Partial discharge location method and system

Abstract

The present invention discloses a local discharge positioning method and system, and relates to the technical field of local discharge monitoring. The method includes: generating local discharge signals of different local discharge types, and establishing a local discharge type identification model; determining the positioning accuracy of ultra-high frequency sensors and ultrasonic sensors for different local discharge types; when a local discharge phenomenon occurs in the equipment to be monitored, positioning is performed by ultra-high frequency sensors and ultrasonic sensors respectively, and a first positioning result and a second positioning result are obtained; when the deviation between the first positioning result and the second positioning result exceeds a preset range, a joint positioning is performed by ultra-high frequency sensors and ultrasonic sensors to obtain a third positioning result; according to the first positioning result, the second positioning result and the third positioning result, the positioning position is determined; and the local discharge signal strength of the positioning position is determined by a Rogowski coil. According to the method of the embodiment of the present invention, the local discharge phenomenon can be accurately identified and accurately positioned.

Description

Technical Field

[0001] The present invention relates to the technical field of partial discharge monitoring, and in particular to a partial discharge positioning method and system. Background Art

[0002] In many electrical equipment, such as transformer equipment, GIS equipment, and distribution cabinets, partial discharge often occurs, causing insulation defects in the equipment. The destructive effect of partial discharge on insulation usually manifests as a slow development process, with the insulation failure area growing from small to large, from local to overall, and eventually developing into a through breakdown or surface flashover, or a rapidly evolving sudden failure. Therefore, rapid and timely detection of partial discharge can effectively eliminate insulation defects, thereby improving the stability of power grid operation and avoiding power grid accidents. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a partial discharge location method and system, which can accurately identify the location and intensity of partial discharge phenomena.

[0004] In a first aspect, a partial discharge location method according to an embodiment of the present invention is applied to a monitoring system, wherein the monitoring system is electrically connected to a device to be monitored, a plurality of ultra-high frequency sensors are arranged outside the device to be monitored, and a plurality of ultrasonic sensors and a plurality of Rogowski coils are arranged inside the device to be monitored; the method comprises:

[0005] Using a simulated discharge source, generating partial discharge signals of different partial discharge types at different locations inside the device to be monitored;

[0006] Establishing a partial discharge type identification model according to characteristic values ​​of the partial discharge signals of different partial discharge types;

[0007] Determining the positioning accuracy of the UHF sensor and the ultrasonic sensor for different types of partial discharges;

[0008] When a partial discharge phenomenon occurs in the device to be monitored, corresponding partial discharge signals are obtained by the ultra-high frequency sensor and the ultrasonic sensor respectively, and the partial discharge position of the device to be monitored is located by the ultra-high frequency sensor and the ultrasonic sensor respectively, to obtain a first positioning result and a second positioning result;

[0009] When the deviation between the first positioning result and the second positioning result exceeds a preset range, the partial discharge type of the partial discharge signal is identified by the partial discharge type identification model, and according to the partial discharge type and the positioning accuracy, the partial discharge position is jointly located by the ultra-high frequency sensor and the ultrasonic sensor to obtain a third positioning result;

[0010] Determine a positioning position according to the first positioning result, the second positioning result and the third positioning result;

[0011] The PD signal strength at the positioning position is determined by the Rogowski coil.

[0012] According to some embodiments of the present invention, the step of establishing a partial discharge type identification model according to the characteristic values ​​of the partial discharge signals of different partial discharge types includes:

[0013] Performing time-frequency analysis on the partial discharge signals of different partial discharge types to obtain time-frequency characteristic values ​​of the partial discharge signals of different partial discharge types;

[0014] A sample set and a test set are constructed according to all the extracted time-frequency feature values, and a neural network model is trained by using the sample set and the test set to form the partial discharge type recognition model.

[0015] According to some embodiments of the present invention, the step of determining a positioning position according to the first positioning result, the second positioning result and the third positioning result includes:

[0016] When a deviation between the first positioning result and the second positioning result is within the preset range, identifying the partial discharge type of the partial discharge signal by using the partial discharge type identification model;

[0017] Determining, according to the partial discharge type and the positioning accuracy, the first positioning result or the second positioning result as the positioning position;

[0018] When the deviation between the first positioning result and the second positioning result exceeds the preset range, the third positioning result is determined as the positioning position.

[0019] According to some embodiments of the present invention, when the deviation between the first positioning result and the second positioning result exceeds a preset value, identifying the partial discharge type of the partial discharge signal by the partial discharge type identification model, and jointly locating the partial discharge position by the ultra-high frequency sensor and the ultrasonic sensor according to the partial discharge type and the positioning accuracy to obtain a third positioning result, the step includes:

[0020] The partial discharge type identification model identifies the partial discharge type according to the characteristic value of the partial discharge signal;

[0021] According to the positioning accuracy of the UHF sensor and the ultrasonic sensor for the partial discharge type, selecting one of the first positioning result and the second positioning result as a reference position and the other as a calibration position;

[0022] Acquire a distance difference between the reference position and the calibration position, and determine a moving distance according to the distance difference;

[0023] The reference position is moved by the moving distance in a direction toward the calibration position to obtain the third positioning result.

