Electrical equipment partial discharge acoustic imaging detection device based on optical fiber microphone

Abstract

The invention discloses an optical fiber microphone-based electrical equipment partial discharge acoustic imaging detection device, which comprises an optical fiber microphone array, a signal acquisition module and data processing equipment, and is characterized in that the optical fiber microphone array comprises a first sub-array and a second sub-array; the first sub-array is arranged close to the center of the optical fiber microphone array and is distributed in an Archimedes spiral structure, and the second sub-array is arranged on the periphery of the second sub-array and is distributed in a rectangular shape; the signal acquisition module outputs light source excitation to each microphone channel in the optical fiber microphone array, so that the optical fiber microphone array acquires a sound pressure signal generated by partial discharge, converts the sound pressure signal into an optical interference signal and outputs the optical interference signal to the signal acquisition module; the signal acquisition module converts the optical interference signals into multi-channel digital signals and outputs the multi-channel digital signals to the data processing equipment; the data processing equipment converts the multiple paths of digital signals into a partial discharge source map; according to the invention, the optical fiber microphone array is used for sound pressure signal acquisition, so that the detection precision of partial discharge is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment detection, and in particular to a fiber optic microphone-based acoustic imaging detection device for partial discharge of power equipment. Background Art

[0002] Partial discharge (PD) is a common phenomenon in power equipment, typically caused by factors such as air gaps, solid defects, or contamination in insulation. PD can not only cause gradual degradation of equipment performance but can also lead to complete equipment failure. Therefore, timely detection of PD in power equipment can effectively prevent accidents.

[0003] Existing partial discharge detection technologies primarily rely on electrical testing methods (such as current and voltage) and electromagnetic signal monitoring methods (such as ultrasound and laser vibration). While these methods can detect discharge phenomena to a certain extent, they suffer from issues such as an inability to accurately locate the discharge source, susceptibility to electromagnetic interference, and poor adaptability to high-voltage power environments. Therefore, stably and accurately detecting partial discharge and obtaining information on the spatial distribution of discharge sources in the complex operating environment of power equipment has long been a technical challenge in the field of power equipment testing.

[0004] For example, in the related technology, the patent application document with publication number CN116643129A proposes the use of acoustic imaging and sound source localization technology to realize the function of displaying the distribution status of the sound source in space in real time in the form of a heat map, which can solve the problem that local discharge in the power field is difficult to capture and accurately locate; the patent application document with publication number CN114859194A proposes an acoustic imaging method to process the collected sound source signal and determine the target audio data, which can effectively suppress other interference signals and improve the processing efficiency and accuracy of the local discharge detection process; the patent application document with publication number CN118688583A proposes a local discharge ultrasonic detection method based on a threshold function and a variable density grid; however, the above-mentioned existing solutions all use traditional electric microphones and use electromagnetic induction changes to collect signals. In a high-voltage environment, there will be strong electromagnetic interference, and the ability of the electric microphone to collect signals will become weak, or even no signal can be collected. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to improve the detection accuracy of partial discharge.

[0006] The present invention solves the above technical problems through the following technical means:

[0007] A fiber optic microphone-based acoustic imaging detection device for partial discharge in power equipment is proposed. The device includes a fiber optic microphone array, a signal acquisition module, and a data processing device. The fiber optic microphone array includes a first subarray and a second subarray. The first subarray is arranged near the center of the fiber optic microphone array and arranged in an Archimedean spiral structure. The second subarray is arranged around the second subarray and arranged in a rectangular shape.

[0008] The signal acquisition module outputs light source excitation to each microphone channel in the fiber optic microphone array, so that the fiber optic microphone array collects the sound pressure signal generated by the partial discharge;

[0009] The fiber optic microphone array converts the collected sound pressure signal into an optical interference signal and outputs it to the signal acquisition module;

[0010] The signal acquisition module converts the optical interference signal into a multi-channel digital signal and outputs it to the data processing equipment;

[0011] The data processing equipment converts the multi-channel digital signals into a partial discharge source spectrum.

