In-situ calibration vibration monitoring device and method for a fan

Abstract

The disclosure provides an in-situ calibration vibration monitoring device and method for a fan, which comprises the following steps: fixing and installing a measurement and control device at a fan site, directly connecting an excitation module output end and a sensor driving part by using a detachable rigid connecting rod, tracking and filtering a rotating speed frequency component in real time by using a phase-locked loop technology under the condition that the fan keeps running at a rated rotating speed, constructing a hardware closed-loop calibration loop connected by an excitation module, a sensor, a signal conditioning module, a data acquisition module and a control card in sequence, realizing dynamic metrological calibration of the sensor on line without shutdown, and calculating core metrological indexes such as reference sensitivity, frequency response error and amplitude linearity based on the returned sensor response data, and real-time alarm for the out-of-tolerance condition. Therefore, the technical problems of long calibration period and poor working condition reproducibility caused by the traditional method of disassembling the sensor and shutdown maintenance are solved, and the calibration efficiency and precision are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of rotating machinery vibration monitoring technology, and in particular to a fieldbus communication method based on dynamic time slot allocation. Background Technology

[0002] With the deep application of Industrial Internet of Things (IIoT) technology, a large number of online vibration monitoring devices have been deployed in process industries such as power, petrochemicals, and metallurgy for condition monitoring and fault early warning of critical rotating machinery. Taking thermal power plants as an example, each unit is equipped with 8 to 12 fans, including forced draft fans, induced draft fans, primary air fans, and desulfurization oxidation fans. Each fan is equipped with 3 to 6 vibration sensors, totaling more than 500 sensors throughout the plant. These sensors operate under harsh conditions of high temperature, high humidity, and strong electromagnetic interference for extended periods, resulting in significant drift in measurement accuracy over time. According to vibration meter calibration procedures, vibration monitoring devices should undergo periodic traceability every 12 months. However, traditional solutions require disassembling the sensors from the fan body and sending them to a metrology laboratory for offline calibration using a standard vibration table. This process suffers from two fundamental technical flaws: First, the disassembly and assembly process requires the unit to be shut down for coordination, and a single calibration takes more than 48 hours, severely impacting the execution of power generation plans. The actual calibration cycle often extends to 3 to 5 years, resulting in a large number of sensors remaining in an untraceable state for extended periods. Second, laboratory standard vibration tables cannot reproduce the actual installation boundary conditions, temperature field distribution, and electromagnetic environment at the wind turbine site, making it difficult to guarantee the measurement accuracy of sensors under actual operating conditions and posing significant safety hazards to wind turbine operation. Therefore, there is an urgent need for a technical solution that allows for in-situ calibration at the wind turbine operating site without disassembly, in order to overcome the technical bottlenecks of difficult periodic traceability and poor reproducibility of operating conditions. Summary of the Invention

[0003] In a first aspect, this disclosure provides an in-situ calibration vibration monitoring device for wind turbines, comprising a host computer (1), a measurement and control device (2), and a sensor (3) installed at the location to be measured on the wind turbine body. The measurement and control device (2) integrates a control card (201), an excitation module (202), a signal conditioning module (203), and a data acquisition module (204). It is fixedly installed at the wind turbine site and is configured to track the wind turbine speed frequency through phase-locked loop technology and filter out the frequency component in the spectrum analysis under the condition that the wind turbine is running at its rated speed, and to implement dynamic measurement calibration. The output of the excitation module (202) is connected to the drive component (301) of the sensor (3) via a detachable rigid linkage. The first communication terminal of the control card (201) is bidirectionally network-connected to the host computer (1). The excitation output terminal of the control card (201) is electrically connected to the input terminal of the excitation module (202). The amplitude of the generated calibration excitation signal is less than 30% of the vibration amplitude during normal operation of the fan. The output terminal of the excitation module (202) is connected to the input terminal of the drive component (301) of the sensor (3). The signal processing component (303) of the sensor (3) is directly connected to the input of the signal conditioning module (203). The output of the signal conditioning module (203) is electrically connected to the input of the data acquisition module (204). The feedback of the data acquisition module (204) is electrically connected to the data input of the control card (201). The control card (201) adjusts the output amplitude and frequency of the excitation module (202) according to the sensor response data returned by the data acquisition module (204). The host computer (1) has a built-in parameter configuration unit, a measurement judgment unit and an alarm output unit. The parameter configuration unit is used to set the vibration amplitude range, vibration frequency range, reference working frequency, number of frequency calibration points and number of amplitude calibration points. The excitation module (202) generates a continuously adjustable sinusoidal excitation signal according to the parameters forwarded by the control card (201). The amplitude and frequency of the sinusoidal excitation signal are remotely controlled by the host computer (1). The measurement judgment unit automatically calculates three core measurement indicators, namely reference sensitivity, frequency response error and amplitude linearity, based on the sensor response data returned by the data acquisition module (204). When any one of the indicators exceeds the preset tolerance range, the alarm output unit generates an unqualified alarm signal.

[0004] In conjunction with the first aspect, the sensor (3) is a piezoelectric vibration velocity sensor or a magnetoelectric vibration acceleration sensor. The driving component (301) of the sensor (3) is rigidly connected to the vibration sensitive element (302). A charge amplification circuit and a low-pass filter circuit are provided between the vibration sensitive element (302) and the signal processing component (303). The output signal of the signal processing component (303) is a 4-20mA current signal or a 0-10V voltage signal.

