Partial discharge positioning method, device and storage medium of cable

Abstract

The application discloses a partial discharge positioning method and device of a cable and a storage medium. The method comprises the following steps: extracting a plurality of original peak signals from a partial discharge signal of the cable; removing interference in the plurality of original peak signals to obtain target peak signals; identifying two target peak signals matched with each other as paired peak signals; calculating candidate discharge positions of partial discharge sources in the cable according to time differences between the paired peak signals; and clustering the candidate discharge positions to obtain target discharge positions of the partial discharge sources in the cable. For multiple partial discharge signals of a single partial discharge source, stable positions can be clustered after interference is removed and preliminary positioning is performed, and the method does not depend on the number of preset partial discharge sources, has strong adaptability to partial discharge sources generated under different conditions, can inhibit the influence caused by time errors and randomness, and improves the positioning accuracy of the partial discharge sources.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power, and particularly relates to a partial discharge positioning method of a cable, a device and a storage medium. BACKGROUND

[0002] Electric power is transmitted to various places through cables in a power grid, cables are widely laid in various areas, the environment of the cables is relatively complex, and the surface of the cables is prone to corrosion, being gnawed by animals and the like, so that the insulation layer of the cable is damaged, partial discharge occurs, and a power grid fault can be caused.

[0003] Therefore, checking the partial discharge of the cable is a conventional detection item of cable maintenance, and positioning of a partial discharge source is beneficial to quickly finding an insulation fault and avoiding checking the entire cable.

[0004] At present, a traveling wave distance positioning method is mainly used, and the position of the partial discharge source is calculated according to the time difference of the partial discharge signal, but the time point determined by a single pair of matched signals has large error and strong randomness, and interference signals and noise data also affect the positioning accuracy. SUMMARY

[0005] The present application provides a partial discharge positioning method of a cable, a device and a storage medium, to solve how to improve the accuracy of checking the position of a partial discharge source of the cable.

[0006] According to an aspect of the present application, a partial discharge positioning method of a cable is provided, comprising:

[0007] extracting a plurality of original peak signals from a partial discharge signal of the cable;

[0008] removing interference from the plurality of original peak signals to obtain target peak signals;

[0009] identifying two target peak signals matched with each other as matched peak signals;

[0010] calculating a candidate discharge position of a partial discharge source in the cable according to the time difference between the matched peak signals;

[0011] clustering the candidate discharge position to obtain a target discharge position of the partial discharge source in the cable.

[0012] Optionally, the extracting a plurality of original peak signals from a partial discharge signal of the cable comprises:

[0013] generating an oscillation wave signal to the cable;

[0014] if it is detected according to the oscillation wave signal that there is a partial discharge source in the cable, collecting a partial discharge signal of the partial discharge source.

[0015] extracting each original peak signal from the partial discharge signal.

[0016] Optionally, the removing interference from the plurality of original peak signals to obtain target peak signals comprises:

[0017] selecting the original peak signal with the largest amplitude from the plurality of original peak signals;

[0018] multiplying the absolute value of the original peak signal with the largest amplitude by a preset amplitude coefficient to obtain an amplitude threshold;

[0019] if the original peak signal is smaller than the amplitude threshold, deleting the original peak signal;

[0020] if the original peak signal is greater than or equal to the amplitude threshold, marking the original peak signal as a candidate peak signal;

[0021] calculating a plurality of time periods of round-trip reflection in the cable for each candidate peak signal;

[0022] finding other candidate peak signals with reflection interference to the current candidate peak signal in the plurality of time periods;

[0023] if other candidate peak signals are found, deleting other candidate peak signals;

[0024] marking the remaining candidate peak signals as target peak signals.

[0025] Optionally, the time period is:

[0026]

[0027] wherein, t i is a time point at which the i-th candidate peak signal is located, L is the length of the cable, v is the propagation speed of the partial discharge signal, f s is the sampling frequency, and β is a positive integer;

[0028] other candidate peak signals with reflection interference to the current candidate peak signal meet the following conditions:

[0029] S Ri *S Rj >0

[0030] |S Ri |>|S Rj |

[0031] wherein, S Ri is the i-th candidate peak signal, SRj is the jth candidate peak signal.

[0032] Optionally, the identifying two target peak signals matching each other as a paired peak signal comprises:

[0033] calculating a time range of pairing for each target peak signal;

[0034] finding other target peak signals matching the current target peak signal in the time range;

[0035] labeling the current target peak signal and the matching other target peak signal as a paired peak signal.

[0036] Optionally, the time range is:

[0037]

[0038] wherein, t Pi is the time point of the ith target peak signal, L is the length of the cable, v is the propagation speed of the partial discharge signal, f s is the sampling frequency;

[0039] the other target peak signal matching the current target peak signal meets the following conditions:

[0040] S Pi S Pj > 0

[0041] |S Pi | > |S Pj | > c|S Pi |

[0042] wherein, S Pi is the ith target peak signal, S Pj is the jth target peak signal, and c is a pairing coefficient.

