Fault detection method and system for wind turbine blade lightning arrester

Abstract

The invention discloses a fault detection method and system for a wind turbine blade lightning arrester, the wind turbine blade lightning arrester comprises a lightning arrester and a wire thereof, the wire is arranged in a wind turbine blade in a feeder mode, the lightning arrester is connected with one end, close to the tip of the wind turbine blade, of the wire, and the fault detection method comprises the following steps: acquiring parameter data of the wind turbine blade; calculating the signal frequency of a to-be-generated alternating current signal based on the fan blade parameter data; generating an AC electrical signal having a signal frequency by an electromagnetic wave emission device including an electromagnetic wave generation circuit; transmitting an alternating current signal of which the signal intensity is gradually increased to an electromagnetic wave receiving device arranged on the unmanned aerial vehicle through a transmitting antenna and a wire included in the electromagnetic wave transmitting device; wherein the alternating current signal is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning arrester breaks down or not based on whether the amplitude of the direct current voltage signal corresponding to the alternating current signal meets a preset threshold range or not.

Description

Technical Field

[0001] The present disclosure generally relates to the fields of wind power generation technology and wireless communication technology, and more specifically, to a fault detection method and system for a lightning protection device for a wind turbine blade. Background Art

[0002] In the wind power industry, as wind energy, a clean and renewable energy source, has gradually become one of the most scalable energy sources, the requirements for various design indicators and parameters of wind turbines (referred to as "units") are becoming increasingly higher. For example, in order to utilize more wind energy, the demand for single-unit capacity is increasing, the hub height is increasing, and the impeller diameter is increasing. In addition, more and more units are being used in areas with complex terrain and harsh environments. These situations may increase the risk of units being struck by lightning.

[0003] In wind turbine (abbreviated as "wind turbine") failures, since lightning has great destructive power, wind turbine failures caused by lightning strikes will have relatively serious consequences. For example, the energy released by lightning strikes can cause damage to the unit blades, insulation breakdown of the unit generator, burning of control components, etc., which will cause considerable losses to related wind farms, etc. Therefore, how to better achieve lightning protection for wind turbines has become one of the key areas of concern for relevant technical personnel in the wind power field. Summary of the invention

[0004] The embodiments of the present disclosure provide a method and system for fault detection of a lightning protection device for a wind turbine blade, which utilize alternating current signals related to wind turbine blade parameters to implement fault detection of the lightning protection device for a wind turbine blade.

[0005] In one general aspect, a fault detection method for a lightning arrester for a wind turbine blade is provided, the lightning arrester comprising a lightning receptor and a conductor thereof, the conductor being arranged in a wind turbine blade in a feeder manner, and the lightning receptor being connected to one end of the conductor close to the tip of the wind turbine blade, the fault detection method comprising: acquiring parameter data of the wind turbine blade; calculating the signal frequency of the alternating current signal to be generated based on the parameter data of the wind turbine blade; generating an alternating current signal having the signal frequency by an electromagnetic wave transmitting device comprising an electromagnetic wave generating circuit, wherein the electromagnetic wave transmitting device is arranged in the wind turbine blade and connected to the other end of the conductor close to the root of the wind turbine blade; transmitting an alternating current signal with gradually increasing signal strength to an electromagnetic wave receiving device arranged on an unmanned aerial vehicle via a transmitting antenna and the conductor included in the electromagnetic wave transmitting device, wherein the unmanned aerial vehicle is located within a preset distance of the wind turbine blade; wherein the alternating current signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning arrester fails based on whether the amplitude of a direct current voltage signal corresponding to the alternating current signal with gradually increasing signal strength satisfies a predetermined threshold range.

[0006] Optionally, the alternating current signal with gradually increasing signal strength may be generated in the following manner: the alternating current signal with gradually increasing signal strength is generated by adjusting the capacitance value of a preset capacitor included in the electromagnetic wave generating circuit.

[0007] Optionally, the electromagnetic wave generating circuit may include a square wave generator and a multi-order RC circuit, wherein the square wave generator may be a symmetrical multivibrator, and the multi-order RC circuit may be a third-order RC circuit.

[0008] Optionally, the waveform of the AC signal with gradually increasing signal strength may be a sinusoidal waveform, and the amplitude of the DC voltage signal depends on the signal frequency of the AC signal with gradually increasing signal strength and is independent of the amplitude of the AC signal with gradually increasing signal strength.

[0009] Optionally, the electromagnetic wave receiving device may include a power amplifier circuit, a diode clamping circuit and a detection circuit, wherein the diode clamping circuit is arranged between the power amplifier circuit and the detection circuit, and the diode clamping circuit includes a clamping diode and a clamping resistor connected in series.

[0010] Optionally, the DC voltage signal may be obtained by the AC signal with gradually increasing signal strength received by the electromagnetic wave receiving device and passing through the power amplifier circuit, the diode clamping circuit and the detection circuit in sequence.

[0011] Optionally, the fan blade parameter data may include the length of the fan blade, and the step of calculating the signal frequency of the alternating current signal to be generated based on the fan blade parameter data may include: calculating the signal frequency based on the length of the fan blade, a preset wavelength coefficient related to the length of the fan blade, and a preset shortening coefficient related to the length of the fan blade.

[0012] In another general aspect, a fault detection method for a lightning protection device for a wind turbine blade is provided, the lightning protection device comprising a lightning receptor and a conductor thereof, the conductor being arranged in the wind turbine blade as a receiving antenna, and the lightning receptor being connected to one end of the conductor close to the tip of the wind turbine blade, the fault detection method comprising: acquiring parameter data of the wind turbine blade; calculating the signal frequency of the alternating current signal to be generated based on the parameter data of the wind turbine blade; generating an alternating current signal having the signal frequency by an electromagnetic wave transmitting device comprising an electromagnetic wave generating circuit, wherein the electromagnetic wave transmitting device is arranged on a drone located within a preset distance of the wind turbine blade; transmitting an alternating current signal with gradually increasing signal strength to an electromagnetic wave receiving device via a transmitting antenna included in the electromagnetic wave transmitting device, wherein the electromagnetic wave receiving device is arranged in the wind turbine blade and connected to the other end of the conductor; wherein the alternating current signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device has a fault based on whether the amplitude of the direct current voltage signal corresponding to the alternating current signal with gradually increasing signal strength satisfies a predetermined threshold range.

[0013] In another general aspect, a fault detection system for a lightning protection device for a wind turbine blade is provided, the lightning protection device comprising a lightning receptor and a conductor thereof, the conductor being arranged in the wind turbine blade in a feeder manner, and the lightning receptor being connected to one end of the conductor close to the tip of the wind turbine blade, the fault detection system comprising: an electromagnetic wave transmitting device, arranged in the wind turbine blade, comprising an electromagnetic wave generating circuit and connected to the other end of the conductor close to the root of the wind turbine blade, and the electromagnetic wave transmitting device being configured to: obtain parameter data of the wind turbine blade; calculate the signal frequency of the alternating current signal to be generated based on the parameter data of the wind turbine blade; generate an alternating current signal having the signal frequency; transmit an alternating current signal with gradually increasing signal strength to an electromagnetic wave receiving device arranged on an unmanned aerial vehicle via a transmitting antenna and the conductor included in the electromagnetic wave transmitting device, wherein the unmanned aerial vehicle is located within a preset distance of the wind turbine blade, wherein the alternating current signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the direct current voltage signal corresponding to the alternating current signal with gradually increasing signal strength satisfies a predetermined threshold range.