[0024] According to some embodiments of the present invention, when a partial discharge phenomenon occurs in the device to be monitored, the steps of respectively acquiring corresponding partial discharge signals by the ultra-high frequency sensor and the ultrasonic sensor, and respectively locating the partial discharge position of the device to be monitored by the ultra-high frequency sensor and the ultrasonic sensor to obtain a first positioning result and a second positioning result include:

[0025] When partial discharge occurs in the device to be monitored, a first partial discharge signal is obtained by the ultra-high frequency sensor, and a second partial discharge signal is obtained by the ultrasonic sensor;

[0026] selecting at least three of the UHF sensors as first positioning sensors according to the first characteristic data of the first partial discharge signal;

[0027] Locating the local position of the device to be monitored by using the first positioning sensor to obtain a first positioning result;

[0028] selecting at least three of the ultrasonic sensors as second positioning sensors according to the second characteristic data of the second partial discharge signal;

[0029] The local position of the device to be monitored is located by the second positioning sensor to obtain a second positioning result.

[0030] According to some embodiments of the present invention, the step of selecting at least three of the UHF sensors as first positioning sensors according to the first characteristic data of the first partial discharge signal includes:

[0031] Extracting first characteristic data of the first partial discharge signal received by all the UHF sensors; the first characteristic data includes the amplitude, frequency and receiving time of the first partial discharge signal;

[0032] The amplitude of each of the first partial discharge signals is compared, at least three of the UHF sensors are selected as first positioning sensors according to the comparison result, and the reception time when each of the first positioning sensors receives the first partial discharge signal is recorded.

[0033] According to some embodiments of the present invention, the number of the first positioning sensors is three; the step of locating the local position of the device to be monitored by using the first positioning sensor to obtain a first positioning result includes:

[0034] Acquire a first time difference between the receiving time of a first first positioning sensor and a second first positioning sensor;

[0035] Determine a first distance between the partial discharge position and the first first positioning sensor according to an axial distance between the first first positioning sensor and the second first positioning sensor, the first time difference, and a transmission rate of the first partial discharge signal;

[0036] Acquire a second time difference between the receiving time of the second first positioning sensor and the receiving time of the third first positioning sensor;

[0037] Determine a second distance between the partial discharge position and the second first positioning sensor according to the axial distance between the second first positioning sensor and the third first positioning sensor, the second time difference, and the transmission rate of the first partial discharge signal;

[0038] Acquire a third time difference between the receiving time of a third first positioning sensor and the first first positioning sensor;

[0039] Determine a third distance between the partial discharge position and the third first positioning sensor according to the axial distance between the third first positioning sensor and the first first positioning sensor, the third time difference, and the transmission rate of the first partial discharge signal;

[0040] The first positioning result is determined according to the first distance, the second distance and the third distance.

[0041] According to some embodiments of the present invention, the UHF sensor is electrically connected to the monitoring system via a first data acquisition unit, and the first data acquisition unit includes: an operational amplifier, a bandpass filter, and a noise processor;

[0042] After the step of respectively acquiring corresponding partial discharge signals through the UHF sensor and the ultrasonic sensor when partial discharge occurs in the device to be monitored, the method further includes:

[0043] The first data acquisition unit amplifies the partial discharge signal received by the UHF sensor through the operational amplifier;

[0044] The amplified partial discharge signal is filtered through the bandpass filter;

[0045] The noise processor identifies the noise signal of the partial discharge signal, denoises the partial discharge signal, and sends it to the monitoring system.

[0046] According to some embodiments of the present invention, the partial discharge locating method further comprises the following steps:

[0047] The monitoring system establishes a three-dimensional display model according to the structure of the device to be monitored and the installation positions of the UHF sensor, the ultrasonic sensor and the Rogowski coil;

[0048] Defining the smallest circumscribed cuboid of the three-dimensional display model as a scene;

[0049] Taking a vertex of the scene as an origin, dividing the scene into a plurality of cubes at a preset resolution on the XYZ coordinate axes;

[0050] According to the serial number of the cube where any point of the scene is located, the coordinates of each point are quantized into digital coordinates, thereby forming a digital twin model;

[0051] The positioning position and the partial discharge signal strength are displayed on the digital twin model.

[0052] In a second aspect, a local discharge locating system according to an embodiment of the present invention comprises at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions executable by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the local discharge locating method described in the embodiment of the above aspect.

[0053] The partial discharge locating method and system according to the embodiments of the present invention have at least the following beneficial effects: placing an ultrasonic sensor inside the device to be monitored and placing an ultra-high frequency sensor outside, establishing a partial discharge type recognition model, and using the ultrasonic sensor and the ultra-high frequency sensor to jointly locate the partial discharge position, can improve the positioning accuracy, detect the partial discharge phenomenon in time, and accurately locate it, thereby ensuring the safe operation of the device to be monitored.