[0043] Optionally, the calculating the candidate discharge position of the partial discharge source in the cable according to the time difference between the paired peak signals comprises:

[0044] substituting the time difference between the paired peak signals into the following formula to calculate the candidate discharge position of the partial discharge source in the cable:

[0045]

[0046] wherein, X is the candidate discharge position of the partial discharge source in the cable, L is the length of the cable, t Pi is the time point of the ith paired peak signal, and tpj a time point where the jth pair of peak signals is located, and v is a propagation speed of the partial discharge signal.

[0047] Optionally, the clustering of the candidate discharge positions to obtain the target discharge position of the partial discharge source in the cable comprises:

[0048] sorting the candidate discharge positions to obtain a position sequence;

[0049] cutting the position sequence into a plurality of data groups, a difference between two adjacent candidate discharge positions in a same data group being less than or equal to a preset first threshold, and a difference between the candidate discharge positions located at boundaries of two adjacent data groups being greater than the preset first threshold;

[0050] if a number of the candidate discharge positions in the data group is less than or equal to a preset second threshold, deleting the data group;

[0051] if the number of the candidate discharge positions in the data group is greater than the preset second threshold, calculating an average value of the candidate discharge positions in the data group to obtain the target discharge position of the partial discharge source in the cable.

[0052] According to another aspect of the present application, there is provided a partial discharge positioning device for a cable, comprising:

[0053] a raw peak signal extraction module configured to extract a plurality of raw peak signals from a partial discharge signal of the cable;

[0054] a target peak signal screening module configured to remove interference from the plurality of raw peak signals to obtain target peak signals;

[0055] a pair of peak signal identification module configured to identify two target peak signals matched with each other as a pair of peak signals;

[0056] a candidate discharge position calculation module configured to calculate candidate discharge positions of a partial discharge source in the cable according to a time difference between the pair of peak signals;

[0057] a target discharge position clustering module configured to cluster the candidate discharge positions to obtain a target discharge position of the partial discharge source in the cable.

[0058] Optionally, the raw peak signal extraction module is further configured to:

[0059] generate an oscillation wave signal for the cable;

[0060] if it is detected that there is a partial discharge source in the cable according to the oscillation wave signal, collect a partial discharge signal for the partial discharge source;

[0061] extracting each original peak signal from the partial discharge signal.

[0062] Optionally, the target peak signal screening module is further configured to:

[0063] screening the original peak signal with the largest amplitude from the plurality of original peak signals;

[0064] multiplying the absolute value of the original peak signal with the largest amplitude by a preset amplitude coefficient to obtain an amplitude threshold;

[0065] if the original peak signal is smaller than the amplitude threshold, deleting the original peak signal;

[0066] if the original peak signal is greater than or equal to the amplitude threshold, marking the original peak signal as a candidate peak signal;

[0067] calculating a plurality of time periods of round-trip reflection in the cable for each candidate peak signal;

[0068] finding other candidate peak signals with reflection interference on the current candidate peak signal in the plurality of time periods;

[0069] if other candidate peak signals are found, deleting other candidate peak signals;

[0070] marking the remaining candidate peak signals as target peak signals.

[0071] Optionally, the time period is:

[0072]

[0073] wherein t i is a time point at which the i-th candidate peak signal is located, L is the length of the cable, v is the propagation speed of the partial discharge signal, f s is the sampling frequency, and β is a positive integer;

[0074] other candidate peak signals with reflection interference on the current candidate peak signal meet the following conditions:

[0075] S Ri * S Rj > 0

[0076] |S Ri | > |S Rj |

[0077] wherein S Ri is the i-th candidate peak signal, and S Rj is the j-th candidate peak signal.

[0078] Optionally, the pair peak signal identifying module is further configured to:

[0079] calculate a time range for each of the target peak signals;

[0080] find other target peak signals matching the current target peak signal within the time range;

[0081] label the current target peak signal and the matching target peak signal as a pair peak signal.

[0082] Optionally, the time range is:

[0083]

[0084] wherein t Pi is a time point at which the ith target peak signal is located, L is a length of the cable, v is a propagation speed of the partial discharge signal, f s is a sampling frequency;

[0085] the other target peak signal matching the current target peak signal satisfies the following conditions:

[0086] S Pi * S Pj > 0

[0087] |S Pi | > |S Pj | > c|S Pi |

[0088] wherein S Pi is the ith target peak signal, S Pj is the jth target peak signal, and c is a pair coefficient.