[0014] Optionally, the electromagnetic wave transmitting device can generate the AC signal with gradually increasing signal strength in the following manner: by adjusting the capacitance value of a preset capacitor included in the electromagnetic wave generating circuit to generate the AC signal with gradually increasing signal strength.

[0015] Optionally, the electromagnetic wave generating circuit may include a square wave generator and a multi-order RC circuit, wherein the square wave generator may be a symmetrical multivibrator, and the multi-order RC circuit may be a third-order RC circuit.

[0016] Optionally, the waveform of the AC signal with gradually increasing signal strength may be a sinusoidal waveform, and the amplitude of the DC voltage signal depends on the signal frequency of the AC signal with gradually increasing signal strength and is independent of the amplitude of the AC signal with gradually increasing signal strength.

[0017] Optionally, the electromagnetic wave receiving device may include a power amplifier circuit, a diode clamping circuit and a detection circuit, wherein the diode clamping circuit is arranged between the power amplifier circuit and the detection circuit, and the diode clamping circuit includes a clamping diode and a clamping resistor connected in series.

[0018] Optionally, the DC voltage signal may be obtained by the AC signal with gradually increasing signal strength received by the electromagnetic wave receiving device and passing through the power amplifier circuit, the diode clamping circuit and the detection circuit in sequence.

[0019] Optionally, the fan blade parameter data may include the length of the fan blade, and the step of calculating the signal frequency of the alternating current signal to be generated based on the fan blade parameter data may include: calculating the signal frequency based on the length of the fan blade, a preset wavelength coefficient related to the length of the fan blade, and a preset shortening coefficient related to the length of the fan blade.

[0020] In another general aspect, a fault detection system for a wind turbine blade lightning protection device is provided, the lightning protection device including a lightning receptor and a conductor thereof, the conductor being arranged in the wind turbine blade as a receiving antenna, and the lightning receptor being connected to one end of the conductor near the tip of the wind turbine blade, the fault detection system comprising: an electromagnetic wave transmitting device including an electromagnetic wave generating circuit and being arranged on a drone located within a preset distance of the wind turbine blade, and the electromagnetic wave transmitting device being configured to: obtain wind turbine blade parameter data; calculate a signal frequency of an alternating current signal to be generated based on the wind turbine blade parameter data; generate an alternating current signal having the signal frequency; and transmit an alternating current signal with gradually increasing signal strength to an electromagnetic wave receiving device via a transmitting antenna included in the electromagnetic wave transmitting device, wherein the electromagnetic wave receiving device is arranged in the wind turbine blade and connected to the other end of the conductor, wherein the alternating current signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device has a fault based on whether the amplitude of a direct current voltage signal corresponding to the alternating current signal with gradually increasing signal strength satisfies a predetermined threshold range.

[0021] In another general aspect, a computer program product is provided, the computer program product comprising a computer program / instructions, which when executed by a processor implement the fault detection method of the wind turbine blade lightning protection device as described above.

[0022] In another general aspect, a computer-readable storage medium is provided, which, when instructions in the computer-readable storage medium are executed by a processor of an electronic device / server, enables the electronic device / server to execute the fault detection method for a lightning protection device for a wind turbine blade as described above.

[0023] In another general aspect, a computing device is provided, comprising: at least one processor; and at least one memory storing computer executable instructions, wherein the computer executable instructions, when executed by the at least one processor, cause the at least one processor to execute the fault detection method for a wind turbine blade lightning protection device as described above.

[0024] According to the fault detection method and system of the wind turbine blade lightning arrester of the embodiment of the present disclosure, the fault detection of the wind turbine blade lightning arrester is realized by using the AC signal related to the wind turbine blade parameters. In addition, the non-contact detection of the fault of the wind turbine blade lightning arrester is realized by using the AC signal, and the detection can be performed not only when the wind turbine is stopped, but also when the wind turbine is running, so that there are fewer application restrictions and a wider range of applications. In addition, the fault detection of the wind turbine blade lightning arrester for different blade parameters can be easily realized by adjusting the capacitance value in the preset capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects and features of the embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings showing the embodiments, in which:

[0026] Figure 1 is a flow chart showing a fault detection method for a wind turbine blade lightning protection device according to an embodiment of the present disclosure;

[0027] Figure 2 is a schematic diagram showing a lightning protection device for wind turbine blades according to an embodiment of the present disclosure;

[0028] Figure 3 is a schematic diagram showing a first application scenario of a fault detection method for a wind turbine blade lightning protection device according to an embodiment of the present disclosure;

[0029] Figure 4 is a flow chart showing an example of a method for detecting a fault of a lightning protection device for a wind turbine blade according to an embodiment of the present disclosure;

[0030] Figure 5 is a circuit diagram illustrating an exemplary square wave generator according to one embodiment of the present disclosure;

[0031] Figure 6 It is shown based on Figure 5 Schematic diagram of a square wave signal generated by a circuit;

[0032] Figure 7 is a circuit diagram showing an exemplary electromagnetic wave generating circuit according to one embodiment of the present disclosure;

[0033] Figure 8 It is shown based on Figure 7 Schematic diagram of an alternating current signal generated by a circuit;

[0034] Fig. 9 is an exemplary circuit diagram showing an AC signal detection circuit as an example;

[0035] Fig.10 is an exemplary circuit diagram showing an AC signal detection circuit according to one embodiment of the present disclosure;

[0036] Fig.11 is a schematic diagram showing an output signal of a power amplifier according to an embodiment of the present disclosure;

[0037] Fig.12 is a schematic diagram showing an output signal of a detection circuit according to an embodiment of the present disclosure;

[0038] Fig.13is a schematic diagram showing various detection points of an AC signal detection circuit according to an embodiment of the present disclosure when the input signal is a low-frequency signal;

[0039] Figure 14 to Figure 15 It is shown based on Fig.13 A schematic diagram of output signals of various detection points of an AC signal detection circuit under different input signals;

[0040] Fig.16 is a flow chart showing a fault detection method for a wind turbine blade lightning protection device according to another embodiment of the present disclosure;

[0041] Fig.17 is a schematic diagram showing a second application scenario of a fault detection method for a wind turbine blade lightning protection device according to another embodiment of the present disclosure;

[0042] Fig.18 is a flow chart showing an example of a method for detecting a fault of a lightning protection device for a wind turbine blade according to another embodiment of the present disclosure;

[0043] Fig.19 is a block diagram showing a fault detection system for a wind turbine blade lightning protection device according to an embodiment of the present disclosure;

[0044] Fig. 20 is a block diagram showing a fault detection system of a wind turbine blade lightning protection device according to another embodiment of the present disclosure;

[0045] Fig.21 is a block diagram illustrating a computing device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be clear. For example, the order of operations described herein is only an example and is not limited to those orders set forth herein, but can be changed as will be clear after understanding the disclosure of the present application, except for operations that must occur in a specific order. In addition, for greater clarity and simplicity, the description of features known in the art may be omitted.

