CN116754910A - Cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference - Google Patents
Cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference Download PDFInfo
- Publication number
- CN116754910A CN116754910A CN202311014815.0A CN202311014815A CN116754910A CN 116754910 A CN116754910 A CN 116754910A CN 202311014815 A CN202311014815 A CN 202311014815A CN 116754910 A CN116754910 A CN 116754910A
- Authority
- CN
- China
- Prior art keywords
- cable
- pulse
- partial discharge
- data
- groups
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 102
- 238000012544 monitoring process Methods 0.000 title claims abstract description 64
- 238000000034 method Methods 0.000 title claims abstract description 56
- 238000001514 detection method Methods 0.000 claims abstract description 145
- 230000003287 optical effect Effects 0.000 claims abstract description 136
- 238000012545 processing Methods 0.000 claims abstract description 68
- 238000003491 array Methods 0.000 claims abstract description 28
- 230000001427 coherent effect Effects 0.000 claims abstract description 26
- 238000000605 extraction Methods 0.000 claims abstract description 10
- 238000009499 grossing Methods 0.000 claims abstract description 10
- 239000000835 fiber Substances 0.000 claims description 21
- 230000008878 coupling Effects 0.000 claims description 19
- 238000010168 coupling process Methods 0.000 claims description 19
- 238000005859 coupling reaction Methods 0.000 claims description 19
- 238000012360 testing method Methods 0.000 claims description 5
- 230000035945 sensitivity Effects 0.000 abstract description 15
- 208000028659 discharge Diseases 0.000 description 90
- 238000005516 engineering process Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 238000004590 computer program Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 238000001069 Raman spectroscopy Methods 0.000 description 3
- 230000032683 aging Effects 0.000 description 3
- 238000004422 calculation algorithm Methods 0.000 description 3
- 108010076504 Protein Sorting Signals Proteins 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000253 optical time-domain reflectometry Methods 0.000 description 2
- 238000010587 phase diagram Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000004873 anchoring Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1218—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing using optical methods; using charged particle, e.g. electron, beams or X-rays
Abstract
The application relates to a cable partial discharge monitoring method, a system and equipment based on multipath optical fiber difference, wherein the method comprises the steps of acquiring a time sequence pulse signal and coherent light, and modulating the coherent light into three pulse lights with different pulse widths according to the time sequence pulse signal; carrying out partial discharge detection on the area of the cable by adopting two paths of optical signals of pulse light to obtain N groups of pulse data; denoising, phase extraction and smoothing classification are sequentially carried out on the N groups of pulse data to obtain three groups of corresponding phase data; and carrying out discrete and dimension-changing processing on each group of phase data to obtain three groups of one-dimensional arrays, and judging whether partial discharge occurs in the area of the cable according to the three groups of one-dimensional arrays. The method carries out partial discharge detection on the area of the cable through two paths of optical signals with three different pulse widths, improves the detection sensitivity, reduces the probability of missing report and false report of detection data, and improves the monitoring reliability; the combined detection of multiple pulse widths is realized, and the richness and the anti-interference capability of the detected optical signals are improved.
Description
Technical Field
The application relates to the technical field of cable monitoring, in particular to a cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference.
Background
The cable is expensive in cost, and is laid on the sea floor, so that the operation and maintenance are difficult. If the cable is partially discharged, the attenuation of the partial discharge electromagnetic wave is serious when the partial discharge electromagnetic wave propagates to the two ends of the sea cable because the sea cable is far longer than the land cable, and the detection means of the land cable is difficult to adopt. The existing technology for detecting the partial discharge of the cable is mainly a vibration monitoring system such as temperature monitoring and anchoring machine.