[0089] Optionally, the candidate discharge location calculating module is further configured to:

[0090] substitute a time difference between the pair peak signals into the following formula to calculate a candidate discharge location of a partial discharge source in the cable:

[0091]

[0092] wherein X is the candidate discharge location of the partial discharge source in the cable, L is a length of the cable, t Pi is a time point at which the ith pair peak signal is located, t pj is a time point at which the jth pair peak signal is located, and v is a propagation speed of the partial discharge signal.

[0093] Optionally, the target discharge location clustering module is further configured to:

[0094] sort the candidate discharge locations to obtain a location sequence;

[0095] divide the location sequence into a plurality of data groups, a difference between two adjacent candidate discharge locations in a same data group being less than or equal to a preset first threshold, and a difference between the candidate discharge locations located at boundaries of two adjacent data groups being greater than the preset first threshold;

[0096] if a number of the candidate discharge locations in the data group is less than or equal to a preset second threshold, delete the data group;

[0097] if the number of the candidate discharge locations in the data group is greater than the preset second threshold, calculate an average value of the candidate discharge locations in the data group to obtain a target discharge location of a partial discharge source in the cable.

[0098] According to another aspect of the present application, an electronic device is provided, which comprises:

[0099] at least one processor; and

[0100] a memory in communication connection with the at least one processor; wherein

[0101] the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the partial discharge positioning method of the cable according to any one of the embodiments of the present application.

[0102] According to another aspect of the present application, a computer readable storage medium is provided, which stores a computer program for enabling a processor to implement the partial discharge positioning method of the cable according to any one of the embodiments of the present application when executed.

[0103] In the embodiment, a plurality of original peak signals are extracted from a partial discharge signal of a cable, interference is removed from the plurality of original peak signals to obtain target peak signals, two target peak signals matched with each other are identified as paired peak signals, candidate discharge locations of a partial discharge source in the cable are calculated according to time differences between the paired peak signals, and the target discharge location of the partial discharge source in the cable is obtained by clustering the candidate discharge locations. For a plurality of partial discharge signals of a single partial discharge source, stable locations can be clustered after interference is removed and preliminary positioning is performed, and the method is not dependent on a preset number of partial discharge sources, has strong adaptability to partial discharge sources generated in different situations, can suppress influences caused by time errors and randomness, and improves positioning accuracy of the partial discharge source.

[0104] It should be understood that nothing in this section is intended to limit the scope of the embodiments of the present application nor are they intended to represent key or essential features of the embodiments of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0105] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative effort.

[0106] Figure 1 is a flow chart of a partial discharge positioning method of a cable according to the first embodiment of the present application;

[0107] Figure 2 is a circuit schematic diagram of collecting partial discharge signals of a cable according to the first embodiment of the present application;

[0108] Figure 3 is a structural schematic diagram of a partial discharge positioning device of a cable according to the second embodiment of the present application;

[0109] Figure 4 is a structural schematic diagram of an electronic device according to the third embodiment of the present application. DETAILED DESCRIPTION

[0110] In order to make the technical personnel in the art better understand the present application scheme, the following will combine the drawings in the embodiments of the present application, and the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only some embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should belong to the scope of protection of the present application.

[0111] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0112] Example 1

[0113] Figure 1 This is a flowchart illustrating a partial discharge location method for a cable according to Embodiment 1 of the present invention. This method can be executed by a partial discharge location device for the cable, which can be implemented in hardware and / or software and can be configured in an electronic device. Figure 1 As shown, the method includes:

[0114] Step 101: Extract multiple raw peak signals from the partial discharge signal of the cable.

[0115] In this embodiment, the cable can be monitored. If a partial discharge signal is detected in the cable, multiple original peak signals can be extracted from the partial discharge signal. The original peak signals are signals at their peak values.

[0116] In practical implementation, data acquisition devices can be deployed over the cable, such as... Figure 2 As shown, one end of cable E is grounded, and the other end is connected to voltage divider VD and inductor L respectively. Voltage divider VD is connected to impedance Z and data acquisition device Q respectively. One end of data acquisition device Q is connected to voltage divider VD, and the other end is connected to impedance Z. Impedance Z is grounded. Inductor L is connected to switch K and current limiting resistor R respectively. Switch K is grounded. Current limiting resistor R is connected to DC power supply S. DC power supply S is grounded.

[0117] Furthermore, the voltage divider VD includes two branches. A first capacitor C1 and a second capacitor C2 are connected in series on one branch closer to cable E, and a first resistor R1 and a second resistor R2 are connected in series on the other branch farther from cable E. Both the second capacitor C2 and the second resistor R2 are connected to impedance Z. The data acquisition device Q is connected to the intersection between the first resistor R1 and the second resistor R2, and the intersection between the first capacitor C1 and the second capacitor C2, respectively.

