Online detection method and device for broken line fault of lightning conductor of fan blade and medium

Abstract

The invention discloses an online detection method and device for a broken line fault of a lightning conductor of a fan blade and a medium. The device comprises an energy taking module, a pulse generation module, a signal detection module and a remote monitoring system. The method comprises the following steps: 1) the signal detection module receives a pulse signal transmitted by the lightning conductor and records the pulse signal as a pulse response signal; and the signal detection module transmits the pulse response signal and the blade code to a remote monitoring system. (2) the remote monitoring system processes the pulse response signal, if the amplitude of the pulse response signal is smaller than 15 v or the pulse width does not belong to the range [470 ns, 530 ns], it is judged that the lightning conductor of the current blade has a broken line fault, and otherwise, the step (3) is executed; and 3) the remote monitoring system analyzes the pulse response signal and the pulse signal, and if the waveform correlation coefficient of the pulse response signal and the pulse signal is less than 0.9, the lightning conductor is judged to have a broken line fault. According to the invention, the broken line fault condition of the lightning conductor of the fan blade after lightning stroke can be detected on line.

Description

Technical Field

[0001] The invention relates to the field of wind power generation equipment fault detection, in particular to a method, a device and a medium for online detection of wind turbine blade lightning arrester disconnection faults. Background Art

[0002] With the continuous development of wind power generation technology, wind power generation equipment is widely used all over the world, from offshore shallows to the Gobi Desert, from high mountain passes to vast grasslands. Among all the components of wind power generation equipment, the rotating parts that are in direct contact with wind energy are the blades. The huge blades may often be struck by lightning during operation, especially in high mountains, offshore and other areas with many lightning. At present, the blades of wind turbines are basically equipped with lightning protection systems, with lightning arresters at the tip of the blades and lightning conductors inside the blades. The huge lightning current is led to the earth through the tower. In the actual operation process, the lightning conductors of wind turbine blades have become an important part of ensuring the normal operation of wind turbines. The lightning conductors of wind turbine blades can effectively prevent lightning from damaging the wind turbine blades.

[0003] However, lightning conductors may break or be damaged during long-term operation, which will lead to the loss of lightning protection function and increase the safety risk of wind power generation equipment. If the lightning conductor cannot play a role in conducting lightning, the isolated wind turbine will produce electric field distortion under the influence of the electric field of the thunderstorm cloud, and a large amount of non-uniform charge of the thunderstorm cloud will accumulate at the tip of the blade, and tip discharge will occur at the same time. When the current generated by the lightning strike enters the hole of the blade, the current of the lightning strike is conducted along the channel inside the blade shell or to the blade surface outside the shell, which will generate a lightning arc in the shell. The high temperature sometimes produces a burning blade shell near the material that generates the arc path. At the same time, this high temperature may also generate a high-pressure shock wave, causing cracks in the outer shell of the blade after being struck by lightning or the blade shell to break. Therefore, a good lightning conductor state for the blades of wind turbines is crucial to ensure the safe, reliable and economical operation of wind turbines.

[0004] Traditional detection methods usually rely on manual inspections, mainly using Ohm's law in circuits. Current detection methods require the assistance of cranes and robots, and have problems such as low efficiency, high cost, and missed detection. It is difficult to achieve real-time monitoring of wind turbine blade lightning arresters. Due to problems such as untimely detection, serious lightning accidents have been recorded in wind farms at home and abroad many times. Therefore, there is an urgent need for an efficient, accurate, and automated online detection method to improve the safety and operational reliability of wind turbines. Summary of the invention

[0005] The purpose of the present invention is to provide an online detection device for a wind turbine blade lightning arrester disconnection fault, comprising an energy taking module, a pulse generating module, a signal detecting module, and a remote monitoring system;

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

[0007] The pulse generating module is installed at the tip of the fan blade and at the end of the lightning protection line;

[0008] The pulse generation module generates a pulse signal according to the pulse signal parameters pre-stored in the remote monitoring system, and transmits the pulse signal to the signal detection module through the lightning protection line;

[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 protection line, 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 a line break fault occurs in the lightning protection line of the current blade.

