35-220kv overhead transmission line composite insulator hydrophobicity detection device and optimization method

Abstract

The application discloses a 35-220 kilovolt overhead transmission line composite insulator hydrophobicity detection device and an optimization method, a support frame of the device comprises side vertical plates, a bottom plate, a middle partition plate and a top plate, the bottom plate is connected with the upper end of a drone through a fixing seat, the middle partition plate and the top plate are connected with a sliding seat and an electric control box respectively, a conical air duct installed on the sliding seat is provided with an axial flow fan with a mist spray head respectively, a water tank arranged on the bottom plate is provided with a water pump, the water pump is connected with the mist spray head through a water stop valve and a water pipe, a power module and a control module arranged in the electric control box provide power supply and control signals for the water pump and the axial flow fan respectively, and a camera recorder is installed on the drone. The application realizes automatic spraying detection on the composite insulator of the overhead transmission line through remote control, effectively improves the efficiency and safety of the composite insulator hydrophobicity detection, reduces the safety risk of artificial climbing operation, and reduces the power loss caused by the pollution flashover accident.

Description

Technical Field

[0001] This invention relates to a hydrophobicity testing technology for insulators, and particularly to a hydrophobicity testing device and optimization method for composite insulators of 35-220 kV overhead transmission lines. Background Technology

[0002] Composite insulators, as key insulation equipment in modern power systems, have been widely used in 35-220 kV overhead transmission lines. Compared with traditional porcelain or glass insulators, composite insulators have outstanding advantages such as light weight, high strength, and excellent resistance to pollution flashover. Their core technological advantage lies in providing the insulator with unique hydrophobic properties; water droplets are difficult to wet the insulator surface and instead fall as beads, effectively suppressing leakage current and significantly improving the insulator's anti-pollution flashover capability.

[0003] However, the hydrophobicity of composite insulators is not static. During long-term operation, factors such as ultraviolet radiation, electric fields, humidity changes, and surface contamination can cause the hardened surface to gradually age and degrade, leading to a decrease or even loss of hydrophobicity. When the hydrophobicity decreases to a certain level, a continuous water film forms on the insulator surface, causing a sharp increase in leakage current and easily triggering flashover accidents, seriously threatening the safe and stable operation of the power grid. Therefore, regularly testing and evaluating the hydrophobicity of composite insulators is of great significance for ensuring the safe and reliable operation of transmission lines.

[0004] Currently, the hydrophobicity testing of composite insulators mainly employs the manual spraying method (HC classification method). This involves personnel spraying water onto the insulator surface after being exposed to radiation, and then observing the distribution of the water droplets to determine the hydrophobicity level. This method has significant limitations: first, it is inefficient, with testing a single tower typically taking 60-90 minutes, which cannot meet the needs of large-scale inspections; second, it carries high safety risks, as personnel must work at heights while the power is on, posing hazards such as electric shock and falls; and third, the test results are highly susceptible to human error, with significant differences in judgment between different personnel. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a device and optimization method for testing the hydrophobicity of composite insulators for 35-220 kV overhead transmission lines that has a reasonable structure, high testing efficiency and good safety.

[0006] The technical solution of this invention is: A hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines includes a drone and a conical air duct. The drone has a fixed base at its upper end, which is connected to the base plate of a support frame via a guide positioning mechanism. A water tank is located on the upper surface of the base plate of the support frame. A middle partition of the support frame is connected to a sliding seat via another guide positioning mechanism. An electrical control box is located on the upper surface of the top plate of the support frame. The conical air duct is mounted on the upper surface of the sliding seat. A mist nozzle is installed in the inner cavity of the small end of the conical air duct, and an axial flow fan is installed in the inner cavity of the large end. A water pump is placed in the water tank and connected to the mist nozzle via a stop valve and a water pipe. The electrical control box contains a power module and a control module, which provide power and control signals to the water pump and axial flow fan, respectively. A camera is mounted on the drone. The drone, camera, and control module are all connected to a ground-based remote control terminal via wireless communication modules.

[0007] Furthermore, the guiding and positioning mechanism includes a guide rail, a guide rail groove, and a positioning pin, wherein the guide rail is located in the guide rail groove and the two are slidably connected.

[0008] Furthermore: the guide rail groove is an open structure at both ends, or the guide rail groove is a structure with one end closed and the other end open; the positioning pin is a tapered pin, which is accurate in positioning and not easy to fall out.

