Discharge fault locating system, discharge fault locating method, device and medium

Abstract

The present application relates to the technical field of fault detection, and particularly relates to a discharge fault positioning system, a discharge fault positioning method, equipment and a medium, wherein the discharge fault positioning system comprises a laser, a first / second acousto-optic modulator, an optical amplifier, a balanced photodetector and a collection card; the laser is split after being modulated into a first pulse sequence; a part of the first pulse sequence is delayed to obtain a delayed pulse sequence; the remaining first pulse sequence is modulated to obtain a second pulse sequence; the two pulse sequences are amplified and then injected into a sensing optical fiber to obtain a target signal; the sensing optical fiber is arranged on the outer surface of a GIL pipeline to be detected, and the target signal is converted into a voltage signal; and the discharge fault is positioned according to the voltage signal. Thus, the problem that the GIL discharge fault positioning technology has high cost, low reliability and is difficult to realize long-distance GIL discharge fault positioning is solved; the present application can cover a length of several kilometers, is easy to install, has accurate positioning and high reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault detection, in particular to a discharge fault positioning system, a discharge fault positioning method, equipment and a medium. BACKGROUND

[0002] GIL (Gas Insulated Transmission Lines) is widely used in long-distance high-voltage transmission projects due to its environmental friendliness, small land occupation, and high operation stability. However, during operation and withstand voltage test, GIL may occur discharge faults such as insulation surface flashover, solid insulation breakdown and air gap breakdown, resulting in power failure and endangering the safe and stable operation of the transmission system.

[0003] Due to the fully enclosed structure of GIL, it is extremely difficult to determine the discharge location for long-distance GIL of several kilometers once a fault occurs, and the maintenance cycle is long. Therefore, it is crucial to quickly and accurately locate the discharge fault of GIL.

[0004] In related technologies, there are mainly two types of positioning technologies for GIL discharge faults: (1) electrical method: the time difference of the transient overvoltage waveform generated by discharge is detected at both ends of GIL to calculate the discharge location. However, this method has limitations: first, the installation of sensors will damage the sealing of GIL, and cannot be installed on the already commissioned GIL; second, as the transient overvoltage waveform propagates along the GIL, its rise time will decay, resulting in reduced positioning accuracy, and the longer the GIL, the worse the positioning accuracy.

[0005] (2) ultrasonic method: a number of point ultrasonic sensors are arranged at certain intervals along the GIL pipe to detect ultrasonic and vibration signals generated by discharge. However, in this method, each sensor can only cover a few meters, and a large number of sensors need to be installed on the outer surface of the GIL tank, which not only has high cost, but also has low reliability due to the need to maintain a large number of sensors and power modules.

[0006] In summary, for the positioning needs of long-distance GIL discharge faults, there is an urgent need for a positioning system and method that can cover several kilometers in length, be easy to install, accurate in positioning, fast in response, and high in reliability. SUMMARY

[0007] The present application provides a discharge fault positioning system, a discharge fault positioning method, equipment and a medium to solve the problems of high cost, low reliability and difficulty in positioning long-distance GIL discharge faults in GIL discharge fault positioning technology. The present application can cover several kilometers in length, be easy to install, accurate in positioning, fast in response, and high in reliability.

[0008] The first aspect of the present application provides a discharge fault positioning system, comprising:

[0009] a laser for emitting laser light;

[0010] a first acousto-optic modulator for modulating the laser light to obtain a first pulse sequence;

[0011] a delay optical fiber for delaying part of the first pulse sequence to obtain a delayed pulse sequence;

[0012] a second acousto-optic modulator for modulating the remaining part of the first pulse sequence to obtain a second pulse sequence;

[0013] an optical amplifier for amplifying a combined pulse sequence generated by the delayed pulse sequence and the second pulse sequence and then injecting the combined pulse sequence into a sensing optical fiber through a circulator to obtain a target signal, wherein the sensing optical fiber is arranged on the outer surface of a GIL pipe to be detected;

[0014] a balanced photodetector for converting the target signal output from the circulator into a voltage signal;

[0015] a data acquisition card for acquiring the voltage signal and positioning a discharge fault according to the voltage signal.

