Broken line fault detection device for lightning conductor of wind turbine generator

Abstract

The utility model discloses a lightning conductor breakage fault detection device for a wind turbine generator, and relates to the technical field of lightning conductor breakage fault detection devices. The device comprises a waterproof portable hand-held instrument installation box body, an industrial control computer, a data acquisition instrument, a high-frequency current sensor, a signal generator and a lithium battery. According to the utility model, the signal generator generates a step voltage signal with a rapid rising edge, the step voltage signal passes through the high-frequency current sensor and then is output to the lightning conductor to be detected, and a breakpoint position is calculated by using incident waves and reflected waves of traveling wave current according to a TDR principle, so as to judge whether the lightning conductor is broken or not and judge the broken line position; a structure in which a mobile power supply can be embedded is additionally arranged, so that the cruising ability is enhanced; the device has a plurality of advantages, is efficient and accurate in detection, and can accurately position a broken line point and an abnormal point; cost is low, and manpower and maintenance cost is reduced; the device is portable and flexible, and detection in the fan is facilitated; the cruising ability is high, and power can be continuously supplied during field operation.

Description

TECHNICAL FIELD

[0001] The utility model relates to lightning conductor broken wire fault detection device technical field, especially in lightning conductor broken wire fault detection device of wind turbine unit. BACKGROUND

[0002] Wind turbine units are mostly distributed in mountainous, coastal and other areas where lightning occurs frequently, and have a high height, so they are easily struck by lightning; lightning can seriously damage the power generation system, leading to long-term shutdown and causing huge economic losses. At the same time, wind turbine units are expensive, and the cost of maintenance, removal and replacement of damaged parts is huge; and during the long-term operation of the wind turbine unit, the lightning conductor in the blade is subjected to a certain tension, plus the multiple impacts of lightning current and aging problems, which can easily cause serious faults such as broken strands and even breakage.

[0003] At present, the traditional detection method of lightning conductor is to form a loop with the lightning conductor outside the blade, and to measure the continuity by using Ohm's law, which requires the staff to work through the basket operation, which is low in efficiency and high in cost; the lightning conductor broken wire detection method based on the single-ended traveling wave distance measurement principle is a new research direction, but the length of the lightning conductor of the blade is limited, and the echo time is in the order of nanoseconds, so it is difficult to accurately detect the key echo signal wave arrival time; therefore, we propose a wind turbine lightning conductor broken wire fault detection device. UTILITY MODEL CONTENT

[0004] The main purpose of the utility model is to provide a wind turbine lightning conductor broken wire fault detection device, which can effectively solve the problems in the background art.

[0005] To achieve the above purpose, the technical scheme adopted by the utility model is:

[0006] A wind turbine lightning conductor broken wire fault detection device, comprising a waterproof portable hand-held instrument installation box body and a waterproof flip cover, one side of the waterproof flip cover is rotatably connected with one side edge of the waterproof portable hand-held instrument installation box body;

[0007] A sealing plate is sealingly connected to the upper part of the inner cavity of the waterproof portable hand-held instrument installation box body, and an industrial computer is fixedly installed on the sealing plate; a data acquisition instrument, a high-frequency current sensor, a signal generator and a lithium battery are fixedly installed in the inner cavity of the waterproof portable hand-held instrument installation box body;

[0008] The industrial computer is electrically connected with the data acquisition instrument and the signal generator, and the lithium battery is electrically connected with the industrial computer, the data acquisition instrument, the high-frequency current sensor and the signal generator.

[0009] Preferably, the sealing plate is fixedly equipped with a charging port, a power switch, a power indicator, a USB port, and two detection line output interfaces with positive and negative terminals. The charging port and the power indicator are connected to the lithium battery. The power switch is electrically connected between the lithium battery and the industrial control computer, the data acquisition instrument, the high-frequency current sensor, and the signal generator. The USB port is connected to the industrial control computer, and the positive detection line output interface is connected to the high-frequency current sensor and the signal generator.

[0010] Preferably, a guide box is enclosed and connected to the sealing plate. The lower end of the guide box is located in the inner cavity of a waterproof portable instrument mounting box. A guide groove is provided inside the guide box. A mobile power supply is embedded in the guide groove. A first magnetic connector is installed on one side of the top of the mobile power supply. A second magnetic connector is fixedly installed on the inner cavity at the top of the guide groove in the guide box. The second magnetic connector is connected to a lithium battery.