[0054] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0056] Figure 1 is a flow chart of the steps of a partial discharge locating method according to an embodiment of the present invention;

[0057] Figure 2 for Figure 1 Specific step flow chart of step S200;

[0058] Figure 3It is a flow chart of processing of partial discharge signals by the first data acquisition unit;

[0059] Figure 4 for Figure 1 Flow chart of step S500. DETAILED DESCRIPTION

[0060] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limitations on the present application. For the step numbers in the following embodiments, they are only provided for the convenience of explanation, and the order between the steps is not limited in any way, and the execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0061] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The terms "first", "second", "third" and "fourth" etc. in the specification and claims of the present invention and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0063] Reference to "embodiments" in the present invention means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0064] In many electrical equipment, such as transformer equipment, GIS equipment, and distribution cabinets, partial discharge often occurs, causing insulation defects in the equipment. The destructive effect of partial discharge on insulation usually manifests as a slow development process, with the insulation failure area growing from small to large, from local to overall, and eventually developing into a through breakdown or surface flashover, or a rapidly evolving sudden failure. Therefore, rapid and timely detection of partial discharge can effectively eliminate insulation defects, thereby improving the stability of power grid operation and avoiding power grid accidents.

[0065] To this end, an embodiment of the present invention provides a partial discharge positioning method and system, in which an ultrasonic sensor is placed inside the device to be monitored and an ultra-high frequency sensor is placed outside. By establishing a partial discharge type recognition model and using the ultrasonic sensor and the ultra-high frequency sensor to jointly locate the partial discharge position, the positioning accuracy can be improved, the partial discharge phenomenon can be detected in time, and the position can be accurately located, thereby ensuring the safe operation of the device to be monitored.

[0066] The partial discharge locating method and system according to the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0067] On the one hand, an embodiment of the present invention provides a partial discharge location method, which is applied to a monitoring system, wherein the monitoring system is electrically connected to a device to be monitored, a dielectric window is arranged outside the device to be monitored, each dielectric window is arranged with a UHF sensor, and a plurality of ultrasonic sensors and a plurality of Rogowski coils are arranged inside the device to be monitored. Figure 1 As shown, the partial discharge locating method according to the embodiment of the present invention comprises the following steps:

[0068] Step S100: using a simulated discharge source to generate partial discharge signals of different partial discharge types at different locations inside the device to be monitored;

[0069] Step S200: establishing a partial discharge type identification model according to characteristic values ​​of partial discharge signals of different partial discharge types;

[0070] Step S300: determining the positioning accuracy of the UHF sensor and the ultrasonic sensor for different types of partial discharge;

[0071] Step S400: when a partial discharge phenomenon occurs in the device to be monitored, a corresponding partial discharge signal is obtained by using a UHF sensor and an ultrasonic sensor respectively, and the partial discharge position of the device to be monitored is located by using the UHF sensor and the ultrasonic sensor respectively, to obtain a first positioning result and a second positioning result;

[0072] Step S500: when the deviation between the first positioning result and the second positioning result exceeds a preset range, the partial discharge type of the partial discharge signal is identified by the partial discharge type identification model, and the partial discharge position is jointly located by the UHF sensor and the ultrasonic sensor according to the partial discharge type and the positioning accuracy to obtain a third positioning result;

[0073] Step S600: determining a positioning position according to the first positioning result, the second positioning result and the third positioning result;

[0074] Step S700: Determine the PD signal strength at the positioning position by using the Rogowski coil.

[0075] It should be noted that there are many locations where partial discharge may occur inside the monitored equipment, such as breakdown of the oil channel in the oil-paper barrier insulation in the middle of the transformer winding, breakdown of the oil channel at the end of the winding, breakdown of the oil gap close to the insulated wire and electrical paper (lead insulation, lap insulation, phase insulation), breakdown of the longitudinal insulation oil channel between coils (between turns and between layers), resin discharge of insulating cardboard screens, surface discharge of solid insulation, discharge of other metal foreign matter infiltrated into the insulation, etc. Partial discharge occurring at different locations will produce partial discharge signals of different types, and the sensitivity of UHF sensors and ultrasonic sensors to different types of partial discharge signals is different, and the positioning accuracy is also different. In order to maximize the positioning accuracy, it is necessary to determine the type of partial discharge. To this end, in this example, a partial discharge type recognition model is established for UHF sensors and ultrasonic sensors to identify the partial discharge type corresponding to the partial discharge signal based on the characteristic value of the partial discharge signal. In order to establish a partial discharge type identification model, in this example, an avalanche transistor discharge signal generator is used as a partial discharge simulation discharge source to generate partial discharge signals of different partial discharge types at different locations inside the equipment to be monitored. Then, the partial discharge signals of different partial discharge types are received by ultra-high frequency sensors and ultrasonic sensors respectively. The characteristic values ​​of the partial discharge signals of different partial discharge types are extracted by the monitoring system, and a partial discharge type identification model is established based on the characteristic values.

[0076] Specifically, Figure 2 As shown, the above step S200: establishing a partial discharge type identification model according to the characteristic values ​​of partial discharge signals of different partial discharge types, includes the following two steps:

[0077] Step S210: performing time-frequency analysis on partial discharge signals of different partial discharge types to obtain time-frequency characteristic values ​​of partial discharge signals of different partial discharge types;

[0078] Step S220: constructing a sample set and a test set according to all the extracted time-frequency feature values, and training a neural network model through the sample set and the test set to form a partial discharge type recognition model.

[0079] When performing time-frequency analysis on partial discharge signals of different partial discharge types, the short-time Fourier transform method can be used to extract the frequency characteristics of the partial discharge signal, and the wavelet transform method can be used to extract the time domain characteristics of the partial discharge signal. The time-frequency characteristic values ​​of the partial discharge signal are formed by comprehensive analysis of the frequency domain characteristics and time domain characteristics of the partial discharge signal. Then, based on the extracted time-frequency characteristic values ​​of the partial discharge signals of different partial discharge types, a sample set and a test set are constructed, and the neural network model is trained through the sample set and the test set to form a partial discharge type recognition model, so that the partial discharge type recognition model can recognize the characteristic values ​​of the partial discharge signal based on the characteristic values ​​of the partial discharge signal.

