A light guide column-based power equipment partial discharge detection positioning system and method

Abstract

The application discloses a kind of power equipment partial discharge detection positioning system and method based on light guide column, light guide module has one or three connecting flanges for connecting external power equipment, the middle part of each connecting flange and four areas in the orthogonal direction of the middle part are all provided with light guide column, each light guide column is used to induct the discharge light signal in its corresponding direction and output;Detection positioning module includes data acquisition unit and data processing unit, data acquisition unit is used to extract original characteristic quantity based on the discharge light signal of each light guide column for acquisition;Data processing unit is used to calculate the response intensity of each light guide column and the response total intensity of corresponding connecting flange according to original characteristic quantity.The application can realize the accurate detection of partial discharge, the judgment of discharge light signal's direction information and the accurate positioning of discharge area, to reduce deployment difficulty, improve detection efficiency.

Description

Technical Field

[0001] This invention relates to the field of power equipment discharge detection technology, and more specifically, to a power equipment partial discharge detection and positioning system and method based on a light guide column. Background Technology

[0002] In power systems, the insulation condition of electrical equipment such as oil-immersed transformers is directly related to the safe operation of the power grid. During long-term operation, electrical equipment is prone to partial discharge due to factors such as concentrated electric fields, insulation aging, moisture, or contamination by impurities. Furthermore, the internal structure of the equipment can obstruct the discharge light signal, making it difficult to accurately identify the discharge area in a timely manner. This makes it difficult to detect and resolve potential hazards in the power grid in a timely manner, increasing the risk of sudden insulation faults and large-scale power outages.

[0003] Currently, most existing technologies employ methods such as optical detection, which rely on single-point fiber optic probes, ordinary optical windows, or single-channel optical sensors to perform simple detection of the presence of discharge light signals. However, these methods struggle to obtain information about the direction of the discharge light, resulting in limited localization capabilities. While localization methods such as optical simulation can locate the discharge light, they rely on data acquisition from diverse sensors or the establishment of machine learning models for complex configurations of external power equipment. They also require high parameter consistency, leading to deployment difficulties and low detection efficiency.

[0004] Therefore, how to obtain the direction information of the discharge optical signal of external power equipment, accurately locate the discharge area, facilitate deployment, and effectively improve detection efficiency has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The present invention aims to overcome the problems of existing power equipment discharge light signal detection, such as difficulty in obtaining discharge light direction information, limited positioning capability, difficult deployment and low detection efficiency.

[0006] To achieve the above objectives, the present invention provides a partial discharge detection and positioning system and method for power equipment based on a light guide column.

[0007] According to a first aspect of the present invention, a partial discharge detection and positioning system for power equipment based on a light guide column is provided, comprising a light guide module and a detection and positioning module; The light guide module has one or three connecting flanges for connecting to external power equipment. Each connecting flange has a light guide column inserted in the middle and in four areas in the orthogonal position in the middle. Each light guide column is used to sense the discharge light signal in its corresponding direction and output it. The detection and positioning module includes a data acquisition unit and a data processing unit; The data acquisition unit is used to acquire and extract raw feature quantities based on the discharge optical signal of each light guide post; The data processing unit is used to calculate the response intensity of each light guide post and the total response intensity of the corresponding connecting flange based on the original feature quantities, so as to filter the corresponding connecting flanges with effective discharge light signals based on the preset intensity threshold, calculate the normalized direction vector and direction confidence of the corresponding connecting flange, and output the positioning parameters when there is only one connecting flange, or; When there are three connecting flanges, a direction indicator line is generated based on the two-dimensional coordinates and normalized direction vector of each connecting flange. Based on each direction indicator line, combined with the weighting coefficient generated by the total response intensity and direction confidence, the two-dimensional projection point coordinates of the effective discharge light signal are calculated. The two-dimensional projection point coordinates are weighted and located based on the intensity weight calculated by the difference in the total response intensity between each connecting flange, so as to output the two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. Based on positioning parameters or two-dimensional projection positioning coordinates, combined with the discharge type of the pre-acquired effective discharge light signal and the a priori set of internal structures of external power equipment, the detection and positioning results are output.

[0008] Optionally, a protective cover is provided on the side of the connecting flange with the optical fiber, one end of the protective cover is connected to a corrugated pipe, and one end of the optical fiber passes through the protective cover and the corrugated pipe in sequence and is connected to the detection and positioning module.

[0009] Optionally, the detection and positioning module further includes a photoelectric detection unit, which includes several photoelectric detectors electrically connected to the corresponding light guide column via optical fiber, in order to convert the discharge light signal into an electrical pulse signal.

[0010] Optionally, the data processing unit is used to process the original feature quantities. Calculate the response intensity of each light guide post. : In the formula: Represented as the first One connecting flange; Represented as the first The connecting flange contains a middle light guide, an upper light guide, a lower light guide, a left light guide, or a right light guide; Represented as dark noise or background baseline; This is expressed as the calibration coefficient of the light guide post; And based on the response intensity of each light guide column Calculate the total response strength of the corresponding connecting flange. : In the formula: , , , and These represent the response intensities of the middle, upper, lower, left, and right light guide pillars, respectively.

[0011] Optionally, the data processing unit further includes a power frequency phase extraction subunit, which calculates the power frequency phase corresponding to the electric pulse signal by obtaining the occurrence time of the electric pulse signal and combining the power frequency period and the power frequency phase conversion formula. A valid discharge light signal is determined to exist when the total response intensity of the corresponding connecting flange is not lower than a preset intensity threshold and the corresponding electrical pulse signal is in phase with the power frequency; otherwise, a valid discharge light signal does not exist.

[0012] Alternatively, the normalized direction vector can be calculated based on the left and right direction components. : and up and down direction vectors : Calculate the normalized direction vector : .

[0013] Alternatively, the direction confidence level The calculation is based on: .