[0011] Preferably, an isosceles triangular locking block is fixedly installed on one side of the lower end of the power bank, with the apex of the isosceles triangular locking block facing downwards. An isosceles triangular unlocking block is provided above the isosceles triangular locking block, with the apex of the isosceles triangular unlocking block facing upwards and slidably installed on one side of the power bank. Two mutually symmetrical right-angled triangular locking tongues are telescopically installed in the guide groove of the guide box, with the hypotenuse of the right-angled triangular locking tongues opening towards the top of the guide groove. A third spring is compressed and connected between the right-angled triangular locking tongues and the inner wall of the guide groove. Two fixing blocks for limiting the movement position of the right-angled triangular locking tongues are fixedly installed on the inner wall of the guide groove.

[0012] Preferably, two second springs for elastically supporting the mobile power supply are fixedly installed on the inner bottom surface of the guide groove, and a buffer plate is fixedly connected to the top of the two second springs. Several first springs are stretched between the isosceles triangular locking block and the isosceles triangular unlocking block.

[0013] Preferably, two signal input interfaces are also fixedly installed on the sealing plate.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. High efficiency and accuracy in detection: The system uses a signal generator to generate a fast-rising-edge step voltage signal, combined with a high-frequency current sensor to collect the incident and reflected waves of the traveling current. Based on the TDR principle, the system calculates the break point location, which can accurately determine the break point and abnormal point location of the lightning protection wire and judge the partial breakage of multi-core conductors.

[0016] 2. Low cost: Compared with traditional inspection methods that require workers to operate in a suspended platform, this device can enter the wind turbine and inspect at the hub, saving labor costs and inspection fees; after the break point is identified, targeted repairs can be carried out, avoiding the need to replace the entire lightning protection wire and saving maintenance costs.

[0017] 3. Portable and flexible: This application adopts a waterproof portable handheld instrument mounting box, which is easy to carry and can flexibly adapt to the testing environment of different wind turbine units.

[0018] 4. Strong battery life: The design of the guide box embedding the mobile power supply allows for uninterrupted power supply replacement during long-term field work, enhancing the lithium battery's battery life and ensuring continuous testing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model. Figure 1 ;

[0020] Figure 2 This is an exploded view of this utility model;

[0021] Figure 3 This is a schematic diagram of the overall structure of this utility model. Figure 2 ;

[0022] Figure 4 This is a schematic diagram of the connection structure between the guide box and the mobile power supply in this utility model.

[0023] In the diagram: 1. Charging port; 2. Power switch; 3. Power indicator; 4. USB port; 5. Detector output interface; 6. Signal input interface; 7. Industrial control computer; 8. Data acquisition instrument; 9. High-frequency current sensor; 10. Signal generator; 11. Lithium battery; 12. Waterproof portable handheld instrument mounting box; 13. Waterproof flip cover; 14. Sealing plate; 15. Guide box; 16. Power bank; 17. Second magnetic connector; 18. First magnetic connector; 19. Isosceles triangle locking block; 20. Isosceles triangle unlocking block; 21. First spring; 22. Second spring; 23. Fixing block; 24. Right-angled triangle locking tongue; 25. Third spring. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0025] Example 1:

[0026] like Figures 1-2A fault detection device for broken lightning protection wires of wind turbine generators includes a waterproof portable instrument mounting box 12 and a waterproof flip cover 13. One side of the waterproof flip cover 13 is rotatably connected to one side edge of the waterproof portable instrument mounting box 12. When the waterproof flip cover 13 is placed on top of the waterproof portable instrument mounting box 12, the waterproof performance and portability of the entire device in outdoor environments can be ensured.

[0027] A sealing plate 14 is sealed above the inner cavity of the waterproof portable instrument mounting box 12. An industrial control computer 7 is fixedly installed on the sealing plate 14. The industrial control computer 7 serves as the main control core unit and the human-machine interface. A data acquisition instrument 8, a high-frequency current sensor 9, a signal generator 10, and a lithium battery 11 are fixedly installed inside the waterproof portable instrument mounting box 12. The components are compactly integrated through a reasonable layout. The industrial control computer 7 is electrically connected to the data acquisition instrument 8 and the signal generator 10 to realize signal generation control, data acquisition, and analysis calculation. The lithium battery 11 is electrically connected to the industrial control computer 7, the data acquisition instrument 8, the high-frequency current sensor 9, and the signal generator 10 to provide power for the equipment operation.