[0047] The features described herein can be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided to illustrate only some of the many possible ways to implement the methods, devices, and / or systems described herein, which will be clear after understanding the disclosure of the present application.

[0048] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0049] The terms used herein are only used to describe various examples and are not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "comprise", "include" and "have" indicate the presence of the described features, quantities, operations, components, elements and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements and / or combinations thereof.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by a person of ordinary skill in the art to which the present disclosure belongs after understanding the present disclosure. Unless explicitly defined as such herein, terms (such as those defined in a general dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and should not be interpreted in an idealized or overly formal manner.

[0051] Furthermore, in the description of examples, when it is considered that a detailed description of a well-known related structure or function would cause vague interpretation of the present disclosure, such a detailed description will be omitted.

[0052] Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like parts throughout. The embodiments will be described below with reference to the drawings in order to explain the present disclosure.

[0053] In the relevant technology, the lightning protection work of wind turbines is a comprehensive project. Whether the lightning protection design is reasonable is related to whether the wind turbine can work normally during thunderstorms, and whether it can ensure that the various equipment inside the wind turbine is not damaged by lightning. Whether it is the wind turbine installation area or the area where the wind turbine is running, relevant lightning protection work needs to be deployed.

[0054] In order to provide lightning protection, the methods that can be used include setting up lightning rods. The functions of lightning rods include: absorbing lightning current when the protected object (for example, a physical object with a certain height) is struck by lightning and guiding the lightning current from the main body of the protected object to the grounding device to reduce charge accumulation, thereby improving lightning protection safety performance. By using lightning rods, the protected object can avoid damage to the protected object and its related electrical equipment by lightning current, and can also avoid damage to the personnel related to it by lightning current.

[0055] In the wind turbine blades, the purpose of lightning protection can be achieved by setting a lightning arrester including a lightning rod. The lightning arrester can achieve lightning protection by introducing lightning current into the earth. By setting up a lightning arrester, the blades can be effectively protected from lightning strikes. However, in an exemplary scenario, for example, after the wind turbine has been running for a long time, the blades may experience faults such as disconnection of the lightning rod wire and increase in resistance under the long-term action of transient wind speed and wind direction, which will cause the lightning arrester to be unable to introduce lightning current into the earth, which may cause safety hazards to the wind turbine. Therefore, fault detection of the lightning arrester of the blade becomes particularly important.

[0056] In the prior art, the detection methods for blade lightning arresters include observation method, tension sensor method and ground resistance measurement method. The following briefly describes the detection methods and shortcomings of these methods.

[0057] For the observation method, the appearance of the blade lightning receptor is regularly observed, especially whether the grounding part is intact, whether there is obvious wear, scratches, cracks, etc. If obvious physical damage or signs of aging are found, the lightning receptor may need to be replaced. However, the disadvantage of this method is that it can only observe obvious abnormalities on the blade surface, but cannot observe the conduction of the wire inside the blade.

[0058] Regarding the tension sensor method, the tension sensor is used to monitor whether the blade lightning receptor is loose, and the tension change measured by the tension sensor is used to determine whether the lightning receptor is loose, thereby preventing the lightning receptor from falling off. However, the disadvantage of this method is that it cannot effectively detect the disconnection of the internal wires, and it cannot achieve safety detection when the wind turbine is in operation. The reason is that when the wind turbine is in operation, the blades move in a circular motion with the impeller. During the rotation of the impeller, a large centrifugal force will be generated (especially when the blade length increases), and this centrifugal force will also act on the tension sensor, which will make it impossible to accurately and effectively detect the abnormality through the tension sensor even if the lightning receptor is loose.

[0059] For the ground resistance measurement method, the blade lightning rod is connected to the ground through certain measures to detect the ground resistance. However, the disadvantage of this method is that for wind turbines that have been hoisted and put into operation, it is quite difficult to accurately connect the external detection device to the location of the blade lightning rod. For example, the traditional method of using a manual hanging basket has great safety risks in actual operation.

[0060] In response to the related problems in the fault detection process of the above-mentioned blade lightning arrester, the present application proposes a fault detection method and system for a wind turbine blade lightning arrester to solve the above-mentioned problems related to the fault detection of the blade lightning arrester.

[0061] Before describing the method and system of the present disclosure in detail, the following terms involved in the present disclosure are explained:

[0062] Regarding wind turbines, they are electrical equipment that converts wind energy into mechanical work, which drives the rotor to rotate and finally outputs alternating current. The principle of wind power generation is to use wind power to drive the fan blades to rotate, and then increase the speed of rotation through a speed increaser to drive the generator to generate electricity.

[0063] Regarding the impeller, the impeller refers to the part of the wind turbine that converts wind energy into mechanical energy, which consists of blades and a hub.

[0064] Regarding lightning arresters, lightning arresters refer to lightning rods, lightning strips (lines), lightning nets that directly receive lightning strikes, as well as metal surfaces and metal components used to terminate lightning.

[0065] Regarding electromagnetic waves, electromagnetic waves are electromagnetic fields that are propagated in the form of fluctuations and are derived from oscillating particle waves emitted in space by electric and magnetic fields that are in phase and perpendicular to each other.

[0066] Regarding antennas, an antenna is a converter that converts guided waves propagating on a transmission line into electromagnetic waves propagating in an unbounded medium (usually free space), or vice versa. Regarding wire antennas, wire antennas are antennas composed of one or more metal wires whose wire diameter is much smaller than the wavelength and whose length is comparable to the wavelength. Its working principle is based on the principle of field superposition. That is, a single wire antenna can be regarded as composed of many infinitely short small wire segments (these infinitely short small wire segments are called current elements), and the radiation fields of many current elements are superimposed together to form the total radiation field of the entire antenna.

[0067] Regarding feeder, feeder is a kind of wire used to transmit electromagnetic energy. It can transmit electrical energy, signals, etc. from one location to another, and is widely used in radio, mobile communications, TV station backhaul, satellite communications, radar and other fields.

[0068] Regarding electrical resonance, when the natural frequency of the circuit used to receive electromagnetic waves is the same as the frequency of the received electromagnetic waves, the strongest induced current will be generated. This process is called electrical resonance. By tuning the circuit, electromagnetic waves of a specific frequency can be selected for reception, and the process of extracting the original signal from the high-frequency oscillating current is called detection (which is the inverse process of modulation).

[0069] Refer to the following Figures 1 to 21 A failure method and system of a wind turbine blade lightning protection device according to an embodiment of the present disclosure are described in detail.

[0070] Figure 1 is a flow chart showing a method for detecting a fault of a lightning protection device for a wind turbine blade according to an embodiment of the present disclosure. Figure 2is a schematic diagram showing a lightning protection device for wind turbine blades according to an embodiment of the present disclosure, Figure 3 is a schematic diagram showing a first application scenario of a fault detection method for a wind turbine blade lightning protection device according to an embodiment of the present disclosure, and Figure 4 is a flowchart showing an example of a fault detection method for a wind turbine blade lightning protection device according to an embodiment of the present disclosure.

[0071] Reference Figure 1 and Figure 2 The lightning protection device may include a lightning rod and a conductor. For example, the lightning rod is pre-buried in the blade (for example, the tip area), and the conductor can be used to connect the lightning rod to the root area of ​​the blade, thereby leading the lightning current to the cabin through the conductor, and then leading the lightning current into the earth through the grounding system in the cabin.

