A fan blade lightning wire breakage fault online detection method, device and medium

Abstract

The application discloses a fan blade lightning conductor wire breakage fault online detection method, device and medium, and the device comprises a power taking module, a pulse generation module, a signal detection module and a remote monitoring system. The method steps are as follows: 1) the signal detection module receives a pulse signal transmitted by the lightning conductor wire, and the pulse signal is recorded as a pulse response signal; the signal detection module transmits the pulse response signal and the blade code to the remote monitoring system. 2) the remote monitoring system processes the pulse response signal, and if the pulse response signal amplitude is less than 15v or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning conductor wire of the current blade has a breakage fault, otherwise, step 3) is entered; 3) the remote monitoring system analyzes the pulse response signal and the pulse signal, and if the pulse response signal and the pulse signal waveform correlation coefficient is less than 0.9, it is determined that the lightning conductor wire has a breakage fault. The application can online detect the breakage fault of the lightning conductor wire of the fan blade after lightning stroke.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power generation equipment fault detection, in particular to a wind turbine blade lightning conductor wire breakage fault online detection method, device and medium. BACKGROUND

[0002] With the continuous development of wind power generation technology, wind power generation equipment is widely used all over the world, from offshore shoal to Gobi desert, from high mountain pass to vast grassland. The rotating part in contact with wind energy among various parts of wind power generation equipment is the blade. The huge blade may be subjected to the action of lightning during operation, especially in high mountain, offshore and other areas with more lightning. At present, the wind turbine blade basically has a lightning protection system, a lightning arrester is arranged at the blade tip, and there is also a lightning conductor wire inside the blade. The huge lightning current is led to the ground through the tower drum, and the lightning conductor wire of the wind turbine blade has become an important part of ensuring the normal operation of the wind turbine. The wind turbine blade lightning conductor wire can effectively prevent damage to the wind turbine blade caused by lightning.

[0003] However, the lightning conductor wire may be broken or damaged during long-term operation, which will result in the loss of lightning protection function and increase the safety risk of wind power generation equipment. If the lightning conductor wire cannot play the role of lightning guide, the isolated wind turbine will produce electric field distortion under the influence of the thundercloud electric field, and a large amount of non-uniform charge of the thundercloud will accumulate at the blade tip, and a tip discharge phenomenon will occur. When the lightning current generated by the lightning enters the hole of the blade, the lightning current will conduct along the channel inside the blade shell or to the blade surface outside the shell, which will produce lightning arc in the shell, and high temperature may cause the blade shell to burn near the material where the arc path is generated. At the same time, such high temperature may also produce a high-pressure shock wave, which will cause cracks or breakage of the blade shell after the blade is struck by lightning. Therefore, the good state of the lightning conductor wire of the wind turbine blade is very important for the safe, reliable and economic operation of the wind turbine.

[0004] The traditional detection method usually relies on manual inspection, mainly using Ohm's law in the circuit. The current detection method needs the assistance of cranes and robots, and has problems such as low efficiency, high cost and missed detection, and it is difficult to realize real-time monitoring of the wind turbine blade lightning conductor wire. Because of the problem of untimely detection, serious lightning accidents have been recorded many times in domestic and foreign wind farms. Therefore, there is an urgent need for an efficient, accurate and automatic online detection method to improve the safety and reliability of wind turbine operation. SUMMARY

[0005] The purpose of the present application is to provide a wind turbine blade lightning conductor wire breakage fault online detection device, which comprises a power taking module, a pulse generating module, a signal detection module and a remote monitoring system.

[0006] The energy collection module collects and converts lightning current energy to provide power for the pulse generation module;

[0007] The pulse generation module is installed at the tip of the fan blade and at the end of the lightning conductor;

[0008] The pulse generation module generates a pulse signal according to the pre-stored pulse signal parameters of the remote monitoring system and transmits it to the signal detection module through the lightning conductor;

[0009] The signal detection module is installed at the root of the fan blade;

[0010] The signal detection module receives the pulse signal transmitted by the lightning conductor, which is recorded as the pulse response signal;

[0011] The signal detection module transmits the pulse response signal and the blade code to the remote monitoring system;

[0012] The remote monitoring system pre-stores pulse signal parameters;

[0013] The remote monitoring system processes and analyzes the pulse response signal and the pulse signal to determine whether the lightning conductor of the current blade has a broken wire fault.

[0014] Further, when processing and analyzing the pulse response signal and the pulse signal, if the pulse response signal amplitude is less than 15v or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning conductor of the current blade has a broken wire fault;

[0015] If the correlation coefficient of the pulse response signal and the pulse signal waveform is less than 0.9, it is determined that the lightning conductor of the current blade has a broken wire fault, otherwise, it is determined that the lightning conductor of the current blade does not have a broken wire fault.

[0016] Further, the induction energy collection module is installed at the tip of the fan blade;

[0017] When the lightning strike arrester and the lightning conductor are struck, the induction energy collection module collects and converts lightning energy.

[0018] The energy collection module provides DC voltage for the pulse generation module.

[0019] Further, the amplitude, frequency and pulse width of the pulse signal are 20V, 0.1HZ and 500ns respectively.

