Experimental device for measuring surface charge of three-post insulator in electrothermal composite field
By designing an experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field, the problem of local electric field distortion caused by surface charge accumulation in the three-post insulator was solved, and the accurate measurement of the surface charge distribution of the insulator was realized, thereby improving the reliability and insulation performance of the GIL.
Patent Information
- Application Number
- CN202421354452.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2034-06-13
AI Technical Summary
In the existing technology, the surface charge accumulation of the three-post insulator in GIL under the electrothermal composite field leads to local electric field distortion, which can easily cause flashover and leg breakage. Moreover, temperature affects its insulation performance, and there is a lack of effective measurement devices and research methods.
An experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field was designed, comprising an experimental chamber, a microwave heating system, a charge measurement device, and a data acquisition system. The microwave heating system simulates different working conditions, and the surface charge is measured by combining a multi-axis rotatable robotic arm and a capacitance probe. This avoids interference between the heating system and the measurement system and provides an efficient and energy-saving heating method.
It enables precise measurement of surface charge distribution in three-post insulators, simulates thermal conditions during long-term operation and startup, improves the reliability design of GIL, reduces the risk of local electric field distortion, and enhances insulation performance.
Smart Images
Figure CN223926534U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to high -voltage transmission line and insulation technical field, concretely relates to a kind of surface charge measurement experimental device of three post insulator under electrothermal composite field. BACKGROUND
[0002] Gas Insulated metal enclosed transmission Line (GIL) is composed of metal shell and tubular conductor, insulator, and is a kind of power transmission equipment using sulfur hexafluoride and other insulating gases as insulating medium. GIL has the advantages of large transmission capacity, low loss, easy installation, high reliability, and is not affected by external environmental factors such as dust, humidity and icing, etc. It is suitable for power transmission occasions in severe weather environment or restricted corridor selection, and can partially replace traditional overhead lines and power cables, and can be used for large-capacity, long-distance power transmission.
[0003] When the insulating gas in GIL undergoes photoionization, positive and negative ions are generated, and under the action of electric field force and diffusion, charged ions accumulate on the surface of insulator, causing the surface electric field of insulator to change, affecting the insulating performance of insulator. Once the insulator in operation has an accident, it will often seriously damage the related power equipment, so the insulator with good insulating performance can ensure the safe and reliable operation of GIL.
[0004] Because GIL is operated under load all year round, the central guide rod transmits the joule heat generated by large current to the three post insulator, affecting the uniformity of its internal temperature space distribution. The influence of temperature on three post insulator mainly reflects on the parameters, the conductivity and dielectric constant of insulator change with temperature, under the action of direct current voltage and temperature gradient, the surface and internal of three post insulator of gas insulated transmission pipeline are easy to accumulate electric charge, causing local electric field distortion, easy to induce three post insulator surface flashover and leg burst.
[0005] At the same time, the increase of temperature will affect the density of insulating gas in local area of chamber, thereby affecting the dielectric strength, leading to the decline of insulating capacity of insulator. As an important component in GIL, the study of surface charge accumulation characteristics of three post insulator and the revelation of its accumulation mechanism are of great significance for solving the problem of frequent accidents of current AC GIL and improving the reliability design of GIL. UTILITY MODEL CONTENT
[0006] In view of the shortcomings of the prior art, the utility model provides a kind of surface charge measurement experimental device of three post insulator under electrothermal composite field, and the specific technical scheme is as follows:
[0007] The utility model provides an experimental device for measuring the surface charge of three -legged insulator under the electric -thermal composite field, including experimental chamber, microwave heating system, charge measuring device, data acquisition system, the experimental chamber includes first experimental chamber and second experimental chamber, first experimental chamber one end is sealed through first basin type insulator, the other end is sealed through second basin type insulator, and second experimental chamber one end is sealed through second basin type insulator, and the other end is sealed through the cover plate, be equipped with glass window on first experimental chamber, and the microwave heating system is equipped with above glass window, and three -legged insulator is arranged in second experimental chamber, and the high -voltage guide rod of first experimental chamber outside embedded center guide rod passes through first experimental chamber and penetrates three -legged insulator, and the bottom of second experimental chamber is equipped with slide rail, and the charge measuring device is slidably connected above slide rail, and the charge measuring device is connected data acquisition system.