[0072] For example, the physical structure of the lightning protection device may specifically include: a lightning receptor is arranged in the tip area of ​​the wind turbine blade, the lightning receptor is exposed on the surface of the blade, and may be composed of, for example, several groups of copper discs or stainless steel discs, but the present disclosure is not limited to this. In addition, the lightning receptor is connected to a wire arranged inside the blade, the wire extends to the root area of ​​the blade, and is connected to the grounding wire of the wind turbine. The lightning protection principle of the lightning protection device with the above structure is: when encountering lightning, the lightning receptor disc receives the lightning, and then the lightning current flows to the wind turbine tower through the wire and the hub. Since the metal structure of the wind turbine tower can act as a conductor, the lightning current can be further introduced into the grounding system of the wind turbine to flow into the earth, thereby protecting the wind turbine and its internal electrical / electronic components.

[0073] In addition, in the fault detection method 100 of the wind turbine blade lightning protection device according to the embodiment of the present disclosure, the lightning protection device includes a lightning receptor and a conductor thereof, wherein the conductor is arranged in the wind turbine blade in a feeder manner, and the lightning receptor is connected to one end of the conductor close to the tip of the wind turbine blade (for example, Figure 3 As shown, a schematic diagram showing a drone 304 approaching a target blade 302 to be detected and an electromagnetic wave transmitting device 305 is arranged in the hub. It should be understood that blades 301 and 303 can also be used as target blades in a similar manner).

[0074] Here, for example, the wire used as a feeder can be set to a double-wire structure to transmit electromagnetic wave signals to an electromagnetic wave receiving device carried on a drone. The specific principle of using a wire as a feeder to transmit electromagnetic wave signals is as follows: When an alternating current is carried in the wire, electromagnetic waves will be radiated. The radiation capacity of the electromagnetic wave is related to the length and shape of the wire. The radiation principle can be understood by referring to the description of the wire antenna above. If the distance between the two wires is close, the electric field is bound between the two wires, and the radiation capacity is weak; if the two wires are opened, the electric field will spread to the surrounding space, and the radiation capacity will be enhanced. When the length of the wire is much smaller than the wavelength of the radiated electromagnetic wave, the radiation capacity is weak; when the length of the wire is at the same or similar order of magnitude as the wavelength of the radiated electromagnetic wave, the current in the wire is greatly increased, and the radiation capacity is stronger.

[0075] According to an embodiment of the present disclosure, in step S101, wind turbine blade parameter data is acquired. For example, the wind turbine blade parameter data may include the length of the wind turbine blade.

[0076] According to an embodiment of the present disclosure, in step S102, the signal frequency of the alternating current signal to be generated is calculated based on the wind turbine blade parameter data.

[0077] As an example, step S102 may further include: calculating the signal frequency based on the length of the fan blade, a preset wavelength coefficient related to the length of the fan blade, and a preset shortening coefficient related to the length of the fan blade. For example, the length of the antenna in the following formula may be associated with the length of the fan blade, such as the two may be approximately equal in size, but the present disclosure is not limited thereto, and the two may also have other quantitative relationships associated with each other according to actual conditions.

[0078] As an example, the formula for an antenna used to transmit electromagnetic waves is shown in the following equation (1):

[0079] L=(300 / F)×λ×η (1)

[0080] Wherein, L is the length of the antenna, F is the frequency of the electromagnetic wave (in MHz), λ is the wavelength coefficient (for example, when the coefficient is 1 / 4, it means that the length of the antenna is 1 / 4 of the wavelength, that is, 0.25) (but not limited to this, it may also include the case where the length of the antenna is 5 / 8 of the wavelength), and η is the shortening coefficient (for example, the value may be 0.96).

[0081] It can be seen from formula (1) that the length of the antenna is proportional to the wavelength and inversely proportional to the frequency of the electromagnetic wave. The higher the frequency of the electromagnetic wave, the shorter the wavelength, and the shorter the antenna can be. For example, in the example where the length of the wind turbine blade is 90 meters, the electromagnetic wave frequency can be calculated by formula (1) to be 300×0.25×0.96 / 90=0.8MHz, that is, the electromagnetic wave frequency corresponds to the medium wave signal (medium wave signal refers to electromagnetic waves with a frequency of 300KHz to 3MHz and a corresponding wavelength of 1km to 100m).

[0082] According to an embodiment of the present disclosure, the corresponding electromagnetic wave emission frequency is calculated according to the length of the target wind turbine blade to be detected, so that the detection of the electromagnetic wave signal is matched with the lightning protection device of the target wind turbine blade, thereby improving the accuracy of fault detection and enabling the fault detection method of the present disclosure to be applicable to lightning protection device fault detection of wind turbine blades of different lengths.

[0083] According to an embodiment of the present disclosure, in step S103, an electromagnetic wave transmitting device including an electromagnetic wave generating circuit is used to generate an AC signal having the above signal frequency. Here, the electromagnetic wave transmitting device is arranged in the wind turbine blade and connected to the other end of the wire close to the root of the wind turbine blade.

[0084] As an example, the electromagnetic wave generating circuit may include a square wave generator and a multi-order RC circuit. For example, the square wave generator may be a symmetrical multivibrator. For example, the multi-order RC circuit may be a third-order RC circuit.

[0085] According to the embodiments of the present disclosure, by using a symmetrical multivibrator as a part of the electromagnetic wave generating circuit, the adjustable frequency range is made wider, and the frequency can be adjusted by only adjusting the capacitance value.

[0086] According to an embodiment of the present disclosure, in step S104, an alternating current signal with gradually increasing signal strength is transmitted to an electromagnetic wave receiving device disposed on the drone via a transmitting antenna and a wire included in the electromagnetic wave transmitting device.

[0087] Here, the drone is located within a preset distance of the wind turbine blades. For example, the drone can be controlled to fly to a position near the tip area of ​​the blades without contacting the wind turbine (e.g., Figure 3 shown).

[0088] As an example, an alternating current signal with gradually increasing signal strength may be generated in the following manner: an alternating current signal with gradually increasing signal strength is generated by adjusting the capacitance value of a preset capacitor included in the electromagnetic wave generating circuit.

[0089] According to the embodiments of the present disclosure, by simply adjusting the capacitance value of a preset capacitor included in the electromagnetic wave generating circuit, lightning protection device fault detection can be performed on blades of different lengths, and by using an alternating current signal with a gradually increasing signal, the influence of interference signals on the detection results can be effectively reduced, thereby improving the detection accuracy.

[0090] Below, refer to Figures 5 to 8 To illustrate the circuit and related simulation diagram of the electromagnetic wave transmitting device generating alternating current signal. Figure 5 is a circuit diagram showing an exemplary square wave generator according to one embodiment of the present disclosure, Figure 6 It is shown based on Figure 5 Schematic diagram of the circuit generating a square wave signal, Figure 7 is a circuit diagram showing an exemplary electromagnetic wave generating circuit according to one embodiment of the present disclosure, and Figure 8 It is shown based on Figure 7 Schematic diagram of a circuit that generates an alternating current signal.

