Lightning conductor detection system and method based on optical fiber transmission

Abstract

The invention provides a lightning conductor detection system and method based on optical fiber transmission. The lightning conductor detection system based on optical fiber transmission comprises an optical transmitting module, an optical receiving module and a signal processing module, the optical transmitting module comprises a triode and a light-emitting diode, and the control signal output end of the signal processing module controls the on and off of the triode through a periodic level signal so as to drive the light-emitting diode to generate an intermittent optical signal; the optical receiving module comprises a photosensitive diode and a pull-up resistor, the photosensitive diode is in light path coupling with the light emitting diode through an optical fiber, and an interruption detection end of the signal processing module is connected to a node between the photosensitive diode and the pull-up resistor. And the signal processing module judges the integrity of the optical fiber transmission path by monitoring the voltage amplitude change of the interruption detection end, so that the workload and property loss of maintenance personnel are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightning protection equipment, and in particular relates to a lightning protection line detection system and method based on optical fiber transmission. Background Art

[0002] Currently, some lightning protection devices, such as those with external display lightning protection devices, especially those used for wind turbines in mountainous areas, cannot automatically report whether a lightning strike requires replacement of the lightning conductor. This is because regular maintenance costs are very high. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a lightning protection line detection system and method based on optical fiber transmission, which are used to solve the technical problems of the above background technology.

[0004] On the one hand, the invention provides the following technical solutions: a lightning protection line detection system based on optical fiber transmission, comprising an optical transmitting module, an optical receiving module and a signal processing module;

[0005] The optical transmission module includes a transistor and a light emitting diode, and the periodic level signal passed through the control signal output end of the signal processing module controls the conduction and cutoff of the transistor to drive the light emitting diode to generate an intermittent optical signal;

[0006] The optical receiving module includes a photodiode and a pull-up resistor. The photodiode maintains optical path coupling with the light-emitting diode through an optical fiber. The interruption detection end of the signal processing module is connected to the node between the photodiode and the pull-up resistor. The signal processing module determines the integrity of the optical fiber transmission path by monitoring the voltage amplitude change at the interruption detection end.

[0007] Compared with the existing technology, the present invention has the following advantages: the control signal output terminal of the signal processing module outputs a periodic level signal, controlling the conduction and cutoff of the transistor, thereby driving the light-emitting diode to generate an intermittent light signal. The signal processing module further monitors the voltage amplitude change at the interruption detection terminal to determine the integrity of the optical fiber transmission path, providing automatic feedback on whether the lightning conductor needs to be replaced due to a lightning strike, reducing the need for passive replacement of lightning protection devices, thereby reducing the workload of maintenance personnel and property losses.

[0008] Furthermore, the base of the transistor is connected to the control signal output end via a current-limiting resistor.

[0009] Furthermore, the cathode of the light emitting diode is grounded, and the collector of the transistor is connected to the positive electrode of the power supply.

[0010] Furthermore, the resistance range of the pull-up resistor is 40.2 kΩ to 47 kΩ.

[0011] Furthermore, the signal processing module has a built-in analog-to-digital conversion unit and a logic judgment unit;

[0012] The analog-to-digital conversion unit is used to convert the analog voltage signal of the interrupt detection end into a digital signal;

[0013] The logic judgment unit is configured to generate a lightning conductor replacement alarm signal when it is detected that the voltage value of the digital signal is lower than a preset threshold and the duration exceeds a set time.

[0014] Furthermore, the preset threshold is an alarm threshold set at 60%-80% of the reference voltage value of the photodiode.

[0015] Furthermore, the optical fiber is an electromagnetic interference resistant multimode optical fiber, and the cladding diameter thereof matches the diameter of the light emitting area of the light emitting diode and the diameter of the light sensitive area of the photosensitive diode.

[0016] On the other hand, the present invention also proposes a lightning protection line detection method based on optical fiber transmission, comprising the following steps:

[0017] Outputting a periodic level signal through the control signal output terminal of the signal processing module to drive the light emitting diode to generate light pulses;

[0018] Transmitting the light pulse to a photodiode via an optical fiber for photoelectric conversion, and generating a corresponding voltage signal at an interruption detection end of the signal processing module;

[0019] Performing analog-to-digital conversion and waveform sampling on the voltage signal of the interruption detection end to obtain the amplitude of the voltage waveform;

[0020] It is determined whether the amplitude is continuously lower than a threshold value. If the amplitude is continuously lower than the threshold value, it is determined that the lightning protection line has been damaged by lightning.

[0021] Furthermore, the step of determining whether the amplitude is continuously lower than a threshold value includes:

[0022] A voltage amplitude reference curve under normal conditions is established, a correlation coefficient between the amplitude of the voltage waveform and the reference curve is calculated in real time, and it is determined whether the correlation coefficient is lower than a threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of module connection of a lightning protection line detection system based on optical fiber transmission in the first embodiment of the present invention.

