[0018] The insulating plate is located on the automatic lifting platform.

[0019] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method of the present invention: the shielding mesh is a stretched and flat copper mesh, which is kept in a horizontal state by a connecting plate and then grounded to form zero potential.

[0020] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method of the present invention, the measuring component further includes:

[0021] a thermal anemometer, mounted on the insulating board and connected to the shielding net;

[0022] The probe of the thermal anemometer is 5-15 mm away from the lower surface of the shielding net, and the axis of the probe is vertically aligned with the tip of the ice spike.

[0023] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method of the present invention, the measuring component further includes:

[0024] A control unit box is used to drive the automatic lifting platform to achieve height adjustment. The control unit box is used to drive the automatic lifting platform to achieve height adjustment. The control unit box is connected to the shielding net through a communication cable, and the thermal anemometer is connected to the control unit box through the communication cable.

[0025] In a preferred embodiment of the non-contact conductor ice spike corona wind and leakage current measuring device and method described in the present invention: the lifting stroke range of the automatic lifting platform covers 20-100 cm, the displacement resolution reaches 0.1 mm, and the field strength distribution is adjusted by changing the distance between the ice spike tip and the shielding net.

[0026] The technical solution also includes the non-contact conductor ice spike corona wind and leakage current measurement method: test sample preparation: controlling the temperature, humidity and wind speed conditions in an artificial climate chamber, synchronously covering multiple conductors with ice to form ice spikes, measuring the length of the ice spikes and retaining only the longest ice spike to form a single ice spike conductor;

[0027] Device assembly: fix the wire to the housing, adjust the ice spike to point vertically downward, connect the step-up transformer and the DC power supply, ground the shielding net, and adjust the distance between the ice spike tip and the shielding net by driving the lifting platform with a motor;

[0028] Corona parameter acquisition: applying voltage to the conductors in stages, adjusting the spacing simultaneously, recording the leakage current value at each voltage level and the dynamic image of the corona wind captured by a high-speed camera;

[0029] Regularity modeling: Based on the measured data in step S, the wire diameter, ice spike length and spacing parameters are set in the finite element simulation software, the electric field intensity distribution at the ice spike tip is calculated, and a voltage and field intensity correlation model is established.

[0030] The beneficial effects of the present invention are: the present invention proposes for the first time a non-contact comprehensive measuring device, which can synchronously measure the corona wind speed and leakage current, and observe the discharge phenomenon in real time, filling the technical gap. Through the transparent acrylic shell (six-piece splicing structure, the upper cover is detachable), the discharge phenomenon at the tip of the ice spike can be directly observed, which is convenient for real-time recording of the discharge morphology during the experiment. The shell fixes the wire at the geometric center to ensure that the ice spike is vertically downward, avoid uneven field strength distribution, and provide a stable electric field environment for measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Among them:

[0032] Figure 1 The overall schematic diagram of the non-contact conductor ice spike corona wind and leakage current measurement device is shown;

[0033] Figure 2 A front view of a non-contact conductor ice spike corona wind and leakage current measuring device is shown;

[0034] Figure 3A front view of a thermal anemometer of a non-contact wire ice spike corona wind and leakage current measuring device is shown;

[0035] Figure 4 A system diagram showing a control unit box for a non-contact wire ice spike corona wind and leakage current measuring device.

[0036] In the picture:

[0037] 1. Outer casing; 11. Removable upper cover; 12. Concave support plate; 2. Measuring assembly; 21. Shielding net; 22. Insulation plate; 23. Thermal anemometer; 24. Control unit box; 25. Communication cable; 26. Connecting plate; 3. Wire; 4. Ice spike; 5. Automatic lifting platform. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0039] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0040] Reference Figures 1 to 4 This embodiment provides a non-contact conductor ice spike corona wind and leakage current measuring device, including a housing 1; a conductor 3, at the geometric center of which is fixed an ice spike 4; a measuring component 2 for detecting the corona wind and leakage current generated by the conductor 3; an automatic lifting platform 5 for controlling the vertical distance between the measuring component 2 and the ice spike 4; the housing 1 fixes the conductor 3, the automatic lifting platform 5 adjusts the distance between the measuring component 2 and the conductor 3, and the measuring component 2 measures the corona wind and leakage current generated by the conductor 3.

