System and method for monitoring large deformation of fan blade based on fiber grating sensor

Abstract

The invention relates to a fan blade large deformation monitoring system and method based on fiber grating sensors, and relates to the technical field of wind power generation, the fan blade large deformation monitoring system comprises a fiber grating sensor array, a photoelectric conversion module, a signal conditioning module, an electromagnetic interference detection module and a compensation control module; the electromagnetic interference detection module is used for carrying out electromagnetic interference detection; an analog-to-digital conversion module; the control module is connected with the compensation control module; the analog-to-digital conversion module is used for converting the compensated analog electric signal into a digital signal; and a deformation analysis module. And processing the digital signal based on a blade deformation analysis algorithm to obtain real-time deformation and deformation trend information of the fan blade, judging whether the fan blade has abnormal deformation or not, and outputting a corresponding analysis result.

Description

Technical Field

[0001] The present application relates to the technical field of wind power generation, and in particular to a system and method for monitoring large deformation of wind turbine blades based on fiber grating sensors. Background Art

[0002] As the global demand for clean energy grows, wind power generation has been widely used as a sustainable and environmentally friendly way to obtain energy. As the core equipment of the wind power generation system, the operating status of the wind turbine is directly related to the power generation efficiency and safety. As the key component for capturing wind energy, wind turbine blades are easily deformed by various factors such as wind loads and vibrations under complex working conditions. Accurate monitoring of blade deformation is of vital importance for timely detection of potential faults and ensuring safe and stable operation of wind turbines.

[0003] At present, in the field of wind turbine blade deformation monitoring, a variety of monitoring technologies and systems have been developed. Among them, the monitoring solution based on fiber Bragg grating sensors has shown certain advantages in practical applications due to the many excellent characteristics of fiber Bragg gratings, such as small size, no electricity, corrosion resistance, long-term stability, and immunity to electromagnetic interference. By placing fiber Bragg grating sensors in key parts of wind turbine blades, the deformation of the blades can be effectively sensed and converted into detectable light signal changes.

[0004] However, the existing wind turbine blade deformation monitoring system based on fiber grating sensors still faces many challenges in actual use. The electrical signal after the optical signal output from the fiber grating sensor is converted by photoelectric conversion is very susceptible to coupling with external electromagnetic interference in the transmission line, resulting in signal waveform distortion and data deviation. How to solve this technical problem is a technical problem that technicians in this field need to overcome. Summary of the invention

[0005] In order to at least partially solve the above technical problems, the present application provides a wind turbine blade large deformation monitoring system and method based on fiber grating sensors.

[0006] In a first aspect, the wind turbine blade large deformation monitoring system based on fiber grating sensors provided in the present application adopts the following technical solution.

[0007] The wind turbine blade large deformation monitoring system based on fiber grating sensor includes: Fiber Bragg grating sensor array; the fiber Bragg grating sensor array is arranged at several positions of the fan blades, and is used to sense the deformation of the fan blades and generate optical signals accordingly; A photoelectric conversion module; the photoelectric conversion module is connected to the fiber grating sensor array; the photoelectric conversion module converts the optical signal output by the fiber grating sensor array into an electrical signal; A signal conditioning module; connected to the photoelectric conversion module; the signal conditioning module comprises a preamplifier, a bandpass filter and a gain amplifier connected in sequence; the preamplifier is used to preliminarily amplify the electrical signal output by the photoelectric conversion module; the bandpass filter is used to filter out electromagnetic interference signals outside a preset frequency band; the gain amplifier is used to amplify the strength of the electrical signal; Electromagnetic interference detection module; the electromagnetic interference detection module is used to perform electromagnetic interference detection; A compensation control module; the compensation control module is electrically connected to the electromagnetic interference detection module and the signal conditioning module respectively; the compensation control module is configured with an interference feature database and a compensation algorithm execution unit; the interference feature database stores a number of interference feature data; the compensation algorithm execution unit matches the interference feature data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database to determine a compensation strategy; the compensation strategy is used to perform compensation processing on the preliminarily conditioned electrical signal output by the signal conditioning module to reduce the impact of electromagnetic interference; an analog-to-digital conversion module; connected to the compensation control module; the analog-to-digital conversion module is used to convert the analog electrical signal after compensation processing into a digital signal; and, The deformation analysis module processes the digital signal based on the blade deformation analysis algorithm to obtain the real-time deformation amount and deformation trend information of the fan blade, judges whether the fan blade has abnormal deformation, and outputs the corresponding analysis results.

