Tethered UAV and Wind Turbine Blade Grounding Resistance Testing System

Abstract

This invention provides a tethered drone and a wind turbine blade grounding resistance testing system. The tethered drone includes a drone body and a testing component. The drone body includes a fuselage and propellers and landing gear connected to the fuselage. The testing component includes a testing rod, one end of which is fixed to the landing gear, and the other end of which protrudes from the rotation area of ​​the propeller and is equipped with a testing head. The testing head is used to connect with a test point on the wind turbine blade. By using a tethered drone to test the grounding resistance of the blades, the drone can operate continuously, reducing charging time and improving testing efficiency. Furthermore, using a tethered drone eliminates the need for cranes and personnel for high-altitude operations, overcoming site limitations and reducing testing costs.

Description

Technical Field

[0001] This utility model relates to the field of wind turbine blade grounding resistance testing technology. Specifically, this utility model relates to a tethered drone and a wind turbine blade grounding resistance testing system. Background Technology

[0002] The grounding resistance at the blade tip of a wind turbine is one of the important indicators for evaluating the grounding performance of a wind turbine and plays a crucial role in the testing and acceptance process. According to relevant standards and specifications, the grounding resistance at the blade tip of a wind turbine should be no greater than 10Ω.

[0003] Currently, the most common method for testing the grounding resistance of wind turbine blades is manual inspection. This requires a crane carrying a basket to transport the personnel to the testing site. Manual inspection is risky, time-consuming, costly, and difficult. Blade grounding resistance testing typically requires a crane to lift personnel and tools to the testing location. However, cranes are often limited by the testing site, making the testing process difficult. Utility Model Content

[0004] The purpose of this invention is to provide a tethered drone that reduces the difficulty of detecting the grounding resistance of wind turbine blades and improves the detection efficiency, as well as a wind turbine blade grounding resistance testing system using the tethered drone.

[0005] To achieve the above objectives, this utility model provides the following technical solution: This utility model provides a tethered drone for testing the grounding resistance of wind turbine blades. It includes a tethered drone body and a testing component. The tethered drone body includes a fuselage and propellers and landing gear connected to the fuselage. The fuselage is equipped with an onboard power supply. The testing component includes a testing rod. One end of the testing rod is fixed to the landing gear, and the other end of the testing rod protrudes from the rotation area of ​​the propeller and is provided with a testing head. The testing head is electrically connected to the onboard power supply and is used to connect with the testing point on the wind turbine blade.

[0006] In one embodiment, the test head includes a suction cup and a test contact. The suction cup is used to attach to the blade under test and cover the test point. The test contact is a contact of the test signal line, which is located in the middle of the suction cup and can be electrically connected to the grounding resistance under test when the suction cup holds the test point.

[0007] In one embodiment, the suction cup is a vacuum suction cup, and the test assembly also includes a miniature vacuum pump and a flexible air tube. The miniature vacuum pump is fixed to the test rod and connected to the vacuum suction cup through the flexible air tube.

[0008] In one embodiment, the miniature vacuum pump is electrically connected to the airborne power supply and controlled by a control signal received by the airborne power supply.

[0009] In one embodiment, a blade cleaning assembly is also included, the blade cleaning assembly including a brush head fixed to the stand.

[0010] In one embodiment, the blade cleaning assembly further includes a brush mounting rod and a brush motor. The brush mounting rod is fixed to the stand and is respectively set at both ends of the machine body in the front-rear direction with the test rod. The brush head is connected to the output shaft of the brush motor, and the brush motor is mounted on the brush mounting rod and electrically connected to the onboard power supply.

[0011] In one embodiment, the brush mounting rod and the test rod are integrally formed from carbon fiber material.

[0012] In one embodiment, the brush mounting rod and the test rod are carbon tubes, which are connected to the legs by elastic rubber components.

[0013] In one embodiment, the carbon tube has a perforation in the middle, and the elastic rubber member has mounting holes at both ends. The elastic rubber member passes through the perforation, and the mounting holes at both ends fit around the leg and are fastened to the leg by means of fastening screws.

[0014] As a second aspect, this utility model also provides a wind turbine blade grounding resistance testing system, which includes the aforementioned tethered drone and tethered cable. The tethered cable is provided with a main current line and a test signal line. The main current line is connected to the airborne power supply inside the fuselage through an aviation plug. The test signal line extends to the test head and is electrically connected to the test point during testing.

[0015] In one embodiment, the testing system further includes a tethered power supply, a grounding resistance detector, and a handheld remote controller. The tethered power supply is used to connect to a generator or mains power supply to access the power supply and to power the tethered drone through the tethered cable. The grounding resistance detector is electrically connected to the tethered power supply. The handheld remote controller is used to control the working status of the miniature vacuum pump or brush motor in the tethered drone.