[0024] Figure 2 This is a circuit connection diagram of a lightning protection line detection system based on optical fiber transmission in the first embodiment of the present invention.

[0025] Figure 3 This is a flow chart of a lightning protection line detection method based on optical fiber transmission in the second embodiment of the present invention.

[0026] Explanation of the main component symbols: 10. Optical transmitting module; 11. Transistor; 12. Light-emitting diode; 20. Optical receiving module; 21. Photosensitive diode; 22. Pull-up resistor; 30. Signal processing module; 31. Control signal output terminal; 32. Interrupt detection terminal; 40. Optical fiber; 41. Lightning conductor.

[0027] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0028] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] See also Figures 1 to 2 As shown, a lightning protection line 41 detection system based on optical fiber 40 transmission in a first embodiment of the present invention includes: an optical transmitting module 10, an optical receiving module 20 and a signal processing module 30;

[0032] The optical transmitting module 10 includes a transistor 11 and a light emitting diode 12. The control signal output terminal 31 of the signal processing module 30 controls the conduction and cutoff of the transistor 11 through a periodic level signal, thereby driving the light emitting diode 12 to generate an intermittent optical signal.

[0033] The optical receiving module 20 includes a photodiode 21 and a pull-up resistor 22. The photodiode 21 maintains optical path coupling with the light-emitting diode 12 through an optical fiber 40. The interruption detection end 32 of the signal processing module 30 is connected to the node between the photodiode 21 and the pull-up resistor 22. The signal processing module 30 determines the integrity of the transmission path of the optical fiber 40 by monitoring the voltage amplitude change of the interruption detection end 32.

[0034] The signal processing module 30 outputs a periodic level signal through the control signal output terminal 31, controlling the conduction and cutoff of the transistor 11, thereby driving the light-emitting diode 12 to generate an intermittent optical signal. The signal processing module 30 further monitors the voltage amplitude changes at the interruption detection terminal 32 to determine the integrity of the optical fiber 40 transmission path. This automatically provides feedback on whether the lightning protection cable 41 needs to be replaced due to a lightning strike, reducing the need for passive replacement of the lightning protection device, thereby reducing the workload of maintenance personnel and property losses.

[0035] Specifically, the base of the transistor 11 is connected to the control signal output terminal 31 via a current-limiting resistor.

[0036] Specifically, the cathode of the light emitting diode 12 is grounded, and the collector of the transistor 11 is connected to the positive electrode of the power supply.

[0037] Specifically, the resistance range of the pull-up resistor 22 is 40.2 kΩ to 47 kΩ.

[0038] Specifically, the signal processing module 30 has a built-in analog-to-digital conversion unit and a logic judgment unit;

[0039] The analog-to-digital conversion unit is used to convert the analog voltage signal of the interrupt detection terminal 32 into a digital signal;

[0040] The logic judgment unit is configured to generate an alarm signal for replacing the lightning conductor 41 when it is detected that the voltage value of the digital signal is lower than a preset threshold and the duration exceeds a set time.

[0041] Specifically, the preset threshold is an alarm threshold set according to 60%-80% of the reference voltage value of the photodiode 21 .

[0042] Specifically, the optical fiber 40 is an electromagnetic interference resistant multimode optical fiber 40 , and the cladding diameter thereof matches the diameter of the light emitting region of the light emitting diode 12 and the diameter of the light sensitive region of the photodiode 21 .

[0043] In this embodiment, the optical fiber 40 is wound around the lightning protection wire 41. On the left, the transistor 11 (Q1) and the light-emitting diode 12 (D1) are connected to the control signal output terminal 31 (GPIO1) of the microcontroller (MCU) of the signal processing module 30 to form an optical transmitting device. On the right, the pull-up resistor 22 (R1) and the photosensitive diode 21 (D2) form an optical receiving device, which is connected to the interrupt detection terminal 32 (ADC3_INT1) of the MCU. Under normal circumstances, the light emitted by the photodiode (D1) is received by D2 through the optical fiber 40, and then transmitted to the MCU through ADC3_INT1. When a severe lightning strike causes the lightning protection wire 41 to overheat, the red optical fiber 40 is damaged by the heat, and D2 cannot receive the normal optical signal. At this time, it is determined that the lightning protection wire 41 has been damaged and needs to be replaced.