[0016] Optionally, in some embodiments, the discharge fault positioning system comprises:

[0017] a first optical coupler arranged between the laser and the first acousto-optic modulator, the first optical coupler being configured to couple the laser light;

[0018] a second optical coupler, one end of the second optical coupler being connected to the first acousto-optic modulator, the other end of the second optical coupler being connected to one end of the delay optical fiber and one end of the second acousto-optic modulator respectively, the second optical coupler being configured to couple the first pulse sequence;

[0019] a third optical coupler, one end of the third optical coupler being connected to the other end of the delay optical fiber and the other end of the second acousto-optic modulator respectively, the other end of the third optical coupler being connected to the optical amplifier, the third optical coupler being configured to couple the delayed pulse sequence and the second pulse sequence to generate the combined pulse sequence;

[0020] a fourth optical coupler, one end of the fourth optical coupler being connected to the circulator, the other end of the fourth optical coupler being connected to the balanced photodetector, the fourth optical coupler being configured to couple the target signal.

[0021] Optionally, in some embodiments, a first end of the circulator is connected to an output end of the optical amplifier, a second end of the circulator is connected to the sensing optical fiber, and a third end of the circulator is connected to the fourth optical coupler.

[0022] The second aspect of the present application provides a discharge fault locating method, comprising: using the discharge fault locating system described above, wherein the method comprises the following steps:

[0023] emitting a laser by a laser;

[0024] modulating the laser by a first acousto-optic modulator to obtain a first pulse sequence;

[0025] delaying part of the first pulse sequence by a delay optical fiber to obtain a delayed pulse sequence;

[0026] modulating the remaining part of the first pulse sequence by a second acousto-optic modulator to obtain a second pulse sequence;

[0027] amplifying a converged pulse sequence generated by the delayed pulse sequence and the second pulse sequence by an optical amplifier, and then injecting the converged pulse sequence into a sensing optical fiber through a circulator to obtain a target signal, wherein the sensing optical fiber is arranged on an outer surface of a GIL pipeline to be detected;

[0028] converting the target signal output from the circulator into a voltage signal by a balanced photodetector;

[0029] acquiring the voltage signal by an acquisition card, and locating a discharge fault according to the voltage signal.

[0030] Optionally, in some embodiments, the locating of the discharge fault according to the voltage signal comprises:

[0031] separating the voltage signal to obtain a first beat frequency signal and a second beat frequency signal;

[0032] phase demodulating the first beat frequency signal and the second beat frequency signal to obtain first phase information and second phase information, and performing distance-time-phase transformation on the first phase information and the second phase information to obtain a first phase matrix and a second phase matrix;

[0033] performing similarity analysis on the first phase matrix and the second phase matrix to obtain a difference value of phase standard deviations between corresponding positions, determining a reconstruction strategy according to the difference value of phase standard deviations between corresponding positions and a first preset threshold, and obtaining a reconstructed phase matrix based on the reconstruction strategy;

[0034] traverse the phase arrays of the reconstructed phase matrix at all distance points, calculate the phase standard deviation of each phase array, and select the maximum value among all phase standard deviations, and determine whether the maximum value is greater than a second preset threshold value;

[0035] If the maximum value is greater than the second preset threshold value, then the distance point corresponding to the maximum value is determined as a discharge fault point.

[0036] Optionally, in some embodiments, the determining the reconstruction strategy according to the difference of the phase standard deviation between corresponding positions and the first preset threshold value, and obtaining the reconstructed phase matrix based on the reconstruction strategy, comprises:

[0037] determining whether the difference of the phase standard deviation between corresponding positions is greater than or equal to the first preset threshold value;

[0038] If the difference of the phase standard deviation between corresponding positions is greater than or equal to the first preset threshold value, then the phase signal corresponding to the pulse sequence with smaller variance is selected for linear interpolation, and the pulse sequence after linear interpolation is filled into the data points of another pulse sequence to obtain the reconstructed phase matrix.

[0039] Optionally, in some embodiments, after determining whether the difference of the phase standard deviation between corresponding positions is greater than or equal to the first preset threshold value, comprising:

[0040] If the difference of the phase standard deviation between corresponding positions is less than the first preset threshold value, then the phases in the first phase matrix and the second phase matrix are staggered and spliced in time sequence to obtain the reconstructed phase matrix.