[0118] Generally, there is an interference signal at the moment when the switch K is closed, therefore, from the first value of the partial discharge signal, the values in a half cycle are set to 0.

[0119] In the embodiment, the collector can be driven to generate an oscillation wave signal to the cable, and in the duration of the oscillation wave signal, if it is detected that there is a partial discharge source in the cable, the collector can be driven to collect a partial discharge signal of the partial discharge source, and each partial discharge source will have multiple discharge phenomena and generate a large amount of partial discharge signals.

[0120] The peak detection algorithm such as sliding window, pre / post optimization is used to extract each original peak signal S from the partial discharge signal K , wherein K is a positive integer, representing the number of original peak signals, and each original peak signal S K carries amplitude, time point and the like.

[0121] Step 102, removing interference from the plurality of original peak signals to obtain target peak signals.

[0122] Since there are various interferences in the cable, such as environmental interference, reflection interference and the like, the corresponding interference can be removed from the plurality of original peak signals according to the interference condition to obtain relatively clean target peak signals, and the quality of the target peak signals is improved.

[0123] In an embodiment of the application, step 102 can include the following steps:

[0124] Step 1021, screening out the original peak signal with the largest amplitude from the plurality of original peak signals.

[0125] In the embodiment, the amplitudes of the plurality of original peak signals S K can be compared to screen out the original peak signal S max with the largest amplitude.

[0126] Step 1022, multiplying the absolute value of the original peak signal with the largest amplitude by a preset amplitude coefficient to obtain an amplitude threshold.

[0127] The absolute value of the original peak signal S max with the largest amplitude is multiplied by a preset amplitude coefficient a to obtain a product, which is recorded as an amplitude threshold a|s max |, and the amplitudes of the plurality of original peak signals S K are compared with the amplitude threshold a|s max |.

[0128] Step 1023, if the original peak signal is smaller than the amplitude threshold, the original peak signal is deleted.

[0129] Step 1024, if the original peak signal is greater than or equal to the amplitude threshold, mark the original peak signal as a candidate peak signal.

[0130] If a certain original peak signal is less than the amplitude threshold, i.e., s i <a|s max |, i∈(1~K), it indicates that the original peak signal belongs to white noise generated by environmental interference, at this time, the original peak signal can be deleted to remove environmental interference.

[0131] If a certain original peak signal is greater than or equal to the amplitude threshold, i.e., s i ≥a|s max |, i∈(1~K), the original peak signal can be marked as a candidate peak signal S R , where R is a positive integer, indicating the number of candidate peak signals, and the candidate peak signal S R is further removed from interference.

[0132] Step 1025, calculate the multiple time periods of round-trip reflection in the cable for each candidate peak signal.

[0133] A single partial discharge signal reaches the head end of the cable, is reflected and then reaches the tail end of the cable, and is reflected to the head end of the cable again, and in positioning the partial discharge source, the partial discharge signal round-trip reflected through the cable is not referenced, therefore, such a partial discharge signal can be regarded as an interference signal.

[0134] In the embodiment, the information of each candidate peak signal S R can be referred to, and the candidate peak signals S R are read one by one, and the multiple time periods of round-trip reflection in the cable are calculated for each candidate peak signal S R .

[0135] Exemplarily, the distance between the partial discharge signal and the first arrival at the head end of the cable is an integer multiple of 2L, where L is the length of the cable, and the time period is:

[0136]

[0137] Where t i is the time point at which the i-th candidate peak signal S Ri (current candidate peak signal) is located, L is the length of the cable, v is the propagation speed of the partial discharge signal, f s is the sampling frequency, and β is a positive integer, the value of β determines the number of time periods, and generally, β=1, 2, 3, i.e., take three consecutive time periods to check whether there is reflected interference.

[0138] Step 1026, searching for other candidate peak signals existing reflection interference to the current candidate peak signal in multiple time periods.

[0139] Step 1027, if other candidate peak signals are found, deleting the other candidate peak signals.

[0140] Step 1028, marking the remaining candidate peak signals as target peak signals.

[0141] In the embodiment, each candidate peak signal can be traversed, and other candidate peak signals existing reflection interference to the current candidate peak signal in multiple time periods are searched in sequence.

[0142] Exemplarily, other candidate peak signals existing reflection interference to the current candidate peak signal meet the following conditions:

[0143] S Ri S Rj > 0, i, j ∈ (1 ~ R)

[0144] |S Ri | > |S Rj |

[0145] Wherein, S Ri is the i-th candidate peak signal, S Rj is the j-th candidate peak signal, then S Rj exists reflection interference to S RI .

[0146] For other candidate peak signals existing reflection interference, the other candidate peak signals can be deleted, such as being set to 0, and the current candidate peak signal is removed reflection interference.