[0008] By adopting the above technical solution, the compensation control module matches a suitable compensation strategy based on the interference feature database and the compensation algorithm execution unit and performs compensation processing on the electrical signal, thereby reducing the impact of electromagnetic interference and improving the accuracy of deformation monitoring.

[0009] Optionally, the compensation algorithm execution unit matches the interference data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database to determine the compensation strategy, including: Receive interference data transmitted by the electromagnetic interference detection module, wherein the interference data includes frequency distribution information, amplitude information, and duration information of interference in each frequency band detected in the current environment; Convert the interference data in the time domain into frequency domain data to extract the frequency components, corresponding amplitude and phase information of the main interference; The frequency components, amplitudes and phases of the main interferences in the interference data are matched with the interference feature database to obtain the electromagnetic interference category that is most similar to the interference data; Obtaining initial compensation parameters according to the matched electromagnetic interference category; A final compensation strategy is obtained based on the initial compensation parameters, the intensity and duration of the current interference data; the compensation strategy includes filter parameters used when compensating the electrical signal, the frequency of the compensation signal, and the amplitude and phase adjustment values; A corresponding compensation signal is generated based on the determined compensation strategy to perform compensation processing on the electrical signal.

[0010] Optionally, the method for constructing the interference feature database includes: Collect interference sample data generated by several electromagnetic interference sources; the electromagnetic interference sources include interference generated by the fan's motor, inverter, control cabinet under different operating conditions, and interference generated by high-voltage transmission lines and communication base stations outside the fan; for each interference source, collect the frequency range, amplitude distribution, phase characteristics and duration of its interference signal, and record them as original feature information; The collected original feature information is classified according to the interference source type, interference frequency band range and interference intensity level to form different types of interference feature data sets. For each type of data set, the corresponding wind turbine operating conditions and environmental influencing factors are marked; For each type of interference feature data set, experimental simulation and actual field data comparison are used to determine the impact on the electrical signal transmission of the fan blade deformation monitoring system under different wind turbine operating conditions and environmental conditions to determine the corresponding initial compensation parameters; the compensation parameters include filter parameters, signal amplitude and phase angle of the compensation signal.

[0011] Optionally, obtaining a final compensation strategy based on the initial compensation parameter, the intensity and duration of the current interference data includes: Match the corresponding intensity level according to the intensity of the current interference data; Matching the corresponding duration level according to the duration of interference in each frequency band in the current interference data; adjusting the filter cutoff frequency, signal amplitude and phase angle in the initial compensation parameters based on the intensity level and the duration level; forming a compensation strategy based on the adjusted filter cutoff frequency, the signal amplitude and the phase angle of the compensation signal; Generating a corresponding compensation signal based on the determined compensation strategy to perform compensation processing on the electrical signal includes: Generate a compensation signal according to the compensation strategy; the compensation signal is a digital signal; Converting the compensation signal in digital form into an analog signal through a digital-to-analog converter; Superimposing the generated analog compensation signal with the electrical signal output by the signal conditioning module; The superimposed electrical signal is filtered based on a filter with an adjusted cutoff frequency to obtain an electrical signal after compensation processing.

[0012] Optionally, the frequency components, amplitudes and phases of the main interferences in the interference data are matched with the interference feature database to obtain the electromagnetic interference category most similar to the interference data, including: Matching the frequency interval based on the frequency of the interference; determining whether the interference category in the matched frequency interval is unique; if so, obtaining the most similar electromagnetic interference category; If it is not unique, continue to match the amplitude interval based on the amplitude of the interference; determine whether the interference category in the matched amplitude interval is unique; if so, obtain the most similar electromagnetic interference category; if it is not unique, continue to match the phase interval based on the phase of the interference, and obtain the most similar electromagnetic interference category based on the matched phase interval.

[0013] Optionally, the system further comprises a communication module, which is connected to the deformation analysis module and is used for transmitting the deformation information of the fan blades and the fault diagnosis result output by the deformation analysis module to a remote monitoring terminal.