[0005] In conjunction with the first aspect, the excitation module (202) integrates a wideband power amplifier and an electromagnetic exciter, with an output frequency range of 5Hz to 2000Hz and an output acceleration amplitude range of 0.5m / s² to 50m / s². The resonant frequency of the detachable rigid connecting rod is higher than 2000Hz.

[0006] In conjunction with the first aspect, the signal conditioning module (203) includes a programmable gain amplifier circuit, an anti-aliasing filter circuit, and a synchronous sample-and-hold circuit. The gain of the programmable gain amplifier circuit is automatically adjusted by the control card (201) according to the amplitude of the sensor output signal, and the adjustment range is from 1 to 128 times. The cutoff frequency of the anti-aliasing filter circuit is 0.45 times the sampling frequency of the data acquisition module (204).

[0007] In conjunction with the first aspect, the data acquisition module (204) adopts a dual-channel 24-bit Sigma-Delta analog-to-digital converter, wherein the first channel acquires the response signal of the sensor (3), and the second channel synchronously acquires the output feedback signal of the excitation module (202) as a reference. The sampling rate of the two channels is not less than 51.2 kS / s and they are synchronized, with a phase difference of less than 0.1 degrees.

[0008] A second aspect of this disclosure provides an in-situ calibration vibration monitoring method for wind turbines, comprising the following steps: S1, in the parameter configuration unit of the host computer (1), according to the technical specifications of the sensor being calibrated, the vibration amplitude range, vibration frequency range, reference working frequency, number of frequency calibration points N and number of amplitude calibration points M are set, and the corresponding measurement tolerance limit is input. S2, the host computer (1) sends the above parameters to the control card (201) via the network. After the control card (201) parses the parameters, it drives the excitation module (202) to generate a first sinusoidal excitation signal. The frequency of the first sinusoidal excitation signal is equal to the reference working frequency, and the amplitude is equal to the median of the vibration amplitude range. The sensor (3) generates a mechanical vibration response under the action of the driving component (301). The response is converted by the vibration sensitive element (302) and amplified by the signal processing component (303) to form an electrical signal. S3, while the excitation module (202) outputs a sinusoidal excitation signal, the data acquisition module (204) synchronously acquires the fan speed signal. The control card (201) extracts the speed frequency in real time as a reference signal through the built-in phase-locked loop circuit, and dynamically adjusts the center frequency of the adaptive notch filter to track speed fluctuations. In the spectrum analysis, the real-time changing speed frequency components and their harmonic components are filtered out to achieve online synchronous isolation of operating condition vibration interference. S4, after the electrical signal is filtered and amplified by the signal conditioning module (203), it is converted from analog to digital by the data acquisition module (204). The control card (201) reads the converted digital signal and sends it back to the host computer (1). The measurement and judgment unit of the host computer (1) calculates the reference sensitivity S0 based on the amplitude ratio of the digital signal and the feedback signal output by the excitation module (202). S5, keeping the excitation amplitude constant, the control card (201) controls the excitation module (202) to output the second sinusoidal excitation signal sequentially at the N frequency points within the vibration frequency range, and repeats steps S2 to S4 to obtain the sensitivity at each frequency point. Where i = 1, 2, ..., N, the measurement determination unit is determined according to the formula Calculate frequency response error ; S6, keeping the reference operating frequency unchanged, the control card (201) controls the excitation module (202) to output the third sinusoidal excitation signal sequentially at the M amplitude points within the vibration amplitude range, and repeats steps S2 to S4 to obtain the sensitivity of each amplitude point. Where j=1,2,...,M, the measurement determination unit is determined according to the formula Calculate amplitude linearity ; S7, when or When any one of the measurement tolerance limits is exceeded, the alarm output unit triggers an audible and visual alarm and writes the non-compliance information to a log file. When both items are within tolerance, the host computer (1) automatically generates a log file containing S0, , An electronic test report with the calibration date is uploaded to the remote monitoring center.

[0009] In conjunction with the second aspect, the number of frequency calibration points N is 11, and the specific frequency points are distributed in 1 / 3 octave bands, namely 5Hz, 6.3Hz, 8Hz, 10Hz, 12.5Hz, 16Hz, 20Hz, 25Hz, 31.5Hz, 40Hz, and 50Hz, and the reference working frequency is selected as 10Hz.

[0010] In conjunction with the second aspect, the number M of amplitude calibration points is set to 9, with specific amplitude points distributed logarithmically at equal intervals within the range of 0.5 m / s² to 50 m / s², namely 0.5 m / s², 1 m / s², 2 m / s², 5 m / s², 10 m / s², 15 m / s², 25 m / s², 35 m / s², and 50 m / s². The measurement and determination unit calculates the amplitude linearity. First, assess the sensitivity at each amplitude point. Least squares linear fitting is performed to eliminate the influence of random errors.

[0011] A third aspect of this disclosure provides an electronic device comprising: One or more processors; A storage unit is used to store one or more programs that, when executed by one or more processors, enable the one or more processors to implement the method.

[0012] A fourth aspect of this disclosure provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the method.

