High-voltage cable partial discharge on-line monitoring and positioning method and system

Abstract

The invention discloses a high-voltage cable partial discharge on-line monitoring and positioning method and system, and the method comprises the steps: obtaining a high-frequency pulse current signal generated by partial discharge and a corresponding time node based on a high-frequency current sensor and a time inductor preset at a high-voltage cable joint or port; obtaining a first prediction area of partial discharge according to the high-frequency pulse current signal generated by partial discharge and the corresponding time node; based on an acoustic sensor and a time sensor preset in a high-voltage cable segment area where the first prediction area is located, obtaining an acoustic wave signal generated by partial discharge and a corresponding time node; obtaining a second prediction area of the partial discharge according to the sound wave signal generated by the partial discharge and the corresponding time node; and extracting an intersection of the first prediction region and the second prediction region of the partial discharge to obtain a prediction region of the partial discharge. According to the invention, through sound-electricity combination, the precision and reliability of high-voltage cable partial discharge monitoring and positioning are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of safety monitoring of power distribution equipment, and more specifically, to an online monitoring and positioning method and system for partial discharge of a high-voltage cable. Background Art

[0002] With the continuous development of the power system, high-voltage cables play a vital role in the transmission of electric energy. However, due to manufacturing defects, improper installation, long-term operation and aging, high-voltage cables may experience partial discharge. Traditional high-voltage cable partial discharge detection requires power outage, which affects the reliability of power supply. Or it is detected through a single high-frequency pulse current signal. Due to the fast propagation speed of the high-frequency pulse current signal, the localized partial discharge position error is relatively large.

[0003] Therefore, the prior art has defects and needs to be improved urgently. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method and system for online monitoring and positioning of partial discharge of high-voltage cables, which improves the accuracy and reliability of partial discharge monitoring and positioning of high-voltage cables through the combination of acoustics and electricity.

[0005] A first aspect of the present invention provides a method for online monitoring and positioning of partial discharge of a high-voltage cable, comprising:

[0006] Based on the high-frequency current sensor and time sensor preset at the high-voltage cable joint or port, the high-frequency pulse current signal and the corresponding time node generated by the partial discharge are obtained;

[0007] Obtaining a first prediction area of ​​the local discharge according to the high-frequency pulse current signal generated by the local discharge and the corresponding time node;

[0008] Based on the preset acoustic sensors and time sensors in the high-voltage cable segment area where the first prediction area is located, the acoustic wave signals generated by the partial discharge and the corresponding time nodes are obtained;

[0009] According to the acoustic wave signal generated by the partial discharge and the corresponding time node, a second prediction area of ​​the partial discharge is obtained;

[0010] The intersection of the first prediction region and the second prediction region of the partial discharge is extracted to obtain the prediction region of the partial discharge.

[0011] This plan also includes:

[0012] Numbering the high-frequency current sensors preset at the high-voltage cable joints or ports to obtain serial numbers of the high-frequency current sensors;

[0013] When the high-frequency current sensor obtains the high-frequency pulse current signal, the high-frequency pulse current signal is sorted and numbered in chronological order, and the high-frequency pulse current signal is marked according to the current time node to obtain a high-frequency pulse current signal with a time mark and a number;

[0014] When there is no high-frequency pulse current signal or only one high-frequency current sensor acquires the high-frequency pulse current signal, and there is voltage at other joints or ports, information is obtained that there is no partial discharge in the high-voltage cable.

[0015] In this solution, the step of obtaining the first predicted area of ​​partial discharge specifically includes:

[0016] When there is a high-frequency current sensor to obtain a high-frequency pulse current signal, and there is no voltage at other connectors or ports, then the connector or port corresponding to the high-frequency current sensor is connected to the power supply end;

[0017] Extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor;

[0018] Calculate the distance value according to the corresponding homologous high-frequency pulse current signal, construct a distance value set, extract the maximum value and the minimum value in the distance value set, and construct a first prediction area with the corresponding maximum value and the minimum value;

[0019] When there are multiple high-frequency current sensors that acquire high-frequency pulse current signals, extract the first high-frequency current sensor that acquires the same high-frequency current signal;

[0020] Taking the first high-frequency current sensor that obtains the high-frequency current signal of the same source as a reference point, extracting the high-frequency current signals of the same source obtained by a preset number of adjacent high-frequency current sensors;

[0021] Distance values ​​are calculated based on homologous high-frequency current signals obtained by a preset number of adjacent high-frequency current sensors, a distance value set is constructed, the maximum value and the minimum value in the distance value set are extracted, and a first prediction area is constructed with the corresponding maximum value and minimum value.