[0012] Furthermore, a camera is arranged at the center of the fiber optic microphone array for collecting image information of the sound field environment.

[0013] Furthermore, the size of the fiber optic microphone array is 0.1m×0.1m, and the size of the first sub-array is 0.08m×0.08m.

[0014] Furthermore, the fiber optic microphones distributed in the fiber optic microphone array are formed by a non-metallic diaphragm, and each fiber optic microphone is configured to respond within a different frequency band.

[0015] Furthermore, the signal acquisition module includes a laser, a splitter is arranged on the laser light path output by the laser, a circulator is arranged on the output light path of the splitter, one output port of the circulator outputs laser to the fiber optic microphone array, and the other output port outputs the reflected light of the fiber optic microphone array to a photodetector, and the output of the photodetector is connected to the data processing equipment after passing through a multi-channel acquisition card.

[0016] Furthermore, the data processing device includes:

[0017] The signal processing module is used to perform denoising and filtering on multiple digital signals to obtain processed digital signals;

[0018] The time-frequency analysis module is used to perform time-domain analysis and frequency-domain analysis on the processed digital signal to obtain the effective signal of partial discharge characteristics;

[0019] The acoustic imaging module is used to perform fusion analysis based on the effective signal of the partial discharge characteristics corresponding to each fiber optic microphone and convert it into a partial discharge source spectrum inside the power equipment.

[0020] Furthermore, the data processing device further includes:

[0021] The three-dimensional reconstruction module is used to generate a spatial distribution map of the partial discharge source through a three-dimensional reconstruction algorithm based on the effective signal and image information of the partial discharge characteristics corresponding to each fiber optic microphone.

[0022] In addition, the present invention also proposes a method for detecting partial discharge of power equipment by acoustic imaging based on a fiber optic microphone. The method uses the above-mentioned device for detecting partial discharge of power equipment by acoustic imaging based on a fiber optic microphone to perform acoustic detection, including:

[0023] determining an optimal working area of ​​the fiber optic microphone array according to the spectrum of each fiber optic microphone in the fiber optic microphone array;

[0024] Based on the characteristic curve of the fiber optic microphone and the requirements for partial discharge detection, the optimal sensitivity range of each fiber optic microphone in the fiber optic microphone array is determined;

[0025] According to the optimal working area of ​​the fiber optic microphone array, the laser wavelength output by the signal acquisition module is adjusted to stimulate the fiber optic microphone array to collect the sound pressure signal generated by the partial discharge and convert the collected sound pressure signal into an optical interference signal before outputting it to the signal acquisition module;

[0026] The optical interference signal is converted into a multi-channel digital signal using a signal acquisition module;

[0027] The multi-channel digital signals are converted into partial discharge source maps using data processing equipment.

[0028] Furthermore, the signal acquisition module is provided with a multi-channel acquisition card, and the method further includes:

[0029] The electrical signals collected simultaneously by multiple acquisition cards are transmitted simultaneously to the data processing equipment through a queue.

[0030] Furthermore, the method further comprises:

[0031] Dynamically update the partial discharge source map based on the sound pressure signal collected in real time by the fiber optic microphone array;

[0032] Monitor the operating status of power equipment based on the real-time updated partial discharge source map.

[0033] The advantages of the present invention are:

[0034] (1) Since the fiber optic microphone has a strong anti-interference ability, the present invention uses a fiber optic microphone array composed of multiple fiber optic microphones to collect the sound wave signal generated by partial discharge, and the fiber optic microphone array adopts an inner circle Archimedean spiral structure and a rectangular structure distribution on the periphery, so that the fiber optic microphone array can capture signals in multiple directions at the same time, and by combining with acoustic imaging technology, it can not only improve the detection accuracy of partial discharge, but also realize the accurate reconstruction of the discharge source position, and can effectively overcome the electromagnetic interference caused by partial discharge, stably operate in a complex power equipment environment with strong electromagnetic interference, and stably detect and image partial discharge signals.

[0035] (2) Since the partial discharge signal data is a high-frequency signal with a high frequency and a short wavelength, the fiber optic microphone array designed in the present invention is small in size and the distance between small arrays is short, which can meet the spatial sampling law and help capture high-frequency signals such as partial discharge.