[0013] Beneficial Effects: This disclosure provides an in-situ calibration vibration monitoring device and method for wind turbines. By fixing a measurement and control device integrating a control card, excitation module, signal conditioning module, and data acquisition module at the wind turbine site, and using a detachable rigid connecting rod to directly connect the output of the excitation module to the sensor drive component, and employing phase-locked loop technology to track and filter out speed frequency components in real time while the wind turbine maintains its rated speed, a hardware closed-loop calibration circuit is constructed, consisting of the excitation module, sensor, signal conditioning module, data acquisition module, and control card connected sequentially. This enables online dynamic metrological calibration of the sensor without shutdown. Furthermore, the host computer automatically sets multi-point calibration parameters, drives the excitation module to generate a controllable sinusoidal excitation signal, and calculates core metrological indicators such as reference sensitivity, frequency response error, and amplitude linearity based on the returned sensor response data, providing real-time alarms for out-of-tolerance conditions. This completely solves the technical problems of traditional methods that require sensor disassembly and shutdown for maintenance, resulting in long calibration cycles and poor reproducibility of operating conditions, significantly improving calibration efficiency and accuracy. Attached Figure Description

[0014] Figure 1 This is a structural diagram of an in-situ calibration vibration monitoring device for a wind turbine according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of a detachable rigid linkage connection structure according to an embodiment of the present disclosure; Figure 3 This is a flowchart of an in-situ calibration vibration monitoring method for wind turbines according to an embodiment of the present disclosure; Figure 4 An electronic device according to an embodiment of this disclosure. Detailed Implementation

[0015] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those disclosed herein.

[0016] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0017] Figure 1 This is a structural diagram of an in-situ calibration vibration monitoring device for a wind turbine according to an embodiment of the present disclosure. It includes a host computer (1), a measurement and control device (2), and a sensor (3) installed at the position to be measured on the wind turbine body. The measurement and control device (2) integrates a control card (201), an excitation module (202), a signal conditioning module (203), and a data acquisition module (204). It is fixedly installed at the wind turbine site and is configured to track the wind turbine speed frequency through phase-locked loop technology and filter out the frequency component in the spectrum analysis under the condition that the wind turbine is running at its rated speed, and to implement dynamic measurement calibration. The output of the excitation module (202) is connected to the drive component (301) of the sensor (3) via a detachable rigid linkage. The first communication terminal of the control card (201) is bidirectionally network-connected to the host computer (1). The excitation output terminal of the control card (201) is electrically connected to the input terminal of the excitation module (202). The amplitude of the generated calibration excitation signal is less than 30% of the vibration amplitude during normal operation of the fan. The output terminal of the excitation module (202) is connected to the input terminal of the drive component (301) of the sensor (3). The signal processing component (303) of the sensor (3) is directly connected to the input of the signal conditioning module (203). The output of the signal conditioning module (203) is electrically connected to the input of the data acquisition module (204). The feedback of the data acquisition module (204) is electrically connected to the data input of the control card (201). The control card (201) adjusts the output amplitude and frequency of the excitation module (202) according to the sensor response data returned by the data acquisition module (204). The host computer (1) has a built-in parameter configuration unit, a measurement judgment unit and an alarm output unit. The parameter configuration unit is used to set the vibration amplitude range, vibration frequency range, reference working frequency, number of frequency calibration points and number of amplitude calibration points. The excitation module (202) generates a continuously adjustable sinusoidal excitation signal according to the parameters forwarded by the control card (201). The amplitude and frequency of the sinusoidal excitation signal are remotely controlled by the host computer (1). The measurement judgment unit automatically calculates three core measurement indicators, namely reference sensitivity, frequency response error and amplitude linearity, based on the sensor response data returned by the data acquisition module (204). When any one of the indicators exceeds the preset tolerance range, the alarm output unit generates an unqualified alarm signal.

[0018] according to Figure 1 The structure shown in this embodiment provides an in-situ calibration vibration monitoring device for wind turbines, including a host computer (1), a measurement and control device (2), and a sensor (3) installed at the test location on the wind turbine body. The measurement and control device (2) integrates a control card (201), an excitation module (202), a signal conditioning module (203), and a data acquisition module (204), and is fixedly installed at a suitable location on the wind turbine site (e.g., a flat surface near the bearing housing). The measurement and control device (2) is configured to track the wind turbine's rotational speed frequency in real time using phase-locked loop technology under the condition that the wind turbine is running at its rated speed, and dynamically filter out the frequency component in subsequent spectrum analysis, thereby implementing dynamic metrological calibration unaffected by vibration interference from the operating conditions.

[0019] Specifically, the output end of the excitation module (202) is mechanically connected to the drive component (301) of the sensor (3) via a detachable rigid connecting rod. The first communication end of the control card (201) establishes a bidirectional network connection with the host computer (1) via an industrial Ethernet network to receive calibration parameters and upload measurement results. The excitation output end of the control card (201) is electrically connected to the input end of the excitation module (202), and the control card (201) generates corresponding excitation control signals according to the instructions issued by the host computer (1). In order to ensure that the calibration process does not affect the safe operation of the fan, the amplitude of the calibration excitation signal generated by the excitation module (202) is controlled within 30% of the normal operating vibration amplitude of the fan.