[0020] Further, the energy collection module includes an energy collection transformer, an RC filter circuit, a regulation protection circuit and an isolation voltage stabilizing circuit;

[0021] The energy collection transformer is a multi-turn coil wound on a core;

[0022] The energy collection transformer is used to reduce the current of the lightning conductor;

[0023] The RC filter circuit is used for transforming the output current of the power taking transformer, and retaining the direct current component;

[0024] The adjustment protection circuit is used for preventing the damage of the voltage signal out of the design value to the circuit, and converting the current signal into voltage;

[0025] The isolation voltage stabilizing circuit outputs the direct current voltage signal to the pulse generation module, and isolates the pulse generation module side and the power supply side.

[0026] Further, the topology of the pulse generation module is as follows:

[0027] The No. 8 terminal and the No. 4 terminal of the timer chip are used as the input terminal of the pulse generation module, and are connected with the power taking module;

[0028] The No. 8 terminal of the timer chip is connected with the collector of the triode VT2 after connecting with the resistance R3 in series;

[0029] The No. 8 terminal of the timer chip is connected with the emitter of the triode VT1;

[0030] The No. 4 terminal of the timer chip is connected with the collector of the triode VT2 after connecting with the resistance R3 in series;

[0031] The No. 4 terminal of the timer chip is connected with the emitter of the triode VT1;

[0032] The base of the triode VT1 is connected with the collector of the triode VT2;

[0033] The collector of the triode VT1 is connected with the No. 7 terminal of the timer chip after connecting with the resistance R1, the slide resistance RP1 and the resistance R2 in series;

[0034] The emitter of the triode VT2 is connected with the ground after connecting with the resistance R4 in series;

[0035] The base of the triode VT2 is connected with the No. 3 terminal of the timer chip;

[0036] The No. 3 terminal of the timer chip is used as the output terminal of the pulse generation module;

[0037] The No. 6 terminal and the No. 2 terminal of the timer chip are connected with the slide terminal of the slide resistance RP1;

[0038] The No. 1 terminal of the timer chip is connected with the ground;

[0039] The No. 1 terminal of the timer chip is connected with the slide terminal of the slide resistance RP1 after connecting with the capacitor C1 in series;

[0040] The No. 5 terminal of the timer chip is connected with the ground after connecting with the capacitor C2 in series.

[0041] Further, the signal detection module comprises a power supply circuit, a current sensor, an acquisition circuit, a sending instruction verification circuit, a wireless sending circuit, and a control unit.

[0042] The power supply circuit is configured to provide power for active devices in the signal detection module.

[0043] The current sensor is configured to transform the pulse signal transmitted by the lightning conductor.

[0044] The acquisition circuit is configured to acquire the pulse signal transformed by the current sensor.

[0045] The sending instruction verification circuit is configured to start the signal detection module when the pulse generation module at the blade tip sends a pulse.

[0046] The wireless sending circuit is configured to transmit the signal acquired by the acquisition circuit and the lightning conductor coding information of the blade to the remote monitoring system by wireless transmission, and pre-store the parameter values in the remote monitoring system.

[0047] The control unit is configured to coordinate and control the circuits and devices in the signal detection module.

[0048] Further, the remote monitoring system comprises a data processing module, a data analysis module, and a warning module.

[0049] The data processing module is configured to filter and denoise the pulse response signal.

[0050] The data analysis module is configured to analyze the denoised pulse response signal and pulse signal, and determine whether the lightning conductor has a broken line fault.

[0051] When the lightning conductor has a broken line fault, the warning module sends a warning signal.

[0052] A method based on the online detection device for the broken line fault of the lightning conductor of the fan blade, comprising the following steps:

[0053] 1) The induction power module is used to collect and convert the lightning energy of the fan blade, thereby providing power for the pulse generator module.

[0054] 2) The pulse generation module generates a pulse signal according to the pre-stored pulse signal parameters of the remote monitoring system, and injects the pulse signal into the lightning conductor.

[0055] 3) The signal detection module receives the pulse signal transmitted by the lightning conductor, which is recorded as a pulse response signal; the signal detection module transmits the pulse response signal and the blade coding to the remote monitoring system.

[0056] 4) The remote monitoring system processes and analyzes the impulse response signal, if the amplitude of the impulse response signal is less than 15v or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning conductor of the current blade has a broken line fault, the determination is ended, and step 1) is returned to wait for the next online detection trigger; otherwise, step 5) is entered;

[0057] 5) The remote monitoring system analyzes the impulse response signal and the pulse signal, if the waveform correlation coefficient of the impulse response signal and the pulse signal is less than 0.9, it is determined that the lightning conductor of the current blade has a broken line fault, otherwise, it is determined that the lightning conductor has no broken line fault, and step 1) is returned to wait for the next online detection trigger.

[0058] The calculation formula of the correlation coefficient CC is as follows:

[0059]

[0060] In the formula, X and Y are characteristic quantities of the transfer function curve and the baseline data respectively. i is the frequency sequence number, X(i) and Y(i) are the amplitudes of the transfer function curve and the baseline data at frequency i respectively. That is, in this example, the baseline data refers to the applied pulse signal waveform, and the transfer function curve refers to the collected response pulse signal waveform.