[0022] In this solution, the step of extracting the homologous high-frequency pulse current signal from the high-frequency pulse current signal obtained by the corresponding high-frequency current sensor specifically includes:

[0023] The high-frequency pulse current signal obtained by the high-frequency current sensor is marked according to the corresponding acquisition time node to obtain high-frequency pulse current signals with different time marks;

[0024] Compare and analyze any two high-frequency pulse current signals with different time stamps to obtain similarity values;

[0025] If the similarity value is greater than a preset similarity threshold, the high-frequency pulse current signals corresponding to two different time stamps are set as homologous high-frequency pulse current signals.

[0026] This plan also includes:

[0027] The homologous high-frequency pulse current signals are sorted according to the time sequence of acquisition, and the time nodes corresponding to the homologous high-frequency pulse current signals are extracted;

[0028] Calculate the difference between the time nodes corresponding to the adjacent high-frequency pulse current signals of the same source, and take the absolute value to obtain a first time difference;

[0029] If the first time difference value is within the preset first time difference range, the corresponding first time difference is saved;

[0030] If the first time difference is not within the preset first time difference range, the adjacent homologous high-frequency pulse current signals corresponding to the first time difference are deleted.

[0031] In this solution, the step of comparing and analyzing any two high-frequency pulse current signals with different time stamps to obtain similarity values ​​specifically includes:

[0032] Extract the characteristics of high-frequency pulse current signals and corresponding characteristic values;

[0033] Based on the same features, the smaller value of the feature values ​​of any two high-frequency pulse current signals with different time stamps is divided by the larger value to obtain the similarity value of the corresponding feature;

[0034] Traverse all the same features and get the similarity values ​​of all the same features;

[0035] The similarity value of the same feature is multiplied by the influence weight coefficient of the corresponding feature, and then accumulated to obtain the similarity value of the high-frequency pulse current signal corresponding to two different time stamps.

[0036] In this solution, the step of calculating the distance value according to the corresponding homologous high-frequency pulse current signal and constructing the distance value set specifically includes:

[0037] Extract the time nodes corresponding to the homologous high-frequency pulse current signals;

[0038] Subtract the time when the corresponding joint is powered on from the time node of the corresponding homologous high-frequency pulse current signal to obtain a second time difference;

[0039] Divide the second time difference by 2, and then multiply by the preset light speed to obtain the distance value corresponding to the homologous high-frequency pulse current signal;

[0040] All homologous high-frequency pulse current signals are traversed to obtain a distance value set corresponding to the homologous high-frequency pulse current signals, that is, a distance value set.

[0041] A second aspect of the present invention provides a high-voltage cable partial discharge online monitoring and positioning system, including a memory and a processor, wherein the memory stores a high-voltage cable partial discharge online monitoring and positioning method program, and when the high-voltage cable partial discharge online monitoring and positioning method program is executed by the processor, the following steps are implemented:

[0042] Based on the high-frequency current sensor and time sensor preset at the high-voltage cable joint or port, the high-frequency pulse current signal and the corresponding time node generated by the partial discharge are obtained;

[0043] Obtaining a first prediction area of ​​the local discharge according to the high-frequency pulse current signal generated by the local discharge and the corresponding time node;

[0044] Based on the preset acoustic sensors and time sensors in the high-voltage cable segment area where the first prediction area is located, the acoustic wave signals generated by the partial discharge and the corresponding time nodes are obtained;

[0045] According to the acoustic wave signal generated by the partial discharge and the corresponding time node, a second prediction area of ​​the partial discharge is obtained;

[0046] The intersection of the first prediction region and the second prediction region of the partial discharge is extracted to obtain the prediction region of the partial discharge.

[0047] This plan also includes:

[0048] Numbering the high-frequency current sensors preset at the high-voltage cable joints or ports to obtain serial numbers of the high-frequency current sensors;

[0049] When the high-frequency current sensor obtains the high-frequency pulse current signal, the high-frequency pulse current signal is sorted and numbered in chronological order, and the high-frequency pulse current signal is marked according to the current time node to obtain a high-frequency pulse current signal with a time mark and a number;

[0050] When there is no high-frequency pulse current signal or only one high-frequency current sensor acquires the high-frequency pulse current signal, and there is voltage at other joints or ports, information is obtained that there is no partial discharge in the high-voltage cable.