Because most of cables are optical fiber composite submarine cables, the state of the cables is monitored mainly through an optical fiber sensing technology at present. The optical fiber sensing technology adopts the partial discharge to generate acoustic, electric and thermal equivalent, the heat generated by the partial discharge is weak, the monitoring precision is not high, and the vibration information detection advantage is more obvious. At present, an optical fiber sensing detection system realized by adopting heat or vibration and the like mainly adopts a monitoring system based on the Brillouin scattering principle. The vibration signal generated by partial discharge is most obvious, and the distributed optical fiber technology is adopted for vibration monitoring, so that the characteristic of the partial discharge of the submarine cable can be reflected; because the back Rayleigh scattering signal is strongest, the vibration identification accuracy is better by adopting the back Rayleigh scattering signal; the back scattering light signal intensity is difficult to promote, only carries out vibration identification through the light intensity, and the signal to noise ratio is low. Therefore, the monitoring system adopting the Brillouin scattering and Rayleigh scattering principles has the defects that the Brillouin scattering signal is extremely weak, useful information is difficult to capture, the monitoring system is influenced by multiple factors such as stress, temperature and the like, the requirements on a light source and detection equipment are high, and the cost is high. If the phase sensitive optical time domain reflectometer phi-OTDR technology is adopted to monitor partial discharge of the cable, the sensitivity and the spatial resolution of detection are improved, and random fluctuation of the signal can occur due to the coherent fading effect, and a large amount of statistical analysis is needed to identify the continuous vibration signal; however, the duration of the partial discharge signal is not long, so that the data quantity of the vibration information acquired by the existing mode is less, and the recognition efficiency is reduced; meanwhile, partial discharge signals in the cable are weak, and requirements on detection sensitivity and anti-interference capability are high, so that the phase sensitive optical time domain reflectometer phi-OTDR technology adopts single optical fiber back light to carry out partial discharge monitoring on the cable, and the problems of low sensitivity and low signal-to-noise ratio of single-path measurement exist.
Disclosure of Invention
The embodiment of the application provides a cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference, which are used for solving the technical problems of poor anti-interference capability and low detection sensitivity of the existing cable discharge monitoring technology.
In order to achieve the above object, the embodiment of the present application provides the following technical solutions:
in one aspect, a cable partial discharge monitoring method based on multipath optical fiber difference is provided, which comprises the following steps:
acquiring a time sequence pulse signal and coherent light, and modulating the coherent light into pulse light with three different pulse widths according to the time sequence pulse signal;
carrying out partial discharge detection on the area of the cable by adopting two paths of optical signals of the three pulse lights with different pulse widths to obtain N groups of pulse data, wherein the N groups of pulse data comprise 3N pulse signals;
sequentially denoising, phase extraction and smoothing classification processing are carried out on the N groups of pulse data, so that three groups of phase data corresponding to three different pulse widths are obtained;
performing discrete and dimension-changing processing on each group of phase data to obtain three groups of one-dimensional arrays, and judging whether partial discharge occurs in the area of the cable according to the three groups of one-dimensional arrays;
Wherein N is a natural number greater than 100.
Preferably, if the cable is a three-core cable, the three-core cable includes a first core optical fiber, a second core optical fiber, and a third core optical fiber, and the pulse light with three different pulse widths is used to perform partial discharge detection on an area of the cable, so as to obtain N groups of pulse data, where the N groups of pulse data include 3N pulse signals including:
acquiring interval time of the time sequence pulse signals, and taking the pulse light with three different pulse widths as a group of detection signals;
carrying out partial discharge detection on the area of the cable through a group of detection signals according to a cycle detection rule to obtain N groups of pulse data;
the loop detection rule includes:
partial discharge detection is carried out on the first core optical fiber and the second core optical fiber of the cable area by adopting two paths of optical signals of a group of detection signals, so as to obtain a first group of pulse data;
after the interval time interval is 2 times, carrying out partial discharge detection on the first core optical fiber and the third core optical fiber of the cable area by adopting two paths of optical signals of a group of detection signals to obtain a second group of pulse data;
wherein the N groups of pulse data comprise N/2 of the first group of pulse data and N/2 of the second group of pulse data.
Preferably, denoising, phase extraction and smoothing classification are sequentially performed on the N groups of pulse data, and obtaining three groups of phase data corresponding to three different pulse widths includes:
carrying out wavelet denoising treatment on each group of pulse data to obtain treatment data corresponding to each group of pulse data;
extracting phases from each group of processing data by adopting an IQ demodulation mode to obtain phase information corresponding to each group of pulse data;
and processing the phase of each group of phase information by adopting a homogeneous cancellation method to obtain phase processing data corresponding to each group of pulse data:
and extracting phases corresponding to three different pulse widths from the three groups of phase processing data to obtain three groups of phase data corresponding to the three different pulse widths, wherein each group of phase data comprises N phases.
Preferably, performing discrete and variable dimension processing on each group of the phase data to obtain a one-dimensional array corresponding to each group of the phase data includes:
taking the pulse width corresponding to each group of phase data as a window length; performing discrete and variable-dimension processing on each group of phase data by taking the window length as a moving unit of a moving window to obtain one-dimensional data corresponding to each group of phase data;
Multiplying the two-phase values corresponding to the three groups of one-dimensional data to obtain three groups of one-dimensional arrays.
Preferably, determining whether partial discharge occurs in the area of the cable according to the three sets of the one-dimensional arrays includes: if the number of at least two one-dimensional arrays in the three one-dimensional arrays is larger than the threshold value data and the number is not smaller than the number threshold value, partial discharge occurs in the area of the cable; otherwise, no partial discharge occurs in the region of the cable.