[0080] In addition, by using a simulated discharge source as a local discharge source at each monitoring point inside the equipment to be monitored, after generating local discharge signals corresponding to different types of local discharge, the local discharge position can be located according to the local discharge signal by a UHF sensor and an ultrasonic sensor, and the positioning result can be compared with the actual discharge position of the simulated discharge source, so as to determine the positioning accuracy of the UHF sensor and the ultrasonic sensor for different types of local discharge.

[0081] When partial discharge actually occurs in the device to be monitored, a partial discharge signal will be generated. At this time, both the UHF sensor and the ultrasonic sensor can detect the partial discharge signal. It should be noted that the UHF sensor is set outside the device to be monitored and receives the signal inside the device to be monitored through the dielectric window. If the UHF sensor is directly set inside the device to be monitored, the UHF sensor will be in direct contact with the gas inside the device to be monitored, which may reduce the insulation inside the device to be monitored, thereby affecting the reliability of the operation of the device to be monitored, and the safety and reliability are poor. However, when the UHF sensor is set outside the device to be monitored, due to the existence of the dielectric window, the UHF sensor still has high sensitivity and high reliability, and is easy to install and more flexible, avoiding the placement of too many sensors inside the device to be monitored. The UHF sensor receives the partial discharge signal in the form of electromagnetic waves, that is, the first partial discharge signal; the ultrasonic sensor receives the partial discharge signal in the form of ultrasonic waves, that is, the second partial discharge signal.

[0082] It should be noted that, in some embodiments of the present invention, the UHF sensor is electrically connected to the monitoring system through the first data acquisition unit, and the ultrasonic sensor is electrically connected to the monitoring system through the second data acquisition unit. After the UHF sensor receives the first partial discharge signal, it is necessary to send the first partial discharge signal to the first data acquisition unit for amplification and denoising, so as to facilitate the monitoring system to receive and identify the first partial discharge signal. In this example, the first data acquisition unit includes: an operational amplifier, a bandpass filter and a noise processor, such as Figure 3As shown, the partial discharge locating method according to the embodiment of the present invention further includes the following steps:

[0083] Step S410: the first data acquisition unit amplifies the partial discharge signal received by the UHF sensor through an operational amplifier;

[0084] Step S420: filtering the amplified partial discharge signal through a bandpass filter;

[0085] Step S430: The noise processor identifies the noise signal of the partial discharge signal, denoises the partial discharge signal, and sends it to the monitoring system.

[0086] It should be noted that the principle of the second data acquisition unit is similar to that of the first data acquisition unit. After the ultrasonic sensor receives the second partial discharge signal, the second partial discharge signal needs to be sent to the second data acquisition unit for amplification and denoising, so as to facilitate the monitoring system to receive and identify the second partial discharge signal.

[0087] Since multiple UHF sensors are installed outside the device to be monitored, if the partial discharge position is located based on the detection results of all the UHF sensors, the data processing process is relatively complicated and takes a long time to process. In addition, the positioning effects of UHF sensors at different positions are different, which may result in the final positioning result being less accurate. If only the detection result of one of the UHF sensors is selected for positioning, the result may be inaccurate due to errors in the UHF sensor. To this end, in this example, step S400: when partial discharge occurs in the device to be monitored, the corresponding partial discharge signal is obtained by the UHF sensor and the ultrasonic sensor respectively, and the partial discharge position of the device to be monitored is located by the UHF sensor and the ultrasonic sensor respectively, to obtain a first positioning result and a second positioning result, including the following four steps:

[0088] (1) When partial discharge occurs in the equipment to be monitored, the first partial discharge signal is obtained through the UHF sensor, and the second partial discharge signal is obtained through the ultrasonic sensor;

[0089] (2) selecting at least three ultra-high frequency sensors as first positioning sensors according to the first characteristic data of the first partial discharge signal;

[0090] (3) Locating the local position of the device to be monitored by using a first positioning sensor to obtain a first positioning result;

[0091] (4) selecting at least three ultrasonic sensors as second positioning sensors according to the second characteristic data of the second partial discharge signal;

[0092] (5) Locate the local position of the monitored device using a second positioning sensor to obtain a second positioning result.

[0093] By selecting three UHF sensors and three ultrasonic sensors to jointly locate the monitored equipment, the positioning accuracy can be improved and positioning errors can be avoided. In order to determine which three UHF sensors to select as the first positioning sensors, in this example, the above step (2) includes the following two steps:

[0094] Step (21): the monitoring system extracts characteristic data of the partial discharge signals received by all UHF sensors; the characteristic data includes the amplitude, frequency and receiving time of the partial discharge signals;

[0095] Step (22): Compare the amplitude of each partial discharge signal, select at least three ultra-high frequency sensors as first positioning sensors according to the comparison result, and record the reception time of each first positioning sensor receiving the partial discharge signal.