[0014] Alternatively, the data processing unit can be based on the pre-acquired discharge type. and the a priori region set of the internal structure of external power equipment Output detection and positioning results : In the formula: This is represented as a positioning correction function.

[0015] Optionally, the direction indicator line is based on defining the connection surfaces of the external power equipment and the three connecting flanges as a two-dimensional monitoring plane, and obtaining the two-dimensional coordinates of the geometric center point of each connecting flange in the two-dimensional monitoring plane, combined with a normalized direction vector. To generate direction indicator lines : In the formula: It is represented as any point on the direction indicator line; This is represented by the two-dimensional coordinates of the m-th connecting flange in the two-dimensional monitoring plane; It is represented as a distance parameter along the direction indicator line.

[0016] Optionally, the two-dimensional projection point coordinates of the effective discharge optical signal are... The calculation is based on: In the formula: Represented as the direction indicator line from point P in the two-dimensional monitoring plane to the m-th direction indicator line. The distance; This represents the weighting coefficient for the m-th connecting flange participating in directional intersection positioning.

[0017] Optionally, the data processing unit calculates the intensity weight. : And based on intensity weight Calculate weighted positioning coordinates : .

[0018] Optionally, the data processing unit outputs two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. : In the formula: Represented as fusion weight, and .

[0019] Alternatively, the data processing unit can be based on the pre-acquired discharge type. and the a priori region set of the internal structure of external power equipment Output detection and positioning results : .

[0020] According to a second aspect of the present invention, a method for detecting and locating partial discharge in power equipment based on a light guide post is also provided, applied to a power equipment partial discharge detection and location system based on a light guide post as described in any of the above claims, the method comprising: Assemble a light guide module with one or three connecting flanges, and connect each connecting flange to an external power device; The light guide column, which passes through the middle of each connecting flange and is located in one of the four regions in the orthogonal orientation of the middle, senses the discharge light signal in the corresponding direction and outputs it. Collect and extract raw feature quantities based on the discharge optical signal of each light guide post; The response intensity of each light guide post and the total response intensity of the corresponding connecting flange are calculated based on the original feature values. The corresponding connecting flanges with effective discharge light signals are screened based on a preset intensity threshold. The normalized direction vector and direction confidence of the corresponding connecting flange are calculated. The positioning parameters are output when there is only one connecting flange. When there are three connecting flanges, a direction indicator line is generated based on the two-dimensional coordinates and normalized direction vector of each connecting flange. Based on each direction indicator line, combined with the weighting coefficient generated by the total response intensity and direction confidence, the two-dimensional projection point coordinates of the effective discharge light signal are calculated. The two-dimensional projection point coordinates are weighted and located based on the intensity weight calculated by the difference in the total response intensity between each connecting flange, so as to output the two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. Based on the positioning parameters or two-dimensional projection positioning coordinates, combined with the discharge type of the pre-acquired effective discharge light signal and the prior area set of the internal structure of the external power equipment, the detection and positioning results are output.

[0021] Compared with the prior art, the present invention has the following beneficial effects: This invention proposes a partial discharge detection and positioning system for power equipment based on light guide columns. By inserting light guide columns in the center of each connecting flange and in four orthogonal regions at the center, it senses and outputs discharge light signals in the corresponding directions, directly acquiring the direction information of the partial discharge light. Then, a data processing unit calculates the response intensity, normalized direction vector, and direction confidence based on the original feature quantities, outputting positioning parameters for a single connecting flange scenario, achieving coarse directional positioning of partial discharge under a single connecting flange. Furthermore, by generating direction indicator lines based on two-dimensional coordinates and normalized direction vectors in three connecting flange scenarios, and combining weighted coefficients to calculate the coordinates of two-dimensional projection points, a weighted positioning system is output for accurate two-dimensional projection positioning of partial discharge. Finally, by combining pre-acquired discharge types and a priori sets of internal structural regions of the external power equipment, the detection and positioning results are output, achieving accurate detection of partial discharge, determination of the direction information of the discharge light signal, and accurate positioning of the discharge area, thereby reducing deployment difficulty and improving detection efficiency.

[0022] The partial discharge detection and location method for power equipment based on light guide pillars proposed in this invention belongs to the same general inventive concept as the partial discharge detection and location system for power equipment based on light guide pillars of this invention. It should at least have the same technical effects as the partial discharge detection and location system for power equipment based on light guide pillars. Therefore, this invention will not elaborate further here.

[0023] As can be seen from the above, the technical solution of the present invention can effectively solve the problems of existing power equipment discharge light signal detection, which is difficult to obtain the direction information of discharge light, has limited positioning capability, is difficult to deploy and has low detection efficiency.

[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a partial discharge detection and positioning system for power equipment based on a light guide post, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a power equipment partial discharge detection and positioning system based on a light guide post, according to an embodiment of the present invention. Figure 3 This is an exploded perspective view of the light guide module according to an embodiment of the present invention; Figure 4 This is a schematic flowchart of a partial discharge detection and location method for power equipment based on a light guide post, according to an embodiment of the present invention.