[0041] Furthermore, the housing 1 is composed of six panels, including a removable upper cover 11 and side panels with concave support plates 12. The housing 1 is made of transparent acrylic, which facilitates observation of the discharge phenomenon at the tip of the ice prism 4.

[0042] The concave support plate is provided with a central groove structure for keeping the ice ridge 4 extending vertically downward, and the axis of the wire 3 coincides with the central axis of the shell 1. The length of the wire 3 is greater than the width of the shell 1 and is fixed at the geometric center by the groove.

[0043] The measuring component 2 includes a shielding net 21, which is fixedly connected to the automatic lifting platform 5 through a connecting plate 26; an insulating plate 22, which is located on the automatic lifting platform 5; the shielding net 21 is horizontally fixed on the insulating plate 22 through the connecting plate 26. The shielding net 21 is a stretched and flat copper net, which is kept horizontal by the connecting plate 26 and then grounded to form zero potential.

[0044] The measuring component 2 also includes: a thermal anemometer 23, which is installed on the insulating board 22 and connected to the shielding net 21; the probe of the thermal anemometer 23 is 5-15 mm away from the lower surface of the shielding net 21, and the axis of the probe is vertically aligned with the tip of the ice ridge 4. The control unit box 24 is used to drive the automatic lifting platform 5 to achieve height adjustment. The lifting stroke range of the automatic lifting platform 5 covers 20-100 cm, and the displacement resolution reaches 0.1 mm. The field strength distribution is adjusted by changing the distance between the tip of the ice ridge 4 and the shielding net 21.

[0045] Among them, the size of the shell 1 is 300*300*400mm. The shell 1 is made of six transparent acrylic plates. The upper cover is removable to facilitate the placement and installation of the wire 3 with ice spikes 4. The other five acrylic plates are fixed with adhesives and screws and nuts and cannot be removed.

[0046] Specifically, the two concave support plates are designed with a central groove design to fix the wire 3 at the geometric center of the device. The length of the wire 3 needs to be greater than the width of the outer shell 1 to facilitate overlapping with the outer shell 1, while keeping the ice ridges 4 vertically downward to ensure a stable distribution of the internal field strength.

[0047] Furthermore, the wire 3 is connected to an external step-up transformer through a lead to obtain high voltage, and the shielding net 21 is connected to the leakage current measurement module in the control unit box 24 and then grounded to obtain zero potential.

[0048] The shielding mesh 21 is fixed to the insulating plate 22 via the connecting plate 26 . Before fixing, the copper mesh needs to be flattened to ensure that its surface is flat and in a horizontal position.

[0049] Among them, the shielding net 21 is made of pure copper, with a parameter of 30 mesh (wire diameter 0.15mm, mesh size 0.6mm), the support column and the insulating plate 22 are made of polytetrafluoroethylene, and the support column is designed with M3 threads inside, which can be fixed by screws.

[0050] The thermal anemometer 23 is fixed to the geometric center of the insulating plate 22 and is used to measure the corona wind generated by the tip of the ice ridge 4. When a fluid (such as air) flows over a hot surface, it removes heat, causing the temperature of the hot surface to drop. The greater the flow rate, the faster the heat dissipation rate. By measuring heat loss or temperature change, the fluid velocity can be inferred. Its expression formula is as follows:

[0051] Q=h·A·(T s +Tf )

[0052] Where Q is the heat dissipated by the hot surface; h is the convective heat transfer coefficient (dependent on flow rate); A is the hot surface area; Ts is the surface temperature; and Tf is the fluid temperature. As the flow rate increases, h increases, causing Q to increase (in constant temperature mode) or Ts to decrease (in constant current mode). In this case, the current through the thermistor is kept constant, and the change in its temperature (or resistance) is measured to infer wind speed.