[0009] Furthermore, the electrical control box is movably connected to the top plate of the support frame via connecting bolts, allowing for disassembly and assembly. Additionally, there are four connecting bolts distributed along the four corners of the electrical control box.

[0010] Furthermore, a safety protection chain is provided between the support frame and the fixed seat. The safety protection chain is made of high-strength nylon rope with a breaking force of over 200 kg, serving as a secondary safety guarantee.

[0011] An optimized method for a 35-220 kV overhead transmission line composite insulator hydrophobicity testing device, comprising the following steps: a. Modular design: Each functional module is designed independently and has a compact layout. The water pump and mist nozzle, the electrical control box and axial flow fan, and the electrical control box and water pump are all connected by plug-and-socket structure, which can be connected by plugging and can be separated for independent storage and transportation. b. Lightweight design: First, the structural components are made of aerospace-grade aluminum alloy and carbon fiber composite materials, which greatly reduces weight while ensuring strength; second, the pipeline design is optimized to shorten the water path length and reduce the amount of excess water carried. c. Adopt a center of gravity coincidence design: The heavier water tank and water pump are placed near the center of gravity of the UAV, and the control module and power module are placed in symmetrical positions, so that the center of gravity offset of the entire device is controlled within 50%, which further improves flight stability. d. Reliable wireless communication design: Industrial-grade data radio is selected, with a working frequency of 433MHz and a communication distance of over 140 meters; e. Functional ground control terminal design: It adopts an industrial tablet computer with a touch screen display interface, which is easy and intuitive to operate. It has the following functions: spray parameter setting, real-time status monitoring, detection data recording and storage, historical data query and export; it is also equipped with a wireless video receiving module to view the high-definition camera footage carried by the UAV in real time, assisting operators to remotely observe the surface condition of the insulator.

[0012] Furthermore, in step d, several technical measures are adopted to improve communication reliability: first, adaptive frequency hopping technology is used to automatically avoid interference frequencies; second, CRC check and retransmission mechanism is used to ensure the accuracy of data transmission; and third, electromagnetic shielding design is applied to the communication module to improve its anti-interference capability in strong electromagnetic environments.

[0013] Further: In step e, the spraying parameters include spraying time, spraying interval and mist particle fineness, and the real-time status monitoring includes device status, battery power and communication signal strength.

[0014] Furthermore: In step a, the mist nozzle employs a swirling design internally and a diversion structure at the outlet to control the mist particle diameter to within 1 mm; the mist nozzle is made of stainless steel to ensure durability in outdoor environments; the axial flow fan is driven by a brushless motor with adjustable speed and a wind speed range of 0-15 m / s; the water pump is a miniature plunger pump with a working pressure of 0.3-0.5 MPa and a flow rate of 50-100 mL / min, and the pump body is made of corrosion-resistant material to adapt to harsh outdoor environments; the stop valve is a miniature solenoid valve with a response time of less than 0.5 seconds, enabling precise control of spraying time and spray volume.

[0015] Further: In step a, the power module is powered by a lithium battery with a rated voltage of 22.2V and a capacity of 3000mAh, which can support the device to work continuously for more than 2 hours.

[0016] The beneficial effects of this invention are: 1. This invention enables automatic spray testing of composite insulators on overhead transmission lines through remote control, effectively improving the efficiency and safety of hydrophobicity testing of composite insulators, reducing the safety risks of manual high-altitude operations, and minimizing power outage losses caused by flashover accidents.

[0017] 2. This invention adopts a lightweight design, and the final total weight is controlled within 3.5 kg, which meets the carrying requirements of mainstream power line inspection drones.

[0018] 3. This invention employs a double-layer safety connection mechanism, including a main connecting frame and a safety protection chain. The main connecting frame is made of aerospace-grade aluminum alloy and precision-machined using CNC to ensure dimensional accuracy and structural strength. The safety protection chain uses high-strength nylon rope with a breaking force exceeding 200kg, serving as a secondary safety guarantee.

[0019] 4. This invention places the heavy water tank and water pump near the center of gravity of the drone, and arranges the control circuit board and battery in symmetrical positions, so that the center of gravity offset of the entire device is controlled within 50%, further improving flight stability.

[0020] 5. This invention adopts a modular design concept, integrating the three subsystems—spraying mechanism, control and power module, and UAV connection mechanism—through standardized interfaces. The modules employ both electrical and mechanical interfaces for connection, ensuring the reliability of signal transmission and physical connections.