[0041] Optionally, in some embodiments, after determining whether the maximum value is greater than the second preset threshold value, comprising:

[0042] If the maximum value is less than or equal to the second preset threshold value, then it is determined that no discharge fault has occurred.

[0043] The third aspect of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement the discharge fault positioning method as described in the above embodiments.

[0044] The fourth aspect of the present application provides a computer readable storage medium having a computer program stored thereon, which is executed by a processor to implement the discharge fault positioning method as described in the above embodiments.

[0045] Therefore, the present application has at least the following beneficial effects:

[0046] (1) This invention can achieve long-distance, high-precision fault location. This invention utilizes distributed fiber optic acoustic sensing technology, which can realize real-time monitoring and location of partial discharge events within a range of several kilometers using only a single-mode silica fiber deployed along the GIL. Unlike electrical methods that rely on the time difference of arrival of the transmission waveform, this invention is based on the phase change of Rayleigh scattering in the fiber caused by the acoustic waves and vibrations generated at the discharge location. It is not affected by the attenuation and broadening of the pulse signal waveform during long-distance propagation, ensuring stable positioning accuracy even at long distances.

[0047] (2) The system structure of this invention is simple, and the engineering implementation complexity and maintenance cost are low. Both electrical methods and point ultrasonic methods require the deployment of a large number of sensors and power supply equipment. This invention only requires laying a passive optical fiber as a sensing medium outside the GIL pipe, which greatly simplifies the system structure. No opening treatment is required in the GIL tank during installation, making it suitable for the retrofitting of in-service equipment. The optical fiber itself is passive and requires no power supply, which significantly improves the reliability and service life of the system, making it suitable for discharge monitoring applications in long-distance, distributed, and complex environments.

[0048] (3) This invention possesses excellent noise immunity and coherent fading compensation mechanism. By acquiring dual-frequency beat signals, demodulating phase, and analyzing the similarity of phase matrix groups, combined with strategies for determining the location of coherent fading and performing signal filtering and linear interpolation, this invention constructs a reconstructed phase matrix with strong anti-interference capabilities and high data integrity. This effectively improves the stability and positioning accuracy of the system under complex backgrounds such as vibration noise and scattering randomness. The reliability of the system is significantly better than that of traditional fiber optic distributed sensing schemes.

[0049] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0050] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0051] Figure 1 This is a schematic diagram of a discharge fault location system provided according to an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of a sensing optical fiber provided according to an embodiment of the present invention;

[0053] Figure 3 A flowchart of a discharge fault location method provided according to an embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram illustrating the principle of a discharge fault location method according to an embodiment of the present invention;

[0055] Figure 5 This is a schematic diagram of a fault location point provided according to an embodiment of the present invention;

[0056] Figure 6 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present invention. Detailed Implementation

[0057] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0058] The following description, with reference to the accompanying drawings, describes a discharge fault location system, method, device, and medium according to embodiments of the present invention. Addressing the problems of high cost, low reliability, and difficulty in long-distance GIL discharge fault location technology mentioned in the background section, the present invention provides a discharge fault location system, comprising a laser, first / second acousto-optic modulators, an optical amplifier, a balanced photodetector, and a data acquisition card. The laser is modulated into a first pulse sequence and then split. A portion of the first pulse sequence is delayed to obtain a delayed pulse sequence, and the remaining first pulse sequence is modulated to obtain a second pulse sequence. The two pulse sequences are amplified and injected into a sensing optical fiber to obtain a target signal. The sensing optical fiber is disposed on the outer surface of the GIL pipe to be detected and converts the target signal into a voltage signal. Discharge fault location is performed based on the voltage signal. Therefore, the present invention solves the problems of high cost, low reliability, and difficulty in long-distance GIL discharge fault location technology. It can cover lengths of several kilometers, is easy to install, provides accurate positioning, and has high reliability.

[0059] Specifically, Figure 1 This is a flowchart illustrating a discharge fault location system provided in an embodiment of the present invention.