[0051] In this solution, the step of obtaining the first predicted area of ​​partial discharge specifically includes:

[0052] When there is a high-frequency current sensor to obtain a high-frequency pulse current signal, and there is no voltage at other connectors or ports, then the connector or port corresponding to the high-frequency current sensor is connected to the power supply end;

[0053] Extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor;

[0054] Calculate the distance value according to the corresponding homologous high-frequency pulse current signal, construct a distance value set, extract the maximum value and the minimum value in the distance value set, and construct a first prediction area with the corresponding maximum value and the minimum value;

[0055] When there are multiple high-frequency current sensors that acquire high-frequency pulse current signals, extract the first high-frequency current sensor that acquires the same high-frequency current signal;

[0056] Taking the first high-frequency current sensor that obtains the high-frequency current signal of the same source as a reference point, extracting the high-frequency current signals of the same source obtained by a preset number of adjacent high-frequency current sensors;

[0057] Distance values ​​are calculated based on homologous high-frequency current signals obtained by a preset number of adjacent high-frequency current sensors, a distance value set is constructed, the maximum value and the minimum value in the distance value set are extracted, and a first prediction area is constructed with the corresponding maximum value and minimum value.

[0058] The invention discloses a method and system for online monitoring and positioning of partial discharge of a high-voltage cable, which improves the accuracy and reliability of partial discharge monitoring and positioning of the high-voltage cable through the combination of sound and electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 A flow chart showing a method for online monitoring and positioning of partial discharge of a high-voltage cable according to the present invention is shown;

[0060] Figure 2 A block diagram of an online monitoring and positioning system for partial discharge of a high-voltage cable according to the present invention is shown. DETAILED DESCRIPTION

[0061] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0062] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0063] Figure 1 The flowchart of the method for online monitoring and positioning of partial discharge of high-voltage cables of the present invention is shown.

[0064] like Figure 1As shown, the present invention discloses a method for online monitoring and positioning of partial discharge of a high-voltage cable, comprising:

[0065] S101, obtaining a high-frequency pulse current signal and a corresponding time node generated by partial discharge based on a high-frequency current sensor and a time sensor preset at a high-voltage cable joint or port;

[0066] S102, obtaining a first prediction area of ​​the local discharge according to the high-frequency pulse current signal generated by the local discharge and the corresponding time node;

[0067] S103, acquiring the acoustic wave signal generated by the partial discharge and the corresponding time node based on the preset acoustic sensor and time sensor in the high-voltage cable segment area where the first prediction area is located;

[0068] S104, obtaining a second prediction area of ​​the local discharge according to the acoustic wave signal generated by the local discharge and the corresponding time node;

[0069] S105, extracting the intersection of the first prediction region and the second prediction region of partial discharge to obtain the prediction region of partial discharge.

[0070] According to an embodiment of the present invention, for a high-voltage cable, a joint or a port is provided at a certain interval according to requirements. At least one high-frequency current sensor and a time sensor are provided at each joint or port. The high-voltage cable between two joints or between a joint and a port is defined as a high-voltage cable segment. The high-frequency current sensor is used to detect whether there is a high-frequency pulse current signal in the high-voltage cable. When there is a high-frequency pulse current signal, the time sensor records the time when the high-frequency current sensor obtains the high-frequency pulse current signal, which is recorded as the time node corresponding to the high-frequency pulse current signal. When determining the first prediction area, at least 2 acoustic sensors and time sensors are provided on the high-voltage cable segment corresponding to the first prediction area and are evenly arranged. The acoustic sensors are used to obtain the acoustic wave signals generated by partial discharge, and the time sensor records the time when the acoustic sensor obtains the acoustic wave signal, which is recorded as the time node corresponding to the acoustic wave signal. When two acoustic sensors obtain acoustic wave signals and the propagation directions of the corresponding acoustic wave signals are opposite, it indicates that the corresponding partial discharge position is in the middle of the two corresponding acoustic sensors. The two acoustic sensors are respectively set as A1 and A2, and the times for obtaining the acoustic wave signals are respectively set as t1 and t2. Then, (t1 - t3)*v1 + (t2 - t3)*v1 = L1, and t3 can be obtained. The corresponding partial discharge position is in the middle of the acoustic sensors A1 and A2, at a distance of (t1 - t3)*v1 from A1 and at a distance of (t2 - t3)*v1 from A2, where t3 is the time when the corresponding acoustic wave signal is generated, v1 is the propagation speed of the acoustic wave signal, and L1 represents the distance value between the acoustic sensors A1 and A2. When two acoustic sensors obtain acoustic wave signals and the propagation directions of the corresponding acoustic wave signals are the same, it indicates that the corresponding partial discharge position is outside the two corresponding acoustic sensors and is close to the outside of the acoustic sensor that first obtains the acoustic wave signal. The middle of the two acoustic sensors is set as the inside. If t2 > t1, then (t2 - t3)*v1 - (t1 - t3)*v1 = L1, and t3 can be obtained. The corresponding partial discharge position is at a distance of (t1 - t3) outside the acoustic sensor A1. If t2 < t1, then (t1 - t3)*v1 - (t2 - t3)*v1 = L1, and t3 can be obtained. The corresponding partial discharge position is at a distance of (t2 - t3) outside the acoustic sensor A2, where t3 is the time when the corresponding acoustic wave signal is generated, v1 is the propagation speed of the acoustic wave signal, and L1 represents the distance value between the acoustic sensors A1 and A2.