[0053] Furthermore, the thermal anemometer probe should be as close as possible to the shielding net 21 to reduce the attenuation of the corona wind of the ice prism 4. The distance between the thermal anemometer and the shielding net 21 is 5 mm, so the measured wind speed attenuation can be ignored.

[0054] The shielding net 21, the thermal anemometer 23 and the insulating plate 22 are fixed on the automatic lifting platform 5, and are controlled by the control unit box 24 to move up and down with the lifting platform.

[0055] Specifically, the control unit box 24 is composed of a DC-DC power supply module, an MCU micro control unit, a communication module, a clock module, a motor drive module, a motor unit, a leakage current measurement module, and a corona wind measurement module. The motor drive module and the motor unit are used to drive the cylinder to drive the automatic lifting platform 5 to rise and fall.

[0056] Specifically, the clock module is used to calibrate the device time and assign a timestamp when the device and the computer host transmit data wirelessly to ensure the continuity of the transmitted data and avoid omissions. The power supply module converts the power supply from AC to DC through rectification, voltage regulation, and filtering circuits, and then supplies power to each module after DC-DC conversion. The MCU microcontroller unit aggregates the data from the sensors, processes the data centrally, and controls the operating status and data communication of the equipment. Communication module: used for the corona wind and leakage current data measured by this device to communicate bidirectionally with the computer host, which can realize the sending of equipment monitoring data to the computer host, and can also be used for the computer host to issue instructions to the device. The electrode drive module is used to convert the control signal of the MCU into an electrode drive voltage, drive the motor to rotate, and then control the movement of the lifting platform.

[0057] Furthermore, the voltage between the tip of the ice ridge 4 of the conductor 3 and the shielding net 21 is constant, and the field strength can be changed by changing the relative distance between the tip of the ice ridge 4 and the shielding net 21.

[0058] The shielding net 21 and the thermal anemometer 23 are connected to the leakage current measurement module and the corona wind measurement module respectively through the communication cable 25. After the measurement, the data is uploaded to the MCU microcontroller unit. After the MCU microcontroller unit is given a timestamp by the clock module, it can remotely transmit data in both directions with the computer host through the communication module, and save data and operation control in real time.

[0059] The operation process of the present invention is as follows: open the upper cover, fix the wire 3 on the shell 1, and adjust the angle of the wire 3 so that the ice ridge 4 is vertically downward; cover the cover, adjust the height of the lifting platform by inputting instructions on the computer to change the distance between the tip of the ice ridge 4 and the shielding net 21; measure the distance between the tip of the ice ridge 4 and the shielding net 21 and record it; connect the wire 3 to the step-up transformer, and the shielding net 21 is connected to the ground electrode after being connected to the control unit box 24, so that the tip of the ice ridge 4 generates a high-voltage field strength, thereby causing corona wind discharge at the tip of the ice ridge 4; the corona wind speed and leakage current will be sent to the computer end through the communication module for automatic storage, and a camera is used to take pictures of the discharge at the tip of the ice ridge 4; while keeping the voltage of the wire 3 unchanged, adjust the height of the lifting platform, change the distance between the tips of the ice ridge 4 to change the field strength at the tip of the ice ridge 4, simulate the corona wind discharge of the wire 3 under different voltage levels, and measure the corona wind speed and leakage current; repeat the above process to obtain the corona wind discharge law of the ice ridge 4 under different voltage levels.