[0060] like Figure 1 As shown, the discharge fault location system 10 includes: a laser 100, a first acousto-optic modulator 200, a delay fiber 300, a second acousto-optic modulator 400, an optical amplifier 500, a balanced photodetector 600, and a data acquisition card 700.

[0061] The system includes: a laser 100 for emitting laser light; a first acousto-optic modulator 200 for modulating the laser light to obtain a first pulse sequence; a delay fiber 300 for obtaining a delayed pulse sequence from a portion of the first pulse sequence; a second acousto-optic modulator 400 for modulating the remaining pulse sequence in the first pulse sequence to obtain a second pulse sequence; an optical amplifier 500 for amplifying the combined pulse sequence generated from the delayed pulse sequence and the second pulse sequence and injecting it into the sensing fiber through a circulator to obtain a target signal, wherein the sensing fiber is disposed on the outer surface of the GIL pipe to be detected; a balanced photodetector 600 for converting the target signal output from the circulator into a voltage signal; and a data acquisition card 700 for acquiring the voltage signal and locating the discharge fault based on the voltage signal.

[0062] It should be noted that, as Figure 2 As shown, in this embodiment of the invention, a sensing optical fiber can be installed on the outer wall of the GIL pipe to be detected. Preferably, the sensing optical fiber is a single-mode silica optical fiber, used to sense the sound waves and vibration signals generated by the GIL discharge. One end of the sensing optical fiber is connected to the discharge fault location system 10 of this embodiment of the invention.

[0063] Specifically, in combination Figure 1 As shown, in this embodiment of the invention, a laser 100 is used to generate a narrow-linewidth continuous laser; an isolator is used to prevent the forward-propagating laser from being reflected back into the laser; a first optical coupler to a fourth optical coupler are used for optical path splitting and combining; a first acousto-optic modulator 200 is used to modulate the continuous laser into pulsed light, while introducing different frequency shifts into the pulsed light; a signal generator is used to drive the first acousto-optic modulator to modulate the continuous laser into pulsed probe light and control the width of the probe light pulse; a delay fiber 300 is used to generate a time delay for the pulsed light; and an optical amplifier is used. 500, preferably, the optical amplifier 500 can be an erbium-doped fiber amplifier, which is used to amplify the pulsed light power; circulator, the probe light is input from the first port of the circulator and output from the second port of the circulator into the sensing fiber, the returned optical signal is input from the second port of the circulator and output from the third port of the circulator; balanced photodetector 600 is used to differentially amplify the optical signal, convert it into an electrical signal, and output it to the acquisition card 700; acquisition card 700 is used to record sensing data and locate discharge faults based on the sensing data.

[0064] In actual operation, laser 100 emits narrow-linewidth continuous light. After passing through the isolator and the first optical coupler C1, most of the power of the continuous light enters the first acousto-optic modulator 200, while a small portion of the power serves as the local oscillator. The first acousto-optic modulator 200 modulates the continuous light into optical pulses with a width on the nanosecond scale and introduces them into the optical frequency. The frequency shift of the light forms a first pulse sequence PS1. The generated Rayleigh scattered light mixes with the local oscillator light to form a first beat frequency signal Ub1 with a frequency of Δf1. The PS1 pulse light from the first acousto-optic modulator 200, after passing through the second optical coupler C2, is half of which passes through the second acousto-optic modulator 400 to form a frequency shift of Δf1. The second pulse sequence PS2 generates Rayleigh scattered light, which mixes with the local oscillator light to form a second beat frequency signal Ub2 with a frequency of Δf2; the other half of the first pulse sequence PS1 passes through the delay fiber 300 and then converges with the first pulse sequence PS2 at the third optical coupler C3. After being amplified by the optical amplifier 500, it is injected into the sensing fiber by the circulator.

[0065] The sensing fiber adopts a tight-buffered optical cable structure with length scale markings. The outer sheath of the optical cable is pre-marked with precise length scale information. After installation, the length of the sensing optical cable is measured and the reflection characteristics are detected by combining optical time domain reflectometer (OTDR) technology. This allows the relative distance coordinates calculated in the system to be calibrated with the actual length of the optical cable. By establishing a one-to-one correspondence between the system positioning distance and the physical length of the optical cable, the fault location results are accurately matched with the actual geographical location, improving the absolute accuracy of fault location and the operability in engineering.