[0091] Reference Figure 5 and Figure 6 , the adjustable frequency range of the exemplary square wave generator circuit is derived as follows:

[0092] When using a symmetrical multivibrator as a square wave generator (such as Figure 5 In the example shown in FIG. 1 , the pulse widths t01 and t02 of the two quasi-stable waveforms of the symmetrical multivibrator are: t01 = t02 = 0.7RC, and the generated stable square wave signal (such as Figure 6 The oscillation frequency of the oscillation is f = 1 / 1.4RC. Figure 5 In the case of R11=R22 shown in FIG. 1 , R=R11=R22, otherwise R is the equivalent resistance value of the circuit, and similarly, when Figure 5 In the case of C11=C22 shown in , C=C11=C22, otherwise C is the equivalent capacitance value of the circuit.

[0093] For example, when R11=R22=R, the values ​​of the three are all less than or equal to 1KΩ, and C11=C2=100pF~100μF, the value range of f can be nHz (corresponding to 100pF)~nMHz (corresponding to 100μF). It can be seen that this frequency range meets the frequency requirements of the medium wave signal mentioned above and can be applied to fan blades of different lengths.

[0094] It should be noted that the values ​​of the circuit elements in the present disclosure shown in the drawings are merely exemplary and not restrictive. The present disclosure is not limited to these values ​​and will not be repeated in the context.

[0095] Reference Figure 7 and Figure 8 The exemplary electromagnetic wave generating circuit also includes a third-order RC loop, which is used to convert the generated square wave signal into a sine wave signal (such as Figure 8 As shown) for use in the electromagnetic wave transmission operation of the present disclosure.

[0096] Specifically, refer to Figure 7 The generated square wave signal is converted into a sawtooth wave through the integrating circuit composed of R01 and C01; then converted into a triangle wave through the integrating circuit composed of R02 and C02; finally converted into a sine wave through the integrating circuit composed of R03 and C03. The frequency of the sine wave is: f = 1 / (2πRC), where the values ​​of R and C are as follows: Figure 7 In the case of R01=R02=R03 shown in FIG, R=R01=R02=R03, otherwise R is the equivalent resistance value of the corresponding circuit, and similarly, when Figure 7 In the case of C11=C02=C03 shown in , C=C11=C02=C03, otherwise C is the equivalent capacitance value of the circuit.

[0097] In addition, for example, the waveform of the gradually increasing AC signal may be a sine wave waveform, and the amplitude of the DC voltage signal depends on the signal frequency of the gradually increasing AC signal and is independent of the amplitude of the gradually increasing AC signal.

[0098] That is, according to the embodiments of the present disclosure, by performing detection using the amplitude of the DC voltage signal that is related to the frequency of the AC signal as input and is independent of its amplitude, it is possible to facilitate signal identification and analysis.

[0099] According to an embodiment of the present disclosure, further, an alternating current signal with gradually increasing signal strength is received by an electromagnetic wave receiving device, so that the electromagnetic wave receiving device can detect whether a lightning protection device fails (for example, to detect the conductivity of the wire) based on whether the amplitude of the direct current voltage signal corresponding to the alternating current signal with gradually increasing signal strength satisfies a predetermined threshold range.

[0100] According to the embodiments of the present disclosure, non-contact detection of wind turbine blade lightning protection devices is achieved by utilizing electromagnetic wave signals and drone equipment. Compared with the prior art, this is easier to implement and more convenient to operate, and can improve the detection cost and efficiency of wind turbine blade lightning protection devices.

[0101] As an example, the electromagnetic wave receiving device may include a power amplifier circuit, a diode clamp circuit and a detection circuit. For example, the diode clamp circuit is arranged between the power amplifier circuit and the detection circuit, and the diode clamp circuit includes a clamp diode and a clamp resistor connected in series.

[0102] According to an embodiment of the present disclosure, the electromagnetic wave signal received by the receiving antenna in the electromagnetic wave receiving device is amplified by using a power amplifier circuit, the voltage of the amplified signal is clamped by using a diode clamp circuit to convert the negative voltage into a positive voltage, and a voltage stabilization detection circuit is used to obtain a constant DC signal. In addition, compared with other methods such as frequency detection that cannot detect medium and high frequency signals, by using a diode clamp circuit and a detection circuit, it is possible to detect medium and high frequency signals.

[0103] In addition, as an example, the DC voltage signal may be an AC signal with gradually increasing signal strength received by the electromagnetic wave receiving device, which is obtained by sequentially passing through a power amplifier circuit, a diode clamping circuit, and a detection circuit.

[0104] According to an embodiment of the present disclosure, by comparing the strength of a DC voltage signal with a preset threshold, it can be used to detect whether a lightning protection device of a wind turbine blade fails.

[0105] Below, refer to Figures 9 to 15 To illustrate the circuit and related simulation diagram of the electromagnetic wave receiving device performing signal detection. Fig. 9 is an exemplary circuit diagram showing an AC signal detection circuit as an example, Fig.10 is an exemplary circuit diagram showing an AC signal detection circuit according to an embodiment of the present disclosure, Fig.11 is a schematic diagram showing an output signal of a power amplifier according to an embodiment of the present disclosure, Fig.12 is a schematic diagram showing an output signal of a detection circuit according to an embodiment of the present disclosure, Fig.13 is a schematic diagram showing various detection points of an AC signal detection circuit according to an embodiment of the present disclosure when the input signal is a low-frequency signal, and Figure 14 to Figure 15 It is shown based on Fig.13 Schematic diagram of the output signals of various detection points of the AC signal detection circuit under different input signals.

[0106] Refer to 9 to Fig.13 , shows a power amplifier circuit (including Fig.10 The power transistor Q1, the resistor R1, the resistor R2, the capacitor C1, the capacitor C2, the resistor R4, the resistor R3 and the capacitor C3 shown), the diode clamp circuit (including Fig.10 The diode D2, resistor R7 shown in FIG. Fig.10 Diode D1, capacitor C4, resistor R5 and capacitor C5 are shown).

[0107] The received AC signal is amplified by a power amplifier circuit, and then the voltage of the amplified AC signal is clamped by a diode clamp circuit. Finally, the voltage-clamped AC signal is output as a stable DC signal through a detection circuit that implements rectification function (implemented by diode D1), filtering function (implemented by capacitor C4 and resistor R5), and high-frequency interference removal function (implemented by capacitor C5).

[0108] Here, the operating principle of the power transistor is explained as follows: In the power amplification operation, since the voltage output by the transistor is a negative value (see Fig. 9 The voltage at D1(A) in the figure is derived as follows:

[0109] For transistors, the output signal Uo is the voltage Uce of the collector to ground potential. The positive power supply voltage Vcc of the transistor is a constant value. Ic represents the collector current and Rc represents the collector resistance. Then Uo = Vcc-Ic×Rc. As the input signal Ui increases, Ic increases, and the voltage drop U on Rc increases. Rc Increases, Uo decreases, that is, Uo and Ui are in opposite phase.

[0110] Furthermore, for an AC signal, the DC power supply is grounded, so Uo=0-Ic×Rc=-Ic×Rc, and thus the output voltage of the transistor is a negative value.

[0111] In this case, if the transistor output signal is directly detected, the output voltage is 0 (see Fig. 9 The voltage at C5 (2) in the circuit is 0.04V, so the electromagnetic wave signal cannot be detected in this case. In addition, if other methods such as frequency detection are used, high-frequency signals cannot be detected. Therefore, the present disclosure proposes to use a diode clamping circuit to solve this problem.