[0020] The output of the excitation module (202) is directly connected to the input of the drive component (301) of the sensor (3) (through the aforementioned rigid connecting rod), thereby directly transmitting the mechanical vibration excitation to the sensor. The output of the signal processing component (303) of the sensor (3) is electrically connected to the input of the signal conditioning module (203), used to transmit the vibration response signal collected by the sensor to the signal conditioning module for filtering, amplification, and other preprocessing. The output of the signal conditioning module (203) is electrically connected to the input of the data acquisition module (204), and the conditioned analog signal is converted into a digital signal. The feedback of the data acquisition module (204) is electrically connected to the data input of the control card (201), thereby transmitting the collected sensor response data back to the control card (201). The control card (201) dynamically adjusts the output amplitude and frequency of the excitation module (202) according to the sensor response data transmitted back by the data acquisition module (204), forming a closed-loop adaptive control.

[0021] The host computer (1) has a built-in parameter configuration unit, a measurement judgment unit, and an alarm output unit. The parameter configuration unit allows operators to set various parameters required for calibration, including vibration amplitude range, vibration frequency range, reference operating frequency, number of frequency calibration points, and number of amplitude calibration points. The excitation module (202) generates a continuously adjustable sinusoidal excitation signal based on the parameters forwarded by the control card (201). The amplitude and frequency of this sinusoidal excitation signal can be remotely and precisely controlled by the host computer (1). The measurement judgment unit automatically calculates three core measurement indicators—reference sensitivity, frequency response error, and amplitude linearity—based on the sensor response data returned by the data acquisition module (204). When any one of these indicators exceeds the preset tolerance range, the alarm output unit immediately generates a non-compliance alarm signal to prompt maintenance personnel to handle it promptly. Through the above structure, this embodiment achieves in-situ, automatic, and high-precision calibration of the vibration sensor without shutting down the fan.

[0022] The sensor (3) is a piezoelectric vibration velocity sensor or a magnetoelectric vibration acceleration sensor. The driving component (301) of the sensor (3) is rigidly connected to the vibration sensing element (302). A charge amplification circuit and a low-pass filter circuit are provided between the vibration sensing element (302) and the signal processing component (303). The output signal of the signal processing component (303) is a 4-20mA current signal or a 0-10V voltage signal.

[0023] In this embodiment, the sensor (3) can be selected as a piezoelectric vibration velocity sensor or a magnetoelectric vibration acceleration sensor according to the on-site measurement requirements. For example Figure 1As shown, the driving component (301) of the sensor (3) is rigidly connected to the vibration-sensitive element (302) to ensure that the mechanical vibration transmitted by the excitation module (202) via the rigid connecting rod can act on the vibration-sensitive element (302) without loss. A charge amplification circuit and a low-pass filter circuit are sequentially arranged between the vibration-sensitive element (302) and the signal processing component (303). The charge amplification circuit is used to convert the weak charge signal generated by the vibration-sensitive element (302) into a voltage signal, and the low-pass filter circuit is used to filter out high-frequency noise and prevent spectral aliasing. The output signal of the signal processing component (303) can be configured as a 4-20mA current signal or a 0-10V voltage signal according to the input requirements of the subsequent signal conditioning module (203). When using a current signal output, it has the advantage of strong anti-interference capability for long-distance transmission; when using a voltage signal output, it is easy to directly match with the standard data acquisition card interface. Through the above internal structure design, the sensor (3) can stably and accurately respond to the calibration vibration signal generated by the excitation module (202) in harsh industrial environments.

[0024] The excitation module (202) integrates a wideband power amplifier and an electromagnetic exciter, with an output frequency range of 5Hz to 2000Hz and an output acceleration amplitude range of 0.5m / s² to 50m / s². The resonant frequency of the detachable rigid connecting rod is higher than 2000Hz.

[0025] The signal conditioning module (203) includes a programmable gain amplifier circuit, an anti-aliasing filter circuit, and a synchronous sample-and-hold circuit. The gain of the programmable gain amplifier circuit is automatically adjusted by the control card (201) according to the amplitude of the sensor output signal, and the adjustment range is from 1 to 128 times. The cutoff frequency of the anti-aliasing filter circuit is 0.45 times the sampling frequency of the data acquisition module (204).

[0026] The data acquisition module (204) adopts a dual-channel 24-bit Sigma-Delta analog-to-digital converter. The first channel acquires the response signal of the sensor (3), and the second channel synchronously acquires the output feedback signal of the excitation module (202) as a reference. The sampling rate of the two channels is not less than 51.2 kS / s and they are synchronized with each other, and the phase difference is less than 0.1 degrees.

[0027] Combination Figures 2-3 In this embodiment, the main body of the rigid connecting rod is made of TC4 titanium alloy, with a diameter of 8mm and a length of 150mm. TC4 titanium alloy has the characteristics of high specific strength, moderate elastic modulus, and excellent fatigue resistance, making it suitable for transmitting high-precision vibration excitation signals in the limited space of a wind turbine site.

[0028] Connection method at both ends: Both ends of the connecting rod are machined with M6 standard threads, which are respectively connected to the output end of the electromagnetic vibrator moving coil assembly inside the excitation module (202) and the input end threaded hole of the drive component (301) of the sensor (3).

[0029] The connection torque is controlled within the range of 3 to 5 N·m. This torque ensures the tightness of the rigid connection, avoids loosening or energy loss during vibration transmission, and prevents deformation of the sensor housing or the moving coil of the exciter due to excessive tightening.