[0014] Furthermore, when the pulse response signal and the pulse signal are processed and analyzed, if the amplitude of the pulse response signal is less than 15V or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning protection line of the current blade has a broken wire fault;

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

[0016] Furthermore, the induction energy acquisition module is installed at the tip of the wind turbine blade;

[0017] When lightning strikes the lightning rod and lightning conductor, the induction energy collection module collects and converts the lightning energy.

[0018] The energy acquisition module provides a DC voltage to the pulse generation module.

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

[0020] Furthermore, the energy acquisition module includes an energy acquisition transformer, an RC filter circuit, a regulation protection circuit, and an isolation voltage stabilization circuit;

[0021] The energy-taking transformer is a multi-turn coil wound around an iron core;

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

[0023] The RC filter circuit is used to transform the output current of the energy transformer and retain the DC component;

[0024] The regulating protection circuit is used to prevent the voltage signal outside the design value from damaging the circuit and convert the current signal into voltage;

[0025] The isolated voltage stabilizing circuit outputs a DC voltage signal to the pulse generating module, and isolates the pulse generating module side from the power supply side.

[0026] Furthermore, the topological structure of the pulse generating module is as follows:

[0027] Terminals 8 and 4 of the timer chip are used as input terminals of the pulse generation module and are connected to the energy acquisition module;

[0028] The 8th terminal of the timer chip is connected in series with the resistor R 3 Then connect the transistor VT 2 The collector;

[0029] Terminal 8 of the timer chip is connected to transistor VT 1 The emitter of

[0030] The No. 4 terminal of the timer chip is connected in series with the resistor R 3 Then connect the transistor VT 2 The collector;

[0031] Terminal 4 of the timer chip is connected to transistor VT 1 The emitter of

[0032] Transistor VT 1 The base of transistor VT is connected 2 The collector;

[0033] Transistor VT 1 The collector series resistance R 1 、Sliding resistance RP 1 , resistor R 2 Then connect to terminal 7 of the timer chip;

[0034] Transistor VT 2 The emitter series resistor R 4 Rear grounding;

[0035] Transistor VT 2 The base of is connected to the No. 3 terminal of the timer chip;

[0036] Terminal 3 of the timer chip is used as the output terminal of the pulse generation module;

[0037] Terminal 6, terminal 2 of the timer chip and the sliding resistor RP1 Sliding end connection;

[0038] Terminal 1 of the timer chip is grounded;

[0039] Terminal 1 of the timer chip is connected in series with capacitor C1 and then connected to sliding resistor RP 1 The sliding end;

[0040] The No. 5 terminal of the timer chip is connected in series with capacitor C 2 Then ground.

[0041] Furthermore, the signal detection module includes a power supply circuit, a current sensor, an acquisition circuit, a sending instruction verification circuit, a wireless transmission circuit, and a control unit;

[0042] The power supply circuit is used to provide power to the active devices in the signal detection module;

[0043] The current sensor is used to transform the pulse signal after being propagated through the lightning protection wire;

[0044] The acquisition circuit is used to acquire the pulse signal after being transformed by the current sensor;

[0045] The sending instruction verification circuit starts the signal detection module when the pulse generation module at the blade tip sends a pulse;

[0046] The wireless transmission circuit transmits the signal collected by the collection circuit and the coding information of the blade lightning protection line to the remote monitoring system by wireless transmission, and pre-stores the parameter value in the remote monitoring system;

[0047] The control unit coordinates and controls the circuits and devices in the signal detection module.

[0048] Furthermore, the remote monitoring system includes a data processing module, a data analysis module, and an early warning module;

[0049] The data processing module performs filtering and denoising on the impulse response signal;

[0050] The data analysis module analyzes the denoised impulse response signal and the impulse signal to determine whether there is a disconnection fault in the lightning protection line;

[0051] When there is a wire break fault in the lightning protection line, the early warning module sends out an early warning signal.

[0052] A method based on the online detection device for the broken wire fault of a wind turbine blade lightning arrester comprises the following steps:

[0053] 1) Use the induction energy acquisition module to collect and convert the lightning energy of the wind turbine blades to provide energy for the pulse generator module;

[0054] 2) The pulse generating module generates a pulse signal according to the pulse signal parameters pre-stored in the remote monitoring system, and injects the pulse signal into the lightning protection line;

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

[0056] 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 does not fall within the range [470ns, 530ns], it is determined that the lightning protection line of the current blade has a broken line fault, the determination is ended, and the system returns to step 1) to wait for the next online detection trigger; otherwise, the system proceeds to step 5);

[0057] 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 the lightning protection line of the current blade has a broken wire fault. Otherwise, it is determined that the lightning protection line has no broken wire fault and returns to step 1) to wait for the next online detection trigger.