[0112] Specifically, refer to Fig.10 , the diode clamping circuit comprises a diode D2 and a resistor R7, wherein the cathode of the diode D2 is connected to the output terminal of the power transistor via the capacitor C2, the anode of the diode D2 is connected in series with the resistor R7, and the other end of the resistor R7 is grounded.

[0113] In addition, refer to Fig.11 and 12, the yellow exemplary signal line represents the original signal received, and its amplitude is 98.79mV and the signal frequency is 500KHz. The blue exemplary signal line represents the signal after power amplification, and its amplitude is 3.76V. The pink exemplary signal line represents the output signal of the detection circuit after adding diode clamping, that is, the DC voltage signal, and the DC voltage is 3.09V. Therefore, the DC voltage detected by the detection circuit can be used to determine whether the wind turbine blade lightning protection device has a fault.

[0114] In addition, refer to Figures 13 to 15 , shows an example where the signal output from the output terminal after detection is a low-level signal when the input signal is a low-frequency signal. Fig.13 As shown in the figure, C1(1) represents the input terminal, and the two terminals measured as outputs are C2(2) and C5(2). Fig.14 As shown, the input signal represented by the yellow exemplary signal line is a low-frequency signal of 100 Hz (whose period is 12.25-2.25=10 ms), and the signals output by the two output terminals represented by the blue and gray exemplary signal lines are both close to 0. Fig.15 As shown, the input signal represented by the yellow exemplary signal line is a low-frequency signal of 4000 Hz, and the signals output by the two output terminals represented by the blue and gray exemplary signal lines respectively are also close to zero.

[0115] Therefore, according to the signal detection method of the embodiment of the present disclosure, it is possible to filter out low-frequency signals, for example, below 5 KHz, reduce the impact of interference signals on detection results, and improve detection precision and accuracy.

[0116] In addition, by using an amplifier to amplify the electromagnetic wave signal, the output signal of the amplifier is voltage clamped, and then a detection circuit is used to obtain a DC voltage. By directly analyzing the DC voltage, the strength information of the received signal can be resolved without modulating and demodulating the electromagnetic wave signal, thereby simplifying the circuit structure.

[0117] As an example, refer to Figure 4 An example of the detection method 400 is illustrated.

[0118] Reference Figure 4 In step S401, the electromagnetic wave emission frequency is set according to the length of the fan blades.

[0119] In step S402, the drone is made to reach a position near the blade tip.

[0120] In step S403, after the UAV is in position, the electromagnetic wave transmitting device located in the root area of ​​the blade is started to transmit electromagnetic waves.

[0121] In step S404, the electromagnetic wave receiving device installed on the drone receives and detects the electromagnetic wave.

[0122] In step S405, it is determined whether the strength of the signal corresponding to the received electromagnetic wave meets the expected requirement.

[0123] In step S406, when the signal strength meets the expected requirement, it is determined that the lightning protection device of the wind turbine blade has not failed.

[0124] In step S407, when the signal strength does not meet the expected requirement, it is determined that the lightning protection device of the wind turbine blade may fail.

[0125] As another example, refer to Figures 16 to 18 16. The exemplary process of a fault detection method 1600 for a wind turbine blade lightning protection device according to another embodiment of the present disclosure is described. Fig.16 is a flow chart showing a method for detecting a fault of a wind turbine blade lightning protection device according to another embodiment of the present disclosure. Fig.17 is a schematic diagram showing a second application scenario of a fault detection method for a wind turbine blade lightning protection device according to another embodiment of the present disclosure, and Fig.18 is a flowchart illustrating an example of a method for detecting a fault of a lightning protection device for a wind turbine blade according to another embodiment of the present disclosure.

[0126] In the fault detection method 1600 of the lightning arrester for a wind turbine blade, the lightning arrester includes a lightning receptor and a wire thereof, the wire is arranged in the wind turbine blade as a receiving antenna, and the lightning receptor is connected to an end of the wire near the tip of the wind turbine blade. Here, for example, the wire used as an antenna can receive electromagnetic wave signals from an electromagnetic wave transmitting device carried by a drone.

[0127] Reference Fig.16 , in step S1601, obtain wind turbine blade parameter data.

[0128] In step S1602, the signal frequency of the alternating current signal to be generated is calculated based on the wind turbine blade parameter data.

[0129] In step S1603, an electromagnetic wave transmitting device including an electromagnetic wave generating circuit is used to generate an alternating current signal having a signal frequency. Here, the electromagnetic wave transmitting device is disposed on a drone located within a preset distance of the wind turbine blades (e.g., Fig.17 As shown, a schematic diagram showing a drone 174 approaching a target blade 172 and an electromagnetic wave receiving device 175 being disposed in the hub is shown. It should be understood that blades 171 and 173 may also be used as target blades in a similar manner).

[0130] In step S1604, an alternating current signal with gradually increasing signal strength is transmitted to the electromagnetic wave receiving device via a transmitting antenna included in the electromagnetic wave transmitting device. Here, the electromagnetic wave receiving device is arranged in the wind turbine blade or in the hub and is connected to the other end of the wire (for example, Fig.17 shown).

[0131] In addition, according to an embodiment of the present disclosure, an alternating current signal with gradually increasing signal strength is received by an electromagnetic wave receiving device, so that the electromagnetic wave receiving device can detect whether a lightning protection device fails based on whether the amplitude of the direct current voltage signal corresponding to the alternating current signal with gradually increasing signal strength satisfies a predetermined threshold range.

[0132] As an example, refer to Fig.18 An example of detection method 1600 is illustrated.

[0133] Reference Fig.18 , in step S1801, the electromagnetic wave emission frequency is set according to the length of the wind turbine blades.

[0134] In step S1802, the drone is made to reach a position near the blade tip.

[0135] In step S1803, after the drone is in position, the electromagnetic wave transmitting device located on the drone is started to transmit electromagnetic waves.

[0136] In step S1804, an electromagnetic wave receiving device disposed in the root area of ​​the wind turbine blade receives and detects electromagnetic waves.

[0137] In step S1805, it is determined whether the strength of the signal corresponding to the received electromagnetic wave meets the expected requirement.

[0138] In step S1806, when the signal strength meets the expected requirement, it is determined that the lightning protection device of the wind turbine blade has not failed.

[0139] In step S1807, when the signal strength does not meet the expected requirement, it is determined that the lightning protection device of the wind turbine blade may fail.

[0140] Fig.19 1 is a block diagram showing a fault detection system 1900 of a lightning protection device for a wind turbine blade according to an embodiment of the present disclosure. In the fault detection system 1900, the lightning protection device includes a lightning receptor and a conductor thereof, the conductor is arranged in a wind turbine blade in a feeder manner, and the lightning receptor is connected to one end of the conductor near the tip of the wind turbine blade.

[0141] Reference Fig.19 According to an embodiment of the present disclosure, the fault detection system 1900 of the wind turbine blade lightning protection device may include an electromagnetic wave transmitting device 1910 and a transmitting antenna 1920. Here, it should be noted that although Fig.19 The electromagnetic wave transmitting device 1910 and the transmitting antenna 1920 are shown as two parts, but the present disclosure is not limited thereto, and may also include a situation where the transmitting antenna 1920 is disposed in the electromagnetic wave transmitting device 1910 .