[0030] The driving component (301) of the sensor (3) is designed as a 50g assembly, which together with the rigid connecting rod and the moving coil of the exciter forms a vibration system. Under a given excitation force, the 50g mass can generate a sufficient and controllable mechanical vibration response, which facilitates subsequent sensitivity calculation.

[0031] With a first-order axial resonant frequency >2500Hz, the rigid connecting rod is in a non-resonant rigid body transmission mode throughout the entire calibration frequency band of 5Hz to 2000Hz. This does not introduce additional resonance peaks or anti-resonance valleys, ensuring that the vibration signal output by the excitation module can be transmitted to the sensor drive component without distortion, thereby significantly improving the amplitude and phase accuracy of in-situ calibration.

[0032] In summary, this figure visually illustrates, through specific dimensions, materials, torque, and frequency parameters, how a carefully designed rigid connecting rod can achieve high-fidelity, modal-free mechanical coupling between the excitation module and the sensor, providing a reliable physical connection basis for accurate online calibration in environments with strong background vibration.

[0033] The signal conditioning module (203) includes a programmable gain amplifier circuit, an anti-aliasing filter circuit, and a synchronous sample-and-hold circuit. The gain factor of the programmable gain amplifier circuit is automatically calculated and adjusted by the control card (201) based on the amplitude of the sensor output signal, with an adjustment range of 1 to 128 times and a step precision of 1. Through adaptive gain adjustment, the output signal amplitude of sensors with different sensitivities can be adjusted to near the full-scale range of the data acquisition module (204), thereby maximizing the quantization signal-to-noise ratio. The anti-aliasing filter circuit adopts a high-order active filter design, and its cutoff frequency is precisely set to 0.45 times the sampling frequency of the data acquisition module (204) to meet the requirements of the Nyquist sampling theorem, effectively suppressing noise components higher than the folding frequency from entering the sampling stage.

[0034] The data acquisition module (204) employs a dual-channel 24-bit Sigma-Delta analog-to-digital converter. The first channel is connected to the output of the signal conditioning module (203) and is used to acquire the response signal of the sensor (3). The second channel is connected to the internal feedback output of the excitation module (202) and is used to synchronously acquire the output feedback signal of the excitation module (202) as a reference. Both channels share the same high-precision clock source, and are controlled by an internal FPGA to achieve strictly synchronous sampling with a sampling rate of no less than 51.2 kS / s. The phase difference between the two channels is controlled to be less than 0.1 degrees. This dual-channel synchronous acquisition architecture enables accurate calculation of the amplitude ratio and phase relationship between the sensor response and the excitation signal during subsequent signal processing, thereby significantly improving the calculation accuracy of core metrological indicators such as reference sensitivity and frequency response error.

[0035] like Figure 3 The diagram shown is a flowchart of an in-situ calibration vibration monitoring method for wind turbines disclosed herein, comprising: S1, in the parameter configuration unit of the host computer (1), according to the technical specifications of the sensor being calibrated, the vibration amplitude range, vibration frequency range, reference working frequency, number of frequency calibration points N and number of amplitude calibration points M are set, and the corresponding measurement tolerance limit is input. S2, the host computer (1) sends the above parameters to the control card (201) via the network. After the control card (201) parses the parameters, it drives the excitation module (202) to generate a first sinusoidal excitation signal. The frequency of the first sinusoidal excitation signal is equal to the reference working frequency, and the amplitude is equal to the median of the vibration amplitude range. The sensor (3) generates a mechanical vibration response under the action of the driving component (301). The response is converted by the vibration sensitive element (302) and amplified by the signal processing component (303) to form an electrical signal. S3, while the excitation module (202) outputs a sinusoidal excitation signal, the data acquisition module (204) synchronously acquires the fan speed signal. The control card (201) extracts the speed frequency in real time as a reference signal through the built-in phase-locked loop circuit, and dynamically adjusts the center frequency of the adaptive notch filter to track speed fluctuations. In the spectrum analysis, the real-time changing speed frequency components and their harmonic components are filtered out to achieve online synchronous isolation of operating condition vibration interference. S4, after the electrical signal is filtered and amplified by the signal conditioning module (203), it is converted from analog to digital by the data acquisition module (204). The control card (201) reads the converted digital signal and sends it back to the host computer (1). The measurement and judgment unit of the host computer (1) calculates the reference sensitivity S0 based on the amplitude ratio of the digital signal and the feedback signal output by the excitation module (202). S5, keeping the excitation amplitude constant, the control card (201) controls the excitation module (202) to output the second sinusoidal excitation signal sequentially at the N frequency points within the vibration frequency range, and repeats steps S2 to S4 to obtain the sensitivity at each frequency point. Where i = 1, 2, ..., N, the measurement determination unit is determined according to the formula Calculate frequency response error ; S6, keeping the reference operating frequency unchanged, the control card (201) controls the excitation module (202) to output the third sinusoidal excitation signal sequentially at the M amplitude points within the vibration amplitude range, and repeats steps S2 to S4 to obtain the sensitivity of each amplitude point. Where j=1,2,...,M, the measurement determination unit is determined according to the formula Calculate amplitude linearity ; S7, when or When any one of the measurement tolerance limits is exceeded, the alarm output unit triggers an audible and visual alarm and writes the non-compliance information to a log file. When both items are within tolerance, the host computer (1) automatically generates a log file containing S0, , An electronic test report with the calibration date is uploaded to the remote monitoring center.