[0096] After the monitoring system receives the first partial discharge signal sent by all UHF sensors, it analyzes the amplitude, frequency, receiving time and period of each first partial discharge signal; then, the three UHF sensors with the highest amplitude are selected as the first positioning sensors, and the receiving time of each first positioning sensor receiving the first partial discharge signal is recorded. It should be noted that the higher the amplitude of the first partial discharge signal, the closer the corresponding UHF sensor is to the partial discharge position, or the more sensitive the corresponding UHF sensor is to the first partial discharge signal. Therefore, by selecting the three UHF sensors with the highest amplitude as the first positioning sensors, the positioning accuracy can be improved.

[0097] After selecting the first positioning sensor and recording the time when each first positioning sensor receives the first partial discharge signal, the time difference of each first positioning sensor receiving the first partial discharge signal can be obtained, and then the partial discharge position of the monitored device is located according to the time difference positioning method, thereby obtaining a first positioning result. Specifically, in this example, the above step (3): locating the partial discharge position of the monitored device by the first positioning sensor to obtain the first positioning result, includes the following seven steps:

[0098] Step (31): obtaining a first time difference between the receiving time of the first first positioning sensor and the receiving time of the second first positioning sensor;

[0099] Step (32): determining a first distance between the partial discharge position and the first first positioning sensor according to the axial distance between the first first positioning sensor and the second first positioning sensor, the first time difference, and the transmission rate of the first partial discharge signal;

[0100] Step (33): obtaining a second time difference between the receiving time of the second first positioning sensor and the receiving time of the third first positioning sensor;

[0101] Step (34): determining a second distance between the partial discharge position and the second first positioning sensor according to the axial distance between the second first positioning sensor and the third first positioning sensor, the second time difference, and the transmission rate of the first partial discharge signal;

[0102] Step (35): obtaining a third time difference between the reception time of the third first positioning sensor and the reception time of the first first positioning sensor;

[0103] Step (36): determining a third distance between the partial discharge position and the third first positioning sensor according to the axial distance between the third first positioning sensor and the first first positioning sensor, the third time difference, and the transmission rate of the first partial discharge signal;

[0104] Step (37): Determine a first positioning result based on the first distance, the second distance and the third distance.

[0105] Among them, assuming that the first time difference is t1, the axial distance between the first first positioning sensor and the second first positioning sensor is d1, and the transmission rate of the first partial discharge signal is v1 (i.e., the transmission rate of the UHF signal), then the first distance between the partial discharge position and the first first positioning sensor is: U1=(d1- v1*t1) / 2. Similarly, assuming that the second time difference is t2, the axial distance between the second first positioning sensor and the third first positioning sensor is d2, then the second distance between the partial discharge position and the second first positioning sensor is: U2=(d2- v1*t2) / 2; assuming that the third time difference is t3, the axial distance between the third first positioning sensor and the first first positioning sensor is d3, then the third distance between the partial discharge position and the third first positioning sensor is: U3=(d3- v1*t3) / 2. After obtaining the distances between the partial discharge position and the three first positioning sensors, the partial discharge position can be jointly located by the three first positioning sensors, and the intersection of the positioning paths of the three first positioning sensors is used as the first positioning result.

[0106] It should be noted that the principle of the monitoring system selecting the second positioning sensor from all ultrasonic sensors is similar to the principle of selecting the first positioning sensor, and the principle of positioning according to the second positioning sensor to obtain the second positioning result is also similar to the principle of obtaining the first positioning result, which will not be elaborated here.

[0107] It should be noted that when the deviation between the first positioning result and the second positioning result is within a preset range, it means that the positioning result obtained by the UHF sensor is basically consistent with the positioning result obtained by the ultrasonic sensor. At this time, the accurate positioning of the PD position has been achieved, and either the first positioning result or the second positioning result can be used as the positioning position, or the PD type corresponding to the PD signal can be identified by the PD type recognition model, and then the UHF sensor / ultrasonic sensor is judged to have a higher recognition accuracy for the PD type, and the one with higher accuracy is selected as the positioning position. For example, if the UHF sensor has a higher recognition accuracy for the PD type, the first positioning result is used as the positioning position, and if the ultrasonic sensor has a higher recognition accuracy for the PD type, the second positioning result is used as the positioning position.

[0108] If the deviation between the first positioning result and the second positioning result exceeds the preset range, it means that the gap between the two positioning methods is large at this time, and the positioning result needs to be corrected to improve the positioning accuracy. To this end, in this example, the local position of the monitored equipment is jointly located by a UHF sensor and an ultrasonic sensor to obtain a third positioning result.

[0109] like Figure 4 As shown, in some embodiments of the present invention, step S500: when the deviation between the first positioning result and the second positioning result exceeds a preset range, the partial discharge type of the partial discharge signal is identified by the partial discharge type identification model, and according to the partial discharge type and the positioning accuracy, the partial discharge position of the monitored equipment is jointly located by the UHF sensor and the ultrasonic sensor to obtain a third positioning result, which specifically includes the following four steps:

[0110] Step S510: The partial discharge type identification model identifies the partial discharge type according to the characteristic value of the partial discharge signal;

[0111] Step S520: selecting one of the first positioning result and the second positioning result as a reference position and the other as a calibration position according to the positioning accuracy of the UHF sensor and the ultrasonic sensor for the PD type;

[0112] Step S530: obtaining a distance difference between the reference position and the calibration position, and determining a moving distance according to the distance difference;

[0113] Step S540: Move the reference position by a moving distance in the direction of the calibration position to obtain a third positioning result.