[0008] The microwave heating system includes a waveguide, a magnetron, and a microwave power source.
[0009] The waveguide is completely attached to the glass window.
[0010] The waveguide is "horn-shaped", which can improve the utilization rate of microwaves.
[0011] The center guide rod of the first experimental chamber is coated with a wave-absorbing and heating coating.
[0012] The charge measuring system includes a multi-axis rotatable mechanical arm and a capacitance probe.
[0013] The data acquisition device includes a Trek electrostatic voltmeter, an oscilloscope, and a high-impedance box.
[0014] Each of the outer walls of the first and second experimental chambers is provided with an air valve for adjusting the internal pressure of the chamber.
[0015] The utility model has the following beneficial effects:
[0016] 1. The microwave heating system is energy-efficient and environmentally friendly, has small thermal inertia and is easy to control instantaneously, facilitating automatic control and improving the controllability of the heating process.
[0017] 2. The microwave heating system of the experimental device can uniformly heat the inside of the chamber without being limited by the shape of the object.
[0018] 3. The utility model discloses a first experiment chamber and second experiment chamber, first experiment chamber heating guide rod, second experiment chamber measures insulator surface electric charge, avoids microwave heating system and electric charge measurement system mutual interference.
[0019] 4. The utility model discloses a center guide rod on the wave -absorbing heating paint and "horn" shape waveguide improve the utilization rate and heating efficiency of microwave energy -conserving and environment -friendly.
[0020] 5. The utility model discloses an experimental device, which can simulate the heating condition of the three -leg insulator caused by the long -term operation of the GIL and simulate the gradual temperature rise condition of the three -leg insulator when the GIL is just started, and realizes the measurement and experimental research on the surface charge distribution of the three -leg insulator under the above two conditions. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 The utility model discloses a kind of surface charge measurement experimental device structures of three -leg insulator under electrothermal composite field;
[0022] In the drawing, 1, first experiment cavity, 2, second experiment cavity, 3, first basin insulator, 4, second basin insulator, 5, three -leg insulator, 6, center guide rod, 7, high voltage guide rod, 8, glass window, 9, cover plate, 10, microwave power supply, 11, magnetron, 12, waveguide, 13, mechanical arm, 14, capacitance probe, 15, slide rail, 16, Trek electrostatic voltmeter, 17, high impedance box, 18, oscilloscope, 19 air valve. DETAILED DESCRIPTION
[0023] The utility model embodiment will be specifically explained in connection with the drawing.
[0024] As Figure 1 As shown in a kind of surface charge measurement experimental device structures of three -leg insulator under electrothermal composite field, including experiment chamber, microwave heating system, electric charge measurement device, data acquisition system;The experiment chamber includes first experiment chamber 1 and second experiment chamber 2, first experiment chamber 1 one end is sealed through first basin insulator 3, the other end is sealed through second basin insulator 4, and second experiment chamber 2 one end is sealed through second basin insulator 4, and the other end is sealed through cover plate 9;Glass window 8 is equipped on the first experiment chamber 1, and microwave heating system is equipped above glass window 8, and three -leg insulator 5 is arranged in second experiment chamber 2, and the center guide rod 6 embedded in the high voltage guide rod 7 outside first experiment chamber 1 penetrates three -leg insulator 5, and the bottom of second experiment chamber 2 is equipped with slide rail 15, and electric charge measurement device is slidably connected above slide rail 15, and electric charge measurement device is connected with data acquisition system;Microwave heating system is arranged above first experiment cavity 1, and the influence of reflected microwave on the surface charge distribution of the three -leg insulator to be measured can be avoided.
[0025] The microwave heating system comprises a waveguide 12, a magnetron 11 and a microwave power supply 10, the waveguide 12 is fixed above the glass window 8, the waveguide 12 is connected with the magnetron 11 and the microwave power supply 10 in sequence, the microwave power supply 10 converts alternating current into direct current, the magnetron 11 converts the direct current into high-frequency microwaves, and the high-frequency microwaves are transmitted into the first experimental cavity 1 through the waveguide 12.
[0026] The waveguide 12 is completely attached to the glass window 8.
[0027] The waveguide 12 is in a "horn shape", and the utilization rate of microwaves can be improved.