[0026] Figure label: 1-External power equipment; 2-Connecting flange; 201-Mounting hole; 202-Through hole; 3-Flange bolts; 4-Middle light guide column; 5- Upper light guide column; 6-Lower light guide column; 7-Left light guide column; 8-Right light guide column; 9-SMA type fiber optic interface; 10-Fiber Optic; 11-Protective cover; 12-Corrugated pipe; 13-Shell. Detailed Implementation

[0027] To enable those skilled in the art to more fully understand the technical solutions of the present invention, exemplary embodiments of the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings. Obviously, the one or more embodiments of the present invention described below are merely one or more specific ways to implement the technical solutions of the present invention, and are not exhaustive. It should be understood that other ways belonging to a general inventive concept can be used to implement the technical solutions of the present invention, and should not be limited to the embodiments described exemplary. Based on one or more embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] Reference Figures 1-3 The present invention provides a partial discharge detection and positioning system for power equipment based on a light guide column, including a light guide module and a detection and positioning module; The light guide module has one or three connecting flanges 2 for connecting external power equipment 1. Each connecting flange 2 has a light guide column in the middle and four areas in the orthogonal position in the middle. Each light guide column is used to sense the discharge light signal in its corresponding direction and output it. The detection and positioning module includes a data acquisition unit and a data processing unit; The data acquisition unit is used to acquire and extract raw feature quantities based on the discharge optical signal of each light guide post; The data processing unit is used to calculate the response intensity of each light guide post and the total response intensity of the corresponding connecting flange 2 based on the original feature quantities, so as to filter the corresponding connecting flange 2 with effective discharge light signals based on the preset intensity threshold, calculate the normalized direction vector and direction confidence of the corresponding connecting flange 2, and output the positioning parameters when there is only one connecting flange 2, or; When there are three connecting flanges 2, a direction indicator line is generated based on the two-dimensional coordinates and normalized direction vector of each connecting flange 2. Based on each direction indicator line, combined with the weighting coefficient generated by the total response intensity and direction confidence, the two-dimensional projection point coordinates of the effective discharge light signal are calculated. The two-dimensional projection point coordinates are weighted and located based on the intensity weight calculated based on the difference in the total response intensity between each connecting flange 2, so as to output the two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. Based on positioning parameters or two-dimensional projection positioning coordinates, combined with the discharge type of the pre-acquired effective discharge light signal and the a priori set of internal structures of external power equipment, the detection and positioning results are output.

[0029] This invention proposes a partial discharge detection and positioning system for power equipment based on light guide columns. By inserting light guide columns in the center of each connecting flange and in four orthogonal regions at the center, it senses and outputs discharge light signals in the corresponding directions, directly acquiring the direction information of the partial discharge light. Then, a data processing unit calculates the response intensity, normalized direction vector, and direction confidence based on the original feature quantities, outputting positioning parameters for a single connecting flange scenario, achieving coarse directional positioning of partial discharge under a single connecting flange. Furthermore, by generating direction indicator lines based on two-dimensional coordinates and normalized direction vectors in three connecting flange scenarios, and combining weighted coefficients to calculate the coordinates of two-dimensional projection points, a weighted positioning system is output for accurate two-dimensional projection positioning of partial discharge. Finally, by combining pre-acquired discharge types and a priori sets of internal structural regions of the external power equipment, the detection and positioning results are output, achieving accurate detection of partial discharge, determination of the direction information of the discharge light signal, and accurate positioning of the discharge area, thereby reducing deployment difficulty and improving detection efficiency.

[0030] Figure 2 This is a schematic diagram of the structure of a power equipment partial discharge detection and positioning system based on a light guide post, according to an embodiment of the present invention. Figure 3 An exploded perspective view of the light guide module according to an embodiment of the present invention, as shown below. Figure 2 and 3 As shown: In one embodiment, each connecting flange 2 is provided with a plurality of mounting holes 201, and each light guide post is inserted into each mounting hole 201 in a corresponding manner.

[0031] In one embodiment, each connecting flange 2 has a plurality of through holes 202 along its periphery, and each through hole 202 is provided with flange bolts 3 for connecting external electrical equipment 1.

[0032] Specifically, the light guide column in the middle of each connecting flange is the middle light guide column 4, and the light guide columns in the four regions in the orthogonal position in the middle are the upper light guide column 5, the lower light guide column 6, the left light guide column 7, and the right light guide column 8.

[0033] The mounting hole 201 enables precise positioning and installation of the middle light guide post 4 with the upper light guide post 5, lower light guide post 6, left light guide post 7, and right light guide post 8, ensuring that the orientation of the light guide posts is perfectly matched with the preset direction. This ensures that partial discharge light signals incident from different directions can be efficiently sensed by the corresponding light guide posts, providing a reliable hardware foundation for subsequent light direction judgment and positioning.

[0034] Meanwhile, the through holes 202 on the two sides of the connecting flange, together with the flange bolts 3, enable a stable mechanical connection between the light guide module and the external power equipment. This allows for flexible deployment of one or three connecting flanges depending on the size of the external power equipment, improving the system's engineering applicability and ease of installation.

[0035] In addition, the external power equipment is an oil-immersed transformer.

[0036] In one embodiment, the middle light guide post 4, the upper light guide post 5, the lower light guide post 6, the left light guide post 7, and the right light guide post 8 each have a light receiving end and a light emitting end. The light receiving end is used to sense the discharge optical signal, and the light receiving end is connected to an SMA type optical fiber interface 9. One end of the SMA type optical fiber interface 9 is connected to an optical fiber 10.

[0037] In one specific embodiment, the cross-section of the light-receiving end of the middle light guide post 4 is a plane, and the cross-sections of the light-receiving ends of the upper light guide post 5, lower light guide post 6, left light guide post 7 and right light guide post 8 are all inclined planes.

[0038] Specifically, the planar structure of the light-receiving end of the middle light guide post 4 can efficiently receive partial discharge light signals incident from directly in front, ensuring the sensitivity of the signal acquisition from directly in front; the inclined structure of the light-receiving ends of the upper light guide post 5, lower light guide post 6, left light guide post 7 and right light guide post 8 can enhance the response intensity of incident light in the corresponding direction, so that partial discharge light signals in different directions produce differentiated responses in the corresponding light guide posts, thereby enabling a single light guide module to have the ability to sense the direction of light, providing a reliable hardware foundation for subsequent directional detection and positioning of partial discharge by the difference in response intensity between the light guide posts.