[0066] Optionally, in some embodiments, it further includes: a first optical coupler to a fourth optical coupler.

[0067] The system includes a first optical coupler C1 positioned between the laser and the first acousto-optic modulator, used for coupling the laser; a second optical coupler C2, one end of which is connected to the first acousto-optic modulator 200, and the other end of which is connected to one end of the delay fiber 300 and one end of the second acousto-optic modulator 400, used for coupling a first pulse sequence; a third optical coupler C3, one end of which is connected to the other end of the delay fiber 300 and the other end of the second acousto-optic modulator 400, and the other end of which is connected to an optical amplifier 500, used for coupling the delayed pulse sequence and the second pulse sequence to generate a converged pulse sequence; and a fourth optical coupler C4, one end of which is connected to a circulator, and the other end of which is connected to a balanced photodetector 600, used for coupling the target signal.

[0068] Optionally, in some embodiments, the first end of the circulator is connected to the output of the optical amplifier 500, the second end of the circulator is connected to the sensing optical fiber, and the third end of the circulator is connected to the fourth optical coupler C4.

[0069] Therefore, this embodiment of the invention uses optical fiber as the sensing medium and optical fiber distributed acoustic sensing technology. Only one optical fiber is placed on the outer surface of the GIL pipe as a sensor to achieve accurate and rapid location of discharge faults. This avoids drilling holes in the GIL to install sensors and also avoids installing a large number of point sensors. At the same time, the positioning accuracy is not affected by the length of the GIL and the transmission process of the discharge signal, and the same positioning accuracy can be maintained over a distance of hundreds of meters to several kilometers.

[0070] The discharge fault location system proposed in this invention includes: a laser, a first acousto-optic modulator, a second acousto-optic modulator, an optical amplifier, a balanced photodetector, and a data acquisition card. The laser is modulated into a first pulse sequence and then split. A portion of the first pulse sequence is delayed to obtain a delayed pulse sequence, and the remaining first pulse sequence is modulated to obtain a second pulse sequence. Both pulse sequences are amplified and injected into a sensing optical fiber to obtain a target signal. The sensing optical fiber is disposed on the outer surface of the GIL (Gas Inlet Lid) to be detected and converts the target signal into a voltage signal. Discharge fault location is then performed based on the voltage signal. This invention solves the problems of high cost, low reliability, and difficulty in long-distance GIL discharge fault location technology. It can cover lengths of several kilometers, is easy to install, provides accurate location, and has high reliability.

[0071] Next, the discharge fault location method proposed according to an embodiment of the present invention is described with reference to the accompanying drawings.

[0072] Figure 3 This is a flowchart of the discharge fault location method according to an embodiment of the present invention.

[0073] In step 301, laser light is emitted by a laser.

[0074] In step 302, the laser is modulated by the first acousto-optic modulator to obtain the first pulse sequence.

[0075] In step 303, a delayed pulse sequence is obtained by using a delayed optical fiber to process a portion of the pulse sequence in the first pulse sequence.

[0076] In step 304, a second pulse sequence is obtained by modulating the remaining pulse sequence in the first pulse sequence using a second acousto-optic modulator.

[0077] In step 305, the converged pulse sequence generated by the delayed pulse sequence and the second pulse sequence is amplified by an optical amplifier and then injected into the sensing fiber through a circulator to obtain the target signal, wherein the sensing fiber is disposed on the outer surface of the GIL pipe to be detected.

[0078] In step 306, the target signal output from the circulator is converted into a voltage signal by a balanced photodetector.

[0079] In step 307, the voltage signal is acquired by the acquisition card, and the discharge fault is located based on the voltage signal.