[0036] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 1 is a schematic structural diagram of an acoustic imaging detection device for partial discharge of power equipment based on an optical fiber microphone, according to one embodiment of the present invention;

[0038] Figure 2 is a schematic diagram of the layout of a fiber optic microphone array in one embodiment of the present invention;

[0039] Figure 3 This is a block diagram of the working principle of an acoustic imaging detection device for partial discharge of power equipment based on an optical fiber microphone in one embodiment of the present invention;

[0040] Figure 4 1 is a schematic diagram of experimental results of partial discharge acoustic imaging of power equipment based on a fiber optic microphone in one embodiment of the present invention;

[0041] Figure 5 The figure is a flow chart of a method for detecting partial discharge of power equipment by acoustic imaging based on a fiber optic microphone, proposed in one embodiment of the present invention. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] like Figure 1 As shown, an embodiment of the present invention provides an acoustic imaging detection device for partial discharge of power equipment based on a fiber optic microphone, comprising a fiber optic microphone array 10, a signal acquisition module 20, and a data processing device 30. The fiber optic microphone array 10 comprises a first subarray and a second subarray. The first subarray is arranged near the center of the fiber optic microphone array and is distributed in an Archimedean spiral structure. The second subarray is arranged on the periphery of the second subarray and is distributed in a rectangular shape.

[0044] The signal acquisition module 20 outputs light source excitation to each microphone channel in the fiber optic microphone array 10 so that the fiber optic microphone array collects the sound pressure signal generated by the partial discharge;

[0045] The fiber optic microphone array 10 converts the collected sound pressure signal into an optical interference signal and outputs it to the signal acquisition module 20;

[0046] The signal acquisition module 20 converts the optical interference signal into a multi-channel digital signal and outputs it to the data processing device 30;

[0047] The data processing device 30 converts the multi-channel digital signals into a partial discharge source map.

[0048] It should be noted that this embodiment uses fiber optic microphones for signal acquisition. Fiber optic sensing technology has the characteristic of working stably in high-voltage environments and can realize long-distance signal acquisition under strong electromagnetic interference. Through the combination of fiber optic microphone arrays and acoustic imaging technology, efficient detection and spatial distribution reconstruction of partial discharge are achieved, making the system suitable for the detection of high-voltage power equipment, breaking through the limitations of traditional detection methods, and having strong technical advantages and application prospects.

[0049] Moreover, because the signals generated by partial discharge are mainly ultrasonic signals of 20kHz to 80kHz with a relatively high frequency, the use of an Archimedean spiral structure distribution as the first sub-array can better capture the ultrasonic signals, because the microphones between the selected Archimedean spiral array are densely distributed and can meet half of the wavelength of the ultrasonic signal. The use of a rectangular distribution as the second sub-array is mainly to collect ultrasonic signals over a larger range; therefore, the distribution structure of the optical fiber microphone array designed in this embodiment is more suitable for collecting ultrasonic signals generated by partial discharge.

[0050] As a further preferred technical solution, Figure 2 As shown, the fiber optic microphone array 10 is distributed in a central Archimedean spiral structure with a rectangular periphery. 16 fiber optic microphones are used, the spiral structure is composed of 8 fiber optic microphones, and the peripheral rectangle is composed of an array of 8 fiber optic microphones.

[0051] It should be noted that the fiber optic microphone array 10 is composed of 16 fiber optic microphones and adopts a combination of spiral and matrix layout to ensure uniform coverage of the local discharge sound field and the collection of multi-directional signals. It can capture local discharge signals from all directions and improve imaging resolution.

[0052] As a further preferred technical solution, a camera 40 is arranged at the center of the fiber optic microphone array 10 for collecting image information of the sound field environment.

[0053] Specifically, the camera 40 is used for video acquisition, the fiber optic microphone is used for audio acquisition, and the fiber optic microphone 10 and the camera 40 are used to simultaneously acquire the sound pressure signal and real-time image information generated by local discharge, so as to realize the synchronous acquisition and processing of multiple data during the sound source imaging and positioning process.