[0060] This embodiment provides a non-contact conductor ice spike corona wind and leakage current measurement device and method, including:

[0061] S1: Test sample preparation: In an artificial climate chamber, control the temperature, humidity, and wind speed conditions, and simultaneously cover multiple conductors 3 with ice to form icicles 4. After measuring the length of the icicles 4, only the longest icicle 4 is retained to form a single icicle 4 conductor 3;

[0062] S2: Device assembly: Fix the wire 3 to the housing 1, adjust the ice ridge 4 to point vertically downward, connect the step-up transformer and the DC power supply, ground the shielding net 21, and adjust the distance between the tip of the ice ridge 4 and the shielding net 21 through the motor-driven lifting platform;

[0063] S3: Corona parameter acquisition: voltage is applied to conductor 3 in stages, the spacing is adjusted synchronously, and the leakage current value at each voltage level and the dynamic image of the corona wind captured by a high-speed camera are recorded;

[0064] S4: Regularity modeling: Based on the measured data of step S3, the diameter of the conductor 3, the length and spacing parameters of the ice spikes 4 are set in the finite element simulation software, the electric field intensity distribution at the tip of the ice spikes 4 is calculated, and a voltage and field intensity correlation model is established.

[0065] Furthermore, in step S1, an icing test is performed on n conductors 3 while controlling environmental conditions such as temperature, humidity, and wind speed in an artificial climate chamber, so that ice ridges 4 are frozen on the conductors 3. After the icing test is completed, the conductors 3 are removed, and the lengths of the ice ridges 4 are measured. The longest ice ridge 4 is retained, and the remaining ice ridges 4 are removed with an ice cutter to obtain a conductor 3 with a single ice ridge 4, thereby completing the preparation of the test sample.

[0066] Furthermore, in step S2, first fix the test device to the horizontal ground, open the upper cover, fix the wire 3 obtained in step S1 to the device housing 1, adjust the angle of the wire 3 so that the ice ridge 4 is vertically downward, and cover the upper cover; secondly, connect the wire 3 to the step-up transformer, connect the step-up transformer to the DC power supply, connect the shielding net 21 to the ground electrode, and connect the lifting platform to the motor; finally, connect the data transmission unit, control unit, test device (high-speed camera), etc.

[0067] Furthermore, in step S3, the voltage level on the conductor 3 is controlled by a step-up transformer, and the height of the lifting platform is driven by a motor to change the distance between the shielding net 21 and the ice ridge 4, so that a high field strength is generated at the tip of the ice ridge 4, thereby generating corona wind and leakage current. The distance and leakage current under different voltage levels are recorded, and corona wind pictures are taken using a high-speed camera.

[0068] Furthermore, in step S4, the initial conditions of the simulation are set in the finite element simulation software, such as temperature, humidity, wind speed, diameter of the conductor 3, length of the ice ridge 4, distance between the tip of the ice ridge 4 and the shielding net 21, and simulation step size, and the electric field strength between the tip of the ice ridge 4 and the shielding net 21 corresponding to different voltage levels is simulated and calculated. By summarizing the data obtained in step S3, the corona wind discharge law can be obtained.

[0069] As an optional embodiment, the thermal anemometer 23 is placed in different positions below the shielding net 21: close to the geometric center of the shielding net 21. After the corona wind is generated from the tip of the ice ridge 4, the intensity will decay due to diffusion or turbulence as the distance increases. The position close to the shielding net 21 can capture the original wind speed of the corona wind more directly, reducing the measurement error caused by distance. The thermal probe is close to the corona wind source, which can improve the response ability to weak wind speed changes, especially in low wind speed scenarios (such as the initial stage of corona of ice ridge 4). After the shielding net 21 is grounded, a zero potential reference surface is formed. Being close to the shielding net 21 can reduce the impact of external electromagnetic interference on wind speed measurement.

[0070] However, if the corona wind has directionality (e.g., biased to one side) due to the shape of the tip of the ice ridge 4, the offset of the conductor 3, or the uneven distribution of the electric field, the geometric center may not fully reflect the extreme value of the local wind speed.

[0071] Position away from the geometric center of the shield: If you want to study the distribution of corona wind in a specific area (such as eddies at the edge of ice spikes or areas with asymmetric electric fields), positions off-center can provide targeted data.