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

[0059]

[0060] In the formula, X and Y are the characteristic quantities of the transfer function curve and the baseline data, respectively. i is the frequency 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.

[0061] A computer-readable storage medium stores a computer program, which is executed by a processor to execute the method.

[0062] The technical effect of the present invention is unquestionable. The present invention can solve the problems that traditional fault detection requires the assistance of cranes and robots, has low efficiency, high cost, missed detection, and complex operation. The present invention has the characteristics of high operability, fast detection speed, high sensitivity, high intelligence level, and high reliability.

[0063] The present invention can detect the disconnection fault in time and improve the fault response speed by online monitoring of the status of the wind turbine blade lightning arrester. Once the disconnection fault is detected, the present invention can automatically issue an early warning and notify relevant personnel, reducing the workload of manual inspections, improving operation and maintenance efficiency, avoiding the safety hazards of wind turbines caused by the disconnection of blade lightning arresters, and ensuring the normal operation of wind turbines. The present invention reduces the downtime and maintenance costs caused by sudden failures through online monitoring and early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 The flowchart of the online detection method of the wind turbine blade lightning arrester disconnection fault is shown;

[0065] Figure 2 It is composed of various modules of the online detection device for the broken wire fault of the wind turbine blade lightning arrester;

[0066] Figure 3 It is the installation position of the module of the online detection device for the broken wire of the wind turbine blade lightning arrester;

[0067] Figure 4 The working relationship of the module of the online detection device for the broken wire fault of the wind turbine blade lightning arrester;

[0068] Figure 5 It is the principle diagram of the energy acquisition module of the online detection device;

[0069] Figure 6 It is the principle diagram of the pulse generation module of the online detection device;

[0070] Figure 7 It is a principle block diagram of a signal detection module of an online detection device;

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

[0072] Fig. 9 A structural block diagram of a device provided by an embodiment of the present invention;

[0073] In the figure, 1: energy acquisition module, 2: pulse generation module, 3: signal detection module, 4: remote monitoring system, 5: lightning protection line. DETAILED DESCRIPTION

[0074] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0075] Embodiment 1:

[0076] See also Figures 1 to 9 , an online detection device for a wind turbine blade lightning arrester disconnection fault, comprising an energy taking module 1, a pulse generating module 2, a signal detecting module 3, and a remote monitoring system 4;

[0077] The energy acquisition module collects and converts lightning current energy to provide energy for the pulse generation module;

[0078] The pulse generating module is installed at the tip of the fan blade and at the end of the lightning protection line 5;

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

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

[0081] The signal detection module receives the pulse signal transmitted by the lightning protection line, which is recorded as the 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 a line break fault occurs in the lightning protection line of the current blade.

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

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

[0087] The induction energy acquisition module is installed at the tip of the fan blade;

[0088] When lightning strikes the lightning rod and lightning conductor, the induction energy collection module collects and converts the lightning energy.

[0089] The energy acquisition module provides a DC voltage to the pulse generation module.

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

[0091] The energy acquisition module includes an energy acquisition transformer, an RC filter circuit, a regulation protection circuit, and an isolation voltage stabilization circuit;

[0092] The energy-taking transformer is a multi-turn coil wound around an iron core;

[0093] The energy transformer is used to reduce the current of the lightning conductor;

[0094] The RC filter circuit is used to transform the output current of the energy transformer and retain the DC component;

[0095] The regulating protection circuit is used to prevent the voltage signal outside the design value from damaging the circuit and convert the current signal into voltage;

[0096] The isolated voltage stabilizing circuit outputs a DC voltage signal to the pulse generating module, and isolates the pulse generating module side from the power supply side.