[0054] Specifically, the camera used in this embodiment is a high-definition camera with a refresh rate of 30 frames per second, enabling real-time acquisition of the sound field environment. The high-definition camera captures real-time visual images of the target area, which, together with the acoustic signals, provide multimodal data support, enabling precise localization and imaging of the partial discharge sound source.

[0055] As a further preferred technical solution, the size of the fiber optic microphone array is 0.1m×0.1m, and the size of the first sub-array is 0.08m×0.08m.

[0056] It should be noted that, since the partial discharge signal data is a high-frequency signal with a high frequency and a short wavelength, this embodiment takes the fiber optic microphone array composed of 16 fiber optic microphones as an example. The size of the fiber optic microphone array is 0.1m×0.1m. Compared with the size of the traditional microphone array, the fiber optic microphone array designed in this embodiment is smaller in size, and the distance between small arrays is short, which can meet the spatial sampling law and help to capture high-frequency signals such as ultrasonic signals generated by partial discharge.

[0057] As a further preferred technical solution, the fiber optic microphones distributed in the fiber optic microphone array are formed of a non-metallic diaphragm, and each fiber optic microphone is configured to respond within a different frequency band.

[0058] It should be noted that this embodiment uses a fiber optic microphone with a non-metallic diaphragm to effectively eliminate electromagnetic interference, ensure high-sensitivity acoustic signal acquisition, and can stably detect and image partial discharge signals in an electrical equipment environment with strong electromagnetic interference.

[0059] It should be noted that, based on the embodiments of the present invention, those skilled in the art may use fiber optic microphones with other structures according to actual conditions, such as a cantilever beam structure fiber optic microphone, a gradient beam structure fiber optic microphone, a corrugated structure fiber optic microphone, etc. This embodiment does not specifically limit the type of fiber optic microphone.

[0060] Furthermore, each fiber optic microphone in the fiber optic microphone array of this embodiment is configured to be able to respond within different frequency bands. The frequency range of the fiber optic microphone configuration is 10kHz-80kHz, so that the system can adapt to various types of sound wave signals that may be generated by different power equipment during operation, especially partial discharge signals.

[0061] As a further preferred technical solution, Figure 1 As shown, the signal acquisition module 20 includes a laser 21, a beam splitter 22 is arranged on the laser light path output by the laser 21, and a circulator 23 is arranged on the output light path of the beam splitter 22. One output port of the circulator 23 outputs the laser to the fiber optic microphone array 10, and the other output port outputs the reflected light of the fiber optic microphone array to the photodetector 24. The output of the photodetector 24 is connected to the data processing device 30 after passing through the multi-channel acquisition card 25.

[0062] Specifically, if Figure 3 As shown, in this embodiment, the laser uses an S7500 tunable MG-Y laser, which can provide a stable optical signal with a wavelength of 1525-1565nm. It serves as the excitation source of the system and ensures the stability and reliability of the optical transmission signal of the fiber optic microphone array. Under laser excitation, 16 fiber optic microphones are used to collect the sound signals generated by partial discharge and convert them into optical interference information to achieve highly sensitive acoustic signal detection.

[0063] The 16-way optical splitter is used to divide the laser signal emitted by the laser into 16 channels and evenly distribute them to multiple fiber optic microphones, ensuring that each fiber optic microphone can receive sufficient optical signal excitation for high-quality sound wave conversion, thereby ensuring the consistency and stability of the signals in each channel;

[0064] The circulator is used to ensure unidirectional signal transmission. Through reasonable optical path design, it prevents the reflected light signal of the fiber optic microphone from interfering with the performance of the laser or other components, thus avoiding affecting the system performance and further improving the signal transmission efficiency of the system.

[0065] Photodetector (PD), used to convert the acoustic wave signal captured by the fiber optic microphone array into an electrical signal, ensuring efficient capture and conversion of the sound signal;

[0066] The 16-channel acquisition card is used to collect signals from 16 photoelectric detectors at the same time, ensuring the synchronous acquisition of data from multiple sensors and performing data conversion and preprocessing at high speed. The multi-channel acquisition card synchronously collects the electrical signals output by the photoelectric detectors and digitizes the signals to ensure the real-time and accuracy of high-frequency sampling.