[0072] Finally, it should be pointed out that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. A non-contact conductor ice spike corona wind and leakage current measuring device, characterized by: include, Housing (1); A conductor (3) having an ice ridge (4) fixed at its geometric center; A measuring component (2) for detecting corona wind and leakage current generated by the conductor (3); An automatic lifting platform (5) for controlling the vertical distance between the measuring assembly (2) and the ice ridge (4); The housing (1) fixes the wire (3), the automatic lifting platform (5) adjusts the distance between the measuring component and the wire (3), and the measuring component (2) measures the corona wind and leakage current generated by the wire (3).

2. The non-contact wire ice spike corona wind and leakage current measuring device according to claim 1, characterized in that: The housing (1) is composed of six plates spliced ​​together, and includes: Removable upper cover (11); Side panels with concave support panels (12).

3. The non-contact conductor ice spike corona wind and leakage current measuring device according to claim 2, characterized in that: The concave support plate (12) is provided with a centrally-digging groove structure for keeping the ice ridge (4) extending vertically downward, and the axis of the wire (3) coincides with the central axis of the housing.

4. The non-contact conductor ice spike corona wind and leakage current measuring device according to claim 3, characterized in that: The length of the wire (3) is greater than the width of the housing (1) and is fixed at the geometric center via a groove.

5. The non-contact wire ice spike corona wind and leakage current measuring device according to claim 4, characterized in that: The measuring component (2) comprises: A shielding net (21) is fixedly connected to the automatic lifting platform (5) via a connecting plate (26); An insulating plate (22) is located on the automatic lifting platform (5).

6. The non-contact conductor ice spike corona wind and leakage current measuring device according to claim 5, characterized in that: The shielding net (21) is a stretched and flat copper net, which is kept in a horizontal state by a connecting plate and then grounded to form a zero potential.

7. The non-contact wire ice spike corona wind and leakage current measuring device according to claim 6, characterized in that: The measuring component (2) further comprises: a thermal anemometer (23) mounted on the insulating plate (22) and connected to the shielding net (21) via a communication cable (25); The probe of the thermal anemometer (23) is 5-15 mm away from the lower surface of the shielding net (21), and the axis of the probe is vertically aligned with the tip of the ice ridge (4).

8. The non-contact wire ice spike corona wind and leakage current measuring device according to claim 7, characterized in that: The measuring component (2) further comprises: A control unit box (24) is used to drive the automatic lifting platform (5) to achieve height adjustment. The control unit box (24) is connected to the shielding net (21) through a communication cable (25), and the thermal anemometer (23) is connected to the control unit box (24) through the communication cable (25).

9. The non-contact conductor ice spike corona wind and leakage current measuring device according to claim 8, characterized in that: The lifting stroke range of the automatic lifting platform (5) covers 20-100 cm, and the displacement resolution reaches 0.1 mm. The field intensity distribution is adjusted by changing the distance between the tip of the ice ridge (4) and the shielding net (21).

10. A non-contact method for measuring conductor ice spike corona wind and leakage current, comprising the non-contact conductor ice spike corona wind and leakage current measuring device according to any one of claims 1 to 9, characterized in that: include: Test sample preparation: In an artificial climate chamber, the temperature, humidity, and wind speed conditions were controlled, and multiple conductors were simultaneously covered with ice to form icicles. After measuring the length of the icicles, only the longest icicle was retained to form a single icicle conductor. Device assembly: fix the wire to the housing, adjust the ice spike to point vertically downward, connect the step-up transformer and the DC power supply, ground the shielding net, and adjust the distance between the ice spike tip and the shielding net by driving the lifting platform with a motor; Corona parameter acquisition: applying voltage to the conductors in stages, adjusting the spacing simultaneously, recording the leakage current value at each voltage level and the dynamic image of the corona wind captured by a high-speed camera; Regularity modeling: Based on the measured data in step S3, the wire diameter, ice spike length, and spacing parameters are set in the finite element simulation software to calculate the electric field intensity distribution at the ice spike tip and establish a voltage and field intensity correlation model.

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