[0114] After the UHF sensor and the ultrasonic sensor identify the first partial discharge signal and the second partial discharge signal, the partial discharge type recognition model identifies the first partial discharge signal or the second partial discharge signal, identifies the characteristic value of the partial discharge signal, and then identifies the partial discharge type according to the characteristic value. According to the partial discharge type, it can be determined which of the UHF sensor and the ultrasonic sensor has a higher positioning accuracy for the partial discharge type. If the UHF sensor has a high positioning accuracy, the first positioning result is used as the reference position and the second positioning result is used as the calibration position; if the ultrasonic sensor has a high positioning accuracy, the second positioning result is used as the reference position and the first positioning result is used as the calibration position. Then, the distance difference between the reference position and the calibration is determined, and the moving distance is determined according to the distance difference, wherein the moving distance is a part of the distance difference, and 1 / 10, 1 / 5 or other values ​​of the distance difference can be set as the moving distance. Then, the reference position is moved toward the calibration position by the moving distance to obtain the third positioning result. For example, if the first positioning result is relatively accurate, due to the large deviation between the first positioning result and the second positioning result, in order to ensure the accuracy of the positioning result, the first positioning result needs to be revised to a certain extent, so that the final determined partial discharge position is between the first positioning result and the second positioning result, and closer to the first positioning result. Then the final third positioning result is the positioning position.

[0115] After obtaining the location, the PD signal strength at the location can also be determined by the Rogowski coil. The Rogowski coil has high sensitivity and can directly detect the discharge charge of the PD. It can accurately reflect the replication changes of the PD inside the monitored equipment and can more clearly show the PD situation. Therefore, by locating the PD position through the UHF sensor and the ultrasonic sensor and identifying the PD signal strength at the PD position through the Rogowski coil, the PD situation can be clearly understood, the PD position and degree can be accurately identified, and it is convenient for operators to take corresponding countermeasures.

[0116] Furthermore, in some embodiments of the present invention, the partial discharge location method further includes the following five steps:

[0117] (1) The monitoring system establishes a three-dimensional display model based on the structure of the equipment to be monitored and the installation locations of the UHF sensor and ultrasonic sensor;

[0118] (2) Define the smallest circumscribed cuboid of the 3D display model as the scene;

[0119] (3) Taking a vertex of the scene as the origin, divide the scene into multiple cubes on the XYZ coordinate axis with a preset resolution;

[0120] (4) According to the serial number of the cube where any point in the scene is located, the coordinates of each point are quantized into digital coordinates to form a digital twin model;

[0121] (5) Display the positioning position and partial discharge signal strength on the digital twin model.

[0122] Step S100: The monitoring system establishes a three-dimensional display model according to the structure of each device to be monitored and the installation position of the UHF sensor and the ultrasonic sensor;

[0123] Specifically, according to the internal and external structures of the equipment to be monitored, as well as the installation positions of each ultrasonic sensor in the equipment to be monitored and each ultra-high frequency sensor outside the equipment to be monitored, a three-dimensional modeling tool such as Solidworks is used to perform three-dimensional modeling on the structure to obtain a three-dimensional display model. Then, the smallest circumscribed cuboid of the entire three-dimensional display model is defined as the "scene", and a vertex of the scene is used as the origin. The length coordinate quantity is converted into a digital coordinate at a resolution of 0.1 meters (or other values) on the three coordinates of X, Y, and Z. For example, if the size of the scene is (5 meters, 4 meters, 3 meters), after quantization, the entire scene is divided into (5 / 0.1)*(4 / 0.1)*(3 / 0.1)=60,000 cubes with a side length of 0.1 meters. The position coordinates of any point in the scene are converted into the serial number of the cube where it is located, i.e., the digital coordinates, based on its distance from the origin. The digital coordinate range of the X direction is 0, 1, ..., 49, the digital coordinate range of the Y direction is 0, 1, ..., 39, and the digital coordinate range of the Z direction is 0, 1, ..., 29. For example, if the original coordinates of the location point in the scene are (3.85 meters, 2.52 meters, 2.01 meters), the digital coordinates after quantization are (39, 25, 20).

[0124] By establishing a digital twin model with self-representation, self-calculation, and self-perception on the software platform of the monitoring system, it is possible to achieve fully automatic calculation and 1:1 three-dimensional display of the monitoring results and positioning position of the monitored equipment, thereby ensuring the safe and stable operation of the power grid equipment.

[0125] According to the partial discharge positioning method of the embodiment of the present invention, an ultrasonic sensor is placed inside the device to be monitored, and a UHF sensor is placed outside. The two sensors are used to jointly locate the partial discharge position, which can improve the positioning accuracy, detect the partial discharge phenomenon in time, and accurately locate it, thereby ensuring the safe operation of the device to be monitored. The monitoring data of each device to be monitored is accessed through the monitoring system, and a digital twin model with self-representation, self-calculation, and self-perception is established on the software platform of the monitoring system, so as to realize the monitoring results of the device to be monitored, the fully automatic calculation of the positioning position and the 1:1 three-dimensional display, thereby ensuring the safe and stable operation of the power grid equipment.