[0014] Optionally, the digital signal is processed based on a blade deformation analysis algorithm to obtain real-time deformation amount and deformation trend information of the fan blade and determine whether the fan blade has abnormal deformation and output corresponding analysis results, including: Calculate the real-time deformation of the fan blades at different positions based on the blade deformation analysis algorithm and the digital signal; The deformation trend of the fan blades is obtained by comparing the deformation changes over a period of time; Judging whether the fan blades have abnormal deformation based on the deformation trend of the fan blades; The analysis results are obtained based on the real-time deformation, deformation trend information and abnormal deformation judgment obtained by analysis.

[0015] In the second aspect, the method for monitoring large deformation of wind turbine blades based on fiber grating sensors provided in the present application adopts the following technical solution.

[0016] A method for monitoring large deformation of wind turbine blades based on fiber grating sensors, based on any of the above-mentioned systems; the method comprises: The deformation condition of the blade is sensed by a fiber grating sensor array and an optical signal is generated accordingly; Convert the optical signal output by the fiber grating sensor array into an electrical signal through a photoelectric conversion module; The signal conditioning module is used to perform a preliminary amplification operation on the electrical signal output by the photoelectric conversion module, filter out electromagnetic interference signals outside the preset frequency band, and amplify the strength of the electrical signal; Perform electromagnetic interference detection through an electromagnetic interference detection module; Determine a compensation strategy by matching the interference data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database through a compensation control module; The analog-to-digital conversion module converts the compensated analog electrical signal into a digital signal; and The digital signal is processed by the deformation analysis module based on the blade deformation analysis algorithm to obtain the real-time deformation amount and deformation trend information of the fan blade, determine whether the fan blade has abnormal deformation, and output the corresponding analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a system diagram of a large deformation monitoring system for wind turbine blades based on a fiber grating sensor according to an embodiment of the present application; In the figure, 101 is a fiber grating sensor array; 102 is a photoelectric conversion module; 103 is a signal conditioning module; 104 is an electromagnetic interference detection module; 105 is a compensation control module; 106 is an analog-to-digital conversion module; and 107 is a deformation analysis module. DETAILED DESCRIPTION

[0018] The following is combined with Figure 1 The present application is further described with specific embodiments: The embodiment of the present application discloses a large deformation monitoring system for wind turbine blades based on a fiber grating sensor, comprising: Fiber Bragg grating sensor array: The fiber Bragg grating sensor array is arranged at several positions of the fan blades to sense the deformation of the fan blades and generate optical signals accordingly. Specifically, the fiber Bragg grating sensor array is a collection of multiple fiber Bragg grating sensors, which are arranged at multiple positions of the fan blades. When the fan blades are deformed, the environment where the fiber Bragg grating is located will be strained, which will cause the wavelength of light reflected or transmitted by the fiber Bragg grating to change, thereby generating corresponding optical signals to sense the deformation of different positions of the blades.

[0019] Photoelectric conversion module; the photoelectric conversion module is connected to the fiber grating sensor array; the photoelectric conversion module converts the optical signal output by the fiber grating sensor array into an electrical signal. Specifically, the photoelectric conversion module is used to realize the conversion from the optical signal to the electrical signal. After receiving the optical signal output from the sensor array, the photoelectric conversion module forms a current based on the principle of photoelectric effect with the help of the internal photoelectric conversion element to convert the optical signal into an electrical signal.

[0020] Signal conditioning module; connected to the photoelectric conversion module; the signal conditioning module includes a preamplifier, a bandpass filter and a gain amplifier connected in sequence; the preamplifier is used to preliminarily amplify the electrical signal output by the photoelectric conversion module; the bandpass filter is used to filter out electromagnetic interference signals outside the preset frequency band; the gain amplifier is used to amplify the strength of the electrical signal. Specifically, the signal conditioning module is composed of a preamplifier, a bandpass filter and a gain amplifier connected in sequence. The electrical signal output by the photoelectric conversion module is relatively weak. The preamplifier performs a preliminary amplification operation on it through its own amplification circuit without introducing too much noise interference; the bandpass filter uses a filtering circuit composed of inductors, capacitors and other components to only allow electrical signals within a specific frequency band to pass through, and filter out electromagnetic interference signals outside the preset frequency band. The gain amplifier is used to further enhance the strength of the electrical signal so that its amplitude reaches a range suitable for the operation of subsequent analog-to-digital conversion modules and other processing modules.