[0016] The beneficial effects of the technical solution provided by this utility model are as follows: In the tethered drone of this utility model, by setting a test component on the tethered drone body, the test head of the test component protrudes out of the rotation range of the drone propeller and can dock with the test point of the blade to be tested, thereby testing the grounding resistance of the test point. By using the tethered drone to detect the grounding resistance of the blade, the drone can work continuously, reducing charging waiting time and improving detection efficiency. In addition, using the tethered drone for detection eliminates the need to call cranes and personnel for high-altitude operations, which can overcome the limitations of the detection site and reduce detection costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments of this utility model will be briefly introduced below.

[0018] Figure 1 This is a schematic diagram of the structure of a tethered drone provided in one embodiment of the present invention; Figure 2 for Figure 1 A structural schematic diagram of the tethered drone from another perspective; Figure 3 This is a circuit diagram of the wind turbine blade grounding resistance testing system of this utility model. Figure 4 This is a schematic diagram of the structure for testing the grounding resistance of wind turbine blades using the wind turbine blade grounding resistance testing system of this utility model. Detailed Implementation

[0019] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0020] It should be understood that the steps described in the method embodiments of this utility model may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this utility model is not limited in this respect.

[0021] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "connection" can refer to a direct connection or an indirect connection via intermediate components (elements). The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description.

[0022] It should be noted that the concepts of "first" and "second" mentioned in this utility model are only used to distinguish between devices, modules or units, and are not used to limit these devices, modules or units to necessarily be different devices, modules or units, nor are they used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0023] See Figure 1 and Figure 2 and combined Figure 4This utility model relates to a tethered drone 100, which integrates testing components on its body for testing the grounding resistance of the blades of a wind turbine generator 1000 (hereinafter referred to as "wind turbine"). Additionally, this utility model also relates to a wind turbine blade grounding resistance testing system (hereinafter referred to as "testing system") based on the tethered drone 100.

[0024] The tethered drone 100 includes a tethered drone body and a test component and a blade cleaning component, both mounted on the tethered drone body. The tethered drone 100 provides flight capability and constitutes an aerial work platform. The test component is used to test the grounding resistance signal of the test point of the blade under test. The blade cleaning component is used to clean the dust on the blade to ensure the accuracy of the test results.

[0025] The tethered drone body includes a fuselage 10, propellers 20, and landing gear 30. The propellers 20 and landing gear 30 are respectively located on the upper and lower sides of the fuselage 10. An onboard power supply 11 is installed on the fuselage 10. The propellers 20 provide lift for the aircraft, and the landing gear 30 provides support for the fuselage 10. The onboard power supply 11 converts 400VDC direct current into 50VDC and 12VDC direct current, with the 50VDC powering the drone for flight and the 12VDC powering the testing components and blade cleaning components.

[0026] The testing assembly includes a test rod 41, one end of which is fixed to the stand 30, and the other end of which protrudes from the rotation area of ​​the blade 20 and is provided with a test head 42. The test head 42 is used to connect with a test point on the wind turbine blade. The connection referred to here means that there is both a mechanical connection and an electrical connection between the test head 42 and the test point.

[0027] In one embodiment, the test head 42 includes a suction cup and a test contact 422. The suction cup is used to attach to the blade to be tested and cover the test point. The test contact 422 is a contact of the test signal line, which is located in the middle of the suction cup and can be electrically connected to the grounding resistance to be tested when the suction cup holds the test point.

[0028] In one embodiment, the suction cup is a vacuum suction cup 421, and the test assembly also includes a miniature vacuum pump 43 and a flexible air tube. The miniature vacuum pump 43 is fixed to the test rod 41 and connected to the vacuum suction cup 421 through the flexible air tube. The miniature vacuum pump 43 is electrically connected to the onboard power supply 11 so that the onboard power supply 11 can supply power to the miniature vacuum pump 43.

[0029] The blade cleaning assembly includes a brush head 52, a brush mounting rod 51, and a brush motor 53. The brush mounting rod 51 is fixed to the stand 30 and is respectively positioned at both ends of the machine body 10 along the front-rear direction with the test rod 41. The brush head 52 is connected to the output shaft of the brush motor 53, and the brush motor 53 is mounted on the brush mounting rod 51. Understandably, the brush mounting rod 51 also protrudes from the rotation area of ​​the blade 20.

[0030] Before the test begins, the image transmission system of the tethered UAV 100 is used to observe the dust accumulation on the outside of the blades. If the dust accumulation affects the test, the dust on the blades is first cleaned with a brush before the test is conducted, thus making the test point clean, ensuring good contact between the suction cup and the test point, and improving the accuracy of the test results.