[0142] The electromagnetic wave transmitting device 1910 according to an embodiment of the present disclosure may be disposed in a wind turbine blade, include an electromagnetic wave generating circuit, and be connected to the other end of the wire near the root of the wind turbine blade. In addition, the electromagnetic wave generating circuit may include a square wave generator and a multi-order RC circuit. For example, the square wave generator may be a symmetrical multivibrator, and the multi-order RC circuit may be a third-order RC circuit.

[0143] According to an embodiment of the present disclosure, the electromagnetic wave transmitting device 1910 performs the following operations 1) to 4):

[0144] In operation 1), the parameter data of the wind turbine blades are obtained.

[0145] For example, wind blade parameter data may include the length of the wind blade.

[0146] In operation 2), based on the wind turbine blade parameter data, the signal frequency of the alternating current signal to be generated is calculated.

[0147] As an example, operation 2) may further include: calculating the signal frequency based on the length of the fan blade, a preset wavelength coefficient related to the length of the fan blade, and a preset shortening coefficient related to the length of the fan blade.

[0148] In operation 3), an alternating current signal having a signal frequency is generated.

[0149] In operation 4), an AC signal with gradually increasing signal strength is transmitted to an electromagnetic wave receiving device disposed on the drone via the transmitting antenna 1920 included in the electromagnetic wave transmitting device 1910 and the wire in the lightning protection device. Here, the drone is located within a preset distance of the wind turbine blades.

[0150] As an example, the electromagnetic wave transmitting device may generate an alternating current signal with gradually increasing signal strength in the following manner: by adjusting the capacitance value of a preset capacitor included in the electromagnetic wave generating circuit to generate an alternating current signal with gradually increasing signal strength.

[0151] Here, according to an embodiment of the present disclosure, the waveform of the AC signal with gradually increasing signal strength may be a sinusoidal waveform, and the amplitude of the DC voltage signal depends on the signal frequency of the AC signal with gradually increasing signal strength and is independent of the amplitude of the AC signal with gradually increasing signal strength.

[0152] In addition, further, the AC signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the DC voltage signal corresponding to the AC signal with gradually increasing signal strength meets the predetermined threshold range.

[0153] As an example, the electromagnetic wave receiving device may include a power amplifier circuit, a diode clamp circuit and a detection circuit. For example, the diode clamp circuit is arranged between the power amplifier circuit and the detection circuit, and the diode clamp circuit includes a clamp diode and a clamp resistor connected in series.

[0154] In addition, for example, the DC voltage signal may be an AC signal with gradually increasing signal strength received by the electromagnetic wave receiving device, which is obtained by sequentially passing through a power amplifier circuit, a diode clamping circuit, and a detection circuit.

[0155] It should be noted that the operations performed on the above-mentioned structural frames can be referred to in Figure 1 The related contents described are similar and will not be repeated here.

[0156] Fig. 20 2 is a block diagram showing a fault detection system 2000 of a lightning protection device for a wind turbine blade according to another embodiment of the present disclosure. In the fault detection system 2000, the lightning protection device includes a lightning receptor and a wire thereof, the wire is arranged in the wind turbine blade as a receiving antenna, and the lightning receptor is connected to one end of the wire near the tip of the wind turbine blade.

[0157] Reference Fig. 20 According to an embodiment of the present disclosure, a fault detection system 2000 for a wind turbine blade lightning protection device may include an electromagnetic wave transmitting device 2010 and a transmitting antenna 2020 .

[0158] According to an embodiment of the present disclosure, the electromagnetic wave transmitting device 2010 may include an electromagnetic wave generating circuit and be disposed on a drone located within a preset distance from a wind turbine blade.

[0159] According to an embodiment of the present disclosure, the electromagnetic wave transmitting device 2010 performs the following operations 1) to 4):

[0160] In operation 1), the parameter data of the wind turbine blades are obtained.

[0161] In operation 2), based on the wind turbine blade parameter data, the signal frequency of the alternating current signal to be generated is calculated.

[0162] In operation 3), an alternating current signal having a signal frequency is generated.

[0163] In operation 4), an alternating current signal with gradually increasing signal strength is transmitted to the electromagnetic wave receiving device via a transmitting antenna included in the electromagnetic wave transmitting device. Here, the electromagnetic wave receiving device is arranged in the wind turbine blade and connected to the other end of the wire.

[0164] In addition, further, the AC signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the DC voltage signal corresponding to the AC signal with gradually increasing signal strength meets the predetermined threshold range.

[0165] It should be noted that the operations performed on the above-mentioned structural frames can be referred to in Fig.18 The related contents described are similar and will not be repeated here.

[0166] Fig.21 is a block diagram illustrating a computing device 2100 according to an embodiment of the present disclosure.

[0167] Reference Fig.21 According to an embodiment of the present disclosure, the computing device 2100 may include a processor 2110 and a memory 2120. The processor 2110 may include (but not limited to) a central processing unit (CPU), a digital signal processor (DSP), a microcomputer, a field programmable gate array (FPGA), a system on a chip (SoC), a microprocessor, an application-specific integrated circuit (ASIC), etc. The memory 2120 may store computer executable instructions to be executed by the processor 2110. The memory 2120 includes a high-speed random access memory and / or a non-volatile computer-readable storage medium. When the processor 2110 executes the computer executable instructions stored in the memory 2120, the fault detection method of the wind turbine blade lightning protection device as described above may be implemented.

[0168] According to the embodiment of the present disclosure, the fault detection method of the wind blade lightning protection device can be written as a computer program / instruction to form a computer program product and stored on a computer-readable storage medium. When the computer program / instruction is executed by the processor, the fault detection method of the wind blade lightning protection device as described above can be implemented. When the instructions in the computer-readable storage medium are executed by the processor of the electronic device / server, the electronic device / server is enabled to execute the fault detection method of the wind blade lightning protection device as described above. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disk storage, hard disk drive (HDD), solid state drive (SSD), card storage (such as, multimedia card, secure digital (SD) card or extreme digital (XD) card), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid state disk and any other device, any other device is configured to store computer program and any associated data, data files and data structures in a non-transitory manner and provide the computer program and any associated data, data files and data structures to a processor or computer so that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files and data structures are distributed on a networked computer system so that the computer program and any associated data, data files and data structures are stored, accessed and executed in a distributed manner by one or more processors or computers.

[0169] According to the fault detection method and system of the wind turbine blade lightning arrester according to the embodiment of the present disclosure, the fault detection of the wind turbine blade lightning arrester is achieved by utilizing an alternating current signal related to the wind turbine blade parameters.

[0170] On the other hand, AC signals are used to achieve non-contact detection of faults in wind turbine blade lightning protection devices. Detection can be performed when the wind turbine is shut down, and detection and / or inspection can also be performed during the operation of the wind turbine. Therefore, it has higher versatility, fewer application restrictions, and a wider range of applications than the existing technology.