[0021] Electromagnetic interference detection module: The electromagnetic interference detection module is used to perform electromagnetic interference detection. Specifically, the electromagnetic interference detection module is used to detect electromagnetic interference in the operating environment of the wind turbine. It uses the principle of electromagnetic induction to sense various electromagnetic interferences in the surrounding space through magnetic field sensors or electric field sensors. Electromagnetic interference may come from the wind turbine's own electrical equipment, such as electromagnetic radiation generated by motors, inverters, control cabinets, etc. during operation, or from electromagnetic signals emitted by high-voltage transmission lines, communication base stations and other facilities outside the wind turbine.

[0022] Compensation control module; the compensation control module is electrically connected to the electromagnetic interference detection module and the signal conditioning module respectively; the compensation control module is configured with an interference feature database and a compensation algorithm execution unit; the interference feature database stores a number of interference feature data; the compensation algorithm execution unit determines a compensation strategy based on the interference data detected by the electromagnetic interference detection module and the interference feature data stored in the interference feature database; the compensation strategy is used to compensate the preliminarily conditioned electrical signal output by the signal conditioning module to reduce the impact of electromagnetic interference. Specifically, the compensation algorithm execution unit receives the real-time interference data detected by the electromagnetic interference detection module, and matches it with the data stored in the interference feature database, determines a suitable compensation strategy based on the matching result, and implements the compensation strategy to reduce the impact of electromagnetic interference on the electrical signal output by the signal conditioning module, so that the final processed electrical signal can more accurately reflect the actual deformation of the fan blade.

[0023] an analog-to-digital conversion module; connected to the compensation control module; the analog-to-digital conversion module is used to convert the analog electrical signal after compensation processing into a digital signal; and, Deformation analysis module: based on the blade deformation analysis algorithm, the digital signal is processed to obtain the real-time deformation amount and deformation trend information of the fan blade, and whether the fan blade has abnormal deformation and output the corresponding analysis results. Specifically, the deformation analysis module relies on the blade deformation analysis algorithm to process the digital signal output by the analog-to-digital conversion module, extracts various characteristic information related to the deformation of the fan blade from the digital signal, and then calculates the real-time deformation amount of the fan blade and analyzes the deformation trend information. At the same time, it can also judge whether the fan blade has abnormal deformation according to the set standards and rules, and finally output the corresponding analysis results. The blade deformation analysis algorithm is not the invention point of the present application. In the prior art, those skilled in the art can also know a variety of implementation methods, so it will not be repeated in this application.

[0024] Specifically, since large deformation monitoring of wind turbine blades is crucial to ensure safe and stable operation of wind turbines, and the operating environment of wind turbines often has complex and changeable electromagnetic interference. In the application, the fiber grating sensor array converts the deformation of the blades into optical signals, and the photoelectric conversion module converts the optical signals into electrical signals; the preamplifier, bandpass filter and gain amplifier in the signal conditioning module preliminarily amplify the electrical signals, filter out electromagnetic interference and further enhance the intensity; the electromagnetic interference detection module continuously monitors the electromagnetic interference of the surrounding environment, and the compensation control module matches the appropriate compensation strategy based on the interference feature database and the compensation algorithm execution unit and performs compensation processing on the electrical signals, reducing the impact of electromagnetic interference; the deformation analysis module processes the compensated signals to obtain the real-time deformation amount and deformation trend information of the wind turbine blades, and determines whether there is abnormal deformation, outputs the corresponding analysis results, and improves the accuracy of deformation monitoring.