[0028] The central guide rod 6 of the first experimental chamber 1 is coated with a wave-absorbing and heating coating, which can effectively convert electromagnetic waves into heat energy after absorbing the electromagnetic waves in the coating, thereby increasing the temperature of the central guide rod 6, reducing the loss of heat energy, saving energy and improving efficiency; the coating has low reflectivity to incident electromagnetic waves and good absorption in a wide frequency band, which can effectively reduce the reflection and scattering of electromagnetic waves and improve the heating efficiency.
[0029] The charge measuring system comprises a multi-axis rotatable mechanical arm 13 and a capacitive probe 14, the mechanical arm 13 is slidingly connected to a sliding rail 15 at the bottom of the second experimental chamber 2, the top of the mechanical arm 13 is connected to the capacitive probe 14, and the mechanical arm 13 adjusts the capacitive probe 14 to be perpendicular to the surface of the three-column insulator 5.
[0030] The data acquisition device comprises a Trek electrostatic voltmeter 16, an oscilloscope 18 and a high-impedance box 17, the Trek electrostatic voltmeter 16 is arranged above the capacitive probe 14, and the Trek electrostatic voltmeter 16 is connected to the high-impedance box 17 and the oscilloscope 18 on the outer wall of the second experimental chamber 2 in sequence; the Trek electrostatic voltmeter 16 is used for outputting the surface charge collected by the electrostatic probe; the high-impedance box 17 protects the circuit by reducing the output load current to improve the input resistance of the circuit to realize the amplification and protection of the signal; and the oscilloscope 18 is used for storing and displaying the surface charge.
[0031] The outer wall of the first experimental cavity 1 and the second experimental cavity 2 is respectively provided with an air valve 19 for adjusting the air pressure in the cavity.
[0032] The pressure in the first experimental chamber 1 is set according to the voltage level, and the air pressure in the second experimental chamber 2 is set according to the measured experimental parameters, so as to meet the measurement experiment requirements under different voltage levels.
[0033] The three-column insulator surface charge measurement experiment method of the electric heating composite field can simulate the following two working conditions and measure the surface charge distribution of the three-column insulator:
[0034] 1. GIL long time operation causes three post insulator to heat up;
[0035] 2. GIL just starts up, three post insulator gradually heats up.
[0036] Embodiment 1
[0037] This embodiment simulates the working condition that GIL long time operation causes three post insulator to heat up. The experimental method includes the following steps:
[0038] Step 1. According to the voltage, current, cavity pressure and environmental temperature parameters of the experiment, the temperature field of the experimental device is simulated to obtain the simulation results of the temperature distribution of the center guide rod 6 and the three post insulator 5;
[0039] Step 2. According to the simulation results of step 1, the heating temperature range is obtained. The microwave heating system controls the microwave heating temperature to be higher than the highest temperature of the simulation results. The temperature in the first experimental cavity 1, the temperature of the center guide rod 6 and the temperature of the three post insulator 5 are measured at certain time intervals. The measurement is stopped when the temperature of the center guide rod 6 and the three post insulator 5 no longer rises. According to the measured data, the temperature curve of the temperature of the center guide rod 6 and the three post insulator 5 with the change of the microwave heating temperature is drawn;
[0040] Step 3. According to the temperature curve obtained in step 2, it is judged whether the center guide rod 6 and the three post insulator 5 can be heated to the required temperature of the experiment under this temperature condition. If yes, proceed to step 4. If not, return to step 2 and adjust the heating temperature of the microwave heating system;
[0041] Step 4. Wipe the surface of the three post insulator 5 with alcohol and dry it at room temperature for 2 hours;
[0042] Step 5. Operate the mechanical arm to move the capacitance probe 14 to a distance of 2mm from the surface of the three post insulator 5 and perpendicular to the surface of the three post insulator 5. The capacitance probe 14 scans the surface of the three post insulator 5. If surface charge is detected, repeat step 1 to ensure that there is no surface charge on the three post insulator 5 before the voltage is applied to the center guide rod 6. If no surface charge is detected, proceed to step 3;
[0043] Step 6. After the measurement is completed, the capacitance probe 14 is moved away from the three post insulator 5 by controlling the mechanical arm 13;
[0044] Step 7. The first experimental chamber 1 and the second experimental chamber 2 are vacuumized by the gas valve 19, and then the first experimental chamber 1 and the second experimental chamber 2 are filled with insulating gas;
[0045] Step 8. Start the microwave heating system and heat the center guide rod 6 to the set temperature;
[0046] Step 9, apply a direct current voltage to the center conductor 6 through the high voltage conductor 7, the voltage duration is determined by the experimental requirements;
[0047] Step 10, operate the mechanical arm 13 to move the capacitance probe 14 to the surface of the three-legged insulator 5 by 2mm and perpendicular to the surface of the three-legged insulator 5, and the capacitance probe 14 scans the surface of the three-legged insulator 5 to obtain experimental data;
[0048] Step 11, discharge the experimental device.