[0147] After traversing all candidate peak signals S R , the remaining candidate peak signals S R are marked as target peak signals S P , wherein P is a positive integer, representing the number of target peak signals.

[0148] Step 103, identifying two target peak signals matched with each other as paired peak signals.

[0149] In actual application, a partial discharge source generates a partial discharge signal, and the partial discharge signal directly from the partial discharge source to the collector (i.e. the cable head) is recorded as S pi，1 , and the partial discharge signal reflected from the cable tail end to the collector is recorded as S pi，2 , S pi，1 and S pi，2The position of the partial discharge source in the cable can be calculated by the time difference between the paired partial discharge signals.

[0150] In this embodiment, two target peak signals that match each other can be identified as paired peak signals, i.e., one of the target peak signals in the paired peak signals is a partial discharge signal reflected by the other target peak signal.

[0151] In one embodiment of the present application, step 103 can include the following steps:

[0152] Step 1031, calculating the paired time range for each target peak signal.

[0153] In this embodiment, the information of each target peak signal S P can be referred to, and each target peak signal S P can be read one by one to calculate the paired time range for each target peak signal S P .

[0154] For example, the time range is:

[0155]

[0156] where t Pi is the time point at which the i-th target peak signal S Pi (i.e., the current target peak signal) is located, L is the length of the cable, v is the propagation speed of the partial discharge signal, and f s is the sampling frequency.

[0157] Step 1032, finding other target peak signals that match the current target peak signal within the time range.

[0158] Step 1033, marking the current target peak signal and the matched other target peak signal as paired peak signals.

[0159] In this embodiment, each target peak signal can be traversed to find other candidate peak signals that have reflection interference with the current candidate peak signal within the corresponding time range. If a matched other target peak signal is found, the current target peak signal and the matched other target peak signal are marked as paired peak signals, and the pairing is completed.

[0160] For example, the other target peak signal that matches the current target peak signal satisfies the following conditions:

[0161] S Pi *S Pj > 0 i, j ∈ (1 ~ P)

[0162] |SPi |>|S Pj |>c|S Pi |

[0163] wherein S Pi is the ith target peak signal, S Pj is the jth target peak signal, and c is a pairing coefficient, then S Pj is a pairing peak signal. Pi

[0164] Step 104, calculating the candidate discharge position of the partial discharge source in the cable according to the time difference between the pairing peak signals.

[0165] In this embodiment, the time difference between the pairing peak signals (i.e. two target peak signals) can be calculated, and the position of the partial discharge source in the cable is calculated according to the time difference, which is recorded as the candidate discharge position.

[0166] In a specific implementation, the time difference between the pairing peak signals can be substituted into the following formula to calculate the candidate discharge position of the partial discharge source in the cable:

[0167]

[0168] wherein X is the candidate discharge position of the partial discharge source in the cable, L is the length of the cable, t Pi is the time point at which the ith target peak signal is located, t pj is the time point at which the jth target peak signal is located, and v is the propagation speed of the partial discharge signal.

[0169] Step 105, clustering the candidate discharge positions to obtain the target discharge position of the partial discharge source in the cable.

[0170] In actual applications, multiple candidate discharge positions are obtained through multiple detections, and the multiple candidate discharge positions fluctuate to form a scatter plot S X Therefore, the multiple candidate discharge positions in the scatter plot S X can be clustered to reduce the interference of fluctuations and obtain the target discharge position of the partial discharge source in the cable, so as to improve the accuracy of the target discharge position.

[0171] In an embodiment of the present application, step 105 can include the following steps:

[0172] Step 1051, sorting the candidate discharge positions to obtain a position sequence.

[0173] In this embodiment, the multiple candidate discharge positions in the scatter plot S X can be sorted in ascending order to obtain a position sequence. ​

[0174] Step 1052, cutting the position sequence into multiple data groups.

[0175] In this embodiment, the position sequence can be cut to obtain multiple data groups, wherein the difference between two adjacent candidate discharge positions in a same data group is less than or equal to a preset first threshold (such as 0.5 meters), and the difference between the candidate discharge positions located at the boundaries of two adjacent data groups (i.e., the candidate discharge position at the end of the previous data group and the candidate discharge position at the beginning of the next data group) is greater than the preset first threshold (such as 0.5 meters).

[0176] In a specific implementation, step 1052 can further include the following steps.

[0177] Step 10521, determining a first variable and a second variable, wherein the first variable is initially the candidate discharge position at the beginning of the position sequence, and the second variable is the candidate discharge position after the first variable in the position sequence.

[0178] Step 10522, calculating the difference between the first variable and the second variable.

[0179] Step 10523, if the difference is less than or equal to the preset first threshold, writing the second variable into the data group where the first variable is located.

[0180] Step 10524, if the difference is greater than the preset first threshold, generating a new data group and writing the second variable into the new data group.