[0036] Specifically, step S1: Under the condition that the fan is running at its rated speed (for example, the rated speed of the induced draft fan of a 300MW unit is 985r / min), firstly, in the parameter configuration interface of the host computer (1), input the calibration parameters according to the technical specifications of the sensor (3) to be calibrated.

[0037] Taking the magnetoelectric velocity sensor as an example, the vibration amplitude range is set to 0.5m / s² to 50m / s² (equivalent acceleration value), the vibration frequency range is 5Hz to 2000Hz, and the reference operating frequency is selected as 10Hz (this frequency is far away from the fan power frequency of 16.4Hz and its harmonics, and is located within the sensor's passband).

[0038] The number of frequency calibration points, N, is set to 11, specifically distributed across 1 / 3 octave bands: 5Hz, 6.3Hz, 8Hz, 10Hz, 12.5Hz, 16Hz, 20Hz, 25Hz, 31.5Hz, 40Hz, and 50Hz. The number of amplitude calibration points, M, is set to 9, selected at logarithmic intervals within the range of 0.5m / s² to 50m / s²: 0.5, 1, 2, 5, 10, 15, 25, 35, and 50 (unit: m / s²). Measurement tolerance limits are also entered, for example, frequency response error tolerance ±5% and amplitude linearity tolerance ±4%.

[0039] Step S2: Generate the first sinusoidal excitation signal and acquire the sensor response.

[0040] The host computer (1) sends the above parameters to the control card (201) of the measurement and control device (2) via industrial Ethernet. After the control card (201) parses the parameters, the drive excitation module (202) generates the first sinusoidal excitation signal. The frequency of this signal is equal to the reference working frequency of 10Hz, and the amplitude is equal to the median of the vibration amplitude range (i.e., (0.5+50) / 2=25.25m / s², which can actually be set to 25m / s²). The excitation module (202) directly applies the mechanical vibration to the drive component (301) of the sensor (3) through a detachable rigid connecting rod. The drive component (301) drives the vibration sensing element (302) to generate forced vibration. The vibration sensing element (302) converts the mechanical deformation into a charge signal. After passing through the charge amplification circuit and the low-pass filter circuit, the signal processing component (303) converts it into a 4-20mA current signal (or a 0-10V voltage signal) for output.

[0041] Step S3: Synchronously acquire speed signals and filter out operating condition interference.

[0042] While the excitation module (202) outputs a sinusoidal excitation signal, the second channel (or dedicated speed input channel) of the data acquisition module (204) synchronously acquires the fan speed signal. The phase-locked loop circuit integrated inside the control card (201) extracts the fan speed frequency in real time (e.g., 985 r / min corresponds to 16.4167 Hz). Using this frequency as a reference signal, the center frequency of the adaptive notch filter is dynamically adjusted to track the possible fluctuations in the fan speed (e.g., ±5%). In the subsequent spectrum analysis, the notch filter actively filters out the speed frequency component and its second and third harmonic components, thereby isolating the strong vibration interference generated by the fan's own operation from the sensor response signal online, ensuring that the extracted signal is mainly the calibration component generated by the excitation module (202).

[0043] Step S4: Signal conditioning, acquisition, and reference sensitivity calculation.

[0044] The electrical signal output by the sensor (3) first enters the signal conditioning module (203). The programmable gain amplifier circuit automatically selects the gain factor according to the current signal amplitude (for example, for a sensor with a sensitivity of 200mV / (m / s²), a 25m / s² excitation corresponds to a 5V output, and the gain is set to 1; if the sensor sensitivity is low, the gain is automatically increased), and then filtered by the anti-aliasing filter circuit (the cutoff frequency is 0.45 times the sampling frequency of the data acquisition module), and finally held by the synchronous sample and hold circuit before being sent to the data acquisition module (204).

[0045] The data acquisition module (204) synchronously acquires data from two channels at a sampling rate of 51.2 kS / s: the first channel acquires the conditioned sensor response signal, and the second channel acquires the voltage feedback signal from the output of the excitation module (202) as a reference. The control card (201) reads the converted digital signal, packages it, adds a timestamp, and sends it back to the host computer (1).

[0046] The measurement and judgment unit of the host computer (1) performs Hanning window weighted FFT spectrum analysis on the collected data, extracts the sensor output amplitude Vout and excitation feedback amplitude Vfb at the 10Hz base frequency, converts the actual excitation acceleration amplitude according to the calibration coefficient Kf of the excitation module (202), and then calculates the reference sensitivity S0.

[0047] Step S5: Frequency response error calibration.

[0048] Keeping the excitation amplitude constant (still the median of the vibration amplitude range), the control card (201) outputs the second sinusoidal excitation signal sequentially at 11 preset frequency points. At each frequency point, steps S2 to S4 are repeated to obtain the sensor sensitivity at that frequency point. Where i = 1, 2, ..., 11. After all 11 frequency points have been measured, the metrology judgment unit determines the appropriate parameters according to the formula. Calculate the frequency response error, which is the maximum relative deviation of the sensitivity at all frequency points from the reference sensitivity S0. For example, if the sensitivity deviates from the reference value by 4.8% at 16Hz and by 4.2% at 40Hz, then Δf is taken as 4.8%.