[0067] Therefore, this embodiment uses 16-channel fiber optic microphones, which need to be implemented through multiplexing.

[0068] As a further preferred technical solution, the data processing device includes:

[0069] The signal processing module is used to perform denoising and filtering on multiple digital signals to obtain processed digital signals;

[0070] Specifically, in this embodiment, a fiber optic microphone array uses multiple sensors to collect acoustic signals from partial discharge sources. The signals first pass through a circulator, converting the optical signals into electrical signals. These signals are then converted by a photodetector and sent to an acquisition card for data transmission to a PC. After denoising and filtering, combined with time-domain and frequency-domain analysis, these signals are effectively removed and the effective signals representing the characteristics of partial discharges are extracted. This further improves signal clarity and resolution, thereby enhancing the system's signal quality and accuracy.

[0071] In this embodiment, signal denoising and filtering are performed using low-pass and high-pass filters to remove high-frequency noise and low-frequency drift, while retaining signals related to the partial discharge source. Common denoising algorithms include wavelet transform and Kalman filtering, and endpoint monitoring is used to ensure that the processed signal is the desired signal.

[0072] The time-frequency analysis module is used to perform time-domain analysis and frequency-domain analysis on the processed digital signal to obtain the effective signal of partial discharge characteristics;

[0073] Specifically, the combination of time domain and frequency domain analysis refers to combining time domain analysis and frequency domain analysis (such as Fourier transform) to refine the signal, extract meaningful frequency components, and improve the clarity and resolution of the signal.

[0074] The acoustic imaging module is used to perform fusion analysis based on the effective signal of the partial discharge characteristics corresponding to each fiber optic microphone and convert it into a partial discharge source spectrum inside the power equipment.

[0075] Specifically, a 16-sensor microphone array is used to acquire signals, and its scanning plane is divided into N×N grid points. Since the delay in the time domain is equal to the phase shift in the frequency domain, these delays can be turned into steering vectors. For the nth grid point, the vector can be expressed as:

[0076]

[0077] Where r0 represents the distance from the center of the array to the nth grid point, where r m,n is the distance from the mth microphone (m≤M, m=1,2,3…16) to the nth grid point, where k represents the beam:

[0078]

[0079] Where f is the scanning frequency and c is the speed of sound. According to the definition of the steering vector, for the nth grid point, the weighted derivative vector can be expressed as:

[0080]

[0081] This allows the measured multi-dimensional signal to be divided into multiple frames to form a cross-spectral matrix.

[0082] The cross-spectral matrix is ​​the correlation matrix of the signals received by multiple channels in the frequency domain, namely:

[0083]

[0084] Here () H represents the conjugate transpose, and we have:

[0085] p j (f) = [p j,1 (f) p j,2 (f) … p j,M (f)] T

[0086] Among them, p j,m (f) represents the nth frame frequency domain signal of the mth microphone.

[0087] The frequencies of all grid points are expressed as acoustic power, i.e., the beamforming diagram, which can be expressed as:

[0088]

[0089] Where b represents the total grid point power collected by the fiber optic microphone. n represents the power at the nth grid point, that is:

[0090]

[0091] Specifically, this embodiment utilizes beamforming technology and other imaging algorithms to convert multi-channel acoustic signals into a map of the localized discharge (PD) source within power equipment. This process accurately locates the PD source through comprehensive analysis of the spatiotemporal signal characteristics collected by each microphone array.

[0092] Beamforming involves weighted combination of multiple acoustic signals collected by a fiber optic microphone array, using a beamforming algorithm to accurately calculate the direction of the sound source. By comprehensively considering the time and frequency domain signals collected by each microphone array, spatiotemporal analysis algorithms (such as backpropagation or reverse time imaging) are used to precisely locate the source of the partial discharge. By combining data from multiple sensors, the beamforming algorithm is optimized to reduce errors and improve positioning accuracy.