[0080] Optionally, in some embodiments, discharge fault location based on voltage signals includes: separating the voltage signals to obtain a first beat frequency signal and a second beat frequency signal; demodulating the first beat frequency signal and the second beat frequency signal to obtain first phase information and second phase information, and performing distance-time-phase transformation on the first phase information and the second phase information to obtain a first phase matrix and a second phase matrix; performing similarity analysis on the first phase matrix and the second phase matrix to obtain the difference in phase standard deviation between corresponding positions, determining a reconstruction strategy based on the difference in phase standard deviation between corresponding positions and a first preset threshold, and obtaining a reconstructed phase matrix based on the reconstruction strategy; traversing the phase arrays of the reconstructed phase matrix at all distance points, calculating the phase standard deviation of each phase array, selecting the maximum value among all phase standard deviations, and determining whether the maximum value is greater than a second preset threshold; if the maximum value is greater than the second preset threshold, then determining the distance point corresponding to the maximum value as the discharge fault point.

[0081] The first and second preset thresholds can be set by the user, obtained through a limited number of experiments, or obtained through a limited number of computer simulations; no specific limitations are made here.

[0082] Specifically, such as Figure 4 As shown, in this embodiment of the invention, two sets of pulsed probe lights, PS1 and PS2, with different frequency shifts are generated by two acousto-optic modulators and injected into sensing optical fibers laid outside the GIL, respectively. Rayleigh scattering signals are generated within the sensing optical fibers. After mixing with the local oscillator light, a first beat frequency signal and a second beat frequency signal are generated, denoted as follows: U b1 and U b2 Data was collected using a data acquisition card. U b1 and U b2 After the voltage signal, a bandpass filter is used to filter the frequency Δ f 1 First beat frequency signal U b1 and frequency Δ f 2 Second beat frequency signal U b2 Separate the two sets of beat frequency signals, demodulate their phase information, and transform them by distance-time-phase transformation to form two sets of distance-time-phase matrices, denoted as the first phase matrix A1 and the second phase matrix A2, respectively.

[0083] Furthermore, in some embodiments, a reconstruction strategy is determined based on the difference in phase standard deviation between corresponding positions and a first preset threshold, and a reconstructed phase matrix is ​​obtained based on the reconstruction strategy, including: determining whether the difference in phase standard deviation between corresponding positions is greater than or equal to the first preset threshold; if the difference in phase standard deviation between corresponding positions is greater than or equal to the first preset threshold, then the phase signal corresponding to the pulse sequence with small variance is selected for linear interpolation, and the pulse sequence after linear interpolation is filled into the data points of another pulse sequence to obtain the reconstructed phase matrix.

[0084] Specifically, in combination Figure 4 As shown, the system performs group similarity analysis on the first phase matrix A1 and the second phase matrix A2, and calculates the difference Δ between the phase standard deviations of their corresponding positions. S This is used to determine whether there is fading noise caused by coherent fading in the two sets of signals.

[0085] If | ΔS |Greater than or equal to the first preset threshold T If 1 is an error, then coherent fading is considered to have occurred at that location, and fading noise exists in both signal sets. Therefore, the phase signal corresponding to the pulse sequence with the smaller variance is selected at that location, and linear interpolation is performed to fill in the data points of the other pulse sequence, forming the reconstructed distance-time-phase matrix A. The phase array of A is traversed at all distance points, its phase standard deviation S is calculated, and the maximum standard deviation is selected. S max ,like S max Exceeding the set second threshold T 2. If the location is determined to be a discharge fault point, as shown in the attached diagram. Figure 5 As shown.

[0086] Optionally, in some embodiments, after determining whether the difference in phase standard deviation between corresponding positions is greater than or equal to a first preset threshold, the method includes: if the difference in phase standard deviation between corresponding positions is less than the first preset threshold, then the phases in the first phase matrix and the second phase matrix are interleaved and spliced ​​in time sequence to obtain the reconstructed phase matrix.

[0087] Specifically, in combination Figure 4 As shown, if | ΔS | Less than the first preset threshold T If 1, it is considered that both sets of signals have correctly acquired the disturbance information at this location, and no coherent fading has occurred at this location. Then, the two sets of vectors are cross-stitched according to the time sequence.

[0088] Optionally, in some embodiments, after determining whether the maximum value is greater than the second preset threshold, the method includes: if the maximum value is less than or equal to the second preset threshold, then determining that no discharge fault has occurred.

[0089] Specifically, if S max Not exceeding the second preset threshold T If 2, then it is determined that no discharge fault has occurred.