[0181] Step 10525, determining whether there is a candidate discharge position after the second variable in the position sequence, if there is, executing step 10526, and if not, ending.

[0182] Step 10526, setting the candidate discharge position of the second variable as the first variable, setting the candidate discharge position after the second variable in the position sequence as the second variable, and returning to execute step 10521.

[0183] Step 1053, if the number of candidate discharge positions in a data group is less than or equal to a preset second threshold, deleting the data group.

[0184] In this embodiment, the number of candidate discharge positions in each data group can be counted.

[0185] If the number of candidate discharge positions in a data group is less than or equal to a preset second threshold (such as 2), it means that the number of the data group is small and has no clustering significance, and thus the data group can be deleted.

[0186] Step 1054, if the number of candidate discharge positions in the data group is greater than the preset second threshold, the average value of the candidate discharge positions in the data group is calculated to obtain the target discharge position of the partial discharge source in the cable.

[0187] If the number of candidate discharge positions in a certain data group is greater than the preset second threshold (such as 2), it means that the number of the data group is relatively large and has clustering significance, and then the average value of each candidate discharge position in the data group can be calculated as the target discharge position of the partial discharge source in the cable.

[0188] In the embodiment, a plurality of original peak signals are extracted from the partial discharge signal of the cable; interference is removed from the plurality of original peak signals to obtain target peak signals; two target peak signals that match each other are identified as paired peak signals; the time difference between the paired peak signals is used to calculate the candidate discharge position of the partial discharge source in the cable; and the candidate discharge position is clustered to obtain the target discharge position of the partial discharge source in the cable. For multiple partial discharge signals of a single partial discharge source, stable positions can be clustered after interference is removed and preliminary positioning is performed, and the number of preset partial discharge sources is not relied on. The adaptability to partial discharge sources generated in different situations is strong, the influence of time error and randomness can be suppressed, and the positioning accuracy of the partial discharge source is improved.

[0189] Embodiment two

[0190] Figure 3 A structural schematic diagram of a partial discharge positioning device of a cable provided for the embodiment two of the application.

[0191] As shown in Figure 3 , the device comprises:

[0192] An original peak signal extraction module 301 is configured to extract a plurality of original peak signals from the partial discharge signal of the cable.

[0193] A target peak signal screening module 302 is configured to remove interference from the plurality of original peak signals to obtain target peak signals.

[0194] A paired peak signal identification module 303 is configured to identify two target peak signals that match each other as paired peak signals.

[0195] A candidate discharge position calculation module 304 is configured to calculate the candidate discharge position of the partial discharge source in the cable according to the time difference between the paired peak signals.

[0196] A target discharge position clustering module 305 is configured to cluster the candidate discharge position to obtain the target discharge position of the partial discharge source in the cable.

[0197] In one embodiment of the present application, the original peak signal extraction module 301 is further configured to:

[0198] generate an oscillation wave signal on the cable;

[0199] collect a partial discharge signal from the partial discharge source if the partial discharge source is detected in the cable according to the oscillation wave signal;

[0200] extract each original peak signal from the partial discharge signal.

[0201] In one embodiment of the present application, the target peak signal screening module 302 is further configured to:

[0202] screen the original peak signal with the largest amplitude from the original peak signals;

[0203] multiply the absolute value of the original peak signal with the largest amplitude by a preset amplitude coefficient to obtain an amplitude threshold;

[0204] delete the original peak signal if the original peak signal is smaller than the amplitude threshold;

[0205] mark the original peak signal as a candidate peak signal if the original peak signal is greater than or equal to the amplitude threshold;

[0206] calculate a plurality of time periods of round-trip reflection in the cable for each candidate peak signal;

[0207] find other candidate peak signals that have reflection interference on the current candidate peak signal in the time periods;

[0208] delete other candidate peak signals if other candidate peak signals are found;

[0209] mark the remaining candidate peak signals as target peak signals.

[0210] For example, the time period is:

[0211]

[0212] wherein t i is a time point at which the i-th candidate peak signal is located, L is the length of the cable, v is the propagation speed of the partial discharge signal, f s is the sampling frequency, and β is a positive integer.

[0213] Other candidate peak signals that have reflection interference on the current candidate peak signal meet the following conditions:

[0214] S Ri *SRj > 0

[0215] |S Ri |> |S Rj |

[0216] wherein, S Ri is the ith candidate peak signal, S Rj is the jth candidate peak signal.

[0217] In an embodiment of the present application, the pair peak signal identification module 303 is further configured to:

[0218] calculate a time range for pairing for each target peak signal;

[0219] find other target peak signals matching the current target peak signal within the time range;

[0220] label the current target peak signal and the matching other target peak signal as pair peak signals.