[0061] A computer readable storage medium, the computer readable storage medium has a computer program stored thereon, the computer program is run by a processor to execute the method.

[0062] The technical effect of the present application is self-evident, the present application can solve the problems of traditional fault detection, such as the need for the assistance of cranes and robots, low efficiency, high cost, missed detection, complex operation and the like. The present application has the characteristics of high operability, fast detection speed, high sensitivity, high intelligent level and high reliability.

[0063] The present application can timely find the broken line fault by online monitoring the state of the lightning conductor of the fan blade, and improve the fault response speed. Once the broken line fault is detected, the present application can automatically issue a warning and notify the relevant personnel, reduce the workload of manual inspection, improve the operation and maintenance efficiency, avoid the safety hidden danger of the wind turbine caused by the broken line of the lightning conductor of the blade, and ensure the normal operation of the wind turbine. The present application reduces the downtime and maintenance cost caused by sudden failure through online monitoring and early warning. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 The working flow chart of the wind turbine blade lightning conductor broken line fault online detection method;

[0065] Figure 2 The modules of the wind turbine blade lightning conductor broken line fault online detection device;

[0066] Figure 3 The installation position of the online detection device module for the lightning conductor wire breakage fault of the fan blade;

[0067] Figure 4 The working relationship of the online detection device module for the lightning conductor wire breakage fault of the fan blade;

[0068] Figure 5 The schematic diagram of the power taking module of the online detection device;

[0069] Figure 6 The schematic diagram of the pulse generation module of the online detection device;

[0070] Figure 7 The principle block diagram of the signal detection module of the online detection device;

[0071] Figure 8 The collected waveform of the signal detection module of the online detection device;

[0072] Figure 9 The structural block diagram of a device provided by the embodiment of the application;

[0073] In the figure, 1: power taking module, 2: pulse generation module, 3: signal detection module, 4: remote monitoring system, 5: lightning conductor. DETAILED DESCRIPTION

[0074] The application will be further described below in conjunction with the embodiments, but should not be understood as limiting the above-mentioned subject matter of the application to the following embodiments. According to the ordinary technical knowledge and conventional means in the art, various substitutions and modifications can be made without departing from the above-mentioned technical idea of the application, and all should be included in the protection scope of the application.

[0075] Embodiment 1:

[0076] Referring to Figures 1 to 9 An online detection device for lightning conductor wire breakage fault of a fan blade, comprising a power taking module 1, a pulse generation module 2, a signal detection module 3, and a remote monitoring system 4;

[0077] The power taking module collects and converts lightning current energy, thereby providing power for the pulse generation module;

[0078] The pulse generation module is installed at the tip position of the fan blade and located at the end of the lightning conductor 5;

[0079] The pulse generation module generates a pulse signal according to the pulse signal parameters pre-stored by the remote monitoring system and transmits the pulse signal to the signal detection module through the lightning conductor;

[0080] The signal detection module is installed at the root position of the fan blade;

[0081] The signal detection module receives the pulse signal transmitted by the lightning conductor, denoted as a pulse response signal;

[0082] The signal detection module transmits the pulse response signal and the blade code to the remote monitoring system;

[0083] The remote monitoring system pre-stores pulse signal parameters;

[0084] The remote monitoring system processes and analyzes the pulse response signal and the pulse signal to determine whether the lightning conductor of the current blade has a broken wire fault.

[0085] When processing and analyzing the pulse response signal and the pulse signal, if the pulse response signal amplitude is less than 15v or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning conductor of the current blade has a broken wire fault;

[0086] If the pulse response signal and the pulse signal waveform correlation coefficient is less than 0.9, it is determined that the lightning conductor of the current blade has a broken wire fault, otherwise, it is determined that the lightning conductor of the current blade does not have a broken wire fault.

[0087] The inductive power module is installed at the tip position of the fan blade;

[0088] When the lightning strikes the lightning arrester and the lightning conductor, the inductive power module collects and converts the lightning energy.

[0089] The power module provides a direct current voltage for the pulse generation module.

[0090] The amplitude, frequency and pulse width of the pulse signal are 20V, 0.1HZ and 500ns respectively.

[0091] The power module includes a power inductor, an RC filter circuit, a regulation protection circuit, and an isolation voltage stabilizing circuit.

[0092] The power inductor is a multi-turn coil wound on a core.

[0093] The power inductor is used to reduce the current of the lightning conductor.

[0094] The RC filter circuit is used to transform the output current of the power inductor and retain the direct current component.

[0095] The regulation protection circuit is used to prevent damage to the circuit by voltage signals outside the design value, and to convert the current signal to voltage.

[0096] The isolation voltage stabilizing circuit outputs a direct current voltage signal to the pulse generation module and isolates the pulse generation module side and the power supply side.