[0025] As a specific implementation of the wind turbine blade large deformation monitoring system based on the fiber grating sensor, the compensation algorithm execution unit matches the interference data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database to determine the compensation strategy, including: Receive interference data transmitted by the electromagnetic interference detection module, wherein the interference data includes frequency distribution information, amplitude information, and duration information of interference in each frequency band detected in the current environment; Convert the interference data in the time domain into frequency domain data to extract the frequency components, corresponding amplitude and phase information of the main interference; The frequency components, amplitudes and phases of the main interferences in the interference data are matched with the interference feature database to obtain the electromagnetic interference category that is most similar to the interference data; Obtaining initial compensation parameters according to the matched electromagnetic interference category; A final compensation strategy is obtained based on the initial compensation parameters, the intensity and duration of the current interference data; the compensation strategy includes filter parameters used when compensating the electrical signal, the frequency of the compensation signal, and the amplitude and phase adjustment values; A corresponding compensation signal is generated based on the determined compensation strategy to perform compensation processing on the electrical signal.

[0026] Specifically, the electromagnetic interference detection module detects interference data containing information such as frequency distribution, amplitude, and duration of interference in each frequency band. The compensation algorithm execution unit first converts the interference data in the time domain into frequency domain data and extracts the frequency component, amplitude, and phase of the interference; based on the extracted frequency component, amplitude, and phase of the main interference, it matches the interference feature database to find the most similar electromagnetic interference category, thereby obtaining the initial compensation parameters. The initial compensation parameters are further optimized in combination with the actual intensity and duration of the current interference data to obtain the final compensation strategy. The frequency of the compensation signal offsets the interference frequency, and the amplitude and phase adjustment value corrects the amplitude and phase deviation of the electrical signal caused by the interference. Based on this compensation strategy, a compensation signal is generated to compensate the electrical signal, thereby greatly reducing the impact of electromagnetic interference on the electrical signal.

[0027] As a specific implementation of a wind turbine blade large deformation monitoring system based on a fiber grating sensor, the method for constructing the interference feature database includes: Collect interference sample data generated by several electromagnetic interference sources; the electromagnetic interference sources include interference generated by the fan's motor, inverter, control cabinet under different operating conditions, and interference generated by high-voltage transmission lines and communication base stations outside the fan; for each interference source, collect the frequency range, amplitude distribution, phase characteristics and duration of its interference signal, and record them as original feature information; The collected original feature information is classified according to the interference source type, interference frequency band range and interference intensity level to form different types of interference feature data sets. For each type of data set, the corresponding wind turbine operating conditions and environmental influencing factors are marked; For each type of interference feature data set, experimental simulation and actual field data comparison are used to determine the impact on the electrical signal transmission of the fan blade deformation monitoring system under different wind turbine operating conditions and environmental conditions to determine the corresponding initial compensation parameters; the compensation parameters include filter parameters, signal amplitude and phase angle of the compensation signal.

[0028] Specifically, collect interference sample data generated by various electromagnetic interference sources such as the fan's motor, inverter, control cabinet under different operating conditions, and high-voltage transmission lines, communication base stations outside the fan, and record their frequency range, amplitude distribution, phase characteristics, and duration information; classify them according to the type of interference source, interference frequency band range, and interference intensity level to form different types of interference feature data sets, and mark the corresponding fan operating conditions and environmental influencing factors for each type of data set; for each type of interference feature data set, use experimental simulation combined with actual field data comparison to determine the initial compensation parameters corresponding to the impact on electrical signal transmission under different fan operating conditions and environmental conditions. When the system encounters corresponding interference, retrieve appropriate initial compensation parameters based on the existing information in the database, and then generate a compensation strategy to process the electrical signal to reduce the impact of electromagnetic interference on electrical signal transmission.

[0029] As a specific implementation of a large deformation monitoring system for wind turbine blades based on a fiber grating sensor, a final compensation strategy is obtained based on the initial compensation parameters, the intensity and duration of the current interference data, including: Match the corresponding intensity level according to the intensity of the current interference data; Matching the corresponding duration level according to the duration of interference in each frequency band in the current interference data; adjusting the filter cutoff frequency, signal amplitude and phase angle in the initial compensation parameters based on the intensity level and the duration level; forming a compensation strategy based on the adjusted filter cutoff frequency, the signal amplitude and the phase angle of the compensation signal; Generating a corresponding compensation signal based on the determined compensation strategy to perform compensation processing on the electrical signal includes: Generate a compensation signal according to the compensation strategy; the compensation signal is a digital signal; Converting the compensation signal in digital form into an analog signal through a digital-to-analog converter; Superimposing the generated analog compensation signal with the electrical signal output by the signal conditioning module; The superimposed electrical signal is filtered based on a filter with an adjusted cutoff frequency to obtain a compensated electrical signal.