[0071] According to an embodiment of the present invention, it further includes:

[0072] Number the pre-set high-frequency current sensors at the high-voltage cable joints or ports to obtain the serial numbers of the high-frequency current sensors;

[0073] When the high-frequency current sensor obtains the high-frequency pulse current signal, the high-frequency pulse current signal is sorted and numbered in chronological order, and the high-frequency pulse current signal is marked according to the current time node to obtain a high-frequency pulse current signal with a time mark and a number;

[0074] When there is no high-frequency pulse current signal or only one high-frequency current sensor acquires the high-frequency pulse current signal, and there is voltage at other joints or ports, information is obtained that there is no partial discharge in the high-voltage cable.

[0075] It should be noted that when there is voltage at other connectors or ports, it means that the corresponding high-voltage cable is in a normal connection state and is not interrupted. Therefore, when only one high-frequency current sensor obtains a high-frequency pulse current signal, it means that the corresponding high-frequency current sensor has an erroneous value.

[0076] According to an embodiment of the present invention, the step of obtaining a first predicted area of ​​partial discharge specifically includes:

[0077] When there is a high-frequency current sensor to obtain a high-frequency pulse current signal, and there is no voltage at other connectors or ports, then the connector or port corresponding to the high-frequency current sensor is connected to the power supply end;

[0078] Extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor;

[0079] Calculate the distance value according to the corresponding homologous high-frequency pulse current signal, construct a distance value set, extract the maximum value and the minimum value in the distance value set, and construct a first prediction area with the corresponding maximum value and the minimum value;

[0080] When there are multiple high-frequency current sensors that acquire high-frequency pulse current signals, extract the first high-frequency current sensor that acquires the same high-frequency current signal;

[0081] Taking the first high-frequency current sensor that obtains the high-frequency current signal of the same source as a reference point, extracting the high-frequency current signals of the same source obtained by a preset number of adjacent high-frequency current sensors;

[0082] Distance values ​​are calculated based on homologous high-frequency current signals obtained by a preset number of adjacent high-frequency current sensors, a distance value set is constructed, the maximum value and the minimum value in the distance value set are extracted, and a first prediction area is constructed with the corresponding maximum value and minimum value.