[0221] Exemplarily, the time range is:

[0222]

[0223] wherein, t Pi is a time point at which the ith target peak signal is located, L is the length of the cable, v is the propagation speed of the partial discharge signal, f s is the sampling frequency;

[0224] the other target peak signal matching the current target peak signal satisfies the following conditions:

[0225] S PI * S Pj > 0

[0226] |S Pi |> |S Pj |> c|S Pi |

[0227] wherein, S Pi is the ith target peak signal, S Pj is the jth target peak signal, and c is a pairing coefficient.

[0228] In an embodiment of the present application, the candidate discharge location calculation module 304 is further configured to:

[0229] substitute the time difference between the pair peak signals into the following formula to calculate the candidate discharge location of the partial discharge source in the cable:

[0230]

[0231] wherein X is a candidate discharge location of a partial discharge source in the cable, L is a length of the cable, t Pi is a time point at which the i-th paired peak signal is located, t pj is a time point at which the j-th paired peak signal is located, and v is a propagation speed of the partial discharge signal.

[0232] In an embodiment of the present application, the target discharge location clustering module 305 is further configured to:

[0233] sort the candidate discharge locations to obtain a location sequence;

[0234] divide the location sequence into a plurality of data groups, a difference between two adjacent candidate discharge locations in a same data group is less than or equal to a preset first threshold, and a difference between the candidate discharge locations located at the boundaries of two adjacent data groups is greater than the preset first threshold;

[0235] if the number of the candidate discharge locations in the data group is less than or equal to a preset second threshold, delete the data group;

[0236] if the number of the candidate discharge locations in the data group is greater than the preset second threshold, calculate an average value of the candidate discharge locations in the data group to obtain a target discharge location of a partial discharge source in the cable.

[0237] The partial discharge positioning device for the cable provided in the embodiments of the present application can execute the partial discharge positioning method for the cable provided in any of the embodiments of the present application, and has the corresponding function modules and beneficial effects of executing the partial discharge positioning method for the cable.

[0238] Embodiment Three

[0239] Figure 4 A block diagram of an electronic device 10 that can be used to implement an embodiment of the present application is shown. The electronic device is intended to represent various forms of digital computers, such as laptops, desktops, tablets, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device can also represent various forms of mobile devices such as personal digital assistants, cellular telephones, smartphones, wearable devices (e.g., headsets, glasses, watches, etc.), and other similar computing devices. The components shown here, their connections and relationships, and their functions, are meant to be examples only, and are not meant to limit implementations of the present application described and / or claimed in this document.

[0240] As Figure 4As shown, the electronic device 10 includes at least one processor 11, and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., communicatively connected to the at least one processor 11, where the memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer programs stored in the read-only memory (ROM) 12 or loaded into the random access memory (RAM) 13 from the storage unit 18. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0241] Various components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc., an output unit 17, such as various types of displays, a speaker, etc., a storage unit 18, such as a magnetic disk, an optical disk, etc., and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunication networks.

[0242] The processor 11 can be various general and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 performs various methods and processes described above, such as the partial discharge localization method for a cable.

[0243] In some embodiments, the partial discharge localization method for a cable can be implemented as a computer program tangibly embodied in a computer readable storage medium, such as the storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the partial discharge localization method for a cable described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to perform the partial discharge localization method for a cable by any other appropriate means, such as by means of firmware.

[0244] The various embodiments of the systems and techniques described above can be implemented in digital electronic circuitry, integrated circuitry, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on a chip (SOC), a load programmable logic device (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include implementation in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which can be special or general purpose, coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device.

[0245] Computer programs used to implement the processes of the application can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer program, when executed, can cause instructions defined in the flow charts and / or block diagrams to be implemented. The computer program can be executed entirely on a machine, partially on a machine, partially on a machine as a standalone software package and partially on a remote machine or entirely on a remote machine or server.

[0246] In the context of the present application, a computer-readable storage medium can be a tangible medium that can contain or store computer programs for use by or in connection with an instruction execution system, apparatus, or device. Computer-readable storage media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium will include one or more lines of electrical connections, portable computer disks, hard disk drives, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), optical fibers, portable compact disc read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0247] To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0248] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0249] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. A server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system, to solve the defects of large management difficulty and weak business scalability in traditional physical host and VPS service.

[0250] Embodiment Four

[0251] The embodiment of the present application further provides a computer program product, which comprises a computer program, and the computer program implements the partial discharge positioning method of the cable as provided in any embodiment of the present application when executed by a processor.

[0252] The computer program code can also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce the computer implemented process such that the

[0253] It should be understood that the various forms of flow shown in the figures are illustrative examples of implementing the steps of the application. Several steps have been described as being performed by a single device. It will be understood that these steps can be performed by a single device or multiple devices, and that the steps can be performed in an order different from that shown in the figures. For example, the steps described in the figures can be performed in parallel or in a different order, as long as the desired results of the application are achieved. The application is not limited in this regard.