[0021] 6. The UAV inspection solution adopted in this invention can significantly reduce labor costs and safety management costs. It is estimated that the inspection cost of a single tower can be reduced by more than 60%, which has significant economic benefits. Attached Figure Description

[0022] Figure 1 Structural diagram of a device for testing the hydrophobicity of composite insulators for 35-220 kV overhead transmission lines; Figure 2 for Figure 1 Enlarged right-side view of the upper part of the drone; Figure 3 for Figure 1 One of the enlarged top views of the central fixed base; Figure 4 for Figure 1 Second enlarged top view of the central fixed base. Detailed Implementation

[0023] Example 1: See Figure 1 -- Figure 3 In the diagram, 1-UAV, 2-Fixed base, 3-Water tank, 4-Mist nozzle, 5-Conical air duct, 6-Power module, 7-Control module, 8-Axial flow fan, 9-Support frame, 10-Sliding seat, 11-Positioning pin, 12-Guide rail groove, 13-Positioning hole.

[0024] A hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines includes a drone 1 and a conical ventilation duct 5. The drone 1 has a fixed base 2 at its upper end (the two can be connected by bolts or clips, a common technique not detailed here). The fixed base 2 is connected to the base plate of a support frame 9 via a guide positioning mechanism. A water tank 3 is installed on the upper surface of the base plate of the support frame 9 (the two are movably connected and can be disassembled). The middle partition of the support frame 9 is connected to a sliding seat 10 via another guide positioning mechanism. An electrical control box is installed on the upper surface of the top plate of the support frame 9. A conical air duct 5 is installed on the upper surface of the sliding seat 10 (the two are movably connected and can be disassembled). A mist nozzle 4 is installed in the inner cavity of the small end of the conical air duct 5, and an axial flow fan 8 is installed in the inner cavity of the large end of the conical air duct 5. A water pump (not shown in the figure) is placed in the water tank 3. The water pump is connected to the mist nozzle 4 through a stop valve and a water pipe. A power module 6 and a control module 7 are installed in the electrical control box. The power module 6 and the control module 7 provide power and control signals to the water pump and the axial flow fan 8, respectively. A camera is installed on the UAV 1. The UAV 1, the camera, and the control module 7 are all connected to the ground remote control terminal through a wireless communication module.

[0025] Preferred solution: The guiding and positioning mechanism between the fixed base 2 and the base plate includes a guide rail, a guide rail groove 12, and a positioning pin 11. The guide rail is located on the lower end face of the base plate, and there is at least one guide rail (two are shown in the figure). The guide rail groove 12 is located on the upper end face of the fixed base 1, and the guide rail groove 12 has a structure that is closed at one end and open at the other end. Figure 3 As shown), this structure allows one end to form a natural position, while the other end can be positioned using a positioning pin 11. The guide rail is located in the guide rail groove 12 and the two are slidably connected. The base plate and the fixed seat 1 are provided with corresponding positioning holes 13 to facilitate the insertion of the positioning pin 11. If necessary, a pull ring can be provided at the upper end of the positioning pin 11 to facilitate the removal of the positioning pin 11. The positioning pin 11 is a tapered pin, which is accurate in positioning and not easy to fall out.

[0026] The guiding and positioning mechanism between the intermediate partition and the sliding seat 10 adopts the same structure. The guide rail is set on the lower end face of the sliding seat 10, and the guide rail groove is set on the upper end face of the intermediate partition. The two are in sliding contact.

[0027] Preferred solution: The electrical control box is movably connected to the top plate of the support frame 9 via connecting bolts, allowing for disassembly and assembly. Four connecting bolts are distributed along the four corners of the electrical control box. A safety chain (not shown in the figure) is installed between the support frame 9 and the fixed base 2. This safety chain uses high-strength nylon rope with a breaking force exceeding 200 kg, serving as a secondary safety guarantee.

[0028] The optimization method for the hydrophobicity testing device of composite insulators for 35-220 kV overhead transmission lines includes the following steps: a. Modular design: Each functional module is designed independently and has a compact layout. The water pump and mist nozzle 4, the electrical control box and axial flow fan 8, and the electrical control box and water pump are all connected by plug-and-socket structures, which can be connected by plugging and can also be separated for independent storage and transportation. b. Lightweight design: First, the structural components are made of aerospace-grade aluminum alloy and carbon fiber composite materials, which greatly reduces weight while ensuring strength; second, the pipeline design is optimized to shorten the water path length and reduce the amount of excess water carried. c. Adopt a center of gravity coincidence design: The heavier water tank 3 and water pump are placed near the center of gravity of the UAV 1, and the control module 7 and power module 6 are placed in symmetrical positions, so that the center of gravity offset of the entire device is controlled within 50%, further improving flight stability. d. Reliable wireless communication design: Industrial-grade data radio is selected, with a working frequency of 433MHz and a communication distance of over 140 meters; e. Functional ground control terminal design: It adopts an industrial tablet computer with a touch screen display interface, which is easy and intuitive to operate. It has the following functions: spray parameter setting, real-time status monitoring, detection data recording and storage, historical data query and export; it is also equipped with a wireless video receiving module to view the high-definition camera footage carried by the UAV in real time, assisting operators to remotely observe the surface condition of the insulator.