[0083] It should be noted that when there is a high-frequency current sensor that obtains a high-frequency pulse current signal, and there is no voltage at other connectors or ports, it means that the connector corresponding to the corresponding high-frequency current sensor is the first connector, one end of the corresponding connector is connected to the power supply end through a high-voltage cable, and the other end is connected to other connectors through a high-voltage cable, and there is an interruption in the high-voltage cable in the position area before connecting to other connectors and after partial discharge. Therefore, other high-frequency current sensors cannot obtain high-frequency pulse current signals, and there is no voltage at the corresponding connector; when there are multiple high-frequency current sensors that obtain high-frequency pulse current signals, it means that the local discharge position is closest to the first high-frequency current sensor B1 that obtains the high-frequency pulse current signal. Therefore, the homologous high-frequency current signals of the corresponding adjacent high-frequency current sensors are extracted for distance calculation, and a distance value set is constructed. For example, the first adjacent high-frequency current sensor that obtains the corresponding homologous high-frequency pulse current signal is extracted for distance value calculation, and the corresponding high-frequency current sensor is set to B2, and the homologous high-frequency pulse current signals obtained by the two corresponding high-frequency current sensors B1 and B2 are set to T1 and T2 respectively according to the order of acquisition time. If there is: (T2-T1)v c =L2, where L2 represents the distance value between the two high-frequency current sensors B1 and B2, indicating that the corresponding local position is outside the corresponding two high-frequency current sensors and close to the outside of the first high-frequency current sensor B1 that obtains the high-frequency pulse current signal. Therefore, it is necessary to extract another adjacent high-frequency current sensor B3 of the first high-frequency current sensor B1 that obtains the high-frequency pulse current signal. The time of the high-frequency pulse current signal obtained by the adjacent high-frequency current sensor B3 is set to T3. The formula is (T1-T0)v c +(T3―T0)v c =L3, where T0 represents the time when the corresponding partial discharge produces the high-frequency pulse current signal, and L3 represents the distance between the adjacent high-frequency current sensors B1 and B3. According to the corresponding formula, T0 is obtained, and the corresponding partial discharge position is in the middle of the high-frequency current sensors B1 and B3, and is close to the high-frequency current sensor B1 by a distance (T1-T0)v c Position, traverse the entire homologous high-frequency current signal to obtain multiple local discharge positions, and combine the corresponding multiple local discharge positions to obtain a corresponding distance value set.

[0084] According to an embodiment of the present invention, the step of extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor specifically includes:

[0085] The high-frequency pulse current signal obtained by the high-frequency current sensor is marked according to the corresponding acquisition time node to obtain high-frequency pulse current signals with different time marks;

[0086] Compare and analyze any two high-frequency pulse current signals with different time stamps to obtain similarity values;

[0087] If the similarity value is greater than a preset similarity threshold, the high-frequency pulse current signals corresponding to two different time stamps are set as homologous high-frequency pulse current signals.

[0088] It should be noted that, at the same local discharge position, due to the inconsistency of the notch mode or form, the high-frequency pulse current signals generated are also different. Therefore, the preset similarity threshold is used for judgment, and the high-frequency pulse current signals with similarity values ​​greater than the preset similarity threshold are uniformly classified and set as homologous high-frequency pulse current signals to prevent the occurrence of multiple local discharge positions to interfere with the positioning of the local discharge.

[0089] According to an embodiment of the present invention, it also includes:

[0090] The homologous high-frequency pulse current signals are sorted according to the time sequence of acquisition, and the time nodes corresponding to the homologous high-frequency pulse current signals are extracted;

[0091] Calculate the difference between the time nodes corresponding to the adjacent high-frequency pulse current signals of the same source, and take the absolute value to obtain a first time difference;

[0092] If the first time difference value is within the preset first time difference range, the corresponding first time difference is saved;

[0093] If the first time difference is not within the preset first time difference range, the adjacent homologous high-frequency pulse current signals corresponding to the first time difference are deleted.

[0094] It should be noted that the time node corresponding to the homologous high-frequency pulse current signal is the time when each segment of the homologous high-frequency pulse current signal begins to appear, and the first time difference corresponding to adjacent homologous high-frequency pulse current signals is the period of the corresponding homologous high-frequency pulse current signal. When the first time difference is not within the preset first time difference range, it means that the high-frequency pulse current signal corresponding to the first time difference is interfered with, and the data deviation of the corresponding high-frequency pulse current signal is large, so the corresponding high-frequency pulse current signal is deleted.

[0095] According to an embodiment of the present invention, the step of comparing and analyzing any two high-frequency pulse current signals with different time stamps to obtain similarity values ​​specifically includes:

[0096] Extract the characteristics of high-frequency pulse current signals and corresponding characteristic values;

[0097] Based on the same features, the smaller value of the feature values ​​of any two high-frequency pulse current signals with different time stamps is divided by the larger value to obtain the similarity value of the corresponding feature;

[0098] Traverse all the same features and get the similarity values ​​of all the same features;

[0099] The similarity value of the same feature is multiplied by the influence weight coefficient of the corresponding feature, and then accumulated to obtain the similarity value of the high-frequency pulse current signal corresponding to two different time stamps.

[0100] It should be noted that the high-frequency pulse current signal includes characteristics such as pulse width, frequency, and amplitude. For example, the pulse width similarity values ​​of two high-frequency pulse current signals are first determined, and then the similarity values ​​of the high-frequency pulse current signals corresponding to two different time marks are calculated based on the influence weight coefficients of the corresponding pulse widths. The cumulative value of the influence weight coefficients of all characteristics is 1.