[0254] The specific embodiments have been shown and described for the purposes of illustrating the physiological principles of the application and its practical application. It is therefore to be understood that various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the application. The scope of the application is not to be limited by specific illustrative embodiments. The application is to cover any and all modifications and the same is therefore intended to be within the scope of the application.

Claims

1. A partial discharge locating method for a cable, characterized by, The method comprises the following steps: extracting a plurality of original peak signals from a partial discharge signal of a cable; removing interference from the plurality of original peak signals to obtain target peak signals; identifying two target peak signals that match each other as paired peak signals; calculating candidate discharge positions of a partial discharge source in the cable according to a time difference between the paired peak signals; clustering the candidate discharge positions to obtain target discharge positions of the partial discharge source in the cable; the step of removing interference from the plurality of original peak signals to obtain target peak signals comprises the following steps: selecting the original peak signal with the largest amplitude from the plurality of original peak signals; multiplying the absolute value of the original peak signal with the largest amplitude by a preset amplitude coefficient to obtain an amplitude threshold; if the original peak signal is smaller than the amplitude threshold, deleting the original peak signal; if the original peak signal is greater than or equal to the amplitude threshold, marking the original peak signal as a candidate peak signal; calculating a plurality of time periods of round-trip reflection in the cable for each candidate peak signal; finding other candidate peak signals that have reflection interference on the current candidate peak signal in the plurality of time periods; if other candidate peak signals are found, deleting other candidate peak signals; marking the remaining candidate peak signals as target peak signals; the step of identifying two target peak signals that match each other as paired peak signals further comprises the following steps: the two target peak signals that match each other meet the following conditions: wherein, is the target peak signal for the th target peak signal, is the target peak signal for the th target peak signal, is the pairing coefficient.

2. The method of claim 1, wherein, the step of extracting a plurality of original peak signals from a partial discharge signal of a cable comprises the following steps: generating an oscillation wave signal for the cable; if a partial discharge source is detected in the cable according to the oscillation wave signal, collecting a partial discharge signal of the partial discharge source; extracting each original peak signal from the partial discharge signal.

3. The method according to claim 1, wherein: the time period meets the following conditions: wherein is the time point at which the th candidate peak signal occurs, is the length of the cable, is the propagation speed of the partial discharge signal, is the sampling frequency, is a positive integer; the other candidate peak signals that have reflection interference on the current candidate peak signal meet the following conditions: wherein is the candidate peak signal, is the candidate peak signal.

4. The method of claim 1, wherein, the step of identifying two target peak signals that match each other as paired peak signals comprises the following steps: calculating a time range for pairing for each target peak signal; finding other target peak signals that match the current target peak signal in the time range; marking the current target peak signal and the matched other target peak signal as paired peak signals.

5. The method according to claim 4, wherein: the time range meets the following conditions: wherein is the time point at which the th target peak signal occurs, is the length of the cable, is the propagation speed of the partial discharge signal, is the sampling frequency.

6. The method of claim 1, wherein, the step of calculating candidate discharge positions of a partial discharge source in the cable according to a time difference between the paired peak signals comprises the following steps: substituting the time difference between the paired peak signals into the following formula to calculate the candidate discharge positions of the partial discharge source in the cable: wherein, is a candidate discharge location of a partial discharge point source in the cable, is a length of the cable, is a time point at which the n-th one of the paired wave crest signals is located, is a time point at which the n-th one of the paired wave crest signals is located, is a time point at which the n-th one of the paired wave crest signals is located, is a time point at which the n-th one of the paired wave crest signals is located, is a propagation speed of the partial discharge signal.

7. The method according to any one of claims 1 to 6, characterized in that, the step of clustering the candidate discharge positions to obtain target discharge positions of the partial discharge source in the cable comprises the following steps: sorting the candidate discharge positions to obtain a position sequence; cutting the position sequence into a plurality of data groups, a difference between two adjacent candidate discharge positions in a same data group being less than or equal to a preset first threshold, a difference between the candidate discharge positions located at boundaries of two adjacent data groups being greater than the preset first threshold; if a number of the candidate discharge positions in the data group is less than or equal to a preset second threshold, deleting the data group; if the number of the candidate discharge positions in the data group is greater than the preset second threshold, calculating an average value of the candidate discharge positions in the data group to obtain a target discharge position of a partial discharge source in the cable.

8. An electronic device, comprising: The electronic device comprises: at least one processor; and a memory connected to the at least one processor in communication; wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to execute the partial discharge positioning method of the cable according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is used to enable the processor to implement the partial discharge positioning method of the cable according to any one of claims 1-7 when executed.

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