[0049] Step S6: Amplitude linearity calibration.

[0050] Keeping the excitation frequency unchanged (still the reference operating frequency of 10Hz), the control card (201) outputs the third sinusoidal excitation signal sequentially according to the preset 9 amplitude points. At each amplitude point, steps S2 to S4 are repeated to obtain the sensor sensitivity at that amplitude point. (j=1,...,9). To eliminate random errors, the measurement judgment unit first performs least-squares linear fitting on the sensitivity measurements at the 9 amplitude points to obtain the fitted line, then calculates the fitting residual for each amplitude point, and finally applies the formula... Calculate the amplitude linearity, which is the ratio of the absolute value of the maximum residual to the reference sensitivity.

[0051] Step S7: Qualification assessment and report generation.

[0052] The calculated frequency response error Δf and amplitude linearity Δa are compared with the measurement tolerance limits input in step S1 (e.g., Δf≤5%, Δa≤4%). If either exceeds the tolerance range, the alarm output unit immediately triggers an audible and visual alarm (e.g., a red warning box pops up on the host computer interface, and an alarm signal is sent to the plant-level monitoring system via the Modbus TCP protocol), and writes the non-compliance information (including the out-of-tolerance item, out-of-tolerance value, calibration time, sensor number, etc.) to the local log file. It is recommended that maintenance personnel arrange subsequent repairs or replacements.

[0053] If both are qualified, the host computer (1) will automatically generate an electronic test report containing the sensor information being calibrated, calibration date, reference sensitivity S0, frequency response error Δf, amplitude linearity Δa and calibration curves (frequency-sensitivity curve, amplitude-sensitivity curve), and upload it to the database of the remote monitoring center according to the preset path to realize the electronic management and long-term traceability of calibration records.

[0054] The entire calibration process is completed automatically without shutting down the fan. A single complete calibration (11 frequency points + 9 amplitude points) takes about 45 minutes. During this process, the fan vibration monitoring and protection function is uninterrupted, truly achieving in-situ, online, and dynamic measurement.

[0055] Electronic device 400 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 400 may include, but is not limited to, processor 401 and memory 402. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 400 and does not constitute a limitation on electronic device 400. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device may also include input / output devices, network access devices, buses, etc.

[0056] Processor 401 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0057] The memory 402 can be an internal storage unit of the electronic device 400, such as a hard disk or RAM of the electronic device 400. The memory 402 can also be an external storage device of the electronic device 400, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the electronic device 400. Furthermore, the memory 402 can include both internal and external storage units of the electronic device 400. The memory 402 is used to store the computer program 403 and other programs and data required by the electronic device. The memory 402 can also be used to temporarily store data that has been output or will be output.

[0058] The above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure, and should all be included within the protection scope of this disclosure.

Claims

1. A vibration monitoring device for in-situ calibration of a wind turbine, comprising a host computer (1), a measurement and control device (2), and a sensor (3) installed at the location to be measured on the wind turbine body, characterized in that, The measurement and control device (2) integrates a control card (201), an excitation module (202), a signal conditioning module (203), and a data acquisition module (204). It is fixedly installed at the wind turbine site and is configured to track the wind turbine speed frequency through phase-locked loop technology and filter out the frequency component in the spectrum analysis under the condition that the wind turbine is running at its rated speed, and to implement dynamic measurement calibration. The output of the excitation module (202) is connected to the drive component (301) of the sensor (3) via a detachable rigid linkage. The first communication terminal of the control card (201) is bidirectionally network-connected to the host computer (1). The excitation output terminal of the control card (201) is electrically connected to the input terminal of the excitation module (202). The amplitude of the generated calibration excitation signal is less than 30% of the vibration amplitude during normal operation of the fan. The output terminal of the excitation module (202) is connected to the input terminal of the drive component (301) of the sensor (3). The signal processing component (303) of the sensor (3) is directly connected to the input of the signal conditioning module (203). The output of the signal conditioning module (203) is electrically connected to the input of the data acquisition module (204). The feedback of the data acquisition module (204) is electrically connected to the data input of the control card (201). The control card (201) adjusts the output amplitude and frequency of the excitation module (202) according to the sensor response data returned by the data acquisition module (204). The host computer (1) has a built-in parameter configuration unit, a measurement judgment unit and an alarm output unit. The parameter configuration unit is used to set the vibration amplitude range, vibration frequency range, reference working frequency, number of frequency calibration points and number of amplitude calibration points. The excitation module (202) generates a continuously adjustable sinusoidal excitation signal according to the parameters forwarded by the control card (201). The amplitude and frequency of the sinusoidal excitation signal are remotely controlled by the host computer (1). The measurement judgment unit automatically calculates three core measurement indicators, namely reference sensitivity, frequency response error and amplitude linearity, based on the sensor response data returned by the data acquisition module (204). When any one of the indicators exceeds the preset tolerance range, the alarm output unit generates an unqualified alarm signal.

2. The apparatus according to claim 1, characterized in that, The sensor (3) is a piezoelectric vibration velocity sensor or a magnetoelectric vibration acceleration sensor. The driving component (301) of the sensor (3) is rigidly connected to the vibration sensing element (302). A charge amplification circuit and a low-pass filter circuit are provided between the vibration sensing element (302) and the signal processing component (303). The output signal of the signal processing component (303) is a 4-20mA current signal or a 0-10V voltage signal.