[0029] Preferred solution: In step d, a number of technical measures are adopted to improve communication reliability: First, adaptive frequency hopping technology is used to automatically avoid interference frequencies; second, CRC check and retransmission mechanism is used to ensure the accuracy of data transmission; third, electromagnetic shielding design is carried out on the communication module to improve the anti-interference ability in strong electromagnetic environment.

[0030] Preferred solution: In step e, the spraying parameters include spraying time, spraying interval and mist particle fineness, and the real-time status monitoring includes device status, battery power and communication signal strength.

[0031] Preferred solution: In step a, the mist nozzle employs a swirling design internally and a diversion structure at the outlet to control the mist particle diameter to within 1 mm; the mist nozzle is made of stainless steel to ensure durability in outdoor environments; the axial flow fan is driven by a brushless motor with adjustable speed and a wind speed range of 0-15 m / s; the water pump is a miniature plunger pump with a working pressure of 0.3-0.5 MPa and a flow rate of 50-100 mL / min, and the pump body is made of corrosion-resistant material to adapt to harsh outdoor environments; the stop valve is a miniature solenoid valve with a response time of less than 0.5 seconds, enabling precise control of spraying time and spray volume.

[0032] Preferred Solution: In step a, the power module is powered by a lithium battery with a rated voltage of 22.2V and a capacity of 3000mAh, capable of supporting continuous operation of the device for more than 2 hours. To ensure stable operation of the battery under different ambient temperatures, an intelligent temperature control system is designed, including three functional modules: temperature sensor monitoring, heating film insulation, and heat sink heat dissipation. When the ambient temperature is below 0℃, the heating film automatically activates to ensure that the battery temperature remains above 5℃; when the ambient temperature is above 40℃, the heat sink automatically activates to control the battery temperature rise to within 20℃.

[0033] One of the core innovations of this scheme lies in decoupling the atomization and aerodynamic radiation processes: first, water is atomized into micron-sized droplets through a high-pressure nozzle, and then the droplets are radiated to the target location by a directional airflow generated by a fan. By coordinating the control of fan speed and nozzle pressure, spray coverage at different distances can be achieved while ensuring the fineness of the droplets. Experimental verification shows that under conditions of wind speed of 10 m / s and nozzle pressure of 0.4 MPa, the diameter of the droplets at a distance of 2 m from the nozzle can still be maintained within 0.8 mm, meeting the detection requirements of the HC classification method.

[0034] This control system adopts a three-layer architecture: ground control terminal + wireless communication + aircraft control unit. The ground control terminal is responsible for sending control commands and receiving detection data, the wireless communication module is responsible for data transmission, and the aircraft control unit is responsible for executing the spraying operation. The control unit uses an STM32 series microcontroller, which features low power consumption and high reliability, and can operate stably in complex electromagnetic environments.

[0035] The hydrophobicity testing process of this solution consists of four stages: preparation stage (drone takeoff, flight to the vicinity of the target tower, and position adjustment), spraying stage (starting the water pump and fan to spray the surface of the insulator), observation stage (observing the distribution of water droplets through a high-definition camera), and evaluation stage (determining the hydrophobicity level based on the observation results). The entire testing process is uniformly controlled by a ground control terminal.