[0090] Therefore, this embodiment of the invention is based on distributed fiber optic acoustic sensing technology, and achieves accurate location of discharge faults by demodulating the phase of the Rayleigh scattering signal generated by two frequencies of probe light in the optical fiber and the beat frequency signal of the local oscillator light.

[0091] It should be noted that the foregoing explanation of the discharge fault location system embodiment also applies to the discharge fault location method of this embodiment, and will not be repeated here.

[0092] The discharge fault location method proposed in this embodiment of the invention involves separating a voltage signal to obtain a first beat frequency signal and a second beat frequency signal, demodulating the first and second beat frequency signals to obtain first and second phase information, performing a distance-time-phase transformation on the first and second phase information to obtain a first phase matrix and a second phase matrix, performing similarity analysis on the first and second phase matrices to obtain the difference in phase standard deviation between corresponding positions, determining a reconstruction strategy based on the difference in phase standard deviation between corresponding positions and a first preset threshold, obtaining a reconstructed phase matrix based on the reconstruction strategy, traversing the phase arrays of the reconstructed phase matrix at all distance points, calculating the phase standard deviation of each phase array, selecting the maximum value among all phase standard deviations, and determining whether the maximum value is greater than a second preset threshold. If the maximum value is greater than the second preset threshold, the distance point corresponding to the maximum value is determined as the discharge fault point. This solves the problems of high cost, low reliability, and difficulty in achieving long-distance GIL discharge fault location technology. This invention can cover lengths of several kilometers, is easy to install, provides accurate positioning, and has high reliability.

[0093] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. The electronic device may include:

[0094] The memory 601, the processor 602, and the computer program stored on the memory 601 and capable of running on the processor 602.

[0095] When the processor 602 executes the program, it implements the discharge fault location method provided in the above embodiments.

[0096] Furthermore, electronic devices also include:

[0097] Communication interface 603 is used for communication between memory 601 and processor 602.

[0098] The memory 601 is used to store computer programs that can run on the processor 602.

[0099] The memory 601 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0100] If the memory 601, processor 602, and communication interface 603 are implemented independently, then the communication interface 603, memory 601, and processor 602 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0101] Optionally, in a specific implementation, if the memory 601, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.

[0102] Processor 602 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention.

[0103] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described discharge fault location method.

[0104] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions 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 one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0105] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0106] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0107] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0108] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0109] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A discharge fault location system, characterized in that, include: A laser, used to emit laser light; A first acousto-optic modulator is used to modulate the laser to obtain a first pulse sequence; Delayed optical fiber, used to obtain a delayed pulse sequence from a portion of the first pulse sequence; The second acousto-optic modulator is used to modulate the remaining pulse sequence in the first pulse sequence to obtain the second pulse sequence; An optical amplifier is used to amplify the converged pulse sequence generated by the delayed pulse sequence and the second pulse sequence, and then inject the amplified pulse sequence into the sensing fiber through a circulator to obtain the target signal, wherein the sensing fiber is disposed on the outer surface of the GIL pipe to be detected. A balanced photodetector is used to convert the target signal output from the circulator into a voltage signal. The data acquisition card is used to acquire the voltage signal and locate the discharge fault based on the voltage signal. Two sets of pulsed probe beams, PS1 and PS2, with different frequency shifts are generated by two acousto-optic modulators and injected into the sensing optical fiber laid outside the GIL, respectively. Rayleigh scattering signals are generated within the sensing fiber. After mixing with the local oscillator light, a first beat frequency signal and a second beat frequency signal are generated, denoted as . U b1 and U b2 Data was collected using a data acquisition card. U b1 and U b2 After the voltage signal, a bandpass filter is used to filter the frequency Δ f 1 First beat frequency signal U b1 and frequency Δ f 2 Second beat frequency signal U b2 Separate the two sets of beat frequency signals, demodulate their phase information, and transform them by distance-time-phase transformation to form two sets of distance-time-phase matrices, denoted as the first phase matrix A1 and the second phase matrix A2, respectively.