[0097] The topological structure of the pulse generation module is as follows:

[0098] Terminals 8 and 4 of the timer chip are used as input terminals of the pulse generation module and are connected to the energy acquisition module;

[0099] The 8th terminal of the timer chip is connected in series with the resistor R 3 Then connect the transistor VT 2 The collector;

[0100] Terminal 8 of the timer chip is connected to transistor VT 1 The emitter of

[0101] The No. 4 terminal of the timer chip is connected in series with the resistor R 3 Then connect the transistor VT 2 The collector;

[0102] Terminal 4 of the timer chip is connected to transistor VT 1 The emitter of

[0103] Transistor VT 1 The base of transistor VT is connected 2 The collector;

[0104] Transistor VT 1 The collector series resistance R 1 、Sliding resistance RP 1 , resistor R 2 Then connect to terminal 7 of the timer chip;

[0105] Transistor VT 2 The emitter series resistor R 4 Rear grounding;

[0106] Transistor VT 2 The base of is connected to the No. 3 terminal of the timer chip;

[0107] Terminal 3 of the timer chip is used as the output terminal of the pulse generation module;

[0108] Terminal 6, terminal 2 of the timer chip and the sliding resistor RP 1 Sliding end connection;

[0109] Terminal 1 of the timer chip is grounded;

[0110] Terminal 1 of the timer chip is connected in series with capacitor C1 and then connected to sliding resistor RP 1 The sliding end;

[0111] The No. 5 terminal of the timer chip is connected in series with capacitor C 2 Then ground.

[0112] 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;

[0113] The power supply circuit is used to provide power to the active devices in the signal detection module;

[0114] The current sensor is used to transform the pulse signal after being propagated through the lightning protection wire;

[0115] The acquisition circuit is used to acquire the pulse signal after being transformed by 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 transmission circuit transmits the signal collected by the collection circuit and the coding information of the blade lightning protection line to the remote monitoring system by wireless transmission;

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

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

[0120] The data processing module performs filtering and denoising on the impulse response signal;

[0121] The data analysis module analyzes the denoised impulse response signal and the impulse signal to determine whether there is a disconnection fault in the lightning protection line;

[0122] When there is a wire break fault in the lightning protection line, the early warning module sends out an early warning signal.

[0123] Embodiment 2:

[0124] An online detection device for a wind turbine blade lightning arrester disconnection fault, comprising an energy acquisition module, a pulse generation module, a signal detection module, and a remote monitoring system;

[0125] The energy acquisition module collects and converts lightning current energy to provide energy for the pulse generation module;

[0126] The pulse generating module is installed at the tip of the fan blade and at the end of the lightning protection line;

[0127] The pulse generation module generates a pulse signal according to the pulse signal parameters pre-stored in the remote monitoring system, and transmits the pulse signal to the signal detection module through the lightning protection line;

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

[0129] The signal detection module receives the pulse signal transmitted by the lightning protection line, which is recorded 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 a line break fault occurs in the lightning protection line of the current blade.

[0133] Embodiment 3:

[0134] An online detection device for a broken wire fault of a wind turbine blade lightning arrester, the technical content of which is the same as that of Example 2. Further, when the pulse response signal and the pulse signal are processed and analyzed, if the amplitude of the pulse response signal is less than 15V or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning arrester of the current blade has a broken wire fault;

[0135] If the correlation coefficient between the impulse response signal and the impulse signal waveform is less than 0.9, it is determined that the lightning protection line of the current blade has a broken wire fault; otherwise, it is determined that the lightning protection line of the current blade does not have a broken wire fault.

[0136] Embodiment 4:

[0137] An online detection device for a wind turbine blade lightning arrester disconnection fault, the technical content of which is the same as any one of Embodiments 2-3, and further, the induction energy acquisition module is installed at the tip of the wind turbine blade;

[0138] When lightning strikes the lightning rod and lightning conductor, the induction energy collection module collects and converts the lightning energy.

[0139] The energy acquisition module provides a DC voltage to the pulse generation module.

[0140] Embodiment 5:

[0141] An online detection device for a wind turbine blade lightning arrester wire break fault, the technical content of which is the same as any one of Examples 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] An online detection device for a wind turbine blade lightning arrester disconnection fault, the technical content of which is the same as any one of Embodiments 2-5, and further, the energy taking module includes an energy taking transformer, an RC filter circuit, a regulating protection circuit, and an isolation voltage stabilizing circuit;

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

[0145] The energy 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 energy transformer and retain the DC component;

[0147] The regulating protection circuit is used to prevent the voltage signal outside the design value from damaging the circuit and convert the current signal into voltage;

[0148] The isolated voltage stabilizing circuit outputs a DC voltage signal to the pulse generating module, and isolates the pulse generating module side from the power supply side.