[0031] The function of the miniature vacuum pump 43 is to ensure good contact between the test contact 422 and the fan blade. The test contact 422 is placed in the suction cup connected to the vacuum pump and placed at the front of the drone via an extension rod on the drone frame. It is used in conjunction with the test contact 422 for testing. When the test contact 422 contacts the fan blade, the vacuum pump is controlled by a handheld remote control, and the suction cup is attached to the blade, so that the test contact 422 makes good contact with the test point of the fan blade.

[0032] In one embodiment, the brush mounting rod 51 and the test rod 41 are integrally formed from carbon fiber material.

[0033] In one embodiment, the brush mounting rod 51 and the test rod 41 are carbon tubes, that is, the brush mounting rod 51 and the test rod 41 are the two ends of the carbon tube, and the brush motor 53 is embedded in the carbon tube. The carbon tube is connected to the stand 30 through an elastic rubber component 60.

[0034] In one embodiment, the carbon tube has a perforation in the middle, and the elastic rubber member 60 has mounting holes at both ends. The elastic rubber member 60 passes through the perforation, and the mounting holes at both ends fit around the leg 30 and are fastened to the leg 30 by means of fastening screws.

[0035] Furthermore, the carbon fiber tube is connected to the tripod 30 via an elastic rubber component 60 to prevent interference between the test rod 41 and the drone under wind conditions. When the drone experiences slight translational movement due to wind, the test head 42 will not detach from the test point, and there will be no interference between the brush mounting rod 51, the test rod 41, and the drone. If the drone's translational movement is significant, the test head 42 will detach first, avoiding the risk of the drone crashing.

[0036] In this invention, using a tethered drone 100 for wind power inspection can improve inspection efficiency. Generally, the inspection time for a single wind turbine is 20-30 minutes. In non-tethered mode, the drone must be charged or have its battery replaced after each inspection. If improper operation or excessive wind speed occurs, the inspection may not be completed within the flight time, requiring the process to start over. The tethered mode eliminates the constraint of inspection time. After inspecting one wind turbine, the drone can proceed directly to the next turbine without returning to charge, enabling large-scale operation of wind turbine blade grounding resistance testing.

[0037] Previously, only one drone could be inspected per day. However, by using tethered drones, it is possible to inspect one drone per hour or even half an hour, reducing time costs, inspection costs, inspection difficulty, and avoiding risks associated with human operation.

[0038] As a second aspect, the present invention also provides a testing system, which includes the aforementioned tethered drone 100 and tethered cable 200. The tethered cable 200 is provided with a main current line and a test signal line. The main current line is connected to the airborne power supply 11 inside the fuselage 10 through an aviation plug to supply power to the tethered drone. The test signal line extends to the test head 42 and is electrically connected to the test point during testing.

[0039] By combining the main current line and the test signal line into one tether cable 200, the number of cables is reduced compared to the existing tether cable 200 which only has a main current line. This avoids the two cables from getting tangled under the influence of wind, thus facilitating detection and recovery.

[0040] In one embodiment, the testing system further includes a tethered power supply 300, a grounding resistance detector 400, and a handheld remote controller 500. The tethered power supply is used to connect to a generator or mains power to access the power supply and to connect to the tethered drone 100 through the tethered cable 200 to supply power to the tethered drone 100. The grounding resistance detector is electrically connected to the tethered power supply. The handheld remote controller is used to control the working status of the miniature vacuum pump 43 or the brush motor 53 in the tethered drone 100.

[0041] The tether power supply is used to convert 220VAC to 400VDC power and transmit DC power to the tether cable. In addition, the tether power supply leads out the signal wires in the tether cable and transmits them to the grounding resistance tester.

[0042] In one embodiment, the testing system further includes a generator that provides power to the tethered power source, and the portable nature of the generator is more advantageous for testing wind turbines in remote areas.

[0043] Understandably, the miniature vacuum pump 43 and the brush motor 53 are each equipped with independent control circuits so that the miniature vacuum pump 43 and the brush motor 53 can be controlled to work by handheld remote control.

[0044] The wind turbine blade grounding resistance testing system of this utility model passes... Figure 3 The circuit shown works as follows: Figure 3 In this circuit, the input levels are 400V and 400VG, introduced through a tethered cable 200. C1 is a 10μF capacitor used for filtering. The BCM6123TD5135T01 chip is used to step down the 400V DC to 50V for the drone's flight. C4 is another 10μF capacitor used for filtering. The LM5050 is a MOSFET controller. When the voltage at the OUT terminal is greater than that at the IN terminal, the GATE pin is pulled low to turn off the MOSFET. When the voltage at the IN terminal is greater than that at the OUT terminal, the GATE pin is output high to turn on the MOSFET, and the circuit is turned on, allowing the BCM6123TD5135T01 chip to power the drone. This circuit prevents excessively high external voltage from supplying reverse power to the chip, thus preventing current backflow. The MOSFETs act as switches; the two MOSFETs connected in parallel in the diagram increase the safety current. C8 is a 0.1μF capacitor used for filtering the OUT terminal of the LM5050.