[0028] In this embodiment, a charging port 1, a power switch 2, a power indicator 3, a USB port 4, and two positive and negative probe output interfaces 5 are fixedly installed on the sealing plate 14. The charging port 1 and the power indicator 3 are connected to the lithium battery 11. The power switch 2 is electrically connected in series between the lithium battery 11 and the industrial control computer 7, the data acquisition instrument 8, the high-frequency current sensor 9, and the signal generator 10 to control the start and stop of the entire device. The USB port 4 is connected to the industrial control computer 7 for data export or peripheral expansion. The positive probe output interface 5 is connected to the high-frequency current sensor 9 and the signal generator 10, and the negative probe output interface 5 is grounded to form a signal loop. Two signal input interfaces 6 are also fixedly installed on the sealing plate 14 for expanding external high-precision high-frequency current sensors to meet different detection accuracy requirements.

[0029] In this embodiment, the signal generator 10 generates a step voltage signal with an adjustable DC 10-30V and a rise time of less than 20ns according to the signal given by the operation controller. This signal is output to the lightning protection line under test through the high-frequency current sensor 9, forming a traveling wave current incident wave in the lightning protection line. This fast-rising-edge signal can effectively generate a clear and measurable traveling wave. Compared with the traditional simple loop continuity detection method, more information about the status of the lightning protection line can be obtained.

[0030] The high-frequency current sensor 9 is responsible for collecting the incident and reflected waves of the traveling wave current. Based on the working principle of the Rogowski coil, it has a response speed at the nanosecond level and a bandwidth of at least 50MHz. It can accurately capture the rapidly changing traveling wave current signal. When the length of the blade lightning arrester wire is limited and the echo time is at the nanosecond level, this high-precision acquisition capability is crucial, making up for the problem of difficulty in detecting the arrival time of the echo signal in the single-end traveling wave ranging principle method.

[0031] The data acquisition instrument 8 performs high-speed acquisition of the signal collected by the high-frequency current sensor 9 with a sampling frequency of at least 1 GHz and a bandwidth of 100 MHz. The acquired data is transmitted to the industrial control computer 7, which is equipped with detection software. The software first performs basic low-pass filtering and window selection on the data to remove noise interference and extract the effective signal. According to the traveling wave theory, when the end of the line is short-circuited, total reflection of voltage and total reflection of current will occur. By measuring the arrival time difference Δt of the incident wave and the reflected wave, combined with the pre-calibrated traveling wave velocity V, and by measuring Δts of the same type of cable with a known length of Ls, V = Ls ÷ Δts is calculated. The distance from the break point of the line under test to the test point is calculated using the formula Δt × V / 2. By comparing this distance with the original length of the lightning protection wire, it can be determined whether there is a break fault in the lightning protection wire and the specific location of the break point. This realizes the core function of lightning protection wire break detection. The break point is accurately located through the TDR principle. It is portable and waterproof and is suitable for detection inside the wind turbine hub.

[0032] It should be noted that the length of the lightning protection wire of the wind turbine blade is limited, and the reflection time of the traveling wave current is on the order of nanoseconds. In order to accurately capture the tiny time difference between the incident wave and the reflected wave of the traveling wave current and accurately calculate the breakpoint location, the high-frequency current sensor 9 must have a response speed on the order of nanoseconds. If the response speed is too slow, it will cause the reflected wave signal acquisition to be delayed or lost, and it will be impossible to accurately measure the time difference Δt between the incident wave and the reflected wave, thus affecting the breakpoint positioning accuracy based on the TDR principle.

[0033] The traveling wave current in the lightning protection wire contains rich high-frequency components. The bandwidth determines the response capability of the high-frequency current sensor to signals of different frequencies. A bandwidth of 50MHz can ensure that the sensor can effectively collect key frequency components in the traveling wave current signal and completely restore the traveling wave current waveform. If the bandwidth is insufficient, some high-frequency signals will be attenuated or distorted, resulting in the collected signal not being able to accurately reflect the true state of the lightning protection wire and reducing the detection accuracy.

[0034] The characteristics of lightning protection wires for wind turbines vary. Different lightning protection wires may require excitation signals of different amplitudes to generate clear and measurable traveling wave currents. The adjustable range of DC10-30V can meet the testing needs of various lightning protection wires, ensuring that the traveling wave current can effectively propagate in the lightning protection wire under different operating conditions, which facilitates the subsequent acquisition and analysis of reflected waves.

[0035] A step voltage signal with a fast rising edge can excite a traveling wave current rich in high-frequency components in the lightning protection wire. The shorter the rising edge, the higher the frequency components of the generated traveling wave signal, which is more conducive to propagation and reflection in a lightning protection wire of limited length. Moreover, the reflected wave is easier to detect and identify. A rising edge of less than 20ns can improve the sensitivity of the detection system to minor faults and enhance the detection capability of lightning protection wire breakage faults.

