A converter valve abnormal discharge monitoring system based on distributed acoustic array group

Abstract

The present invention relates to a converter valve abnormal discharge monitoring system based on a distributed acoustic array group. The monitoring system includes a plurality of acoustic array groups, which are symmetrically distributed on both sides of a converter valve tower, and the axis of symmetry is the common central axis of the converter valve tower. Each acoustic array group includes a rigid support and a plurality of circular acoustic arrays fixed thereon at equal intervals. In the vertical direction, the distance between adjacent circular acoustic arrays is equal to the distance between adjacent converter valve bodies in a single converter valve tower. Each distributed data acquisition device is fixed on a corresponding rigid support and is located at the center of the plurality of circular acoustic arrays. The distributed data acquisition device is connected to a local server for communication. The distributed data acquisition device collects analog signals monitored by the acoustic array group and converts them into digital acoustic signals. The local server receives and processes the digital acoustic signals and obtains abnormal discharge positioning results. Compared with the prior art, the present invention has the advantages of real-time monitoring of abnormal discharge phenomena of converter valves and rapid and accurate positioning.

Description

Technical Field

[0001] The invention relates to the technical field of acoustic fault diagnosis of high-voltage direct current converter valves, and in particular to a converter valve abnormal discharge monitoring system based on a distributed acoustic array group. Background Art

[0002] The converter valve is a key core equipment of high-voltage direct current transmission. In actual operation, it will be affected by harsh electromagnetic environment and natural aging of components, which will lead to abnormal partial discharge of the converter valve. Abnormal discharge of the converter valve is difficult to detect through conventional electrical signal monitoring and manual inspection, which poses a great potential threat to the safe and stable operation of the DC system.

[0003] At present, there are pulse current method, acoustic array positioning method and other methods for detecting partial discharge of electrical equipment. The pulse current method is seriously affected by electromagnetic interference on site and is difficult to be effectively applied online. The acoustic array positioning method determines the spatial position of the discharge source based on the sound signal of partial discharge of the converter valve components, and has the advantages of strong anti-interference ability and non-contact measurement. However, the existing fault diagnosis of power equipment based on sound characteristics is mainly carried out for specific components of a single device, and focuses on the extraction of sound characteristic parameters to determine the fault type, which is difficult to adapt to the environmental requirements of the numerous valve tower components inside the converter valve hall. Therefore, how to monitor the abnormal discharge of electrical components in the entire converter valve hall in real time and accurately locate the abnormal discharge signal has become a problem that needs to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a converter valve abnormal discharge monitoring system based on a distributed acoustic array group in order to overcome the defect of the above-mentioned prior art that it is difficult to adapt to the environmental requirements of the numerous valve tower components inside the converter valve hall.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention provides a converter valve abnormal discharge monitoring system based on a distributed acoustic array group, which is used to monitor abnormal discharge conditions inside a plurality of converter valve towers. Each of the converter valve towers includes a plurality of converter valve bodies arranged in sequence. The monitoring system includes a distributed acoustic array group, a plurality of distributed data acquisition devices and a local server. The distributed acoustic array group includes a plurality of acoustic array groups, and the plurality of acoustic array groups are symmetrically distributed on both sides of the plurality of converter valve towers, and the axis of symmetry is a common central axis of the plurality of converter valve towers. Each of the acoustic array groups includes a rigid support and a plurality of circular acoustic arrays equidistantly fixed on the rigid support. In the vertical direction, the distance between adjacent circular acoustic arrays is equal to the distance between adjacent converter valve bodies in a single converter valve tower. Each of the distributed data acquisition devices is fixed on a corresponding rigid support and is located at the center of the plurality of circular acoustic arrays. The distributed data acquisition device is communicatively connected to the local server.

[0007] During the monitoring process, the distributed data acquisition device collects the analog signals monitored by the distributed array group and converts them into digital sound signals. The local server receives and processes the digital sound signals and obtains abnormal discharge positioning results.

[0008] As a preferred technical solution, each of the circular acoustic arrays includes a plurality of single microphones.

[0009] As a preferred technical solution, the aperture and number of array elements of the circular acoustic array are determined according to the resolution of abnormal discharges in different ultrasonic frequency bands.

[0010] As a preferred technical solution, the circular acoustic array is fixed to the rigid bracket by fasteners.