[0149] Embodiment 7:

[0150] An online detection device for a wind turbine blade lightning arrester disconnection fault, the technical content of which is the same as any one of Embodiments 2-6, and further, the topological structure of the pulse generating module is as follows:

[0151] Terminals 8 and 4 of the timer chip are used as input terminals of the pulse generation module and are connected to the energy acquisition module;

[0152] The 8th terminal of the timer chip is connected in series with the resistor R 3 Then connect the transistor VT 2 The collector;

[0153] Terminal 8 of the timer chip is connected to transistor VT 1 The emitter of

[0154] The No. 4 terminal of the timer chip is connected in series with the resistor R 3 Then connect the transistor VT 2 The collector;

[0155] Terminal 4 of the timer chip is connected to transistor VT 1 The emitter of

[0156] Transistor VT 1 The base of transistor VT is connected2 The collector;

[0157] Transistor VT 1 The collector series resistance R 1 、Sliding resistance RP 1 , resistor R 2 Then connect to terminal 7 of the timer chip;

[0158] Transistor VT 2 The emitter series resistor R 4 Rear grounding;

[0159] Transistor VT 2 The base of is connected to the No. 3 terminal of the timer chip;

[0160] Terminal 3 of the timer chip is used as the output terminal of the pulse generation module;

[0161] Terminal 6, terminal 2 of the timer chip and the sliding resistor RP 1 Sliding end connection;

[0162] Terminal 1 of the timer chip is grounded;

[0163] Terminal 1 of the timer chip is connected in series with capacitor C1 and then connected to sliding resistor RP 1 The sliding end;

[0164] The No. 5 terminal of the timer chip is connected in series with capacitor C 2 Then ground.

[0165] Embodiment 8:

[0166] An online detection device for a wind turbine blade lightning arrester disconnection fault, the technical content of which is the same as any one of Embodiments 2-7, and 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 to provide power to the active devices in the signal detection module;

[0168] The current sensor is used to transform the pulse signal after being propagated through the lightning protection wire;

[0169] The acquisition circuit is used to acquire the pulse signal after being transformed by 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 transmission circuit transmits the signal collected by the collection circuit and the coding information of the blade lightning protection line to the remote monitoring system by wireless transmission, and pre-stores the parameter value 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] An online detection device for a wind turbine blade lightning arrester disconnection fault, the technical content of which is the same as any one of Embodiments 2-8, and further, the remote monitoring system includes a data processing module, a data analysis module, and an early warning module;

[0175] The data processing module performs filtering and denoising on the impulse response signal;

[0176] The data analysis module analyzes the denoised impulse response signal and the impulse signal to determine whether there is a disconnection fault in the lightning protection line;

[0177] When there is a wire break fault in the lightning protection line, the early warning module sends out an early warning signal.

[0178] Embodiment 10:

[0179] A method for online detection of wind turbine blade lightning arrester disconnection faults based on any one of embodiments 1-9, comprising the following steps:

[0180] 1) Use the induction energy acquisition module to collect and convert the lightning energy of the wind turbine blades to provide energy for the pulse generator module;

[0181] 2) The pulse generating module generates a pulse signal according to the pulse signal parameters pre-stored in the remote monitoring system, and injects the pulse signal into the lightning protection line;

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

[0183] 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 does not fall within the range [470ns, 530ns], it is determined that the lightning protection line of the current blade has a broken line fault, the determination is ended, and the system returns to step 1) to wait for the next online detection trigger; otherwise, the system proceeds to step 5);

[0184] 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 the lightning protection line of the current blade has a broken wire fault. Otherwise, it is determined that the lightning protection line has no broken wire fault and returns to step 1) to wait for the next online detection trigger.

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

[0186]

[0187] In the formula, X and Y are the characteristic quantities of the transfer function curve and the baseline data, respectively. i is the frequency 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 stores a computer program, which executes the method described in any one of embodiments 1-9 when executed by a processor.