[0126] On the other hand, an embodiment of the present invention further provides a partial discharge locating system, the device comprising:

[0127] The processor may be implemented by a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application;

[0128] The memory may be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device or a random access memory (RAM). The memory may store an operating system and other application programs. When the technical solution provided in the embodiments of this specification is implemented by software or firmware, the relevant program code is stored in the memory and is called by the processor to execute the partial discharge location method in the embodiments of this application;

[0129] Input / output interface, used to realize information input and output;

[0130] Communication interface, used to realize communication interaction between this device and other devices. Communication can be realized through wired methods (such as USB, network cable, etc.) or wireless methods (such as mobile network, WIFI, Bluetooth, etc.);

[0131] The bus, which transfers information between the various components of the device (such as the processor, memory, input / output interfaces, and communication interfaces);

[0132] The processor, memory, input / output interface and communication interface are connected to each other through a bus inside the device.

[0133] On the other hand, an embodiment of the present invention further provides an electronic device, including the partial discharge locating system as described above.

[0134] On the other hand, an embodiment of the present invention further provides a storage medium, which is a computer-readable storage medium and stores a computer program. When the computer program is executed by a processor, the above-mentioned partial discharge locating method is implemented.

[0135] As a non-transient computer-readable storage medium, the memory can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and are implemented to be located in one place, or may also be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0136] Although specific embodiments are described herein, those of ordinary skill in the art will recognize that many other modifications or alternative embodiments are also within the scope of the present disclosure. For example, any of the functions and / or processing capabilities described in conjunction with a particular device or component may be performed by any other device or component. In addition, although various exemplary implementations and architectures have been described according to embodiments of the present disclosure, those of ordinary skill in the art will recognize that many other modifications to the exemplary implementations and architectures described herein are also within the scope of the present disclosure.

[0137] Some aspects of the present disclosure are described above with reference to the block diagram and flow chart of the system, method, system and / or computer program product according to the exemplary embodiments.It should be understood that the combination of one or more blocks in the block diagram and the flow chart and the blocks in the block diagram and the flow chart can be realized by executing computer executable program instructions respectively.Equally, according to some embodiments, some blocks in the block diagram and the flow chart may not need to be executed in the order shown, or may not need to be executed in full.In addition, additional components and / or operations beyond those components and / or operations shown in the blocks in the block diagram and the flow chart may be present in certain embodiments.

[0138] Therefore, the blocks in the block diagrams and flow charts support the combination of devices for performing the specified functions, the combination of elements or steps for performing the specified functions, and the program instruction devices for performing the specified functions. It should also be understood that each block in the block diagrams and flow charts and the combination of blocks in the block diagrams and flow charts can be implemented by a special-purpose hardware computer system or a combination of special-purpose hardware and computer instructions that performs a specific function, element or step.

[0139] The program modules, applications, etc. described herein may include one or more software components, including, for example, software objects, methods, data structures, etc. Each such software component may include computer-executable instructions that, in response to execution, cause at least a portion of the functionality described herein (e.g., one or more operations of the illustrative methods described herein) to be performed.

[0140] Software components can be encoded with any of various programming languages. An exemplary programming language can be a low-level programming language, such as an assembly language associated with a specific hardware architecture and / or an operating system platform. The software component comprising assembly language instructions may need to be converted to executable machine code by an assembler before being executed by hardware architecture and / or platform. Another exemplary programming language can be a higher-level programming language, which can be transplanted across multiple architectures. The software component comprising a higher-level programming language may need to be converted to an intermediate representation by an interpreter or a compiler before execution. Other examples of programming languages ​​include but are not limited to macro languages, shells or command languages, job control languages, scripting languages, database queries or search languages ​​or report writing languages. In one or more exemplary embodiments, the software component comprising the instruction of one of the above-mentioned programming language examples can be directly executed by an operating system or other software components, without first being converted into another form.

[0141] Software components may be stored as files or other data storage structures. Software components of similar type or related functions may be stored together, such as in a specific directory, folder, or library. Software components may be static (e.g., preset or fixed) or dynamic (e.g., created or modified at execution time).

[0142] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for locating partial discharge, characterized in that: Applied to a monitoring system, the monitoring system is electrically connected to a device to be monitored, a plurality of ultra-high frequency sensors are arranged outside the device to be monitored, and a plurality of ultrasonic sensors and a plurality of Rogowski coils are arranged inside the device to be monitored; the method comprises: Using a simulated discharge source, generating partial discharge signals of different partial discharge types at different locations inside the device to be monitored; Establishing a partial discharge type identification model according to characteristic values ​​of the partial discharge signals of different partial discharge types; Determining the positioning accuracy of the UHF sensor and the ultrasonic sensor for different types of partial discharges; When a partial discharge phenomenon occurs in the device to be monitored, corresponding partial discharge signals are obtained by the ultra-high frequency sensor and the ultrasonic sensor respectively, and the partial discharge position of the device to be monitored is located by the ultra-high frequency sensor and the ultrasonic sensor respectively, to obtain a first positioning result and a second positioning result; When the deviation between the first positioning result and the second positioning result is within a preset range, identifying the partial discharge type of the partial discharge signal by using the partial discharge type identification model, and determining the first positioning result or the second positioning result as a positioning position according to the partial discharge type and the positioning accuracy; When the deviation between the first positioning result and the second positioning result exceeds the preset range, the partial discharge type identification model identifies the partial discharge type according to the characteristic value of the partial discharge signal; according to the positioning accuracy of the UHF sensor and the ultrasonic sensor for the partial discharge type, one of the first positioning result and the second positioning result is selected as the reference position, and the other is selected as the calibration position; the distance difference between the reference position and the calibration position is obtained, and the moving distance is determined according to the distance difference; the reference position is moved in the direction of the calibration position by the moving distance to obtain a third positioning result; and the third positioning result is determined as the positioning position; wherein the moving distance is a part of the distance difference; The PD signal strength at the positioning position is determined by the Rogowski coil.