[0093] This embodiment can accurately locate the position of the local discharge source through beamforming technology, improve imaging accuracy, and reduce errors caused by inaccurate sensor positioning.

[0094] It should be noted that this embodiment uses a computer (PC) as a data storage and processing center to receive and analyze data transmitted from the acquisition card in real time, execute sound source localization and imaging algorithms, and generate a visual image of the partial discharge signal.

[0095] As a further preferred technical solution, the data processing device further includes:

[0096] The three-dimensional reconstruction module is used to generate a spatial distribution map of the partial discharge source through a three-dimensional reconstruction algorithm based on the effective signal and image information of the partial discharge characteristics corresponding to each fiber optic microphone.

[0097] Specifically, this embodiment generates a spatial distribution map of the partial discharge source through a three-dimensional reconstruction algorithm (such as a three-dimensional interpolation algorithm) based on the optimized spatiotemporal signal.

[0098] It should be noted that this embodiment combines data input from multiple microphone arrays, optimizes algorithms, and fusions data to accurately reconstruct the three-dimensional spatial distribution of local discharge sources. Acoustic imaging technology enables this process to not only detect the presence of discharge sources, but also reveal their specific locations within power equipment.

[0099] As a further preferred technical solution, in the process of environmental fusion of sound atlas and video acquisition, the pixel coordinates are converted into world coordinates for fusion, which helps to achieve perfect fusion without errors; finally, a color atlas is used to represent the intensity of local discharge sound, and the greater the sound pressure, the more obvious the color.

[0100] Furthermore, the acoustic imaging achieved by the present invention was experimentally verified. In the experiment, a 20kHz point sound source was used for testing to verify the imaging capability and positioning accuracy of the system. In the experimental setup, the fiber optic microphone array was arranged around the sound field to collect the sound pressure signal generated by the 20kHz point sound source. After processing by the signal acquisition module, the system used the sound source localization and imaging algorithm to generate the following Figure 4The acoustic imaging results shown in the figure show that the system can accurately capture the spatial position of the point sound source, and its sound field energy distribution is clearly presented in the visualization image. Figure 4 The middle red area represents the location of the strongest energy in the sound field, showing the specific location of the point sound source, while the color gradient around the periphery indicates the gradual attenuation of the sound field energy. This demonstrates that the present invention can accurately locate the location of acoustic signal sources such as partial discharge in complex acoustic environments and provide intuitive imaging results.

[0101] This embodiment further verifies the application capability of the system in high-frequency acoustic signal detection and imaging through experiments, providing solid technical support for subsequent partial discharge detection of power equipment.

[0102] As a further preferred technical solution, this device utilizes parallel computing or GPU acceleration to process collected signals, ensuring data processing speeds fast enough to support real-time data transmission and processing. This enables real-time imaging, ensuring that the imaging map can be dynamically adjusted during device operation to reflect changes in the sound source location in real time. This technology enables accurate device status monitoring data to be obtained, allowing for timely implementation of appropriate maintenance measures. Based on the real-time collected signals, the system dynamically updates the discharge source map, providing real-time feedback on device status. This real-time updated imaging map monitors device operating status, promptly identifies anomalies, and generates alarm signals.

[0103] It should be noted that this embodiment has strong real-time performance and can dynamically adjust the imaging map according to changes in the operating status of the equipment, promptly reflect changes in the sound source position, and ensure the accuracy and timeliness of equipment maintenance.

[0104] In addition, if Figure 5 As shown, another embodiment of the present invention provides a method for detecting partial discharge of power equipment by acoustic imaging based on a fiber optic microphone. Acoustic detection is performed using the device for detecting partial discharge of power equipment by acoustic imaging based on a fiber optic microphone as described in the above embodiment, and includes the following steps:

[0105] S10, determining an optimal working area of ​​the fiber optic microphone array according to the spectrum of each fiber optic microphone in the fiber optic microphone array;