[0049] Example 2
[0050] This embodiment simulates the gradual temperature rise of the three-legged insulator when the GIL is started, and the measurement method includes the following steps:
[0051] Step 1, wipe the surface of the three-legged insulator 5 with alcohol, and dry it thoroughly at room temperature;
[0052] Step 2, operate the mechanical arm 13 to move the capacitance probe 14 to the surface of the three-legged insulator 5 by 2mm and perpendicular to the surface of the three-legged insulator 5, and the capacitance probe 14 scans the surface of the three-legged insulator 5, if surface charge is detected, repeat Step 1 to ensure that there is no surface charge on the three-legged insulator 5 before the voltage is applied to the center conductor 6, if no surface charge is detected, proceed to Step 3 operation;
[0053] Step 3, after the detection is completed, move the capacitance probe 14 away from the three-legged insulator 5;
[0054] Step 4, vacuumize the first experimental chamber 1 and the second experimental chamber 2 through the gas valve 19, and then fill the first experimental chamber 1 and the second experimental chamber 2 with insulating gas;
[0055] Step 5, turn on the microwave heating system and apply a direct current voltage to the center conductor 6 through the high voltage conductor 7;
[0056] Step 6, operate the mechanical arm 13 to move the capacitance probe 14 to the surface of the three-legged insulator 5 by 2mm and perpendicular to the surface of the three-legged insulator 5;
[0057] Step 7, during the slow heating process of the center conductor 6, the capacitance probe 14 scans the surface of the three-legged insulator 5 at certain time intervals and records the experimental data, the time interval is set according to the experimental requirements;
[0058] Step 8, discharge the experimental device.
Claims
1. An experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field, characterized in that, The system includes an experimental chamber, a microwave heating system, a charge measuring device, and a data acquisition system. The experimental chamber comprises a first experimental chamber and a second experimental chamber. The first experimental chamber is sealed at one end by a first basin-type insulator and at the other end by a second basin-type insulator. The second experimental chamber is sealed at one end by a second basin-type insulator and at the other end by a cover plate. The first experimental chamber has a glass window, and the microwave heating system is located above the glass window. A three-post insulator is installed in the second experimental chamber. A central guide rod embedded in the high-voltage guide rod outside the first experimental chamber passes through the first experimental chamber and through the three-post insulator. The bottom of the second experimental chamber has a slide rail, and the charge measuring device is slidably connected above the slide rail. The charge measuring device is connected to the data acquisition system.
2. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 1, characterized in that, The microwave heating system includes a waveguide, a magnetron, and a microwave power supply. The waveguide is fixed above the glass window and is connected to the magnetron and the microwave power supply in sequence.
3. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 2, characterized in that, The waveguide is completely fitted to the glass window.
4. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 2, characterized in that, The waveguide is shaped like a trumpet.
5. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 1, characterized in that, The central guide rod of the first experimental chamber is coated with a wave-absorbing and heat-increasing coating.
6. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 1, characterized in that, The charge measuring device includes a multi-axis rotatable robotic arm and a capacitance probe. The robotic arm is slidably connected to a slide rail at the bottom of the second experimental chamber, and the capacitance probe is connected to the top of the robotic arm. The robotic arm adjusts the capacitance probe to be perpendicular to the surface of the three-post insulator.
7. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 1, characterized in that, The data acquisition device includes a Trek electrostatic voltmeter, an oscilloscope, and a high-impedance box. The Trek electrostatic voltmeter is located above the capacitance probe and is connected in sequence to the high-impedance box and the oscilloscope on the outer wall of the experimental chamber.
8. The experimental device for measuring the surface charge of a three-post insulator under an electrothermal composite field according to claim 1, characterized in that, Each of the first and second experimental chambers has an air valve on its outer wall.