[0036] Example 2: See Figure 4 This embodiment is basically the same as the first embodiment, and the similarities will not be repeated. The difference is that the guide rail 12 is an open structure at both ends. At this time, the guide rail groove is a through groove, which is easy to process and reduces the processing difficulty. However, two positioning pins need to be set to improve the positioning effect.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications made based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

A 1.35-220 kV overhead transmission line composite insulator hydrophobicity testing device, comprising a drone and a conical ventilation duct, characterized by: The drone is equipped with a fixed base at its upper end, which is connected to the base plate of the support frame via a guide positioning mechanism. A water tank is installed on the upper surface of the base plate of the support frame. The middle partition of the support frame is connected to a sliding seat via another guide positioning mechanism. An electrical control box is installed on the upper surface of the top plate of the support frame. The conical air duct is installed on the upper surface of the sliding seat. A mist nozzle is installed in the inner cavity of the small end of the conical air duct, and an axial flow fan is installed in the inner cavity of the large end of the conical air duct. A water pump is placed in the water tank, and the water pump is connected to the mist nozzle via a stop valve and a water pipe. The electrical control box is equipped with a power module and a control module, which provide power and control signals to the water pump and the axial flow fan, respectively. A camera is installed on the drone, and the drone, camera, and control module are all connected to a ground remote control terminal via a wireless communication module.

2. The hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 1, characterized in that: The guiding and positioning mechanism includes a guide rail, a guide rail groove, and a positioning pin. The guide rail is located in the guide rail groove and the two are slidably connected.

3. The hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 2, characterized in that: The guide rail groove is an open structure at both ends, or a structure with one end closed and the other end open; the positioning pin is a tapered pin, which is accurate in positioning and not easy to fall out.

4. The hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 1, characterized in that: The electrical control box is movably connected to the top plate of the support frame via connecting bolts, allowing for disassembly and assembly. There are four connecting bolts distributed along the four corners of the electrical control box.

5. The hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 1, characterized in that: A safety chain is installed between the support frame and the fixed base. The safety chain is made of high-strength nylon rope with a breaking force of over 200 kg, serving as a secondary safety guarantee.

6. An optimized method for the 35-220 kV overhead transmission line composite insulator hydrophobicity testing device according to any one of claims 1-5, comprising the following steps: a. Modular design: Each functional module is designed independently and has a compact layout. The water pump and mist nozzle, the electrical control box and axial flow fan, and the electrical control box and water pump are all connected by plug-and-socket structure, which can be connected by plugging and can be separated for independent storage and transportation. b. Lightweight design: First, the structural components are made of aerospace-grade aluminum alloy and carbon fiber composite materials, which greatly reduces weight while ensuring strength; second, the pipeline design is optimized to shorten the water path length and reduce the amount of excess water carried. c. Adopt a center of gravity coincidence design: The heavier water tank and water pump are placed near the center of gravity of the UAV, and the control module and power module are placed in symmetrical positions, so that the center of gravity offset of the entire device is controlled within 50%, which further improves flight stability. d. Reliable wireless communication design: Industrial-grade data radio is selected, with a working frequency of 433MHz and a communication distance of over 140 meters; e. Functional ground control terminal design: It adopts an industrial tablet computer with a touch screen display interface, which is easy and intuitive to operate. It has the following functions: spray parameter setting, real-time status monitoring, detection data recording and storage, historical data query and export; it is also equipped with a wireless video receiving module to view the high-definition camera footage carried by the UAV in real time, assisting operators to remotely observe the surface condition of the insulator.

7. The optimized method for the hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 6, characterized in that: in In step d, several technical measures are adopted to improve communication reliability: first, adaptive frequency hopping technology is used to automatically avoid interference frequencies; second, CRC check and retransmission mechanism is used to ensure the accuracy of data transmission; and third, electromagnetic shielding design is applied to the communication module to improve its anti-interference capability in strong electromagnetic environments.

8. The optimized method for the hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 6, characterized in that: in In step e, the spraying parameters include spraying time, spraying interval, and mist particle fineness, and the real-time status monitoring includes device status, battery power, and communication signal strength.

9. The optimized method for the hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 6, characterized in that: in In step a, the mist nozzle employs a swirling design internally and a diversion structure at the outlet to control the mist particle diameter to within 1 mm; the mist nozzle is made of stainless steel to ensure durability in outdoor environments; the axial flow fan is driven by a brushless motor with adjustable speed and a wind speed range of 0-15 m / s; the water pump is a miniature plunger pump with a working pressure of 0.3-0.5 MPa and a flow rate of 50-100 mL / min, and the pump body is made of corrosion-resistant material to adapt to harsh outdoor environments; the stop valve is a miniature solenoid valve with a response time of less than 0.5 seconds, enabling precise control of spraying time and spray volume.

10. The optimized method for the hydrophobicity testing device for composite insulators of 35-220 kV overhead transmission lines according to claim 6, characterized in that: in In step a, the power module is powered by a lithium battery with a rated voltage of 22.2V and a capacity of 3000mAh, which can support the device to work continuously for more than 2 hours.

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