[0039] It is worth noting that the middle light guide post 4, upper light guide post 5, lower light guide post 6, left light guide post 7, and right light guide post 8 are all made of high-transparency mineral glass, and their sidewalls are provided with reflective films to reduce lateral leakage of the discharge light signal during the light guiding process. The reflective film can be made of aluminum film, silver film, dielectric high-reflection film, metal-dielectric composite reflective film, or aluminum-based reflective film with a protective layer. Preferably, it is an aluminum-based reflective film with a protective layer, that is, an oil-resistant protective layer is coated on the surface of the aluminum base. The oil-resistant protective layer can be formed of one or more inorganic materials selected from silicon dioxide, aluminum oxide, and magnesium fluoride, preferably silicon dioxide, to isolate direct contact between the aluminum reflective layer and materials such as transformer oil, thereby improving the stability of the reflective film in an oil-immersion environment, while taking into account reflection efficiency, oil resistance, and processing costs.

[0040] In addition, the middle light guide 4, the upper light guide 5, the lower light guide 6, the left light guide 7, and the right light guide 8 are divided into a main body and a rear end from the light receiving end to the light emitting end. The main body is cylindrical in shape and has a diameter of 15mm. The rear end is elliptical in shape with a tapering section and a length of 40mm. The diameter of the light emitting end is 2mm. The total length of each light guide is 100mm.

[0041] The main body is conducive to collecting weak optical signals generated by partial discharge from external power equipment. The tapered section at the rear end adopts a quasi-elliptical arc profile with slower contraction at the front and faster contraction at the rear. This can shorten the length of the narrow neck region while ensuring that the size of the light guide post's output end meets the requirements for fiber coupling, reducing mechanical fragility and improving the stability of the light guide module in the vibration environment of external power equipment. This ensures high light transmittance, reduces lateral leakage of discharge optical signals, lowers processing and deployment costs, and improves engineering applicability.

[0042] The elliptical arc tapering relationship at the rear end of each light guide post can be expressed as: In the formula: The starting point of the distance taper segment in the taper segment of the rear part is represented as... Diameter of the light guide post at that location; Indicates the diameter of the light-emitting end of the rear section; This refers to the diameter of the main body. It is represented as the length of the tapered segment, and .

[0043] From the above relationship, it can be seen that when hour, The diameter of the corresponding main body; when hour, This corresponds to the diameter of the light-emitting end of the rear section. Therefore, the elliptical arc tapering structure of the rear section allows each light guide post to maintain a large light-transmitting cross-section near the main body, and then rapidly contract to a small-diameter light-emitting end near the SMA-type fiber interface 9, thus achieving a good balance between discharge optical signal collection, fiber coupling, and mechanical strength.

[0044] In one embodiment, a protective cover 11 is provided on the side of the connecting flange 2 with the optical fiber 10. One end of the protective cover 11 is connected to a corrugated pipe 12, and one end of the optical fiber 10 passes through the protective cover 11 and the corrugated pipe 12 in sequence and is connected to the detection and positioning module.

[0045] Specifically, the protective cover 11 can cover and protect the SMA type fiber optic interface 9 outside the connecting flange 2, the light-emitting surface of the rear end of each light guide post, and the starting connection section of the fiber optic cable 10. At the same time, it works with the corrugated pipe 12 to provide centralized protection for the outgoing fiber optic cable 10. This can achieve mechanical protection, sealing protection, and vibration protection for the fiber optic cable 10 and the connection parts, preventing vibration, oil, dust, etc. during the operation of external power equipment from interfering with or damaging the transmission of the discharge optical signal, and ensuring the stability of the long-distance transmission of the partial discharge optical signal. In addition, the corrugated pipe 12 can guide the fiber optic cable 10 in a regular manner, making it easier to lead the fiber optic cable 10 to the detection and positioning module, thereby improving the system's installation convenience and engineering adaptability.

[0046] In one embodiment, the detection and positioning module further includes a housing 13, in which the data acquisition unit and the data processing unit are both disposed, to protect the data acquisition unit and the data processing unit, and to improve the convenience of the system and enable flexible deployment.

[0047] In one embodiment, the detection and positioning module further includes a photoelectric detection unit, which includes a plurality of photodetectors electrically connected to the corresponding light guide column via an optical fiber 10, so as to convert the discharge light signal into an electrical pulse signal.

[0048] Specifically, the photodetector can be a silicon photomultiplier detector array (SiPM), a photomultiplier tube (PMT), or an avalanche photodiode (APD).

[0049] By electrically connecting several photodetectors to corresponding light guide pillars via optical fiber 10, the precise conversion of partial discharge optical signals to electrical pulse signals is achieved, retaining the advantage of strong anti-electromagnetic interference capability of optical detection, and providing a stable electrical signal foundation for the data acquisition unit and data processing unit.

[0050] In one embodiment, the detection and positioning module further includes a signal conditioning circuit, which amplifies, filters, and performs baseline correction on the electrical pulse signal to obtain a standardized electrical pulse signal.

[0051] Specifically, the electrical pulse signal is standardized through a signal conditioning circuit to eliminate interference components and adjust the signal to a standardized form that meets the requirements of the data acquisition unit, providing a stable and accurate signal foundation for subsequent data acquisition and processing. The signal conditioning circuit consists of an amplifier, a filter, and a baseline correction circuit; its specific structure and operating principle are existing technologies and will not be elaborated upon further here.

[0052] In one specific embodiment, the data acquisition unit is configured to synchronously sample the electrical pulse signal output by each light guide post at the same time reference, and extract the pulse peak value, pulse integral energy or pulse count corresponding to each light guide post and define them as original feature quantities.

[0053] Specifically, the data acquisition unit can be a high-speed analog-to-digital converter (ADC). This invention is not limited thereto; any data acquisition unit capable of achieving the same technical effects as this invention is within the scope of protection of this invention.