[0036] Because the traveling wave current signal changes rapidly and the echo time is on the order of nanoseconds, the data acquisition instrument 5 needs a high sampling rate to accurately acquire the waveform of the traveling wave current signal. A sampling rate of 1 GHz means that it can acquire 1 billion data points per second, which can capture the details of the changes in the traveling wave current signal in detail, and record the waveform characteristics of the incident wave and the reflected wave completely, providing a reliable data basis for subsequent accurate calculation of the time difference Δt and the location of the breakpoint.

[0037] The 100MHz bandwidth is matched with the high-frequency current sensor 9 to ensure that signals containing key frequency components of traveling wave current can be acquired. The 100MHz bandwidth ensures that the acquisition instrument will not lose important information due to bandwidth limitations when acquiring high-frequency signals, thus ensuring the quality of the acquired signal and improving detection accuracy.

[0038] Example 2: Example 2 is based on Example 1 and increases the battery life of this invention. It can increase the battery life of the lithium battery 11 in Example 1 by connecting it to a mobile power supply 16. The main differences are as follows:

[0039] like Figures 3-4 A guide box 15 is sealed and connected to the sealing plate 14. The lower end of the guide box 15 is located in the inner cavity of the waterproof portable instrument mounting box 12. A guide groove is provided inside the guide box 15. A mobile power supply 16 is installed in the guide groove. A first magnetic connector 18 is fixedly installed on one side of the top of the mobile power supply 16. A second magnetic connector 17 is fixedly installed on the inner cavity of the top of the guide groove in the guide box 15. The second magnetic connector 17 is connected to the lithium battery 11. When the mobile power supply 16 is installed in the guide groove, the second magnetic connector 17 and the first magnetic connector 18 automatically connect through magnetic attraction to achieve power replenishment. This supports the replacement of the mobile power supply 16 during long-term field operations to extend the battery life and increase the battery life of the lithium battery 11.

[0040] In this embodiment, an isosceles triangle locking block 19 is fixedly installed on one side of the lower end of the power bank 16, with the apex of the isosceles triangle locking block 19 facing downwards. An isosceles triangle unlocking block 20 is installed above the isosceles triangle locking block 19, with the apex of the isosceles triangle unlocking block 20 facing upwards and slidably installed on one side of the power bank 16. The width of the isosceles triangle locking block 19 is smaller than the width of the isosceles triangle unlocking block 20. Several first springs 21 are stretched between the isosceles triangle locking block 19 and the isosceles triangle unlocking block 20. The first springs 21 are mainly used to pull the isosceles triangle unlocking block 20 closer to the isosceles triangle locking block 19. The guide box 15 is telescopically installed in the guide groove. The device is equipped with two symmetrical right-angled triangular latches 24. The hypotenuse of the right-angled triangular latches 24 is inclined towards the top opening of the guide groove. A third spring 25 is compressed between the right-angled triangular latches 24 and the inner wall of the guide groove. The elastic force of the third spring 25 is greater than that of the first spring 21. Two fixing blocks 23 are fixedly installed on the inner wall of the guide groove to limit the movement of the right-angled triangular latches 24. The two fixing blocks 23 are used to limit the distance between the two right-angled triangular latches 24. Two second springs 22 are fixedly installed on the inner bottom surface of the guide groove to elastically support the mobile power supply 16. The top ends of the two second springs 22 are fixedly connected to a buffer plate.

[0041] The installation process of the portable power bank 16 is as follows: When installing the portable power bank 16, first align the side of the portable power bank 16 with the isosceles triangular locking block 19 with the opening of the guide groove of the guide box 15. When the isosceles triangular locking block 19 approaches the two right-angled triangular locking tongues 24, since the apex of the isosceles triangular locking block 19 is facing down, during the insertion process, the hypotenuse of the isosceles triangular locking block 19 will gradually squeeze the two right-angled triangular locking tongues 24. After being squeezed, the right-angled triangular locking tongues 24 will retract to both sides along the inner wall of the guide groove under the elastic force of the third spring 25. As the isosceles triangular locking block 19 continues to be inserted, when it completely passes through... After the two right-angled triangular locking tongues 24 are in place, the third spring 25 will push the right-angled triangular locking tongues 24 back to their original position, so that the hypotenuse of the right-angled triangular locking tongues 24 tightly abuts against the side of the isosceles triangular locking block 19. At this time, the two second springs 22 on the bottom surface of the guide groove will push the buffer plate upward, so that the bottom plate of the isosceles triangular locking block 19 on one side of the power supply 16 is firmly abutted against the two right-angled triangular locking tongues 24, realizing the stable installation of the power supply 16. At the same time, the first magnetic connector 18 on the top side of the power supply 16 will automatically magnetically connect with the second magnetic connector 17 on the inner cavity of the top of the guide groove in the guide box 15 to complete the power connection.