In still another aspect, a cable partial discharge monitoring system based on multipath optical fiber difference is provided, including a light source, an acousto-optic modulation unit, a coupling unit, a first optical signal detection unit, a second optical signal detection unit, a photoelectric detection unit and a signal processing unit, wherein the acousto-optic modulation unit is respectively connected with the light source, the coupling unit and the signal processing unit, the coupling unit is respectively connected with the first optical signal detection unit and the second optical signal detection unit, the first optical signal detection unit and the second optical signal detection unit are both connected with a cable to be tested, and the signal processing unit is respectively connected with the first optical signal detection unit and the second optical signal detection unit through the photoelectric detection unit;
The light source is used for providing coherent light;
the acousto-optic modulation unit is used for modulating the coherent light into pulse light with three different pulse widths according to a time sequence pulse signal;
the coupling unit is used for dividing the pulse light into two paths of optical signals;
the first optical signal detection unit is used for detecting the area of the cable to be detected through one path of optical signal and transmitting the optical signal fed back by detection to the photoelectric detection unit;
the second optical signal detection unit is used for detecting the cable to be detected through another path of optical signal and transmitting the optical signal fed back by detection to the photoelectric detection unit;
the photoelectric detection unit is used for carrying out differential processing on the two paths of fed-back optical signals to obtain pulse signals and transmitting the pulse signals to the signal processing unit;
the signal processing unit is used for processing all the collected pulse signals by adopting the cable partial discharge monitoring method based on the multipath optical fiber difference, and determining whether partial discharge occurs in the area of the cable.
Preferably, the first optical signal detecting unit and the second optical signal detecting unit each comprise a first amplifier connected with the coupling unit, a second amplifier connected with the first amplifier and a circulator connected with the second amplifier, the circulator of the second optical signal detecting unit is connected with the cable to be detected through an optical switch, and the circulators of the first optical signal detecting unit and the second optical signal detecting unit are both connected with the photoelectric detecting unit.
Preferably, the cable to be tested comprises a first core optical fiber, a second core optical fiber and a third core optical fiber, wherein the first core optical fiber is connected with the circulator of the first optical signal detection unit, the optical switch is respectively connected with the second core optical fiber and the third core optical fiber, and the optical switch is used for switching the circulator of the second optical signal detection unit to be connected with the second core optical fiber or the third core optical fiber of the cable to be tested.
Preferably, a signal generating unit for generating a trigger signal is further connected between the signal processing unit and the acousto-optic modulation unit.
In yet another aspect, a terminal device is provided that includes a processor and a memory;
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is used for executing the cable partial discharge monitoring method based on the multipath optical fiber difference according to the instructions in the program codes.
The method comprises the steps of obtaining a time sequence pulse signal and coherent light, and modulating the coherent light into pulse light with three different pulse widths according to the time sequence pulse signal; partial discharge detection is carried out on the area of the cable by adopting two paths of optical signals of three pulse lights with different pulse widths, so that N groups of pulse data are obtained, wherein the N groups of pulse data comprise 3N pulse signals; sequentially denoising, phase extraction and smoothing classification processing are carried out on the N groups of pulse data, so that three groups of phase data corresponding to three different pulse widths are obtained; and carrying out discrete and dimension-changing processing on each group of phase data to obtain three groups of one-dimensional arrays, and judging whether partial discharge occurs in the area of the cable according to the three groups of one-dimensional arrays. From the above technical solutions, the embodiment of the present application has the following advantages: according to the cable partial discharge monitoring method based on the multipath optical fiber difference, the partial discharge detection is carried out on the area of the cable by adopting two paths of optical signals of three pulse lights with different pulse widths, so that the differential detection is carried out on the two paths of optical signals, the detection sensitivity is further improved, the probability of missing report and false report of detection data is also reduced, and the monitoring reliability is improved; the combined detection of multiple pulse widths is realized, and the richness and the anti-interference capability of the detected optical signals are improved; the technical problems of poor anti-interference capability and low detection sensitivity in the existing cable discharge monitoring technology are solved. The cable partial discharge monitoring method based on multipath optical fiber difference is more suitable for detecting micro signals, and meanwhile, the influence of integral aging of the cable optical fibers is reduced.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the application, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a flow chart of steps of a cable partial discharge monitoring method based on multi-path fiber differential according to an embodiment of the present application;
FIG. 2 is a timing pulse signal diagram of a cable partial discharge monitoring method based on multi-path fiber differential according to an embodiment of the present application;
FIG. 3 is a phase diagram of phase processing data in a cable partial discharge monitoring method based on multi-path fiber differential according to an embodiment of the present application;
FIG. 4 is a three-group one-dimensional array diagram of a cable partial discharge monitoring method based on multi-path fiber differential according to an embodiment of the present application;
FIG. 5 is a schematic diagram of an optical path of a cable partial discharge monitoring system based on multi-path fiber differential in an embodiment of the present application;
FIG. 6 is a graph of light intensity versus distance for a typical prior art optical signal;
FIG. 7 is a graph of phase versus time for a typical phase sensitive coherent light of the prior art;
fig. 8 is a typical Φ -OTDR graph of a prior art optical signal.