[0045] Figure 3 Starting from the top left corner is the power supply circuit for the brush motor and miniature vacuum pump. The core component is the LM2576-12, which steps down the 50V DC to 12V DC to power the brush motor and miniature vacuum pump. The input terminal of the LM2576-12 is connected to the OUT terminal of the MOSFET, mainly because the OUT terminal is also connected to the drone's battery, which can power the remote control module. C5 is an electrolytic capacitor used for filtering. IN5822 is a Zener diode used to prevent excessive output voltage. L1 is an inductor used to maintain current stability. The yaokong module is the receiver of the remote control, used to receive control signals from the remote control. The handheld remote control can control the output and disconnection of the 12V DC power from the P+ and P- interfaces of the yaokong module. Jidianqi is a Panasonic relay module. When the yaokong module outputs 12V DC, the two XQ relays are connected, and vice versa, used to control the on / off state of the two motors.

[0046] This enables the tethered power source to power the drone's flight, testing, and cleaning operations, ensuring the tethered drone's endurance and the smooth and continuous progress of testing, improving the detection efficiency of wind turbine blade grounding resistance, and increasing economic benefits.

[0047] The above description is merely a preferred embodiment of this utility model and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this utility model is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features of the utility model in this utility model that have similar functions.

[0048] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A tethered drone for testing the ground resistance of a wind turbine blade, characterized in that, The device includes a tethered drone body and a testing component. The tethered drone body includes a fuselage and propellers and landing gear connected to the fuselage. The fuselage is equipped with an onboard power supply. The testing component includes a testing rod. One end of the testing rod is fixed to the landing gear, and the other end of the testing rod protrudes from the rotation area of ​​the propeller and is equipped with a testing head. The testing head is electrically connected to the onboard power supply and is used to dock with test points on the wind turbine blades.

2. The tethered drone of claim 1, wherein, The test head includes a suction cup and test contacts. The suction cup is used to attach to the blade under test and cover the test point. The test contacts are the contacts of the test signal line, which are located in the middle of the suction cup and can be electrically connected to the grounding resistance under test when the suction cup holds the test point.

3. The tethered drone of claim 2, wherein, The suction cup is a vacuum suction cup. The test assembly also includes a miniature vacuum pump and a flexible air tube. The miniature vacuum pump is fixed to the test rod and connected to the vacuum suction cup through the flexible air tube.

4. The tethered drone of claim 3, wherein, The miniature vacuum pump is electrically connected to the airborne power supply and is controlled by the control signal received by the airborne power supply.

5. The tethered drone of claim 1, wherein, It also includes a blade cleaning assembly, which includes a brush head fixed to the stand.

6. The tethered drone of claim 5, wherein, The blade cleaning assembly also includes a brush mounting rod and a brush motor. The brush mounting rod is fixed to the stand and is respectively set at both ends of the machine body along the front-rear direction with the test rod. The brush head is connected to the output shaft of the brush motor. The brush motor is mounted on the brush mounting rod and electrically connected to the onboard power supply.

7. The tethered drone of claim 6, wherein, The brush mounting rod and the test rod are integrally formed from carbon fiber material and are connected to the stand by elastic rubber parts.

8. The tethered drone of claim 7, wherein, The carbon fiber material is a carbon tube with a perforation in the middle. The elastic rubber component has mounting holes at both ends. The elastic rubber component passes through the perforation, and the mounting holes at both ends fit around the leg and are fastened to the leg with fastening screws.

9. A wind turbine blade earth resistance testing system, characterised in that, The invention includes a tethered drone and a tethered cable as described in any one of claims 1 to 8, wherein the tethered cable contains a main current line and a test signal line, the main current line is connected to an onboard power supply inside the fuselage via an aviation plug, and the test signal line extends to the test head and is electrically connected to the test point during testing.

10. The fan blade ground resistance testing system of claim 9, wherein, It also includes a tethered power supply, a grounding resistance detector, and a handheld remote controller. The tethered power supply is used to connect to a generator or mains power to access the power supply and to connect to the tethered drone through the tethered cable to supply power to the tethered drone. The grounding resistance detector is electrically connected to the tethered power supply. The handheld remote controller is used to control the working status of the miniature vacuum pump or brush motor in the tethered drone.

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