[0044] Example 2

[0045] Refer to FIG3 , which shows a lightning protection line detection method based on optical fiber transmission in a second embodiment of the present invention, comprising the following steps S01 to S04:

[0046] S01, outputting a periodic level signal through the control signal output terminal of the signal processing module to drive the light emitting diode to generate light pulses;

[0047] S02, transmitting the light pulse to a photodiode via an optical fiber for photoelectric conversion, and generating a corresponding voltage signal at an interruption detection end of the signal processing module;

[0048] S03, performing analog-to-digital conversion and waveform sampling on the voltage signal of the interruption detection end to obtain the amplitude of the voltage waveform;

[0049] S04, determining whether the amplitude is continuously lower than a threshold value; if the amplitude is continuously lower than the threshold value, determining that the lightning protection line is damaged by lightning.

[0050] Specifically, the step of determining whether the amplitude is continuously lower than the threshold value includes:

[0051] A voltage amplitude reference curve under normal conditions is established, a correlation coefficient between the amplitude of the voltage waveform and the reference curve is calculated in real time, and it is determined whether the correlation coefficient is lower than a threshold.

[0052] In summary, the lightning protection line detection system and method based on optical fiber transmission in the above embodiments of the present invention are

[0053] The signal processing module's control signal output terminal outputs a periodic level signal, controlling the on / off switching of the transistor, which in turn drives the light-emitting diode to produce an intermittent optical signal. The signal processing module then monitors the voltage amplitude changes at the interruption detection terminal to determine the integrity of the optical fiber transmission path. This automatically provides feedback on whether the lightning conductor needs to be replaced due to a lightning strike, reducing the need for passive replacement of lightning arresters, thereby reducing maintenance workload and property losses.

[0054] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0055] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A lightning protection line detection system based on optical fiber transmission, characterized in that: It includes an optical transmitting module, an optical receiving module and a signal processing module; The optical transmission module includes a transistor and a light emitting diode, and the periodic level signal passed through the control signal output end of the signal processing module controls the conduction and cutoff of the transistor to drive the light emitting diode to generate an intermittent optical signal; The optical receiving module includes a photodiode and a pull-up resistor. The photodiode maintains optical path coupling with the light-emitting diode through an optical fiber. The interruption detection end of the signal processing module is connected to the node between the photodiode and the pull-up resistor. The signal processing module determines the integrity of the optical fiber transmission path by monitoring the voltage amplitude change at the interruption detection end.

2. The lightning protection line detection system based on optical fiber transmission according to claim 1, characterized in that: The base of the transistor is connected to the control signal output end through a current limiting resistor.

3. The lightning protection line detection system based on optical fiber transmission according to claim 1 is characterized in that: The cathode of the light emitting diode is grounded, and the collector of the transistor is connected to the positive electrode of the power supply.

4. The lightning protection line detection system based on optical fiber transmission according to claim 1, characterized in that: The resistance range of the pull-up resistor is 40.2 kΩ to 47 kΩ.

5. The lightning protection line detection system based on optical fiber transmission according to claim 1, characterized in that: The signal processing module has a built-in analog-to-digital conversion unit and a logic judgment unit; The analog-to-digital conversion unit is used to convert the analog voltage signal of the interrupt detection end into a digital signal; The logic judgment unit is configured to generate a lightning conductor replacement alarm signal when it is detected that the voltage value of the digital signal is lower than a preset threshold and the duration exceeds a set time.

6. The lightning protection line detection system based on optical fiber transmission according to claim 5, characterized in that: The preset threshold is an alarm threshold set at 60%-80% of the reference voltage value of the photodiode.

7. The lightning protection line detection system based on optical fiber transmission according to claim 1, characterized in that: The optical fiber is an electromagnetic interference resistant multimode optical fiber, and the cladding diameter thereof matches the diameter of the light emitting area of the light emitting diode and the diameter of the light sensitive area of the photosensitive diode.

8. A lightning protection line detection method based on optical fiber transmission, characterized in that: The detection circuit according to any one of claims 1 to 7 is used for implementation, comprising the following steps: Outputting a periodic level signal through the control signal output terminal of the signal processing module to drive the light emitting diode to generate light pulses; Transmitting the light pulse to a photodiode via an optical fiber for photoelectric conversion, and generating a corresponding voltage signal at an interruption detection end of the signal processing module; Performing analog-to-digital conversion and waveform sampling on the voltage signal of the interruption detection end to obtain the amplitude of the voltage waveform; It is determined whether the amplitude is continuously lower than a threshold value. If the amplitude is continuously lower than the threshold value, it is determined that the lightning protection line has been damaged by lightning.

9. The method for detecting lightning protection lines based on optical fiber transmission according to claim 8, characterized in that: The step of determining whether the amplitude is continuously lower than the threshold comprises: A voltage amplitude reference curve under normal conditions is established, a correlation coefficient between the amplitude of the voltage waveform and the reference curve is calculated in real time, and it is determined whether the correlation coefficient is lower than a threshold.

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