[0011] As a preferred technical solution, the process of the local server receiving and processing the digital sound signal and obtaining the abnormal discharge positioning result includes:

[0012] Perform valve tower basic noise removal on the received digital sound signal;

[0013] Determine abnormal discharge on the acoustic signal after noise removal;

[0014] When an abnormal discharge signal is detected, the corresponding circular acoustic array is marked and the corresponding acoustic signal is compressed and sensed;

[0015] Based on the signal data after compressed sensing, the beamforming method is used to obtain the abnormal discharge positioning results.

[0016] As an optimal technical solution, the compressed sensing process specifically includes: based on the sound signal after noise removal, the time domain signal is converted into the frequency domain through discrete Fourier transform to obtain the key components in the frequency spectrum; the key components are reconstructed into a time signal through inverse transformation to complete the compression of the signal data.

[0017] As a preferred technical solution, the monitoring system also includes a fiber optic transmission module and a remote server. The local server is connected to the remote server via the fiber optic transmission module. The local server transmits the processed digital acoustic signal and the abnormal discharge positioning result to the remote server for storage via the fiber optic transmission module.

[0018] As a preferred technical solution, along the extension direction of the common central axis, the distance between adjacent acoustic array groups is equal to the distance between adjacent converter valve towers.

[0019] As a preferred technical solution, the number of the circular sound arrays is 8.

[0020] As a preferred technical solution, the aperture of the circular sound array is 80 mm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. Aiming at the abnormal discharge fault of the electrical components in the valve tower in the entire valve hall, the present invention constructs an acoustic monitoring system, uses a distributed acoustic array group to acoustically monitor the acoustic signal of the converter valve, uses a distributed data acquisition device to collect the monitored analog signal, and uses a local server to filter the basic noise of the valve tower and judge the abnormal discharge. The acoustic signal can be used to comprehensively judge the abnormal discharge in the valve tower and accurately locate the abnormal discharge;

[0023] 2. After filtering out the basic noise of the valve tower and determining the abnormal discharge, the present invention only performs distributed compressed sensing data processing on the microphone group sound signal under the abnormal discharge condition, and finally realizes accurate positioning of the abnormal discharge sound source through the beam forming method, thereby reducing the amount of data, thereby reducing the pressure of large-scale data processing and transmission, improving processing efficiency, and being able to improve the real-time and flexibility of abnormal discharge signal monitoring, and improving the operating efficiency of the system;

[0024] 3. The abnormal discharge monitoring system for converter valves based on the distributed acoustic array group provided by the present invention can realize the intelligent positioning of abnormal discharge inside multiple converter valve towers, and can be installed in a distributed multi-point manner in UHV DC power switching stations. The abnormal discharge phenomenon of the converter valve towers in the UHV DC power switching stations can be monitored in real time without human supervision all day long, and an automatic alarm can be given in time when abnormal discharge occurs, which is helpful for fault handling and reduces the safety hazards caused by faults. It is of great significance to the safe operation of my country's power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the spatial position installation of the distributed acoustic array group and the converter valve tower provided in Example 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the planar position of the distributed acoustic array group and the converter valve tower provided in Example 1 of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of a single acoustic array group provided in Example 1 of the present invention;

[0028] Figure 4 This is a schematic diagram of the hardware composition of the converter valve abnormal discharge monitoring system provided in Example 1 of the present invention;

[0029] Figure 5 This is an operation flow chart of the converter valve abnormal discharge monitoring system provided in Example 1 of the present invention;

[0030] Among them: 101~114, the first sound array group to the fourteenth sound array group; 201~206, the first converter valve tower to the sixth converter valve tower; 3, rigid bracket; 4, circular sound array; 401~408, the first microphone to the eighth microphone; 501~514, the first distributed data acquisition device to the fourteenth distributed data acquisition device; 6, local server; 7, optical fiber transmission module; 8, remote server. DETAILED DESCRIPTION

[0031] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0032] Example 1

[0033] This embodiment provides a converter valve abnormal discharge monitoring system based on a distributed acoustic array group, which is used to monitor abnormal discharge conditions of multiple converter valve towers. Figure 1The spatial position installation of the distributed acoustic array group and multiple converter valve towers is shown. As can be seen from the figure, the monitoring system includes 14 acoustic array groups with the same structure (i.e., the first acoustic array group 101 to the fourteenth acoustic array group 114), which are used to monitor the DC transmission converter valve tower. The DC transmission converter valve tower in the figure is grouped in 6 rows (i.e., the first converter valve tower 201 to the sixth converter valve tower 206), and each converter valve tower includes a plurality of converter valve bodies arranged vertically in sequence. The 6 rows of converter valve towers are arranged equidistantly in sequence, and the 14 acoustic array groups are symmetrically installed on both sides of the 6 rows of DC converter valve towers. The axis of symmetry is the common central axis AA of the 6 rows of converter valve towers, that is, the first acoustic array group 101 and the eighth acoustic array group 108, ..., the seventh acoustic array group 107 and the fourteenth acoustic array group 114 are symmetrical along the central axis AA respectively.