3. The apparatus according to claim 1, characterized in that, The excitation module (202) integrates a wideband power amplifier and an electromagnetic exciter, with an output frequency range of 5Hz to 2000Hz and an output acceleration amplitude range of 0.5m / s² to 50m / s². The resonant frequency of the detachable rigid connecting rod is higher than 2000Hz.

4. The apparatus according to claim 1, characterized in that, The signal conditioning module (203) includes a programmable gain amplifier circuit, an anti-aliasing filter circuit, and a synchronous sample-and-hold circuit. The gain of the programmable gain amplifier circuit is automatically adjusted by the control card (201) according to the amplitude of the sensor output signal, and the adjustment range is from 1 to 128 times. The cutoff frequency of the anti-aliasing filter circuit is 0.45 times the sampling frequency of the data acquisition module (204).

5. The apparatus according to claim 1, characterized in that, The data acquisition module (204) adopts a dual-channel 24-bit Sigma-Delta analog-to-digital converter. The first channel acquires the response signal of the sensor (3), and the second channel synchronously acquires the output feedback signal of the excitation module (202) as a reference. The sampling rate of the two channels is not less than 51.2 kS / s and they are synchronized with each other, and the phase difference is less than 0.1 degrees.

6. A method for in-situ calibration vibration monitoring of a wind turbine, implemented using the apparatus described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1, in the parameter configuration unit of the host computer (1), according to the technical specifications of the sensor being calibrated, the vibration amplitude range, vibration frequency range, reference working frequency, number of frequency calibration points N and number of amplitude calibration points M are set, and the corresponding measurement tolerance limit is input. S2, the host computer (1) sends the above parameters to the control card (201) via the network. After the control card (201) parses the parameters, it drives the excitation module (202) to generate a first sinusoidal excitation signal. The frequency of the first sinusoidal excitation signal is equal to the reference working frequency, and the amplitude is equal to the median of the vibration amplitude range. The sensor (3) generates a mechanical vibration response under the action of the driving component (301). The response is converted by the vibration sensitive element (302) and amplified by the signal processing component (303) to form an electrical signal. S3, while the excitation module (202) outputs a sinusoidal excitation signal, the data acquisition module (204) synchronously acquires the fan speed signal. The control card (201) extracts the speed frequency in real time as a reference signal through the built-in phase-locked loop circuit, and dynamically adjusts the center frequency of the adaptive notch filter to track speed fluctuations. In the spectrum analysis, the real-time changing speed frequency components and their harmonic components are filtered out to achieve online synchronous isolation of operating condition vibration interference. S4, after the electrical signal is filtered and amplified by the signal conditioning module (203), it is converted from analog to digital by the data acquisition module (204). The control card (201) reads the converted digital signal and sends it back to the host computer (1). The measurement and judgment unit of the host computer (1) calculates the reference sensitivity S0 based on the amplitude ratio of the digital signal and the feedback signal output by the excitation module (202). S5, keeping the excitation amplitude constant, the control card (201) controls the excitation module (202) to output the second sinusoidal excitation signal sequentially at the N frequency points within the vibration frequency range, and repeats steps S2 to S4 to obtain the sensitivity at each frequency point. Where i = 1, 2, ..., N, the measurement determination unit is determined according to the formula Calculate frequency response error ; S6, keeping the reference operating frequency unchanged, the control card (201) controls the excitation module (202) to output the third sinusoidal excitation signal sequentially at the M amplitude points within the vibration amplitude range, and repeats steps S2 to S4 to obtain the sensitivity of each amplitude point. Where j=1,2,...,M, the measurement determination unit is determined according to the formula Calculate amplitude linearity ; S7, when or When any one of the measurement tolerance limits is exceeded, the alarm output unit triggers an audible and visual alarm and writes the non-compliance information to a log file. When both items are within tolerance, the host computer (1) automatically generates a log file containing S0, , An electronic test report with the calibration date is uploaded to the remote monitoring center.

7. The in-situ calibration vibration monitoring method for wind turbines according to claim 6, characterized in that, The number of frequency calibration points N is 11, and the specific frequency points are distributed in 1 / 3 octave bands, namely 5Hz, 6.3Hz, 8Hz, 10Hz, 12.5Hz, 16Hz, 20Hz, 25Hz, 31.5Hz, 40Hz, and 50Hz. The reference working frequency is selected as 10Hz.

8. The in-situ calibration vibration monitoring method for wind turbines according to claim 6, characterized in that, The number M of amplitude calibration points is 9, and the specific amplitude points are logarithmically distributed in the range of 0.5 m / s² to 50 m / s², namely 0.5 m / s², 1 m / s², 2 m / s², 5 m / s², 10 m / s², 15 m / s², 25 m / s², 35 m / s², and 50 m / s². The measurement and determination unit calculates the amplitude linearity. First, assess the sensitivity at each amplitude point. Least squares linear fitting is performed to eliminate the influence of random errors.

9. An electronic device, characterized in that, include: One or more processors; A storage unit for storing one or more programs that, when executed by one or more processors, enable the one or more processors to implement the method according to any one of claims 6 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it can implement the method according to any one of claims 6 to 8.

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