[0097] The topology of the pulse generation module is shown as follows:

[0098] The No. 8 terminal and the No. 4 terminal of the timer chip are connected with the energy-taking module as the input end of the pulse generation module;

[0099] The No. 8 terminal of the timer chip is connected with the collector of the transistor VT2 after being connected with the resistance R3 in series;

[0100] The No. 8 terminal of the timer chip is connected with the emitter of the transistor VT1;

[0101] The No. 4 terminal of the timer chip is connected with the collector of the transistor VT2 after being connected with the resistance R3 in series;

[0102] The No. 4 terminal of the timer chip is connected with the emitter of the transistor VT1;

[0103] The base of the transistor VT1 is connected with the collector of the transistor VT2;

[0104] The collector of the transistor VT1 is connected with the No. 7 terminal of the timer chip after being connected with the resistance R1, the sliding resistance RP1 and the resistance R2 in series;

[0105] The emitter of the transistor VT2 is connected with the ground after being connected with the resistance R4 in series;

[0106] The base of the transistor VT2 is connected with the No. 3 terminal of the timer chip;

[0107] The No. 3 terminal of the timer chip is used as the output end of the pulse generation module;

[0108] The No. 6 terminal and the No. 2 terminal of the timer chip are connected with the sliding end of the sliding resistance RP1;

[0109] The No. 1 terminal of the timer chip is connected with the ground;

[0110] The No. 1 terminal of the timer chip is connected with the sliding end of the sliding resistance RP1 after being connected with the capacitor C1 in series;

[0111] The No. 5 terminal of the timer chip is connected with the ground after being connected with the capacitor C2 in series.

[0112] The signal detection module comprises a power supply circuit, a current sensor, an acquisition circuit, a sending instruction verification circuit, a wireless sending circuit and a control unit;

[0113] The power supply circuit is used for providing electric energy for active devices in the signal detection module;

[0114] The current sensor is used for transforming the pulse signal propagated through the lightning conductor;

[0115] The acquisition circuit is used for acquiring the pulse signal transformed through the current sensor;

[0116] The sending instruction verification circuit starts the signal detection module when the pulse generation module at the blade tip sends a pulse;

[0117] The wireless sending circuit transmits the signal collected by the collection circuit and the lightning conductor code information of the blade to the remote monitoring system through wireless transmission;

[0118] The control unit coordinates the control of the circuits and devices in the signal detection module.

[0119] The remote monitoring system includes a data processing module, a data analysis module, and a warning module;

[0120] The data processing module filters and denoises the pulse response signal;

[0121] The data analysis module analyzes the denoised pulse response signal and pulse signal to determine whether the lightning conductor has a broken line fault;

[0122] When the lightning conductor has a broken line fault, the warning module sends a warning signal.

[0123] Embodiment 2:

[0124] A wind turbine blade lightning conductor broken line fault online detection device includes a power taking module, a pulse generation module, a signal detection module, and a remote monitoring system;

[0125] The power taking module collects and converts lightning current energy to power the pulse generation module;

[0126] The pulse generation module is installed at the blade tip of the wind turbine and located at the end of the lightning conductor;

[0127] The pulse generation module generates a pulse signal based on the pre-stored pulse signal parameters of the remote monitoring system and transmits it to the signal detection module through the lightning conductor;

[0128] The signal detection module is installed at the blade root of the wind turbine;

[0129] The signal detection module receives the pulse signal transmitted by the lightning conductor, which is denoted as the pulse response signal;

[0130] The signal detection module transmits the pulse response signal and the blade code to the remote monitoring system;

[0131] The remote monitoring system pre-stores pulse signal parameters;

[0132] The remote monitoring system processes and analyzes the pulse response signal and the pulse signal to determine whether the lightning conductor of the current blade has a broken line fault.

[0133] Embodiment 3:

[0134] The technical content of the fan blade lightning conductor wire breakage fault online detection device is the same as that of embodiment 2, and further, when the pulse response signal and the pulse signal are processed and analyzed, if the pulse response signal amplitude is less than 15v or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning conductor wire of the current blade has a breakage fault.

[0135] If the pulse response signal and the pulse signal waveform correlation coefficient is less than 0.9, it is determined that the lightning conductor wire of the current blade has a breakage fault, otherwise, it is determined that the lightning conductor wire of the current blade does not have a breakage fault.

[0136] Embodiment 4:

[0137] The technical content of the fan blade lightning conductor wire breakage fault online detection device is the same as that of any one of embodiments 2-3, and further, the induction power module is installed at the blade tip position of the fan blade.

[0138] When the lightning strike arrester and the lightning conductor are struck, the induction power module collects and converts the lightning strike energy.

[0139] The power module provides a direct current voltage for the pulse generation module.

[0140] Embodiment 5:

[0141] The technical content of the fan blade lightning conductor wire breakage fault online detection device is the same as that of any one of embodiments 2-4, and further, the amplitude, frequency and pulse width of the pulse signal are 20V, 0.1HZ and 500ns respectively.

[0142] Embodiment 6:

[0143] The technical content of the fan blade lightning conductor wire breakage fault online detection device is the same as that of any one of embodiments 2-5, and further, the power module includes a power taking transformer, an RC filter circuit, a regulation protection circuit and an isolation voltage stabilizing circuit.

[0144] The power taking transformer is a multi-turn coil wound on an iron core;

[0145] The power taking transformer is used to reduce the current of the lightning conductor;

[0146] The RC filter circuit is used to transform the output current of the power taking transformer and retain the direct current component;

[0147] The regulation protection circuit is used to prevent damage to the circuit by voltage signals outside the design value, and convert the current signal into voltage;

[0148] The isolation voltage stabilizing circuit outputs a direct current voltage signal to the pulse generation module and isolates the pulse generation module side and the power supply side.