[0034] Figure 2 The planar position of the distributed acoustic array group and the converter valve tower is shown. It can be seen from the figure that the distance between each acoustic array group and the common central axis AA is 5000 mm. Along the extension direction of the common central axis AA, the distance between two adjacent converter valve towers (for example, the second converter valve tower 202 and the third converter valve tower 203) is equal to the distance between two adjacent acoustic array groups (for example, the first acoustic array group 101 and the second acoustic array group 102), both of which are 8000 mm.

[0035] Specifically, the installation points of the second acoustic array group 102 to the sixth acoustic array group 106 and the ninth acoustic array group 109 to the thirteenth acoustic array group 113 are located 5 meters on both sides of the midpoint between each two adjacent groups of valve towers (for example, the second acoustic array group 102 is located 5 meters to the left of the midpoint between the first valve tower 201 and the second valve tower 202, and the ninth acoustic array group 109 is located 5 meters to the right of the same midpoint, and the two acoustic array groups are symmetrically distributed along the central axis AA). At the same time, since the distance between two adjacent acoustic array groups is 8000 mm, the installation points of the first acoustic array group 101, the eighth acoustic array group 108, the seventh acoustic array group 107, and the fourteenth acoustic array group 114 can be determined.

[0036] Figure 3 The structure of a single acoustic array group is shown. Taking the first acoustic array group 101 as an example: the first acoustic array group 101 includes a rigid support 3 and 8 identical circular acoustic arrays fixed on the rigid support 3 at equal distances. The center of the array is about 4000 mm from the ground (equal to the center height of the converter valve tower), and the distance from the array fixing point to the midpoint of the adjacent converter valve tower is 5000 mm. Taking the circular acoustic array 4 as an example, the circular acoustic array 4 has the first microphone 401 to the eighth microphone 408. Similarly, each circular acoustic array has 8 single microphones.

[0037] The eight circular sound arrays are arranged vertically in sequence, and the vertical distance between two adjacent circular sound arrays is equal to the distance between the adjacent converter valve bodies in a single converter valve tower in the vertical direction, which is 934 mm in this embodiment. In other words, the center of each circular sound array is on the same horizontal plane as the corresponding converter valve body, and the eight circular sound arrays are linearly mounted on the corresponding rigid bracket of the sound array group. In some embodiments, they can be mounted on a rigid bracket by fasteners such as bolts. The microphone aperture and the number of array elements are designed and optimized with the goal of achieving high resolution of abnormal discharges in different ultrasonic frequency bands, which can improve the collection effect of abnormal discharge sounds of converter valves, thereby improving the positioning accuracy of the system. For example, it is known that the array resolution depends on the main lobe width and is affected by the shape of the array. Because the sound frequency involved in the monitored abnormal discharge phenomenon is between 20KHz and 2MHz, the array aperture obtained by simulation according to the Rayleigh criterion (diffraction limit resolution definition) is 80mm, which can meet the requirements. Therefore, the aperture of each circular sound array can be designed to be 80mm.

[0038] Still Figure 3 Taking the first acoustic array group 101 in the example, the first distributed data acquisition device 501 is fixedly mounted on the rigid support 3 and is located at the center of the 8 circular acoustic arrays, that is, the first distributed data acquisition device 501 is about 4000 mm above the ground. Each distributed data acquisition device is mounted on the rigid support of the corresponding acoustic array group, responsible for collecting the analog signal of the single microphone array group and performing AD conversion.

[0039] Figure 4 The hardware composition structure of the converter valve abnormal discharge monitoring system provided in this embodiment is shown. The monitoring system includes 14 acoustic array groups and 14 distributed data acquisition devices (i.e., the first distributed data acquisition device 501 to the fourteenth distributed data acquisition device 514), each distributed data acquisition device is installed on a rigid bracket of the corresponding acoustic array group, and the monitoring system also includes a local server 6, an optical fiber transmission module 7, and a remote server 8. All distributed data acquisition devices are communicatively connected to the local server 6, and the local server 6 is connected to the remote server 8 via the optical fiber transmission module 7. During the monitoring process, the distributed data acquisition device collects the analog signals monitored by the distributed array group and converts them into digital acoustic signals. The local server 6 receives and processes the digital acoustic signals, obtains the abnormal discharge positioning results, and transmits the processed digital acoustic signals and the abnormal discharge positioning results to the remote server 8 for storage via the optical fiber transmission module 7. Specifically:

[0040] The local server 6 is used to remove the valve tower basic noise from the digital acoustic signal collected by distributed data, and to determine abnormal discharge on the acoustic signal after noise removal. When abnormal discharge is detected, a specific microphone group is marked, and the corresponding microphone group acoustic signal is processed and stored using distributed compressed sensing data. After reducing the amount of data and improving processing efficiency, a beamforming method is used to locate the position of abnormal discharge, store it, and transmit it.