[0106] Specifically, in this embodiment, 16 fiber optic microphones are used to collect local discharge acoustic wave signals. In order to collect signals synchronously, the 16 fiber optic microphones need to be demodulated simultaneously. According to the previous demodulation method, if simultaneous demodulation is achieved, 16 corresponding lasers are required. Therefore, in this embodiment, a splitter is used to provide light source excitation for each fiber optic microphone, so that the spectra of the 16 fiber optic microphones can be obtained. By using Gaussian filtering for noise reduction, a standard sine wave signal can be obtained. Then, the derivatives of the spectra of the 16 fiber optic microphones are taken, and then the sum is taken to obtain a new curve. The largest point on the curve is selected as the common working point of the 16 fiber optic microphones, which is the optimal working area.

[0107] Specifically, this embodiment obtains the derivative of the spectrum of each fiber optic microphone, sums the derivatives, and finds the point with the largest derivative as the optimal working area.

[0108] S20. Determine the optimal sensitivity range of each fiber optic microphone in the fiber optic microphone array based on the characteristic curve of the fiber optic microphone and the detection requirements of partial discharge;

[0109] S30, adjusting the laser wavelength output by the signal acquisition module according to the optimal working area of ​​the fiber optic microphone array to stimulate the fiber optic microphone array to collect the sound pressure signal generated by the partial discharge, and converting the collected sound pressure signal into an optical interference signal and outputting it to the signal acquisition module;

[0110] S40, converting the optical interference signal into a multi-channel digital signal using a signal acquisition module;

[0111] S50, using data processing equipment to convert the multi-channel digital signals into a partial discharge source spectrum.

[0112] It should be noted that this embodiment first performs initialization and working point selection. By selecting the optimal working points of 16 fiber optic microphones through the PC or the spectrum of the fiber optic microphone, the optimal sensitivity range of each microphone is determined based on the characteristic curve of the fiber optic microphone and the specific needs of partial discharge detection. Then, the MG-Y laser is used to adjust the wavelength of the output light to the optimal working wavelength range (1525-1565nm) according to the selected optimal working point. The laser is evenly distributed to each microphone channel in the fiber optic microphone array through a multi-way splitter to ensure that all fiber optic microphones can obtain sufficient light source excitation, thereby ensuring that the fiber optic microphone can operate in a high-sensitivity state and improving the reliability of signal acquisition.

[0113] Specifically, fiber optic microphones collect the sound pressure signals generated during the partial discharge process, convert the sound waves into optical interference signals, and then transmit them to a photodetector via a circulator. The photodetector converts the optical signals transmitted by the microphones into electrical signals, which are then output to an acquisition card. Multiple acquisition cards simultaneously collect electrical signals and transmit them to a data processing device via a queue. Synchronous sampling and digitization of the 16-channel electrical signals ensures signal timing consistency. The digitized signals are then transmitted to a PC via a high-speed interface. On the PC, a signal processing algorithm filters, amplifies, and suppresses noise on the collected sound pressure data. This data is then combined with real-time image data from a high-definition camera for multimodal data fusion. Using sound source localization and imaging algorithms, the system generates a spatial distribution map of the partial discharge sound source and displays it in real time on the PC. This enables precise localization and visualization of the partial discharge source, providing data support for monitoring equipment operating status and fault analysis.

[0114] It should be noted that, after verification, the present invention can use any imaging algorithm and is not limited to the CBF algorithm used in the present invention.

[0115] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0116] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0117] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0118] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0119] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An acoustic imaging detection device for partial discharge of power equipment based on a fiber optic microphone, characterized in that: The invention comprises a fiber optic microphone array, a signal acquisition module and a data processing device, wherein the fiber optic microphone array comprises a first subarray and a second subarray, wherein the first subarray is arranged near the center of the fiber optic microphone array and is distributed in an Archimedean spiral structure, and the second subarray is arranged on the periphery of the second subarray and is distributed in a rectangular shape; The signal acquisition module outputs light source excitation to each microphone channel in the fiber optic microphone array, so that the fiber optic microphone array collects the sound pressure signal generated by the partial discharge; The fiber optic microphone array converts the collected sound pressure signal into an optical interference signal and outputs it to the signal acquisition module; The signal acquisition module converts the optical interference signal into a multi-channel digital signal and outputs it to the data processing equipment; The data processing equipment converts the multi-channel digital signals into a partial discharge source spectrum.