[0149] Embodiment 7

[0150] A fan blade lightning wire breakage fault online detection device, the technical content is same as any one of embodiments 2-6, further, the topology structure of the pulse generation module is as follows:

[0151] The 8th terminal and the 4th terminal of the timer chip are connected with the power taking module as the input end of the pulse generation module;

[0152] The 8th terminal of the timer chip is connected with the collector of the triode VT2 after connecting the resistance R3 in series;

[0153] The 8th terminal of the timer chip is connected with the emitter of the triode VT1;

[0154] The 4th terminal of the timer chip is connected with the collector of the triode VT2 after connecting the resistance R3 in series;

[0155] The 4th terminal of the timer chip is connected with the emitter of the triode VT1;

[0156] The base of the triode VT1 is connected with the collector of the triode VT2;

[0157] The collector of the triode VT1 is connected with the 7th terminal of the timer chip after connecting the resistance R1, the slide resistance RP1 and the resistance R2 in series;

[0158] The emitter of the triode VT2 is connected with the ground after connecting the resistance R4 in series;

[0159] The base of the triode VT2 is connected with the 3rd terminal of the timer chip;

[0160] The 3rd terminal of the timer chip is as the output end of the pulse generation module;

[0161] The 6th terminal and the 2nd terminal of the timer chip are connected with the slide end of the slide resistance RP1;

[0162] The 1st terminal of the timer chip is connected with the ground;

[0163] The 1st terminal of the timer chip is connected with the slide end of the slide resistance RP1 after connecting the capacitor C1 in series;

[0164] The 5th terminal of the timer chip is connected with the ground after connecting the capacitor C2 in series.

[0165] Embodiment 8

[0166] A fan blade lightning wire breakage fault online detection device, the technical content is same as any one of embodiments 2-7, further, the signal detection module includes a power supply circuit, a current sensor, an acquisition circuit, a sending instruction verification circuit, a wireless sending circuit and a control unit;

[0167] The power supply circuit is used for providing power for active devices in the signal detection module;

[0168] The current sensor is used for transforming the pulse signal transmitted through the lightning conductor;

[0169] The acquisition circuit is used for acquiring the pulse signal transformed through the current sensor;

[0170] The sending instruction verification circuit starts the signal detection module when the pulse generation module at the blade tip sends a pulse;

[0171] The wireless sending circuit transmits the signal acquired by the acquisition circuit and the lightning conductor coding information of the blade to the remote monitoring system through wireless transmission, and pre-stores the parameter values in the remote monitoring system;

[0172] The control unit coordinates and controls the circuits and devices in the signal detection module.

[0173] Embodiment 9:

[0174] A wind turbine blade lightning conductor breakage fault online detection device, the technical content is the same as any one of embodiments 2-8, further, the remote monitoring system comprises a data processing module, a data analysis module, and a warning module;

[0175] The data processing module filters and denoises the pulse response signal;

[0176] The data analysis module analyzes the denoised pulse response signal and the pulse signal to determine whether the lightning conductor has a breakage fault;

[0177] When the lightning conductor has a breakage fault, the warning module sends a warning signal.

[0178] Embodiment 10:

[0179] A method based on the wind turbine blade lightning conductor breakage fault online detection device according to any one of embodiments 1-9, comprising the following steps:

[0180] 1) The induction power module is used to collect and convert the lightning energy of the wind turbine blade, thereby providing power for the pulse generator module;

[0181] 2) The pulse generation module generates a pulse signal according to the pre-stored pulse signal parameters of the remote monitoring system, and injects the pulse signal into the lightning conductor;

[0182] 3) The signal detection module receives the pulse signal transmitted by the lightning conductor, which is recorded as a pulse response signal; the signal detection module transmits the pulse response signal and the blade coding to the remote monitoring system;

[0183] 4) The remote monitoring system processes and analyzes the impulse response signal, if the amplitude of the impulse response signal is less than 15v or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning conductor of the current blade has a broken line fault, the determination is ended, and step 1) is returned to wait for the next online detection trigger; otherwise, step 5) is entered;

[0184] 5) The remote monitoring system analyzes the impulse response signal and the pulse signal, if the waveform correlation coefficient of the impulse response signal and the pulse signal is less than 0.9, it is determined that the lightning conductor of the current blade has a broken line fault, otherwise, it is determined that the lightning conductor has no broken line fault, and step 1) is returned to wait for the next online detection trigger.

[0185] The calculation formula of the correlation coefficient CC is as follows:

[0186]

[0187] In the formula, X and Y are characteristic quantities of the transfer function curve and the baseline data respectively. i is the frequency sequence number, and X(i) and Y(i) are the amplitudes of the transfer function curve and the baseline data at frequency i respectively. That is, in this example, the baseline data refers to the applied pulse signal waveform, and the transfer function curve refers to the collected response pulse signal waveform.

[0188] Embodiment 11:

[0189] A computer readable storage medium, the computer readable storage medium has a computer program stored thereon, the computer program is run by a processor to execute the method of any one of embodiments 1-9.