[0171] On the other hand, by adopting the electromagnetic wave transmitting device according to the embodiment of the present disclosure, it is possible to set the emission of electromagnetic wave signals of different frequencies according to the blade length in actual use, and it is possible to easily realize the fault detection of the lightning arrester of the wind turbine blade for different blade parameters by adjusting the capacitance value in the preset capacitor. For example, compared with other electromagnetic wave generating circuits (such as Siler oscillator, etc.), the advantage of adopting the electromagnetic wave generating circuit of the present disclosure is that the adjustable frequency range is wider, and only the relevant capacitance value in the circuit needs to be adjusted, which makes it easier to meet the frequency requirements of medium-frequency electromagnetic waves and can be applied to the fault detection of lightning arresters of wind turbine blades of different lengths.

[0172] On the other hand, the advantages of the electromagnetic wave receiving device according to the embodiment of the present disclosure also lie in that the magnitude of the output voltage value is related to the frequency of the input signal, and the magnitude of the output voltage value is independent of the amplitude of the input signal, so the signal can be easily identified and analyzed.

[0173] On the other hand, the signal detection method according to the embodiment of the present disclosure can filter out low-frequency signals, reduce the impact of interference signals on detection results, and improve detection precision and accuracy.

[0174] Although some embodiments of the present disclosure have been disclosed and described, it will be appreciated by those skilled in the art that modifications and variations may be made to the embodiments without departing from the concept and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A fault detection method for a wind turbine blade lightning protection device, characterized in that: The lightning protection device includes a lightning receptor and a conductor thereof, wherein the conductor is arranged in a wind turbine blade in a feeder manner, and the lightning receptor is connected to an end of the conductor close to a tip of the wind turbine blade. The fault detection method includes: Obtain fan blade parameter data; Based on the fan blade parameter data, calculating the signal frequency of the alternating current signal to be generated; An alternating current signal having the signal frequency is generated by an electromagnetic wave transmitting device including an electromagnetic wave generating circuit, wherein the electromagnetic wave transmitting device is arranged in the fan blade and connected to the other end of the wire close to the root of the fan blade; Transmitting an alternating current signal with gradually increasing signal strength to an electromagnetic wave receiving device disposed on a drone via a transmitting antenna included in the electromagnetic wave transmitting device and the wire, wherein the drone is located within a preset distance from the wind turbine blades; In which, the AC signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the DC voltage signal corresponding to the AC signal with gradually increasing signal strength meets a predetermined threshold range.

2. The fault detection method according to claim 1, characterized in that: The alternating current signal with gradually increasing signal strength is generated in the following manner: The alternating current signal with gradually increasing signal strength is generated by adjusting the capacitance value of a preset capacitor included in the electromagnetic wave generating circuit.

3. The fault detection method according to claim 1, characterized in that: The electromagnetic wave generating circuit includes a square wave generator and a multi-stage RC loop. Wherein, the square wave generator is a symmetrical multivibrator, and the multi-order RC circuit is a third-order RC circuit.

4. The fault detection method according to claim 1, characterized in that: The waveform of the AC signal with gradually increasing signal strength is a sine wave waveform, and the amplitude of the DC voltage signal depends on the signal frequency of the AC signal with gradually increasing signal strength and is independent of the amplitude of the AC signal with gradually increasing signal strength.

5. The fault detection method according to claim 1, characterized in that: The electromagnetic wave receiving device includes a power amplifier circuit, a diode clamping circuit and a detection circuit. The diode clamping circuit is arranged between the power amplifying circuit and the detection circuit, and the diode clamping circuit includes a clamping diode and a clamping resistor connected in series.

6. The fault detection method according to claim 5, characterized in that: The DC voltage signal is obtained by the AC signal with gradually increasing signal strength received by the electromagnetic wave receiving device, which passes through the power amplifier circuit, the diode clamping circuit, and the detection circuit in sequence.

7. The fault detection method according to claim 1, characterized in that: The fan blade parameter data includes the length of the fan blade, and the step of calculating the signal frequency of the alternating current signal to be generated based on the fan blade parameter data includes: The signal frequency is calculated based on the length of the fan blade, a preset wavelength factor related to the length of the fan blade, and a preset shortening factor related to the length of the fan blade.

8. A method for detecting a fault of a wind turbine blade lightning protection device, characterized in that: The lightning protection device includes a lightning receptor and a conductor thereof, wherein the conductor is arranged in a wind turbine blade as a receiving antenna, and the lightning receptor is connected to an end of the conductor close to a tip of the wind turbine blade. The fault detection method includes: Obtain fan blade parameter data; Based on the fan blade parameter data, calculating the signal frequency of the alternating current signal to be generated; An alternating current signal having the signal frequency is generated by an electromagnetic wave transmitting device including an electromagnetic wave generating circuit, wherein the electromagnetic wave transmitting device is disposed on a drone located within a preset distance from the wind turbine blades; Transmitting an alternating current signal with gradually increasing signal strength to an electromagnetic wave receiving device via a transmitting antenna included in the electromagnetic wave transmitting device, wherein the electromagnetic wave receiving device is disposed in the wind turbine blade and connected to the other end of the wire; In which, the AC signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the DC voltage signal corresponding to the AC signal with gradually increasing signal strength meets a predetermined threshold range.

9. A fault detection system for a wind turbine blade lightning protection device, characterized in that: The lightning protection device includes a lightning receptor and a conductor thereof, wherein the conductor is arranged in a wind turbine blade in a feeder manner, and the lightning receptor is connected to an end of the conductor close to the tip of the wind turbine blade. The fault detection system includes: The electromagnetic wave transmitting device is arranged in the wind turbine blade, includes an electromagnetic wave generating circuit and is connected to the other end of the wire close to the root of the wind turbine blade, and the electromagnetic wave transmitting device is configured as follows: Obtain fan blade parameter data; Based on the fan blade parameter data, calculating the signal frequency of the alternating current signal to be generated; generating an alternating current signal having the signal frequency; An alternating current signal with gradually increasing signal strength is transmitted to an electromagnetic wave receiving device disposed on a drone via a transmitting antenna and the wire included in the electromagnetic wave transmitting device, wherein the drone is located within a preset distance from the wind turbine blades. In which, the AC signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the DC voltage signal corresponding to the AC signal with gradually increasing signal strength meets a predetermined threshold range.

10. A fault detection system for a wind turbine blade lightning protection device, characterized in that: The lightning protection device includes a lightning receptor and a conductor thereof, wherein the conductor is arranged in a wind turbine blade as a receiving antenna, and the lightning receptor is connected to an end of the conductor close to a tip of the wind turbine blade. The fault detection system includes: The electromagnetic wave transmitting device includes an electromagnetic wave generating circuit and is arranged on a UAV located within a preset distance of a wind turbine blade, and the electromagnetic wave transmitting device is configured as follows: Obtain fan blade parameter data; Based on the fan blade parameter data, calculating the signal frequency of the alternating current signal to be generated; generating an alternating current signal having the signal frequency; An alternating current signal with gradually increasing signal strength is transmitted to an electromagnetic wave receiving device via a transmitting antenna included in the electromagnetic wave transmitting device, wherein the electromagnetic wave receiving device is arranged in the wind turbine blade and connected to the other end of the wire, In which, the AC signal with gradually increasing signal strength is received by the electromagnetic wave receiving device, so that the electromagnetic wave receiving device detects whether the lightning protection device fails based on whether the amplitude of the DC voltage signal corresponding to the AC signal with gradually increasing signal strength meets a predetermined threshold range.

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