[0101] According to an embodiment of the present invention, the step of calculating the distance value according to the corresponding homologous high-frequency pulse current signal and constructing a distance value set specifically includes:

[0102] Extract the time nodes corresponding to the homologous high-frequency pulse current signals;

[0103] Subtract the time when the corresponding joint is powered on from the time node of the corresponding homologous high-frequency pulse current signal to obtain a second time difference;

[0104] Divide the second time difference by 2, and then multiply by the preset light speed to obtain the distance value corresponding to the homologous high-frequency pulse current signal;

[0105] All homologous high-frequency pulse current signals are traversed to obtain a distance value set corresponding to the homologous high-frequency pulse current signals, that is, a distance value set.

[0106] It should be noted that when there is a high-frequency current sensor that obtains a high-frequency pulse current signal and there is no voltage at other connectors or ports, it means that the corresponding high-frequency pulse current signal is propagated in the reverse direction, and the corresponding connector is the connector where the high-frequency current sensor that obtains the same high-frequency pulse current signal is located; because there is an interruption in the high-voltage cable, multiple sets of high-frequency pulse current signal data can be obtained by repeated power-on tests.

[0107] Figure 2 A block diagram of an online monitoring and positioning system for partial discharge of a high-voltage cable according to the present invention is shown.

[0108] like Figure 2 As shown, the second aspect of the present invention provides a high-voltage cable partial discharge online monitoring and positioning system 2, including a memory 21 and a processor 22, wherein the memory stores a high-voltage cable partial discharge online monitoring and positioning method program, and the high-voltage cable partial discharge online monitoring and positioning method program is executed by the processor to implement the following steps:

[0109] Based on the high-frequency current sensor and time sensor preset at the high-voltage cable joint or port, the high-frequency pulse current signal and the corresponding time node generated by the partial discharge are obtained;

[0110] Obtaining a first prediction area of ​​the local discharge according to the high-frequency pulse current signal generated by the local discharge and the corresponding time node;

[0111] Based on the preset acoustic sensors and time sensors in the high-voltage cable segment area where the first prediction area is located, the acoustic wave signals generated by the partial discharge and the corresponding time nodes are obtained;

[0112] According to the acoustic wave signal generated by the partial discharge and the corresponding time node, a second prediction area of ​​the partial discharge is obtained;

[0113] The intersection of the first prediction region and the second prediction region of the partial discharge is extracted to obtain the prediction region of the partial discharge.

[0114] According to an embodiment of the present invention, it also includes:

[0115] Numbering the high-frequency current sensors preset at the high-voltage cable joints or ports to obtain serial numbers of the high-frequency current sensors;

[0116] When the high-frequency current sensor obtains the high-frequency pulse current signal, the high-frequency pulse current signal is sorted and numbered in chronological order, and the high-frequency pulse current signal is marked according to the current time node to obtain a high-frequency pulse current signal with a time mark and a number;

[0117] When there is no high-frequency pulse current signal or only one high-frequency current sensor acquires the high-frequency pulse current signal, and there is voltage at other joints or ports, information is obtained that there is no partial discharge in the high-voltage cable.

[0118] According to an embodiment of the present invention, the step of obtaining a first predicted area of ​​partial discharge specifically includes:

[0119] When there is a high-frequency current sensor to obtain a high-frequency pulse current signal, and there is no voltage at other connectors or ports, then the connector or port corresponding to the high-frequency current sensor is connected to the power supply end;

[0120] Extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor;

[0121] Calculate the distance value according to the corresponding homologous high-frequency pulse current signal, construct a distance value set, extract the maximum value and the minimum value in the distance value set, and construct a first prediction area with the corresponding maximum value and the minimum value;

[0122] When there are multiple high-frequency current sensors that acquire high-frequency pulse current signals, extract the first high-frequency current sensor that acquires the same high-frequency current signal;

[0123] Taking the first high-frequency current sensor that obtains the high-frequency current signal of the same source as a reference point, extracting the high-frequency current signals of the same source obtained by a preset number of adjacent high-frequency current sensors;

[0124] Distance values ​​are calculated based on homologous high-frequency current signals obtained by a preset number of adjacent high-frequency current sensors, a distance value set is constructed, the maximum value and the minimum value in the distance value set are extracted, and a first prediction area is constructed with the corresponding maximum value and minimum value.