[0190] Embodiment 12:

[0191] An online detection method for a wind turbine blade lightning arrester disconnection fault specifically comprises the following steps:

[0192] Step 1: By installing an inductive energy harvesting module at the tip of the blade, energy can be collected and converted after the lightning strikes the lightning rod and the lightning conductor, providing a stable DC voltage to power the pulse generator module.

[0193] Step 2: After the lightning striker and 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: A signal detection module is installed at the blade root and paired with the pulse generating module at the blade tip. After receiving the pulse command, the module detects and collects the pulse signal transmitted from the lightning conductor. The detection module numbers the blade and transmits it together with the collected signal wirelessly to the remote monitoring system.

[0195] Step 4: In the remote monitoring system, analyze the signal sent by the detection module and filter out smaller signal noise. If no larger pulse is detected, that is, the amplitude is lower than 15V and the pulse width is not between 470ns and 530ns, it can be considered that the lightning conductor has a broken wire fault, and an early warning is issued through the remote monitoring system; if a pulse is detected, further analyze the waveform of the pulse. If it is not much different from the preset value in step 2, it can be considered that the lightning conductor has no broken wire fault, and go to step 1 to continue waiting for the next online detection trigger.

[0196] Embodiment 13:

[0197] An online detection device for a wind turbine blade lightning arrester disconnection fault comprises an energy acquisition module, a pulse generation module, a signal detection module and a remote monitoring system.

[0198] The energy acquisition module is used to collect lightning current energy and provide a stable DC voltage through circuit conversion.

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

[0200] The signal detection module is used to detect and collect the pulse signal transmitted from the lightning protection line after receiving the instruction from the pulse generation module.

[0201] The remote monitoring system is used to wirelessly receive the blade number and the acquisition signal sent by the signal detection module, and analyze the acquisition signal to make a judgment on the disconnection state of the lightning protection line.

[0202] The energy acquisition module includes an energy acquisition mutual inductor, an RC filtering circuit, a regulating and protecting circuit, an isolation voltage stabilizing circuit, and a pulse generating module.

[0203] The energy-taking transformer is used to transform the current of the lightning conductor, and is formed by winding a plurality of turns of coil around an iron core, thereby reducing the current of the original lightning conductor.

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

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

[0206] The isolated voltage stabilizing circuit is used to output a stable DC voltage signal and isolate the load side and the power supply side at the same time.

[0207] The pulse generation module includes a timer chip, a capacitor, a resistor, a triode, etc. The pulse generation module controls the output waveform pulse width, frequency and other parameters by adjusting the values ​​of components such as capacitors and resistors.

[0208] 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 core.

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

[0210] The current sensor is used to transform the pulse signal transmitted through the lightning protection line.

[0211] The acquisition circuit is used to acquire the pulse signal transformed by the current sensor.

[0212] The sending instruction verification circuit is used to indicate the pulse generation module at the blade tip to send a pulse, thereby starting the signal detection module to start working.

[0213] The wireless transmission circuit is used to wirelessly transmit the signal obtained by the acquisition circuit together with the blade lightning protection line number information to the remote monitoring system, and pre-store its parameter value in the remote monitoring system.

[0214] The control core is used to coordinate and control various circuits, devices, etc. in the signal detection module.

[0215] The remote monitoring system also includes a host computer for receiving, processing and analyzing the signal transmitted by the signal detection module.

[0216] The host computer includes a data processing module, a data analysis module, and an early warning module. It is used to compare and analyze the received pulse signals. If no large pulse is detected, it can be considered that the lightning conductor has a disconnection fault, and an early warning is issued through the remote monitoring system; if a pulse is detected and the difference with the preset value is not large, it can be considered that the lightning conductor has no disconnection fault.

[0217] Embodiment 14:

[0218] An online detection device for a wind turbine blade lightning arrester disconnection fault comprises an energy acquisition module, a pulse generation module, a signal detection module and a remote monitoring system. Figure 2 The figure shows the components of various modules of the online detection device for the broken wire of the wind turbine blade lightning arrester.

[0219] The energy acquisition module is used to collect lightning current energy and provide a stable DC voltage through circuit conversion.

[0220] The pulse generating 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 protection line to be inspected for propagation.