[0042] Disassembly procedure of power bank 16: When disassembling power bank 16, first press down on power bank 16 to move isosceles triangle unlocking block 20 downward. When the apex of isosceles triangle unlocking block 20 passes between two right triangle locking tongues 24, since the width of isosceles triangle locking block 19 is smaller than the width of isosceles triangle unlocking block 20, under the elastic pulling force of several first springs 21, isosceles triangle unlocking block 20 will move closer to isosceles triangle locking block 19, and the bases of the two will gradually stick together. At this time, continue to pull power bank 16 upward, and isosceles triangle unlocking block 20 will move upward with power bank 16. The hypotenuse of isosceles triangle unlocking block 20 will push the two right triangle locking tongues 24 to retract to both sides again. During the retraction of right triangle locking tongues 24, third spring 25 is further compressed. When isosceles triangle locking block 19 is completely free from the restriction of right triangle locking tongues 24, power bank 16 can be pulled out smoothly, completing the disassembly operation.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A fault detection device for broken lightning protection wires of wind turbine generators, comprising a waterproof portable handheld instrument mounting box (12) and a waterproof flip cover (13), characterized in that: The waterproof flip cover (13) is rotatably connected to one side edge of the waterproof portable instrument mounting box (12). A sealing plate (14) is sealed above the inner cavity of the waterproof portable instrument mounting box (12). An industrial control computer (7) is fixedly installed on the sealing plate (14). A data acquisition instrument (8), a high-frequency current sensor (9), a signal generator (10), and a lithium battery (11) are fixedly installed in the inner cavity of the waterproof portable instrument mounting box (12). The industrial control computer (7) is electrically connected to the data acquisition instrument (8) and the signal generator (10) respectively, and the lithium battery (11) is electrically connected to the industrial control computer (7), the data acquisition instrument (8), the high-frequency current sensor (9), and the signal generator (10) respectively.

2. The wind turbine lightning protection wire breakage fault detection device according to claim 1, characterized in that: The sealing plate (14) is fixedly installed with a charging port (1), a power switch (2), a power indicator (3), a USB port (4), and two probe line output interfaces (5) with positive and negative terminals. The charging port (1) and the power indicator (3) are connected to the lithium battery (11). The power switch (2) is electrically connected between the lithium battery (11) and the industrial control computer (7), the data acquisition instrument (8), the high-frequency current sensor (9), and the signal generator (10). The USB port (4) is connected to the industrial control computer (7), and the positive probe line output interface (5) is connected to the high-frequency current sensor (9) and the signal generator (10).

3. The wind turbine lightning protection wire breakage fault detection device according to claim 1, characterized in that: A guide box (15) is enclosed on the sealing plate (14). The lower end of the guide box (15) is located in the inner cavity of the waterproof portable instrument mounting box (12). A guide groove is provided inside the guide box (15). A mobile power supply (16) is installed in the guide groove. A first magnetic connector (18) is installed on one side of the top of the mobile power supply (16). A second magnetic connector (17) is fixedly installed on the inner cavity of the top of the guide groove in the guide box (15). The second magnetic connector (17) is connected to the lithium battery (11).

4. The wind turbine lightning protection wire breakage fault detection device according to claim 3, characterized in that: An isosceles triangular locking block (19) is fixedly installed on one side of the lower end of the power bank (16). The apex of the isosceles triangular locking block (19) is set downward. An isosceles triangular unlocking block (20) is set above the isosceles triangular locking block (19). The apex of the isosceles triangular unlocking block (20) is slidably installed on one side of the power bank (16) with its apex facing upward. Two mutually symmetrical right-angled triangular locking tongues (24) are telescopically installed in the guide groove of the guide box (15). The hypotenuse of the right-angled triangular locking tongues (24) is inclined towards the top of the guide groove. A third spring (25) is compressed and connected between the right-angled triangular locking tongues (24) and the inner wall of the guide groove. Two fixing blocks (23) for limiting the movement position of the right-angled triangular locking tongues (24) are fixedly installed on the inner wall of the guide groove.

5. The wind turbine lightning protection wire breakage fault detection device according to claim 4, characterized in that: Two second springs (22) for elastically supporting the mobile power supply (16) are fixedly installed on the inner bottom surface of the guide groove. A buffer plate is fixedly connected to the top of the two second springs (22). Several first springs (21) are stretched between the isosceles triangular locking block (19) and the isosceles triangular unlocking block (20).

6. The wind turbine lightning protection wire breakage fault detection device according to claim 1, characterized in that: Two signal input interfaces (6) are also fixedly installed on the sealing plate (14).

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