[0190] Embodiment 12:

[0191] An online detection method for broken line fault of a lightning conductor of a fan blade, specifically comprising the following steps:

[0192] Step one: install an inductive power module at the blade tip, which can collect and convert energy after the lightning arrester and the lightning conductor, and provide stable DC voltage to power the pulse generator module.

[0193] Step two: after the lightning arrester and the lightning conductor, the pulse generator module installed at the end of the lightning conductor at the blade tip generates a pulse signal with an amplitude of 20V, a frequency of 0.1HZ, and a pulse width of 500ns according to the set rules, and injects these pulse signals into the lightning conductor for propagation.

[0194] Step three: install a signal detection module at the blade root, which is paired with the pulse generation module at the blade tip, detects and collects the pulse signal from the lightning conductor after receiving the pulse instruction, and transmits the collected signal to the remote monitoring system through wireless mode.

[0195] Step four: in the remote monitoring system, the signal sent by the detection module is analyzed, and small signal noise is filtered out. If no large pulse is detected, that is, the amplitude is lower than 15V and the pulse width is not between 470ns and 530ns, it is considered that the lightning conductor has a broken line fault, and a warning is given through the remote monitoring system; if the pulse is detected, the waveform of the pulse is further analyzed. If the difference between the preset value in step two is not large, it is considered that the lightning conductor has no broken line fault, and step one is turned to continue waiting for the next online detection trigger.

[0196] Embodiment 13:

[0197] A lightning conductor broken line fault online detection device for fan blades, comprising: a power taking module, a pulse generating module, a signal detection module, and a remote monitoring system.

[0198] The power taking module is used to collect lightning current energy and provide stable DC voltage through circuit transformation.

[0199] The pulse generating module is used to generate a pulse signal with a specific amplitude, frequency and pulse width, and the parameters can be set as amplitude 20V, frequency 0.1HZ and pulse width 500ns. The signal is input to the lightning conductor to be detected for propagation.

[0200] The signal detection module is used to detect and collect the pulse signal propagated by the lightning conductor after receiving the instruction from the pulse generating module.

[0201] The remote monitoring system is used to wirelessly receive the blade number and collected signal from the signal detection module, analyze the collected signal, and then make a judgment on the lightning conductor broken line state.

[0202] The power taking module comprises a power taking transformer, an RC filter circuit, a regulation protection circuit, an isolation voltage stabilizing circuit, and a pulse generating module.

[0203] The power taking transformer is used to transform the current of the lightning conductor, and is composed of a core wound multi-turn coil, thereby reducing the original lightning conductor current.

[0204] The RC filter circuit is used to transform the output current of the power taking transformer and retain the DC component.

[0205] The regulation protection circuit is used to prevent voltage signals outside the design value from damaging the circuit, and to convert the current signal into voltage.

[0206] The isolation voltage stabilizing circuit is used to output a stable DC voltage signal, while isolating the load side and the power supply side.

[0207] The pulse generation module comprises a timer chip, a capacitor, a resistor, a transistor and the like.

[0208] The signal detection module comprises a power supply circuit, a current sensor, an acquisition circuit, a sending instruction verification circuit, a wireless sending circuit and a control core.

[0209] The power supply circuit is used for providing electric energy for active devices in the signal detection module.

[0210] The current sensor is used for transforming the pulse signal propagated through the lightning conductor.

[0211] The acquisition circuit is used for acquiring the pulse signal transformed through the current sensor.

[0212] The sending instruction verification circuit is used for instructing the pulse generation module at the blade tip to send a pulse at a moment, so as to start the signal detection module to work.

[0213] The wireless sending circuit is used for wirelessly transmitting the signal obtained by the acquisition circuit together with the lightning conductor lightning conductor number information to the remote monitoring system, and pre-storing the parameter value in the remote monitoring system.

[0214] The control core is used for coordinately controlling each circuit, device and the like in the signal detection module.

[0215] The remote monitoring system further comprises an upper computer, which is used for receiving and processing the signal transmitted by the signal detection module.

[0216] The upper computer comprises a data processing module, a data analysis module and a pre-warning module, which are used for comparing and analyzing the received pulse signal, if a larger pulse is not detected, it is considered that the lightning conductor has a broken line fault, and a pre-warning is given through the remote monitoring system; if a pulse is detected and the difference with the preset value is not large, it is considered that the lightning conductor has no broken line fault.

[0217] Embodiment 14:

[0218] An online detection device for a broken line fault of a fan blade lightning conductor, comprising a power taking module, a pulse generation module, a signal detection module and a remote monitoring system. Figure 2 The online detection device for a broken line fault of a fan blade lightning conductor comprises various modules.

[0219] The power taking module is used for collecting lightning current energy and transforming the energy through a circuit to provide a stable direct current voltage.

[0220] The pulse generation module is used to generate a pulse signal with an amplitude of 20V, a frequency of 0.1HZ and a pulse width of 500ns, and input the signal to the lightning conductor to be detected for propagation.

[0221] The signal detection module is used to detect and collect the pulse signal propagated by the lightning conductor after receiving the instruction from the pulse generation module.