[0030] Specifically, the intensity of the current interference data is matched to the corresponding intensity level, and the duration level is matched to the corresponding duration level according to the duration of the interference in each frequency band; based on the determined intensity level and duration level, the filter cutoff frequency, signal amplitude and phase angle in the initial compensation parameters are adjusted, and the filter cutoff frequency can block unnecessary interference frequency bands more accurately according to the actual interference situation, and the signal amplitude and phase angle can also correct the amplitude and phase deviations of the original electrical signal caused by the interference, thereby forming an effective compensation strategy that fits the current interference situation; a compensation signal in digital form is generated according to the compensation strategy, which is converted into an analog signal through a digital-to-analog converter, and then superimposed with the electrical signal output by the signal conditioning module, and the compensation signal is applied to the interfered electrical signal to offset or correct the interference; the superimposed electrical signal is filtered by adjusting the cutoff frequency filter to further remove possible residual interference components and excess clutter generated during the superposition process, so as to obtain an electrical signal after compensation processing.

[0031] As one of the implementation methods of the large deformation monitoring system of wind turbine blades based on fiber grating sensors, the frequency components, amplitudes and phases of the main interferences in the interference data are matched with the interference feature database to obtain the electromagnetic interference category most similar to the interference data, including: Matching the frequency interval based on the frequency of the interference; determining whether the interference category in the matched frequency interval is unique; if so, obtaining the most similar electromagnetic interference category; If it is not unique, continue to match the amplitude interval based on the amplitude of the interference; determine whether the interference category in the matched amplitude interval is unique; if so, obtain the most similar electromagnetic interference category; if it is not unique, continue to match the phase interval based on the phase of the interference, and obtain the most similar electromagnetic interference category based on the matched phase interval.

[0032] Specifically, the frequency interval is matched based on the frequency of the interference, and the possible corresponding interference category range is preliminarily screened out. If the interference category in the matched frequency interval is unique at this time, the most similar electromagnetic interference category is directly determined, saving matching time and computing resources. When the interference category is not unique after the frequency interval is matched, the amplitude interval is continued to be matched based on the amplitude of the interference, and the screening conditions are further refined. If a unique interference category can be determined in this amplitude interval matching, the most similar electromagnetic interference category is obtained. If the interference category is still not unique after the amplitude interval is matched, the phase interval is continued to be matched based on the phase of the interference.

[0033] As one embodiment of a large deformation monitoring system for wind turbine blades based on fiber grating sensors, the system also includes a communication module, which is connected to the deformation analysis module, and is used to transmit the deformation information and fault diagnosis results of the wind turbine blades output by the deformation analysis module to a remote monitoring terminal.

[0034] As one implementation of a large deformation monitoring system for fan blades based on a fiber grating sensor, the digital signal is processed based on a blade deformation analysis algorithm to obtain real-time deformation amount and deformation trend information of the fan blade, determine whether the fan blade has abnormal deformation, and output corresponding analysis results, including: Calculate the real-time deformation of the fan blades at different positions based on the blade deformation analysis algorithm and the digital signal; The deformation trend of the fan blades is obtained by comparing the deformation changes over a period of time; Judging whether the fan blades have abnormal deformation based on the deformation trend of the fan blades; The analysis results are obtained based on the real-time deformation, deformation trend information and abnormal deformation judgment obtained by analysis.

[0035] The present application also provides a method for monitoring large deformation of wind turbine blades based on a fiber grating sensor, based on the above system; the method comprises: The deformation condition of the blade is sensed by a fiber grating sensor array and an optical signal is generated accordingly; Convert the optical signal output by the fiber grating sensor array into an electrical signal through a photoelectric conversion module; The signal conditioning module is used to perform a preliminary amplification operation on the electrical signal output by the photoelectric conversion module, filter out electromagnetic interference signals outside the preset frequency band, and amplify the strength of the electrical signal; Perform electromagnetic interference detection through an electromagnetic interference detection module; Determine a compensation strategy by matching the interference data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database through a compensation control module; The analog-to-digital conversion module converts the compensated analog electrical signal into a digital signal; and The digital signal is processed by the deformation analysis module based on the blade deformation analysis algorithm to obtain the real-time deformation amount and deformation trend information of the fan blade, determine whether the fan blade has abnormal deformation, and output the corresponding analysis results.