[0221] The signal detection module is used to detect and collect the pulse signal transmitted from the lightning protection line after receiving the instruction from the pulse generation module.

[0222] The remote monitoring system is used to wirelessly receive the blade number and the acquisition signal sent by the signal detection module, and analyze the acquisition signal to make a judgment on the disconnection state of the lightning protection line.

[0223] Figure 3 The figure shows the installation position of the online detection device module for the broken lightning protection line of the wind turbine blade. Figure 4 The figure shows the working relationship of the modules of the online detection device for the broken lightning protection line of the wind turbine blade.

[0224] The energy acquisition module includes an energy acquisition transformer, an RC filter circuit, a regulation protection circuit, an isolation voltage stabilization circuit, and a pulse generation module. Figure 5 Shown is the schematic diagram of the energy acquisition module of the online detection device.

[0225] The energy-taking transformer is used to transform the current of the lightning conductor, and is composed of a multi-turn coil wound around an iron core, thereby reducing the current of the original lightning conductor. The iron core is made of 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 energy transformer and retain the DC component. The low-frequency cutoff frequency of the RC filter circuit is less than 20 Hz.

[0227] The regulating protection circuit is used to prevent the surge voltage outside the design value from damaging 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 stabilization circuit is used to output a stable DC voltage signal and isolate the load side from the power supply side. A transformer is used to isolate the voltage stabilization circuit.

[0229] The pulse generation module includes a timer chip, a capacitor, a resistor, a triode, etc. The pulse generation module controls the output waveform pulse width, frequency and other parameters by adjusting the values ​​of components such as capacitors and resistors.

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

[0231] The signal detection module includes a power supply circuit, a current sensor, a collection circuit, a transmission instruction verification circuit, a wireless transmission circuit, and a control core. Figure 7 Shown is a principle block diagram of the signal detection module of the online detection device.

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

[0233] The current sensor is used to transform the pulse signal transmitted through the lightning protection line. A high-frequency current sensor is used, and the frequency band is not less than 1Hz-1MHz.

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

[0235] The sending instruction verification circuit is used to indicate the pulse generation module at the blade tip to send a pulse, thereby starting the signal detection module to start working.

[0236] The wireless transmission circuit is used to wirelessly transmit the signal obtained by the acquisition circuit together with the blade lightning protection line number information to the remote monitoring system, using 4G / 5G, LoRa and other communication methods.

[0237] The control core is used to coordinate and control various circuits and devices in the signal detection module, and a 32-bit single-chip microcomputer chip is used as the core device.

[0238] The remote monitoring system also includes a host computer for receiving, processing and analyzing the signal transmitted by the signal detection module.

[0239] The host computer includes a data processing module, a data analysis module, and an early warning module. It is used to compare and analyze the received pulse signal. 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 can be considered that the lightning conductor has a disconnection fault, and an early warning is issued through the remote monitoring system; if the pulse is detected and the difference with the preset value is not large, it can be considered that the lightning conductor has no disconnection fault. If the correlation coefficient between the applied pulse signal waveform and the collected response pulse signal waveform is less than 0.9, it can be considered that the difference is greater than the preset value, and it is considered that the lightning conductor has a disconnection fault.

Claims

1. An online detection device for a wind turbine blade lightning arrester disconnection fault, characterized in that: It includes an energy acquisition module, a pulse generation module, a signal detection module, and a remote monitoring system. The energy acquisition module collects and converts lightning current energy to provide energy for the pulse generation module; The pulse generating module is installed at the tip of the fan blade and at the end of the lightning protection line; The pulse generation module generates a pulse signal according to the pulse signal parameters pre-stored in the remote monitoring system, and transmits the pulse signal to the signal detection module through the lightning protection line; The signal detection module is installed at the root of the fan blade; The signal detection module receives the pulse signal transmitted by the lightning protection line, which is recorded as the pulse response signal; The signal detection module transmits the pulse response signal and the blade code 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 a line break fault occurs in the lightning protection line of the current blade.