2. The discharge fault location system according to claim 1, characterized in that, Also includes: A first optical coupler is disposed between the laser and the first acousto-optic modulator, the first optical coupler being used to couple the laser; A second optical coupler is provided, with one end connected to the first acousto-optic modulator and the other end connected to one end of the delay fiber and one end of the second acousto-optic modulator, respectively. The second optical coupler is used to couple the first pulse sequence. A third optical coupler, one end of which is connected to the other end of the delay fiber and the other end of the second acousto-optic modulator, and the other end of which is connected to the optical amplifier, is used to couple the delayed pulse sequence and the second pulse sequence to generate the converged pulse sequence; A fourth optical coupler, one end of which is connected to the circulator and the other end of which is connected to the balanced photodetector, is used to couple the target signal.

3. The discharge fault location system according to claim 2, characterized in that, The first end of the circulator is connected to the output end of the optical amplifier, the second end of the circulator is connected to the sensing optical fiber, and the third end of the circulator is connected to the fourth optical coupler.

4. A method for locating discharge faults, characterized in that, The discharge fault location system as described in any one of claims 1-3 is used, wherein the method includes the following steps: Emitting laser light through a laser; The laser is modulated by a first acousto-optic modulator to obtain a first pulse sequence; A delayed pulse sequence is obtained by using a delayed optical fiber to process a portion of the pulse sequence in the first pulse sequence; The second pulse sequence is obtained by modulating the remaining pulse sequence in the first pulse sequence using a second acousto-optic modulator. The target signal is obtained by amplifying the converged pulse sequence generated from the delayed pulse sequence and the second pulse sequence through an optical amplifier and then injecting it into the sensing fiber through a circulator. The sensing fiber is disposed on the outer surface of the GIL pipe to be detected. The target signal output from the circulator is converted into a voltage signal by a balanced photodetector. The voltage signal is acquired by a data acquisition card, and the discharge fault is located based on the voltage signal.

5. The discharge fault location method according to claim 4, characterized in that, The step of locating the discharge fault based on the voltage signal includes: The voltage signal is separated to obtain a first beat frequency signal and a second beat frequency signal; Phase demodulation is performed on the first beat frequency signal and the second beat frequency signal to obtain first phase information and second phase information, and distance-time-phase transformation is performed on the first phase information and the second phase information to obtain a first phase matrix and a second phase matrix; A similarity analysis is performed on the first phase matrix and the second phase matrix to obtain the difference in phase standard deviation between corresponding positions. A reconstruction strategy is determined based on the difference in phase standard deviation between corresponding positions and a first preset threshold, and the reconstructed phase matrix is ​​obtained based on the reconstruction strategy. Traverse the phase arrays of the reconstructed phase matrix at all distance points, calculate the phase standard deviation of each phase array, select the maximum value among all phase standard deviations, and determine whether the maximum value is greater than a second preset threshold. If the maximum value is greater than the second preset threshold, then the distance point corresponding to the maximum value is determined as the discharge fault point.

6. The discharge fault location method according to claim 5, characterized in that, The step of determining a reconstruction strategy based on the difference in phase standard deviations between corresponding positions and a first preset threshold, and obtaining the reconstructed phase matrix based on the reconstruction strategy, includes: Determine whether the difference in phase standard deviation between corresponding positions is greater than or equal to the first preset threshold; If the difference in phase standard deviation between corresponding positions is greater than or equal to the first preset threshold, then the phase signal corresponding to the pulse sequence with small variance is selected for linear interpolation, and the pulse sequence after linear interpolation is filled into the data points of another pulse sequence to obtain the reconstructed phase matrix.

7. The discharge fault location method according to claim 6, characterized in that, After determining whether the difference in phase standard deviation between corresponding positions is greater than or equal to the first preset threshold, the process includes: If the difference in the phase standard deviation between corresponding positions is less than the first preset threshold, then the phases in the first phase matrix and the second phase matrix are interleaved and spliced ​​in time sequence to obtain the reconstructed phase matrix.

8. The discharge fault location method according to claim 5, characterized in that, After determining whether the maximum value is greater than the second preset threshold, the process includes: If the maximum value is less than or equal to the second preset threshold, it is determined that no discharge fault has occurred.

9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the discharge fault location method as described in any one of claims 4-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor to implement the discharge fault location method as described in any one of claims 4-8.

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