2. The optical fiber microphone-based acoustic imaging detection device for partial discharge of electric power equipment according to claim 1, characterized in that: A camera is arranged at the center of the fiber optic microphone array for collecting image information of the sound field environment.

3. The device for detecting partial discharge of electric power equipment by acoustic imaging according to claim 1, wherein: The size of the fiber optic microphone array is 0.1m×0.1m, and the size of the first sub-array is 0.08m×0.08m.

4. The optical fiber microphone-based acoustic imaging detection device for partial discharge of electric power equipment according to claim 1, characterized in that: The fiber optic microphones distributed in the fiber optic microphone array are formed by a non-metallic diaphragm, and each fiber optic microphone is configured to respond within a different frequency band.

5. The optical fiber microphone-based acoustic imaging detection device for partial discharge of electric power equipment according to claim 1, characterized in that: The signal acquisition module includes a laser, a beam splitter is arranged on the laser light path output by the laser, and a circulator is arranged on the output light path of the beam splitter. One output port of the circulator outputs laser to the fiber optic microphone array, and the other output port outputs the reflected light of the fiber optic microphone array to a photodetector. The output of the photodetector is connected to the data processing equipment after passing through a multi-channel acquisition card.

6. The optical fiber microphone-based partial discharge acoustic imaging detection device for electric power equipment according to claim 1, characterized in that: The data processing device comprises: The signal processing module is used to perform denoising and filtering on multiple digital signals to obtain processed digital signals; The time-frequency analysis module is used to perform time-domain analysis and frequency-domain analysis on the processed digital signal to obtain the effective signal of partial discharge characteristics; The acoustic imaging module is used to perform fusion analysis based on the effective signal of the partial discharge characteristics corresponding to each fiber optic microphone and convert it into a partial discharge source spectrum inside the power equipment.

7. The optical fiber microphone-based acoustic imaging detection device for partial discharge of electric power equipment according to claim 6, characterized in that: The data processing device further includes: The three-dimensional reconstruction module is used to generate a spatial distribution map of the partial discharge source through a three-dimensional reconstruction algorithm based on the effective signal and image information of the partial discharge characteristics corresponding to each fiber optic microphone.

8. A method for detecting partial discharge of power equipment by acoustic imaging based on a fiber optic microphone, characterized in that: Acoustic detection is performed using the optical fiber microphone-based partial discharge acoustic imaging detection device for electric power equipment according to any one of claims 1 to 7, characterized in that it comprises: determining an optimal working area of ​​the fiber optic microphone array according to the spectrum of each fiber optic microphone in the fiber optic microphone array; Based on the characteristic curve of the fiber optic microphone and the requirements for partial discharge detection, the optimal sensitivity range of each fiber optic microphone in the fiber optic microphone array is determined; According to the optimal working area of ​​the fiber optic microphone array, the laser wavelength output by the signal acquisition module is adjusted to stimulate the fiber optic microphone array to collect the sound pressure signal generated by the partial discharge and convert the collected sound pressure signal into an optical interference signal before outputting it to the signal acquisition module; The optical interference signal is converted into a multi-channel digital signal using a signal acquisition module; The multi-channel digital signals are converted into partial discharge source maps using data processing equipment.

9. The method for detecting partial discharge of electric power equipment by acoustic imaging based on an optical fiber microphone according to claim 8, wherein: The signal acquisition module is provided with a multi-channel acquisition card, and the method further comprises: The electrical signals collected simultaneously by multiple acquisition cards are transmitted simultaneously to the data processing equipment through a queue.

10. The method for detecting partial discharge of electric power equipment by acoustic imaging based on an optical fiber microphone according to claim 8, characterized in that: The method further comprises: Dynamically update the partial discharge source map based on the sound pressure signal collected in real time by the fiber optic microphone array; Monitor the operating status of power equipment based on the real-time updated partial discharge source map.

Images