[0125] The invention discloses a method and system for online monitoring and positioning of partial discharge of a high-voltage cable, which improves the accuracy and reliability of partial discharge monitoring and positioning of the high-voltage cable through the combination of sound and electricity.

[0126] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0127] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0128] In addition, all functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0129] A person of ordinary skill in the art can understand that: all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks or optical disks, and other media that can store program codes.

[0130] Alternatively, if the above-mentioned integrated unit of the present invention is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

Claims

1. A method for online monitoring and positioning of partial discharge of high voltage cables, characterized in that: include: Based on the high-frequency current sensor and time sensor preset at the high-voltage cable joint or port, the high-frequency pulse current signal and the corresponding time node generated by the partial discharge are obtained; Obtaining a first prediction area of ​​the local discharge according to the high-frequency pulse current signal generated by the local discharge and the corresponding time node; Based on the preset acoustic sensors and time sensors in the high-voltage cable segment area where the first prediction area is located, the acoustic wave signals generated by the partial discharge and the corresponding time nodes are obtained; According to the acoustic wave signal generated by the partial discharge and the corresponding time node, a second prediction area of ​​the partial discharge is obtained; The intersection of the first prediction region and the second prediction region of the partial discharge is extracted to obtain the prediction region of the partial discharge.

2. A method for online monitoring and positioning of partial discharge of a high-voltage cable according to claim 1, characterized in that: Also includes: Numbering the high-frequency current sensors preset at the high-voltage cable joints or ports to obtain serial numbers of the high-frequency current sensors; When the high-frequency current sensor obtains the high-frequency pulse current signal, the high-frequency pulse current signal is sorted and numbered in chronological order, and the high-frequency pulse current signal is marked according to the current time node to obtain a high-frequency pulse current signal with a time mark and a number; When there is no high-frequency pulse current signal or only one high-frequency current sensor acquires the high-frequency pulse current signal, and there is voltage at other joints or ports, information is obtained that there is no partial discharge in the high-voltage cable.

3. A method for online monitoring and positioning of partial discharge of a high-voltage cable according to claim 1, characterized in that: The step of obtaining the first predicted area of ​​partial discharge specifically includes: When there is a high-frequency current sensor to obtain a high-frequency pulse current signal, and there is no voltage at other connectors or ports, then the connector or port corresponding to the high-frequency current sensor is connected to the power supply end; Extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor; Calculate the distance value according to the corresponding homologous high-frequency pulse current signal, construct a distance value set, extract the maximum value and the minimum value in the distance value set, and construct a first prediction area with the corresponding maximum value and the minimum value; When there are multiple high-frequency current sensors that acquire high-frequency pulse current signals, extract the first high-frequency current sensor that acquires the same high-frequency current signal; Taking the first high-frequency current sensor that obtains the high-frequency current signal of the same source as a reference point, extracting the high-frequency current signals of the same source obtained by a preset number of adjacent high-frequency current sensors; Distance values ​​are calculated based on homologous high-frequency current signals obtained by a preset number of adjacent high-frequency current sensors, a distance value set is constructed, the maximum value and the minimum value in the distance value set are extracted, and a first prediction area is constructed with the corresponding maximum value and minimum value.

4. A method for online monitoring and positioning of partial discharge of a high-voltage cable according to claim 3, characterized in that: The step of extracting the homologous high-frequency pulse current signal from the high-frequency pulse current signal obtained by the corresponding high-frequency current sensor specifically includes: The high-frequency pulse current signal obtained by the high-frequency current sensor is marked according to the corresponding acquisition time node to obtain high-frequency pulse current signals with different time marks; Compare and analyze any two high-frequency pulse current signals with different time stamps to obtain similarity values; If the similarity value is greater than a preset similarity threshold, the high-frequency pulse current signals corresponding to two different time stamps are set as homologous high-frequency pulse current signals.

5. A method for online monitoring and positioning of partial discharge of a high-voltage cable according to claim 4, characterized in that: Also includes: The homologous high-frequency pulse current signals are sorted according to the time sequence of acquisition, and the time nodes corresponding to the homologous high-frequency pulse current signals are extracted; Calculate the difference between the time nodes corresponding to the adjacent high-frequency pulse current signals of the same source, and take the absolute value to obtain a first time difference; If the first time difference value is within the preset first time difference range, the corresponding first time difference is saved; If the first time difference is not within the preset first time difference range, the adjacent homologous high-frequency pulse current signals corresponding to the first time difference are deleted.