[0036] It should be noted that the above embodiments are only used to illustrate the present application and are not intended to limit the technical solutions described in the present application. Although the present application has been described in detail in this specification with reference to the above embodiments, a person of ordinary skill in the art should understand that a person of ordinary skill in the art can still modify or make equivalent substitutions to the present application, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present application should be included in the scope of the claims of the present application.

Claims

1. A large deformation monitoring system for wind turbine blades based on fiber grating sensors, characterized in that: include: Fiber Bragg grating sensor array; the fiber Bragg grating sensor array is arranged at several positions of the fan blades, and is used to sense the deformation of the fan blades and generate optical signals accordingly; A photoelectric conversion module; the photoelectric conversion module is connected to the fiber grating sensor array; the photoelectric conversion module converts the optical signal output by the fiber grating sensor array into an electrical signal; A signal conditioning module; connected to the photoelectric conversion module; the signal conditioning module comprises a preamplifier, a bandpass filter and a gain amplifier connected in sequence; the preamplifier is used to preliminarily amplify the electrical signal output by the photoelectric conversion module; the bandpass filter is used to filter out electromagnetic interference signals outside a preset frequency band; the gain amplifier is used to amplify the strength of the electrical signal; Electromagnetic interference detection module; the electromagnetic interference detection module is used to perform electromagnetic interference detection; A compensation control module; the compensation control module is electrically connected to the electromagnetic interference detection module and the signal conditioning module respectively; the compensation control module is configured with an interference feature database and a compensation algorithm execution unit; the interference feature database stores a number of interference feature data; the compensation algorithm execution unit matches the interference feature data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database to determine a compensation strategy; the compensation strategy is used to perform compensation processing on the preliminarily conditioned electrical signal output by the signal conditioning module to reduce the impact of electromagnetic interference; An analog-to-digital conversion module; connected to the compensation control module; the analog-to-digital conversion module is used to convert the analog electrical signal after compensation processing into a digital signal; as well as, Deformation analysis module; The digital signal is processed based on a blade deformation analysis algorithm to obtain the real-time deformation amount and deformation trend information of the fan blade, determine whether the fan blade has abnormal deformation, and output corresponding analysis results.

2. The wind turbine blade large deformation monitoring system based on fiber grating sensor according to claim 1 is characterized in that: The compensation algorithm execution unit matches the interference data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database to determine a compensation strategy, including: Receive interference data transmitted by the electromagnetic interference detection module, wherein the interference data includes frequency distribution information, amplitude information, and duration information of interference in each frequency band detected in the current environment; Convert the interference data in the time domain into frequency domain data to extract the frequency components, corresponding amplitude and phase information of the main interference; The frequency components, amplitudes and phases of the main interferences in the interference data are matched with the interference feature database to obtain the electromagnetic interference category that is most similar to the interference data; Obtaining initial compensation parameters according to the matched electromagnetic interference category; A final compensation strategy is obtained based on the initial compensation parameters, the intensity and duration of the current interference data; the compensation strategy includes filter parameters used when compensating the electrical signal, the frequency of the compensation signal, and the amplitude and phase adjustment values; Based on the determined compensation strategy, a corresponding compensation signal is generated to perform compensation processing on the electrical signal.

3. The wind turbine blade large deformation monitoring system based on fiber grating sensor according to claim 2 is characterized in that: The method for constructing the interference feature database includes: Collect interference sample data generated by several electromagnetic interference sources; the electromagnetic interference sources include interference generated by the fan's motor, inverter, control cabinet under different operating conditions, and interference generated by high-voltage transmission lines and communication base stations outside the fan; for each interference source, collect the frequency range, amplitude distribution, phase characteristics and duration of its interference signal, and record them as original feature information; The collected original feature information is classified according to the interference source type, interference frequency band range and interference intensity level to form different types of interference feature data sets. For each type of data set, the corresponding wind turbine operating conditions and environmental influencing factors are marked; For each type of interference feature data set, experimental simulation and actual field data comparison are used to determine the impact on the electrical signal transmission of the fan blade deformation monitoring system under different wind turbine operating conditions and environmental conditions to determine the corresponding initial compensation parameters; the compensation parameters include filter parameters, signal amplitude and phase angle of the compensation signal.