[0041] The optical fiber transmission module 7 is used to transmit the basic data after the compressed sensing of the abnormal discharge signal and the positioning result of the beam forming. The transmission of the optical fiber transmission module 7 is not affected by electromagnetic interference, and can effectively avoid the problem that the transmission signal is interfered, distorted or weakened by electromagnetic waves. In contrast, traditional cable transmission is easily interfered by electromagnetic interference, resulting in signal quality degradation or data loss. The transmission has a high bandwidth characteristic and can support a large amount of data transmission. In the intelligent positioning system of abnormal discharge of the converter valve, a large amount of sound signal data needs to be transmitted. Optical fiber transmission can transmit this data quickly and stably to ensure the integrity and accuracy of the data. Optical fiber transmission has a low loss characteristic and can achieve long-distance transmission. Inside the substation, the converter valve tower may be distributed at a long distance. The use of optical fiber transmission can maintain the stability and reliability of the signal, and effectively solves the problem of signal attenuation caused by too long transmission distance. Optical fiber transmission has high security and is difficult to be eavesdropped and interfered. In important facilities such as substations, it is very important to ensure the security of the signal to prevent data from being stolen, tampered with or interrupted. The optical fiber transmission system uses optical signal transmission and does not generate electromagnetic radiation, so it can provide higher signal security.

[0042] The remote server 8 is used to receive and store the basic data after the abnormal discharge signal is compressed and sensed, as well as the positioning results of beamforming. It can quickly and accurately find and trace back the historical data of abnormal discharge, which is convenient for further research and analysis. In addition, the remote server 8 presents the processing results to the operator in a visual form, providing intuitive and clear information on the abnormal discharge location of the converter valve, and real-time warning helps the operator make decisions quickly.

[0043] In the above process, compressed sensing and beamforming methods are used. Among them, the key to the compressed sensing (CS) algorithm or other new theoretical methods for compressible signal acquisition and recovery is to make full use of the sparsity of the signal (the number of non-zero items in the representation of the signal under a certain basis is small) and compress the information as much as possible in the acquisition stage. The compressed sensing algorithm overcomes the limitations of equal-interval sampling and full sampling in the traditional Nyquist theorem, allowing the signal to be acquired at a low sampling rate much lower than the Nyquist sampling rate. The premise of compressed sensing is that the target signal is sparse, that is, the signal can be sparsely represented by a set of bases. The theory of compressed sensing has been deeply studied and has found applications in many fields.

[0044] Beamforming technology is a signal processing technology widely used in radar, wireless communication, sound processing and other fields. Beamforming technology uses spatial filters to perform weighted processing of phase and amplitude according to the wave arrival direction and detection target, thereby achieving selective gain for signal sources in different directions, optimizing signal quality, suppressing interference and noise, and improving signal reception power. In radar and sonar systems, beamforming can improve the signal-to-noise ratio and directional resolution of target signals, reconstruct a three-dimensional image of the physical space sound field, and achieve precise positioning of the direction of the signal source. In wireless communications, multi-antenna beamforming technology can achieve spatial multiplexing, improve spectrum utilization, and enhance the communication quality and capacity of the system.

[0045] The specific operation process of the above monitoring system is as follows: Figure 5 As shown. After the system is started, the distributed data acquisition device starts to run, collects the sound signals of the distributed sound array group, and removes the valve tower basic noise from the sound signal. The sound signal after noise removal is judged as abnormal discharge. When abnormal discharge is detected, the specific microphone group is marked, and the corresponding microphone group sound signal is processed by distributed compressed sensing data, and the data is stored locally. The specific steps include: converting the time domain signal to the frequency domain through discrete Fourier transform, finding the key components in the frequency spectrum, and reconstructing the key components into time signals through inverse transform, thereby completing the information compression. After reducing the amount of data and improving the processing efficiency, each group of sensor arrays is given a corresponding time signal, and the accurate position of the abnormal discharge event of the converter valve is calculated through beamforming technology. In this step, the system will use the geometric and physical principles according to the delay and amplitude of each sound signal to obtain the precise position of the abnormal discharge of the converter valve, store the results in the local server, and transmit optical fiber data at the same time. The remote server performs remote data storage and visual monitoring results display of the fault data, and users can easily view and analyze the location of the abnormal discharge of the converter valve. The processing results can be saved for future search and backtracking of historical data, facilitating the research and analysis of historical data.