[0054] The data acquisition unit can synchronously acquire the electrical pulse signals corresponding to each light guide column in the same time dimension under the same time reference. At the same time, it extracts the pulse peak value, pulse integral energy or pulse count as the original feature quantity from the acquired electrical pulse signals to ensure that the electrical pulse signals acquired by each light guide column are strictly aligned in time. This avoids the time difference affecting the calculation accuracy of the response intensity of subsequent light guide columns, thereby ensuring the accuracy of partial discharge direction determination.

[0055] In one specific embodiment, the data processing unit is used to process the original feature quantities. Calculate the response intensity of each light guide post. : In the formula: Represented as the first Two connecting flanges; Represented as the first The connecting flange contains a middle light guide post 4, an upper light guide post 5, a lower light guide post 6, a left light guide post 7, or a right light guide post 8; Represented as dark noise or background baseline; This is expressed as the calibration coefficient of the light guide post; And based on the response intensity of each light guide column Calculate the total response strength of the corresponding connecting flange 2. : In the formula: , , , and These represent the response intensities of the middle light guide post 4, the upper light guide post 5, the lower light guide post 6, the left light guide post 7, and the right light guide post 8, respectively.

[0056] Specifically, by calculating the response intensity of each light guide post, signal errors caused by differences in fiber length, SMA fiber interface coupling efficiency, and photodetector gain can be effectively eliminated, unifying the outputs of different light guide posts to a comparable response intensity scale and avoiding subsequent directional judgment deviations due to device differences.

[0057] Based on this, the total response intensity of the corresponding connecting flange 2 is further calculated, which can comprehensively reflect the overall partial discharge light intensity received by the corresponding connecting flange 2, and provide a quantitative basis for determining whether the corresponding connecting flange 2 has detected an effective discharge light signal within the current time window.

[0058] In addition, dark noise or background baseline is obtained by synchronous acquisition from the data acquisition unit.

[0059] In one specific embodiment, the data processing unit further includes a power frequency phase extraction subunit, which calculates the power frequency phase corresponding to the electric pulse signal by acquiring the occurrence time of the electric pulse signal and combining the power frequency period and the power frequency phase conversion formula. A valid discharge light signal is determined to exist when the total response intensity of the corresponding connecting flange 2 is not lower than the preset intensity threshold and the corresponding electrical pulse signal is in phase with the power frequency; otherwise, a valid discharge light signal does not exist.

[0060] Specifically, let the preset intensity threshold be... When the light guide module has only one connecting flange 2, the total response intensity of connecting flange 2 is... When the corresponding electrical pulse signal is in phase with the power frequency, it is determined that there is a valid discharge light signal. When the light guide module has three connecting flanges 2, then: In the formula: These represent the total response strength of the three connecting flanges 2, respectively. ; Furthermore, if the corresponding electrical pulse signal is in phase with the power frequency, it is determined that there is a valid discharge light signal.

[0061] in, It is set comprehensively based on the dark noise of the photodetector, the background light noise, the fiber transmission loss, and the background noise of the on-site operating environment.

[0062] In addition, combined with the power frequency cycle Using the power frequency phase conversion formula, calculate the power frequency phase corresponding to the electrical pulse signal. : In the formula: It represents the relative time of the occurrence of the electrical pulse signal within the current power frequency cycle.

[0063] The principle for determining whether the corresponding electrical pulse signal is consistent with the power frequency phase is as follows: Based on the power frequency phase corresponding to the electrical pulse signal, count the electrical pulses corresponding to each electrical pulse signal for each partial discharge. If the electrical pulses are concentrated in a specific phase interval of the power frequency cycle, and the repetition of the electrical pulses conforms to the periodic characteristics of partial discharge rather than a random distribution, then the electrical pulse signal is considered to be consistent with the power frequency phase.

[0064] As can be seen from the above, based on the dual judgment logic of preset intensity threshold and power frequency phase, it can eliminate meaningless low-intensity signal interference such as background light and dark noise of photodetector, and further filter out random electromagnetic interference signals that are not related to power frequency phase, thus greatly improving the accuracy of partial discharge optical signal detection.

[0065] In one specific embodiment, the data processing unit further includes a discharge type determination subunit. The discharge type determination subunit can extract the corresponding power frequency phase, light intensity amplitude and pulse count based on the electrical pulse corresponding to the effective discharge optical signal to generate an optical phase-resolved partial discharge pattern (PRPD) and extract the optical PRPD pattern feature vector to determine the discharge type.

[0066] Specifically, the corresponding power frequency phase, light intensity amplitude, and pulse count are extracted. An optical PRPD map is generated, and concentrated discharge regions are extracted. Integral energy of light intensity E and concentrated discharge phase distribution width The optical PRPD spectral feature vector is obtained. : In the formula: This is expressed as the maximum light intensity amplitude; It is expressed as the average light intensity amplitude.

[0067] Based on this, the extracted optical PRPD map feature vectors are matched with typical feature libraries for different types of partial discharges using support vector machines or random forest classification algorithms. This allows for accurate determination of specific discharge types such as surface discharge, suspended discharge, oil gap discharge, tip discharge, or particle discharge. The typical feature libraries for different types of partial discharges are constructed based on the structure and insulation system of external power equipment, a standard feature library in existing technologies, and will not be elaborated upon further here.

[0068] In one specific embodiment, the calculation of the normalized direction vector is based on the left and right direction components. : and up and down direction vectors : Calculate the normalized direction vector : .

[0069] Specifically, since the light-receiving end of the middle light guide post 4 has a planar cross-section, it mainly receives light signals directly in front. The light-receiving ends of the upper light guide post 5, lower light guide post 6, left light guide post 7, and right light guide post 8 have inclined planes facing the corresponding directions, which will produce differentiated responses to partial discharge light incident from different directions. Based on this, by dividing the response intensity difference between the right light guide post 8 and the left light guide post 7, and the response intensity difference between the upper light guide post 5 and the lower light guide post 6 by the total response intensity of the corresponding connecting flange 2, the normalized left-right direction component and the up-down direction component are obtained. Then, the left-right direction component and the up-down direction component are combined into a two-dimensional normalized direction vector, thereby quantifying the left-right and up-down offset directions of the effective discharge light signal relative to the connecting flange 2, realizing the conversion of the light intensity response of the five light guide posts into two-dimensional direction information.