2. The online detection device for wind turbine blade lightning arrester disconnection fault according to claim 1 is characterized in that: When processing and analyzing the pulse response signal and the pulse signal, if the amplitude of the pulse response signal is less than 15V or the pulse width does not belong to the range [470ns, 530ns], it is determined that the lightning protection line of the current blade has a broken wire fault; If the correlation coefficient between the impulse response signal and the impulse signal waveform is less than 0.9, it is determined that the lightning protection line of the current blade has a broken wire fault; otherwise, it is determined that the lightning protection line of the current blade does not have a broken wire fault.

3. The online detection device for wind turbine blade lightning arrester disconnection fault according to claim 1 is characterized in that: The induction energy acquisition module is installed at the tip of the fan blade; When lightning strikes the lightning rod and lightning conductor, the induction energy collection module collects and converts the lightning energy. The energy acquisition module provides a DC voltage to the pulse generation module.

4. The online detection device for wind turbine blade lightning arrester disconnection fault according to claim 1 is 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 wind turbine blade lightning arrester disconnection fault according to claim 1 is characterized in that: The energy acquisition module includes an energy acquisition transformer, an RC filter circuit, a regulation protection circuit, and an isolation voltage stabilization circuit; The energy-taking transformer is a multi-turn coil wound around an iron core; The energy transformer is used to reduce the current of the lightning conductor; The RC filter circuit is used to transform the output current of the energy transformer and retain the DC component; The regulating protection circuit is used to prevent the voltage signal outside the design value from damaging the circuit and convert the current signal into voltage; The isolated voltage stabilizing circuit outputs a DC voltage signal to the pulse generating module, and isolates the pulse generating module side from the power supply side.

6. The online detection device for wind turbine blade lightning arrester disconnection fault according to claim 1, characterized in that: The topological structure of the pulse generation module is as follows: Terminals 8 and 4 of the timer chip are used as input terminals of the pulse generation module and are connected to the energy acquisition module; Terminal 8 of the timer chip 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; Terminal 4 of the timer chip is connected in series with resistor R3 and then connected to the collector of transistor VT2; 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 in series with resistor R4 and then grounded; The base of transistor VT2 is connected to terminal 3 of the timer chip; Terminal 3 of the timer chip is used as the output terminal of the pulse generation module; Terminal 6 and terminal 2 of the timer chip are connected to the sliding end of the sliding resistor RP1; Terminal 1 of the timer chip is grounded; Terminal 1 of the timer chip is connected in series with capacitor C1 and then connected to the sliding end of the sliding resistor RP1; Terminal 5 of the timer chip is connected in series with capacitor C2 and then grounded.

7. The online detection device for wind turbine blade lightning arrester disconnection fault according to claim 1 is characterized in that: 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; 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 after being propagated through the lightning protection wire; The acquisition circuit is used to acquire the pulse signal after being transformed by the current sensor; The sending instruction verification circuit starts the signal detection module when the pulse generation module at the blade tip sends a pulse; The wireless transmission circuit transmits the signal collected by the collection circuit and the coding information of the blade lightning protection line to the remote monitoring system by wireless transmission; The control unit coordinates and controls the circuits and devices in the signal detection module.

8. The online detection device for wind turbine blade lightning arrester disconnection fault 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 performs filtering and denoising on the impulse response signal; The data analysis module analyzes the denoised impulse response signal and the impulse signal to determine whether there is a disconnection fault in the lightning protection line; When there is a wire break fault in the lightning protection line, the early warning module sends out an early warning signal.

9. A method for online detection of wind turbine blade lightning arrester disconnection fault based on any one of claims 1 to 8, characterized in that: The following steps are involved: 1) Use the induction energy acquisition module to collect and convert the lightning energy of the wind turbine blades to provide energy for the pulse generator module; 2) The pulse generating module generates a pulse signal according to the pulse signal parameters pre-stored in the remote monitoring system, and injects the pulse signal into the lightning protection line; 3) The signal detection module receives the pulse signal transmitted by the lightning protection line, which is recorded as the pulse response signal; The signal detection module transmits the pulse response signal and the blade code 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 does not fall within the range [470ns, 530ns], it is determined that the lightning protection line of the current blade has a broken line fault, the determination is ended, and the system returns to step 1) to wait for the next online detection trigger; otherwise, the system 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 the lightning protection line of the current blade has a broken wire fault. Otherwise, it is determined that the lightning protection line has no broken wire fault and returns to step 1) to wait for the next online detection trigger.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 8 is executed.

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