4. The wind turbine blade large deformation monitoring system based on fiber grating sensor according to claim 3 is characterized in that: A final compensation strategy is obtained based on the initial compensation parameters, the intensity and duration of the current interference data, including: Match the corresponding intensity level according to the intensity of the current interference data; Matching the corresponding duration level according to the duration of interference in each frequency band in the current interference data; adjusting the filter cutoff frequency, signal amplitude and phase angle in the initial compensation parameters based on the intensity level and the duration level; forming a compensation strategy based on the adjusted filter cutoff frequency, the signal amplitude and the phase angle of the compensation signal; Generating a corresponding compensation signal based on the determined compensation strategy to perform compensation processing on the electrical signal includes: Generate a compensation signal according to the compensation strategy; the compensation signal is a digital signal; Converting the compensation signal in digital form into an analog signal through a digital-to-analog converter; Superimposing the generated analog compensation signal with the electrical signal output by the signal conditioning module; The superimposed electrical signal is filtered based on a filter with an adjusted cutoff frequency to obtain an electrical signal after compensation processing.

5. The wind turbine blade large deformation monitoring system based on fiber grating sensor according to claim 4 is characterized in that: The frequency components, amplitudes and phases of the main interferences in the interference data are matched with the interference feature database to obtain the electromagnetic interference category that is most similar to the interference data, including: Matching the frequency interval based on the frequency of the interference; determining whether the interference category in the matched frequency interval is unique; if so, obtaining the most similar electromagnetic interference category; If it is not unique, continue to match the amplitude interval based on the amplitude of the interference; determine whether the interference category in the matched amplitude interval is unique; if so, obtain the most similar electromagnetic interference category; if it is not unique, continue to match the phase interval based on the phase of the interference, and obtain the most similar electromagnetic interference category based on the matched phase interval.

6. The wind turbine blade large deformation monitoring system based on fiber grating sensor according to claim 5 is characterized in that: The system further comprises a communication module, which is connected to the deformation analysis module and is used for transmitting the deformation information of the fan blades and the fault diagnosis result output by the deformation analysis module to a remote monitoring terminal.

7. The wind turbine blade large deformation monitoring system based on fiber grating sensor according to claim 6 is characterized in that: The digital signal is processed based on the blade deformation analysis algorithm to obtain the real-time deformation amount and deformation trend information of the fan blade and determine whether the fan blade has abnormal deformation and output the corresponding analysis results, including: Calculate the real-time deformation of the fan blades at different positions based on the blade deformation analysis algorithm and the digital signal; The deformation trend of the fan blades is obtained by comparing the deformation changes over a period of time; Judging whether the fan blades have abnormal deformation based on the deformation trend of the fan blades; The analysis results are obtained based on the real-time deformation, deformation trend information and abnormal deformation judgment obtained by analysis.

8. A method for monitoring large deformation of wind turbine blades based on fiber grating sensors, characterized in that: Based on the system according to any one of claims 1 to 7; the method comprises: The deformation condition of the blade is sensed by a fiber grating sensor array and an optical signal is generated accordingly; Convert the optical signal output by the fiber grating sensor array into an electrical signal through a photoelectric conversion module; The signal conditioning module is used to perform a preliminary amplification operation on the electrical signal output by the photoelectric conversion module, filter out electromagnetic interference signals outside the preset frequency band, and amplify the strength of the electrical signal; Perform electromagnetic interference detection through an electromagnetic interference detection module; Determine a compensation strategy by matching the interference data detected by the electromagnetic interference detection module with the interference feature data stored in the interference feature database through a compensation control module; The analog-to-digital conversion module converts the compensated analog electrical signal into a digital signal; and The digital signal is processed by the deformation analysis module based on the blade deformation analysis algorithm to obtain the real-time deformation amount and deformation trend information of the fan blade, determine whether the fan blade has abnormal deformation, and output the corresponding analysis results.

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