[0070] Furthermore, if the left-right component is positive, it indicates that the effective discharge light signal is biased to the right relative to the corresponding connecting flange 2; if the left-right component is negative, it indicates that the effective discharge light signal is biased to the left relative to the corresponding connecting flange 2. If the up-down component is positive, it indicates that the effective discharge light signal is biased to the up relative to the corresponding connecting flange 2; if the up-down component is negative, it indicates that the effective discharge light signal is biased to the down relative to the corresponding connecting flange 2.

[0071] By calculating the normalized direction vector, the discrete light intensity data of each light guide post can be transformed into intuitive two-dimensional direction information. The direction of arrival of a single module can be determined without relying on complex models or external references, which greatly simplifies the detection process of the direction of arrival of partial discharge light.

[0072] Meanwhile, normalization can eliminate the influence of total light intensity on direction determination, ensuring that effective discharge light signals of different intensities can obtain stable and accurate directional offset quantization results, thereby effectively improving the positioning capability and reliability of partial discharge optical detection.

[0073] In one specific embodiment, the direction confidence The calculation is based on: Specifically, the larger the value of the direction confidence score, the more significant the response difference between the upper light guide 5, lower light guide 6, left light guide 7, and right light guide 8, and the clearer the direction offset feature of the effective discharge light signal. Conversely, if the value is smaller, it means that the response intensity of the five light guides is closer, and the effective discharge light signal may come from the front of the corresponding connecting flange 2, or be interfered with by factors such as oil scattering, structural obstruction, and multiple reflections, which weakens the response difference between the upper light guide 5, lower light guide 6, left light guide 7, and right light guide 8, and the direction feature is unclear.

[0074] Thus, the direction confidence can intuitively quantify the reliability of the direction judgment result when there is only one connecting flange 2, so as to output the positioning parameters based on the normalized direction vector and direction confidence corresponding to one connecting flange 2.

[0075] Alternatively, it can provide important weighting references for positioning when there are three connecting flanges 2: when the direction confidence value is high, it indicates that the normalized direction vector of the corresponding connecting flange 2 can accurately reflect the true direction of the effective discharge light signal, and can be given higher weight in the subsequent positioning of the three connecting flanges 2 to improve the overall positioning accuracy; when the direction confidence value is low, it can be identified that the reliability of the direction judgment result of the corresponding connecting flange 2 is insufficient, and the weight is reduced in the subsequent positioning to effectively avoid the influence of direction judgment error caused by interference factors such as oil scattering and structural obstruction on the positioning result. At the same time, it can also help determine whether the effective discharge light signal comes from the front of the corresponding connecting flange 2, providing supplementary information for the preliminary prediction of the discharge position.

[0076] In one specific embodiment, the direction indicator line is based on defining the connection surfaces between the external power equipment and the three connecting flanges 2 as a two-dimensional monitoring plane, and obtaining the two-dimensional coordinates of the geometric center point of each connecting flange 2 within the two-dimensional monitoring plane, combined with a normalized direction vector. To generate direction indicator lines : In the formula: It is represented as any point on the direction indicator line; This is represented by the two-dimensional coordinates of the m-th connecting flange 2 in the two-dimensional monitoring plane; It is represented as a distance parameter along the direction indicator line.

[0077] Specifically, this embodiment, based on the linear propagation characteristics of the effective discharge light signal and the directional sensing capability of each light guide post, first simplifies the connection surface between the external power equipment and the three connecting flanges into a two-dimensional monitoring plane for easy calculation. The actual two-dimensional coordinates of the geometric center point of each connecting flange 2 are recorded as a positioning reference. Then, combined with the normalized direction vector of each connecting flange 2, an extended direction indicator line is generated starting from the geometric center point of each connecting flange 2 along the direction of the normalized direction vector. These three direction indicator lines can simulate the direction of the effective discharge light signal sensed by each connecting flange 2.

[0078] This transforms the abstract normalized direction vector into an intuitive spatial direction indicator line, enabling the conversion of the direction information of a single connecting flange 2 into the spatial intersection clues of three connecting flanges 2. Moreover, it eliminates the need for complex 3D models or offline training, significantly reducing the complexity of positioning calculations simply through 2D plane simplification.

[0079] The installation of the three connecting flanges 2 can follow an equilateral triangle or an approximately equilateral triangle. This invention is not limited to this. As long as the two-dimensional coordinates of the geometric center points of the three connecting flanges 2 can be recorded during actual installation, it can be adapted to external power equipment of different sizes, effectively improving the engineering adaptability and calculation efficiency of partial discharge optical positioning.

[0080] In one specific embodiment, the coordinates of the two-dimensional projection point of the effective discharge optical signal The calculation is based on: In the formula: Represented as the direction indicator line from point P in the two-dimensional monitoring plane to the m-th direction indicator line. The distance; It represents the weighting coefficient for the m-th connecting flange 2 participating in the directional intersection positioning.

[0081] Specifically, the three connecting flanges 2 each generate three direction indicator lines. , and If the orientation of the three connecting flanges 2 is completely accurate, the three direction indicator lines should intersect near the projection position of the effective discharge light signal on the two-dimensional monitoring plane. However, due to the internal structure of external power equipment, such as the windings, insulating paperboard, iron core, clamps, and metal connectors inside an oil-immersed transformer, the effective discharge light signal may experience attenuation, scattering, reflection, and obstruction during propagation. Therefore, the three direction indicator lines usually do not strictly intersect at the same point in actual detection. To improve the stability of the positioning results, the two-dimensional projection point of the effective discharge light signal can be defined as the point that minimizes the combined distance to the three direction indicator lines.