6. A method for online monitoring and positioning of partial discharge of a high-voltage cable according to claim 4, characterized in that: The step of comparing and analyzing any two high-frequency pulse current signals with different time stamps to obtain similarity values ​​specifically includes: Extract the characteristics of high-frequency pulse current signals and corresponding characteristic values; Based on the same features, the smaller value of the feature values ​​of any two high-frequency pulse current signals with different time stamps is divided by the larger value to obtain the similarity value of the corresponding feature; Traverse all the same features and get the similarity values ​​of all the same features; The similarity value of the same feature is multiplied by the influence weight coefficient of the corresponding feature, and then accumulated to obtain the similarity value of the high-frequency pulse current signal corresponding to two different time stamps.

7. A method for online monitoring and positioning of partial discharge of a high-voltage cable according to claim 5, characterized in that: The step of calculating the distance value according to the corresponding homologous high-frequency pulse current signal and constructing the distance value set specifically includes: Extract the time nodes corresponding to the homologous high-frequency pulse current signals; Subtract the time when the corresponding joint is powered on from the time node of the corresponding homologous high-frequency pulse current signal to obtain a second time difference; Divide the second time difference by 2, and then multiply by the preset light speed to obtain the distance value corresponding to the homologous high-frequency pulse current signal; All homologous high-frequency pulse current signals are traversed to obtain a distance value set corresponding to the homologous high-frequency pulse current signals, that is, a distance value set.

8. A high voltage cable partial discharge online monitoring and positioning system, characterized in that: The invention comprises a memory and a processor, wherein the memory stores a program of a method for online monitoring and positioning of partial discharge of a high-voltage cable, and when the program of online monitoring and positioning of partial discharge of a high-voltage cable is executed by the processor, the following steps are implemented: Based on the high-frequency current sensor and time sensor preset at the high-voltage cable joint or port, the high-frequency pulse current signal and the corresponding time node generated by the partial discharge are obtained; Obtaining a first prediction area of ​​the local discharge according to the high-frequency pulse current signal generated by the local discharge and the corresponding time node; Based on the preset acoustic sensors and time sensors in the high-voltage cable segment area where the first prediction area is located, the acoustic wave signals generated by the partial discharge and the corresponding time nodes are obtained; According to the acoustic wave signal generated by the partial discharge and the corresponding time node, a second prediction area of ​​the partial discharge is obtained; The intersection of the first prediction region and the second prediction region of the partial discharge is extracted to obtain the prediction region of the partial discharge.

9. A high-voltage cable partial discharge online monitoring and positioning system according to claim 8, characterized in that: Also includes: Numbering the high-frequency current sensors preset at the high-voltage cable joints or ports to obtain serial numbers of the high-frequency current sensors; When the high-frequency current sensor obtains the high-frequency pulse current signal, the high-frequency pulse current signal is sorted and numbered in chronological order, and the high-frequency pulse current signal is marked according to the current time node to obtain a high-frequency pulse current signal with a time mark and a number; When there is no high-frequency pulse current signal or only one high-frequency current sensor acquires the high-frequency pulse current signal, and there is voltage at other joints or ports, information is obtained that there is no partial discharge in the high-voltage cable.

10. A high-voltage cable partial discharge online monitoring and positioning system according to claim 8, characterized in that: The step of obtaining the first predicted area of ​​partial discharge specifically includes: When there is a high-frequency current sensor to obtain a high-frequency pulse current signal, and there is no voltage at other connectors or ports, then the connector or port corresponding to the high-frequency current sensor is connected to the power supply end; Extracting a homologous high-frequency pulse current signal from a high-frequency pulse current signal obtained by a corresponding high-frequency current sensor; Calculate the distance value according to the corresponding homologous high-frequency pulse current signal, construct a distance value set, extract the maximum value and the minimum value in the distance value set, and construct a first prediction area with the corresponding maximum value and the minimum value; When there are multiple high-frequency current sensors that acquire high-frequency pulse current signals, extract the first high-frequency current sensor that acquires the same high-frequency current signal; Taking the first high-frequency current sensor that obtains the high-frequency current signal of the same source as a reference point, extracting the high-frequency current signals of the same source obtained by a preset number of adjacent high-frequency current sensors; Distance values ​​are calculated based on homologous high-frequency current signals obtained by a preset number of adjacent high-frequency current sensors, a distance value set is constructed, the maximum value and the minimum value in the distance value set are extracted, and a first prediction area is constructed with the corresponding maximum value and minimum value.

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