[0222] The remote monitoring system is used to wirelessly receive the paddle number and the collected signal from the signal detection module, analyze the collected signal, and then make a judgment on the lightning conductor breakage state.

[0223] Figure 3 The installation position of the fan blade lightning conductor breakage fault online detection device module is shown. Figure 4 The working relationship of the fan blade lightning conductor breakage fault online detection device module is shown.

[0224] The power taking module includes a power taking transformer, an RC filter circuit, an adjustment protection circuit, an isolation voltage stabilizing circuit and a pulse generation module. Figure 5 The principle diagram of the power taking module of the online detection device is shown.

[0225] The power taking transformer is used to transform the current of the lightning conductor, adopts a multi-turn coil composed of a core, thereby reducing the original lightning conductor current. The core adopts nanocrystalline soft magnetic alloy to improve the high-frequency response characteristics.

[0226] The RC filter circuit is used to transform the output current of the power taking transformer and retain the DC component. The low-frequency cutoff frequency of the RC filter circuit is less than 20Hz.

[0227] The adjustment protection circuit is used to prevent the damage of surge voltage beyond the design value to the circuit, and convert the current signal into voltage. The circuit is composed of protection components such as metal oxide varistors and transient suppression diodes.

[0228] The isolation voltage stabilizing circuit is used to output a stable DC voltage signal, and simultaneously isolate the load side and the power supply side. A transformer isolation voltage stabilizing circuit is adopted.

[0229] The pulse generation module includes a timer chip, a capacitor, a resistor, a transistor and the like. The pulse generation module controls the output waveform pulse width, frequency and other parameters by adjusting the values of the capacitor, resistor and other elements.

[0230] The principle diagram of the pulse generation module of the online detection device is shown. Figure 6 The principle diagram of the pulse generation module of the online detection device is shown. The timer chip adopts a 555 chip, and the transistor adopts 2N3904 and 2N3906.

[0231] The signal detection module comprises a power supply circuit, a current sensor, an acquisition circuit, a sending instruction verification circuit, a wireless sending circuit and a control core. Figure 7 Fig. 1 shows a principle block diagram of a signal detection module of an online detection device.

[0232] The power supply circuit is used to provide power for active devices in the signal detection module. The core uses an AC-DC conversion chip.

[0233] The current sensor is used to convert the pulse signal propagated through the lightning conductor. A high-frequency current sensor is used, with a frequency band not less than 1Hz-1MHz.

[0234] The acquisition circuit is used to acquire the pulse signal converted by the current sensor. A high-speed sampling chip is used, with a bit number not less than 12-14 bits and a sampling rate not less than 5Msps.

[0235] The sending instruction verification circuit is used to instruct the pulse generation module at the blade tip to send a pulse, so as to start the signal detection module to work.

[0236] The wireless sending circuit is used to wirelessly transmit the signal obtained by the acquisition circuit together with the lightning conductor number information to the remote monitoring system. A 4G / 5G, LoRa or other communication mode is used.

[0237] The control core is used to coordinately control each circuit and device in the signal detection module. A 32-bit single-chip microcomputer chip is used as the core device.

[0238] The remote monitoring system further comprises an upper computer. The upper computer is used to receive and process the signal transmitted by the signal detection module.

[0239] The upper computer comprises a data processing module, a data analysis module and a warning module. The received pulse signal is compared and analyzed. If no large pulse is detected, i.e. the amplitude is lower than 15V and the pulse width is not between 470ns and 530ns, it is considered that the lightning conductor has a broken line fault, and a warning is given through the remote monitoring system. If the detected pulse has no large difference from the preset value, it is considered that the lightning conductor has no broken line fault. If the correlation coefficient between the applied pulse signal waveform and the acquired response pulse signal waveform is less than 0.9, it is considered that the difference is greater than the preset value, and it is considered that the lightning conductor has a broken line fault.