2. The method for locating partial discharge according to claim 1, characterized in that: The step of establishing a partial discharge type identification model according to the characteristic values ​​of the partial discharge signals of different partial discharge types comprises: Performing time-frequency analysis on the partial discharge signals of different partial discharge types to obtain time-frequency characteristic values ​​of the partial discharge signals of different partial discharge types; A sample set and a test set are constructed according to all the extracted time-frequency feature values, and a neural network model is trained by using the sample set and the test set to form the partial discharge type recognition model.

3. The method for locating partial discharge according to claim 1, characterized in that: When a partial discharge phenomenon occurs in the device to be monitored, the steps of respectively acquiring corresponding partial discharge signals by the ultra-high frequency sensor and the ultrasonic sensor, and respectively locating the partial discharge position of the device to be monitored by the ultra-high frequency sensor and the ultrasonic sensor to obtain a first positioning result and a second positioning result include: When partial discharge occurs in the device to be monitored, a first partial discharge signal is obtained by the UHF sensor, and a second partial discharge signal is obtained by the ultrasonic sensor; selecting at least three of the UHF sensors as first positioning sensors according to the first characteristic data of the first partial discharge signal; Locating the local position of the device to be monitored by using the first positioning sensor to obtain a first positioning result; selecting at least three of the ultrasonic sensors as second positioning sensors according to the second characteristic data of the second partial discharge signal; The local position of the device to be monitored is located by the second positioning sensor to obtain a second positioning result.

4. The method for locating partial discharge according to claim 3, characterized in that: The step of selecting at least three of the UHF sensors as first positioning sensors according to the first characteristic data of the first partial discharge signal comprises: Extracting first characteristic data of the first partial discharge signal received by all the UHF sensors; the first characteristic data includes the amplitude, frequency and receiving time of the first partial discharge signal; The amplitude of each of the first partial discharge signals is compared, at least three of the UHF sensors are selected as first positioning sensors according to the comparison result, and the receiving time when each of the first positioning sensors receives the first partial discharge signal is recorded.

5. The method for locating partial discharge according to claim 4, characterized in that: The number of the first positioning sensors is three; the step of locating the local position of the device to be monitored by using the first positioning sensor to obtain a first positioning result includes: Acquire a first time difference between the receiving time of a first first positioning sensor and a second first positioning sensor; Determine a first distance between the partial discharge position and the first first positioning sensor according to an axial distance between the first first positioning sensor and the second first positioning sensor, the first time difference, and a transmission rate of the first partial discharge signal; Acquire a second time difference between the receiving time of the second first positioning sensor and the receiving time of the third first positioning sensor; Determine a second distance between the partial discharge position and the second first positioning sensor according to the axial distance between the second first positioning sensor and the third first positioning sensor, the second time difference, and the transmission rate of the first partial discharge signal; Acquire a third time difference between the receiving time of a third first positioning sensor and the first first positioning sensor; Determine a third distance between the partial discharge position and the third first positioning sensor according to the axial distance between the third first positioning sensor and the first first positioning sensor, the third time difference, and the transmission rate of the first partial discharge signal; The first positioning result is determined according to the first distance, the second distance and the third distance.

6. The method for locating partial discharge according to claim 1, characterized in that: The UHF sensor is electrically connected to the monitoring system via a first data acquisition unit, wherein the first data acquisition unit comprises: an operational amplifier, a bandpass filter and a noise processor; After the step of respectively acquiring corresponding partial discharge signals through the UHF sensor and the ultrasonic sensor when partial discharge occurs in the device to be monitored, the method further includes: The first data acquisition unit amplifies the partial discharge signal received by the UHF sensor through the operational amplifier; The amplified partial discharge signal is filtered through the bandpass filter; The noise processor identifies the noise signal of the partial discharge signal, denoises the partial discharge signal, and sends it to the monitoring system.

7. The method for locating partial discharge according to claim 1, characterized in that: The local discharge locating method further comprises the following steps: The monitoring system establishes a three-dimensional display model according to the structure of the device to be monitored and the installation positions of the UHF sensor, the ultrasonic sensor and the Rogowski coil; Defining the smallest circumscribed cuboid of the three-dimensional display model as a scene; Taking a vertex of the scene as an origin, dividing the scene into a plurality of cubes at a preset resolution on the XYZ coordinate axes; According to the serial number of the cube where any point of the scene is located, the coordinates of each point are quantized into digital coordinates, thereby forming a digital twin model; The positioning position and the partial discharge signal strength are displayed on the digital twin model.

8. A partial discharge location system, characterized in that: The invention comprises at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions executable by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the partial discharge locating method according to any one of claims 1 to 7.

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