[0046] This intelligent positioning system can monitor abnormal discharge of converter valves in real time and locate them quickly and accurately, greatly improving the safety and stability of substation operation. At the same time, it can also detect faults in the first place, prevent them from causing more serious problems, and ensure the safe operation of the power grid.

[0047] Example 2

[0048] The difference between this embodiment and embodiment 1 is that the abnormal discharge monitoring system of the converter valve provided includes 20 acoustic array groups of the same structure, which are used to monitor the DC transmission converter valve tower. Accordingly, the DC transmission converter valve tower is grouped into 9 rows, and each converter valve tower includes a plurality of converter valve bodies arranged vertically in sequence. The 9 rows of converter valve towers are arranged equidistantly in sequence, and the 20 acoustic array groups are symmetrically installed on both sides of the 9 rows of converter valve towers, and the axis of symmetry is the common central axis of the 9 rows of converter valve towers. The rest of the system is basically the same as the specific structure provided in embodiment 1, and the operation process of the system is also basically the same as the process provided in embodiment 1, which will not be repeated here.

[0049] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A converter valve abnormal discharge monitoring system based on a distributed acoustic array group, used to monitor abnormal discharge conditions inside a plurality of converter valve towers, each of the converter valve towers comprising a plurality of converter valve bodies arranged in sequence, characterized in that: The monitoring system includes a distributed acoustic array group, a plurality of distributed data acquisition devices and a local server. The distributed acoustic array group includes a plurality of acoustic array groups, which are symmetrically distributed on both sides of the plurality of converter valve towers, and the axis of symmetry is a common central axis of the plurality of converter valve towers. Each of the acoustic array groups includes a rigid support and a plurality of circular acoustic arrays equidistantly fixed on the rigid support. In the vertical direction, the distance between adjacent circular acoustic arrays is equal to the distance between adjacent converter valve bodies in a single converter valve tower. Each of the distributed data acquisition devices is fixed on a corresponding rigid support and is located at the center of the plurality of circular acoustic arrays. The distributed data acquisition device is communicatively connected to the local server. During the monitoring process, the distributed data acquisition device collects the analog signals monitored by the distributed acoustic array group and converts them into digital acoustic signals. The local server receives and processes the digital acoustic signals and obtains abnormal discharge positioning results.

2. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: Each of the circular acoustic arrays includes a plurality of single microphones.

3. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: The aperture and number of array elements of the circular acoustic array are determined according to the resolution of abnormal discharges in different ultrasonic frequency bands.

4. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: The circular acoustic array is fixed on the rigid support by fasteners.

5. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: The process of the local server receiving and processing the digital sound signal and obtaining the abnormal discharge positioning result includes: Perform valve tower basic noise removal on the received digital sound signal; Determine abnormal discharge on the acoustic signal after noise removal; When an abnormal discharge signal is detected, the corresponding circular acoustic array is marked and compressed sensing is performed on the corresponding acoustic signal; Based on the signal data after compressed sensing, the beamforming method is used to obtain the abnormal discharge positioning results.

6. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 5 is characterized in that: The compressed sensing process specifically includes: based on the acoustic signal after noise removal, converting the time domain signal into the frequency domain through discrete Fourier transform to obtain the key components in the frequency spectrum; reconstructing the key components into a time signal through inverse transform to complete the compression of the signal data.

7. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: The monitoring system also includes an optical fiber transmission module and a remote server. The local server is connected to the remote server via the optical fiber transmission module. The local server transmits the processed digital acoustic signal and the abnormal discharge positioning result to the remote server for storage via the optical fiber transmission module.

8. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: Along the extension direction of the common central axis, the distance between adjacent acoustic array groups is equal to the distance between adjacent converter valve towers.

9. The converter valve abnormal discharge monitoring system based on a distributed acoustic array group according to claim 1, characterized in that: The number of the circular sound arrays is 8.

10. The converter valve abnormal discharge monitoring system based on the distributed acoustic array group according to claim 1 is characterized in that: The aperture of the circular acoustic array is 80 mm.

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