[0082] Based on this, by obtaining the coordinates of the two-dimensional projection point of the effective discharge light signal, the interference of weak signals and low-confidence direction judgment on the positioning results can be reduced, thereby improving the accuracy of obtaining the two-dimensional projection positioning coordinates of the effective discharge light signal.

[0083] It is worth noting that the weighting coefficient for: In the formula: , and The directional confidence levels are for the three connecting flanges 2, respectively.

[0084] As can be seen from the above formula, if a certain connecting flange 2 has both a strong total response intensity and a high directional confidence, then its corresponding directional indicator line will contribute more to the detection and positioning results; if its light response is weak or its directional confidence is low, then the corresponding weight will decrease.

[0085] In one specific embodiment, the data processing unit calculates the intensity weight. : And based on intensity weight Calculate weighted positioning coordinates : In one specific embodiment, the data processing unit outputs two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. : In the formula: Represented as fusion weight, and .

[0086] The detection and localization results output by the embodiments of the present invention have the following two implementation methods: In one implementation, the data processing unit is based on the pre-acquired discharge type. and the a priori region set of the internal structure of external power equipment Output detection and positioning results : In the formula: This is represented as a positioning correction function.

[0087] Specifically, the output of the detection and positioning results can be used with a light guide module and a detection and positioning module that have only one connecting flange 2 to accurately locate the partial discharge area of ​​external power equipment. This allows for the identification of the validity of the partial discharge, the connecting flange with the highest total response intensity, the normalized direction vector, the direction confidence, the optical PRPD spectrum, and the discharge type. This provides quantitative data references for suggesting defect investigations of external power equipment and effectively ensures the safe operation of the power grid.

[0088] In another implementation, the data processing unit is based on the pre-acquired discharge type. and the a priori region set of the internal structure of external power equipment Output detection and positioning results : .

[0089] Specifically, the output of the detection and positioning results can utilize the light guide module with three connecting flanges 2 and the detection and positioning module to accurately locate the partial discharge area of ​​external power equipment, thereby clarifying the validity of the partial discharge, the connecting flange with the highest total response intensity, the normalized direction vector, the direction confidence, the optical PRPD spectrum, the two-dimensional projection positioning coordinates, and the discharge type. This enables the provision of quantitative data references for defect investigation suggestions for external power equipment, effectively ensuring the safe operation of the power grid.

[0090] In addition, the prior area set of the internal structure of external power equipment is obtained by collecting the design drawings, internal structural parameters and operation and maintenance records of the monitored external power equipment in advance, and summarizing and organizing them in combination with the common high-incidence areas of partial discharge defects.

[0091] Accordingly, refer to Figure 4 The embodiments of the present invention also provide a method for detecting and locating partial discharge in power equipment based on a light guide post, applicable to the power equipment partial discharge detection and location system based on a light guide post as described in any of the above embodiments. The method for detecting and locating partial discharge in power equipment includes: Step S1: Assemble the light guide module with one or three connecting flanges 2, and connect each connecting flange 2 to the external power equipment; Step S2: Based on the light guide columns inserted in the middle of each connecting flange 2 and in the four regions of the orthogonal orientation in the middle, sense the discharge light signal in the corresponding direction and output it; Step S3: Collect and extract the original feature quantities based on the discharge optical signal of each light guide post; Step S4: Calculate the response intensity of each light guide post and the total response intensity of the corresponding connecting flange 2 based on the original feature quantities, and filter the corresponding connecting flange 2 with effective discharge light signals based on the preset intensity threshold. Calculate the normalized direction vector and direction confidence of the corresponding connecting flange 2. Output the positioning parameters when there is only one connecting flange 2, or... When there are three connecting flanges 2, a direction indicator line is generated based on the two-dimensional coordinates and normalized direction vector of each connecting flange 2. Based on each direction indicator line, combined with the weighting coefficient generated by the total response intensity and direction confidence, the two-dimensional projection point coordinates of the effective discharge light signal are calculated. The two-dimensional projection point coordinates are weighted and located based on the intensity weight calculated based on the difference in the total response intensity between each connecting flange 2, so as to output the two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. Step S5: Based on the positioning parameters or two-dimensional projection positioning coordinates, combined with the discharge type of the pre-acquired effective discharge light signal and the prior area set of the internal structure of the external power equipment, output the detection and positioning results.

[0092] The partial discharge detection and location method for power equipment based on light guide pillars proposed in this invention belongs to the same general inventive concept as the partial discharge detection and location system for power equipment based on light guide pillars of this invention. It should at least have the same technical effects as the partial discharge detection and location system for power equipment based on light guide pillars. Therefore, this invention will not elaborate further here.

[0093] While one or more embodiments of the present invention have been described above, those skilled in the art will recognize that the present invention can be implemented in any other form without departing from its spirit and scope. Therefore, the embodiments described above are illustrative and not restrictive, and many modifications and substitutions will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A partial discharge detection and positioning system for power equipment based on a light guide column, characterized in that, Includes a light guide module and a detection and positioning module; The light guide module has one or three connecting flanges for connecting to external power equipment. Each connecting flange has a light guide column inserted in the middle and in four areas in the orthogonal position in the middle. Each light guide column is used to sense the discharge light signal in its corresponding direction and output it. The detection and positioning module includes a data acquisition unit and a data processing unit; The data acquisition unit is used to acquire and extract raw feature quantities based on the discharge optical signal of each light guide post; The data processing unit is used to calculate the response intensity of each light guide post and the total response intensity of the corresponding connecting flange based on the original feature quantities, so as to filter the corresponding connecting flanges with effective discharge light signals based on the preset intensity threshold, calculate the normalized direction vector and direction confidence of the corresponding connecting flange, and output the positioning parameters when there is only one connecting flange, or; When there are three connecting flanges, a direction indicator line is generated based on the two-dimensional coordinates and normalized direction vector of each connecting flange. Based on each direction indicator line, combined with the weighting coefficient generated by the total response intensity and direction confidence, the two-dimensional projection point coordinates of the effective discharge light signal are calculated. The two-dimensional projection point coordinates are weighted and located based on the intensity weight calculated by the difference in the total response intensity between each connecting flange, so as to output the two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. Based on positioning parameters or two-dimensional projection positioning coordinates, combined with the discharge type of the pre-acquired effective discharge light signal and the a priori set of internal structures of external power equipment, the detection and positioning results are output.

2. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 1, characterized in that, A protective cover is provided on the side of the connecting flange with the optical fiber. One end of the protective cover is connected to a corrugated pipe, and one end of the optical fiber passes through the protective cover and the corrugated pipe in sequence and is connected to the detection and positioning module.

3. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 2, characterized in that, The detection and positioning module further includes a photoelectric detection unit, which includes several photoelectric detectors electrically connected to the corresponding light guide column via optical fiber to convert the discharge light signal into an electrical pulse signal.

4. The partial discharge detection and positioning system for power equipment based on a light guide column according to claim 3, characterized in that, The data processing unit is used to process the original feature values. Calculate the response intensity of each light guide post. : In the formula: Represented as the first One connecting flange; Represented as the first The connecting flange contains a middle light guide, an upper light guide, a lower light guide, a left light guide, or a right light guide; Represented as dark noise or background baseline; This is expressed as the calibration coefficient of the light guide post; And based on the response intensity of each light guide column Calculate the total response strength of the corresponding connecting flange. : In the formula: , , , and These represent the response intensities of the middle, upper, lower, left, and right light guide pillars, respectively.

5. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 4, characterized in that, The data processing unit further includes a power frequency phase extraction subunit, which calculates the power frequency phase corresponding to the electric pulse signal by obtaining the occurrence time of the electric pulse signal and combining the power frequency period and the power frequency phase conversion formula. A valid discharge light signal is determined to exist when the total response intensity of the corresponding connecting flange is not lower than a preset intensity threshold and the corresponding electrical pulse signal is in phase with the power frequency; otherwise, a valid discharge light signal does not exist.

6. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 5, characterized in that, The calculation of the normalized direction vector is based on the left and right direction components. : and up and down direction vectors : Calculate the normalized direction vector : 。 7. The partial discharge detection and positioning system for power equipment based on a light guide column according to claim 6, characterized in that, The direction confidence The calculation is based on: 。 8. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 7, characterized in that, The data processing unit is based on the pre-acquired discharge type. and the a priori region set of the internal structure of external power equipment Output detection and positioning results : In the formula: This is represented as a positioning correction function.

9. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 7, characterized in that, The direction indicator line is based on defining the connection surfaces between the external power equipment and the three connecting flanges as a two-dimensional monitoring plane, and obtaining the two-dimensional coordinates of the geometric center point of each connecting flange within the two-dimensional monitoring plane, combined with a normalized direction vector. To generate direction indicator lines : In the formula: It is represented as any point on the direction indicator line; This is represented by the two-dimensional coordinates of the m-th connecting flange in the two-dimensional monitoring plane; It is represented as a distance parameter along the direction indicator line.

10. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 9, characterized in that, The two-dimensional projection point coordinates of the effective discharge light signal The calculation is based on: In the formula: Represented as the direction indicator line from point P in the two-dimensional monitoring plane to the m-th direction indicator line. The distance; This represents the weighting coefficient for the m-th connecting flange participating in directional intersection positioning.

11. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 10, characterized in that, The data processing unit calculates the intensity weight. : And based on intensity weight Calculate weighted positioning coordinates : 。 12. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 11, characterized in that, The data processing unit outputs two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. : In the formula: Represented as fusion weight, and .

13. The power equipment partial discharge detection and positioning system based on a light guide column according to claim 12, characterized in that, The data processing unit is based on the pre-acquired discharge type. and the a priori region set of the internal structure of external power equipment Output detection and positioning results : 。 14. A method for detecting and locating partial discharge in power equipment based on a light guide post, characterized in that, Applied to the partial discharge detection and positioning system for power equipment based on a light guide post as described in claim 1, the partial discharge detection and positioning method for power equipment includes: Assemble a light guide module with one or three connecting flanges, and connect each connecting flange to an external power device; The light guide column, which passes through the middle of each connecting flange and is located in one of the four regions in the orthogonal orientation of the middle, senses the discharge light signal in the corresponding direction and outputs it. Collect and extract raw feature quantities based on the discharge optical signal of each light guide post; The response intensity of each light guide post and the total response intensity of the corresponding connecting flange are calculated based on the original feature values. The corresponding connecting flanges with effective discharge light signals are screened based on a preset intensity threshold. The normalized direction vector and direction confidence of the corresponding connecting flange are calculated. The positioning parameters are output when there is only one connecting flange. When there are three connecting flanges, a direction indicator line is generated based on the two-dimensional coordinates and normalized direction vector of each connecting flange. Based on each direction indicator line, combined with the weighting coefficient generated by the total response intensity and direction confidence, the two-dimensional projection point coordinates of the effective discharge light signal are calculated. The two-dimensional projection point coordinates are weighted and located based on the intensity weight calculated by the difference in the total response intensity between each connecting flange, so as to output the two-dimensional projection positioning coordinates based on the two-dimensional projection point coordinates and the weighted positioning coordinates. Based on the positioning parameters or two-dimensional projection positioning coordinates, combined with the discharge type of the pre-acquired effective discharge light signal and the prior area set of the internal structure of the external power equipment, the detection and positioning results are output.

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