Claims

1. An online detection device for broken lightning protection wire faults of wind turbine blades, characterized in that, Includes an energy harvesting module, a pulse generation module, a signal detection module, and a remote monitoring system; The energy harvesting module collects and converts lightning current energy to power the pulse generation module; The pulse generation module is installed at the tip of the wind turbine blade and is located at the end of the lightning protection wire; The pulse generation module generates a pulse signal based on the pulse signal parameters pre-stored in the remote monitoring system, and transmits it to the signal detection module through the lightning protection line; The signal detection module is installed at the root of the wind turbine blades; The signal detection module receives the pulse signal transmitted by the lightning protection wire, which is denoted as the pulse response signal; The signal detection module transmits the pulse response signal and the code of the blade to the remote monitoring system; The remote monitoring system pre-stores pulse signal parameters; The remote monitoring system processes and analyzes the pulse response signal and the pulse signal to determine whether the lightning protection wire of the blade has broken. The energy harvesting module includes an energy harvesting transformer, an RC filter circuit, an adjustment and protection circuit, and an isolation and voltage regulation circuit. The energy harvesting transformer is a multi-turn coil wound with an iron core; The current-collecting transformer is used to reduce the current in the lightning protection wire; The RC filter circuit is used to transform the output current of the energy harvesting transformer while retaining the DC component; The regulating protection circuit is used to prevent voltage signals outside the design value from damaging the circuit, and to convert the current signal into voltage; The isolation voltage regulator circuit outputs a DC voltage signal to the pulse generation module and isolates the pulse generation module side from the power supply side. The topology of the pulse generation module is shown below: Terminals 8 and 4 of the timer chip serve as input terminals for the pulse generation module and are connected to the power extraction module. The timer chip's terminal 8 is connected in series with resistor R3 and then connected to the collector of transistor VT2; Terminal 8 of the timer chip is connected to the emitter of transistor VT1; The collector of transistor VT2 is connected in series with resistor R3 at terminal 4 of the timer chip. Terminal 4 of the timer chip is connected to the emitter of transistor VT1; The base of transistor VT1 is connected to the collector of transistor VT2; The collector of transistor VT1 is connected in series with resistor R1, sliding resistor RP1, and resistor R2, and then connected to terminal 7 of the timer chip. The emitter of transistor VT2 is connected to ground after being connected in series with resistor R4. The base of transistor VT2 is connected to terminal 3 of the timer chip; Terminal 3 of the timer chip serves as the output terminal of the pulse generation module; Terminals 6 and 2 of the timer chip are connected to the sliding end of the sliding resistor RP1; Terminal 1 of the timer chip is grounded; The timer chip's terminal 1 is connected in series with capacitor C1 and then connected to the sliding end of sliding resistor RP1; The timer chip's terminal 5 is connected to ground via a series capacitor C2.

2. The online detection device for broken lightning protection wire of wind turbine blades according to claim 1, characterized in that, When processing and analyzing pulse response signals and pulse signals, if the amplitude of the pulse response signal is less than 15V or the pulse width is not within the range [470ns, 530ns], it is determined that there is a break in the lightning protection wire of the current blade. If the correlation coefficient between the pulse response signal and the pulse signal waveform is less than 0.9, it is determined that there is a breakage fault in the lightning protection wire of the current blade; otherwise, it is determined that there is no breakage fault in the lightning protection wire of the current blade.

3. The online detection device for broken lightning protection wire of wind turbine blades according to claim 1, characterized in that, The inductive energy harvesting module is installed at the tip of the wind turbine blades; After the lightning arrester and lightning protection wire are installed, the inductive energy harvesting module collects and converts the lightning energy. The power harvesting module provides DC voltage to the pulse generation module.

4. The online detection device for broken lightning protection wire of wind turbine blades according to claim 1, characterized in that, The amplitude, frequency, and pulse width of the pulse signal are 20V, 0.1Hz, and 500ns, respectively.

5. The online detection device for broken lightning protection wire of wind turbine blades according to claim 1, characterized in that, The signal detection module includes a power supply circuit, a current sensor, a data acquisition circuit, a transmission command verification circuit, a wireless transmission circuit, and a control unit. The power supply circuit is used to provide power to the active devices in the signal detection module; The current sensor is used to transform the pulse signal propagated through the lightning protection wire; The acquisition circuit is used to acquire the pulse signal after it has been transformed by the current sensor; The transmission command verification circuit activates the signal detection module at the moment the pulse generation module at the blade tip emits a pulse. The wireless transmission circuit transmits the signals collected by the acquisition circuit and the lightning protection wire coding information of the blade to the remote monitoring system via wireless transmission. The control unit coordinates and controls the circuits and devices in the signal detection module.

6. The online detection device for broken lightning protection wire of wind turbine blades according to claim 1, characterized in that, The remote monitoring system includes a data processing module, a data analysis module, and an early warning module; The data processing module filters and denoises the impulse response signal; The data analysis module analyzes the denoised pulse response signal and pulse signal to determine whether there is a breakage fault in the lightning protection wire. When there is a break in the lightning protection wire, the early warning module will issue an early warning signal.

7. A method for online detection of broken wire faults in the lightning protection wire of a wind turbine blade according to any one of claims 1-6, characterized in that, Includes the following steps: 1) The energy from lightning strikes on the wind turbine blades is collected and converted using an inductive energy harvesting module, thereby powering the pulse generator module; 2) The pulse generation module generates a pulse signal based on the pulse signal parameters pre-stored in the remote monitoring system and injects it into the lightning protection line; 3) The signal detection module receives the pulse signal transmitted by the lightning protection wire, which is denoted as the pulse response signal; The signal detection module transmits the pulse response signal and the code of the blade to the remote monitoring system; 4) The remote monitoring system processes and analyzes the pulse response signal. If the amplitude of the pulse response signal is less than 15V or the pulse width is not within the range [470ns, 530ns], it is determined that there is a broken wire fault in the current blade's lightning protection wire, the determination ends, and the system returns to step 1) to wait for the next online detection trigger; otherwise, it proceeds to step 5). 5) The remote monitoring system analyzes the pulse response signal and the pulse signal. If the correlation coefficient between the pulse response signal and the pulse signal waveform is less than 0.9, it is determined that there is a breakage fault in the lightning protection wire of the current blade. Otherwise, it is determined that there is no breakage fault in the lightning protection wire, and the system returns to step 1) to wait for the next online detection trigger.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the method described in any one of claims 1 to 7.

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