Detailed Description
In order to make the objects, features and advantages of the present application more comprehensible, the technical solutions in the embodiments of the present application are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In the description of embodiments of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless explicitly defined otherwise.
In the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and include, for example, either permanently connected, removably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.
The embodiment of the application provides a cable partial discharge monitoring method, a system and equipment based on multipath optical fiber difference, which are used for sensing two groups of optical fibers for cable partial discharge detection, and performing differential detection on two groups of back optical signals, so that the detection sensitivity is improved, the pulse width of pulse light is changed, and the signal richness and the anti-interference capability are improved. In this embodiment, the method, system and apparatus for monitoring partial discharge of a cable based on multi-path fiber differential are described with a three-core submarine cable as an example.
Embodiment one:
fig. 1 is a step flowchart of a cable partial discharge monitoring method based on multi-path optical fiber difference according to an embodiment of the present application, and fig. 2 is a timing pulse signal diagram of a cable partial discharge monitoring method based on multi-path optical fiber difference according to an embodiment of the present application.
As shown in fig. 1, the embodiment of the application provides a cable partial discharge monitoring method based on multipath optical fiber difference, which comprises the following steps:
s1, acquiring a time sequence pulse signal and coherent light, and modulating the coherent light into pulse light with three different pulse widths according to the time sequence pulse signal.
It should be noted that, in step S1, a timing pulse signal and coherent light are acquired to provide detection light for monitoring the cable partial discharge subsequently; and secondly, modulating each beam of detected coherent light into pulse light with three different pulse widths according to a time sequence pulse signal. In this embodiment, as shown in fig. 2, three different pulse widths may be 100 ns, 200 ns, 400 ns.
S2, carrying out partial discharge detection on the area of the cable by adopting two paths of optical signals of three pulse lights with different pulse widths to obtain N groups of pulse data, wherein the N groups of pulse data comprise 3N pulse signals. Wherein N is a natural number greater than 100.
In step S2, partial discharge detection is performed on the area of the cable according to the two paths of optical signals of the pulse light in step S1, so as to obtain N groups of pulse data, and data is provided for analyzing whether partial discharge occurs in the area of the cable in the subsequent step.
S3, sequentially carrying out denoising, phase extraction and smoothing classification treatment on the N groups of pulse data to obtain three groups of phase data corresponding to three different pulse widths.
In step S3, all the pulse data detected in step S2 are processed to obtain three sets of phase data with three pulse widths. In this embodiment, the N groups of pulse data are denoised by signals, so as to filter interference signals, noise signals and the like, and then phase extraction and smooth classification are performed to implement waveform statistics, so that data is provided for completing partial discharge diagnosis and positioning.
S4, performing discrete and dimension-changing processing on each group of phase data to obtain three groups of one-dimensional arrays, and judging whether partial discharge occurs in the area of the cable according to the three groups of one-dimensional arrays.
In step S4, the dimension reduction processing is performed according to the three sets of phase data with three pulse widths obtained in step S3, so as to obtain a one-dimensional array capable of determining whether partial discharge occurs in the cable area. The application provides a cable partial discharge monitoring method based on multipath optical fiber difference, which comprises the steps of acquiring a time sequence pulse signal and coherent light, and modulating the coherent light into three pulse lights with different pulse widths according to the time sequence pulse signal; partial discharge detection is carried out on the area of the cable by adopting two paths of optical signals of three pulse lights with different pulse widths, so that N groups of pulse data are obtained, wherein the N groups of pulse data comprise 3N pulse signals; sequentially denoising, phase extraction and smoothing classification processing are carried out on the N groups of pulse data, so that three groups of phase data corresponding to three different pulse widths are obtained; and carrying out discrete and dimension-changing processing on each group of phase data to obtain three groups of one-dimensional arrays, and judging whether partial discharge occurs in the area of the cable according to the three groups of one-dimensional arrays. According to the cable partial discharge monitoring method based on the multipath optical fiber difference, the partial discharge detection is carried out on the area of the cable by adopting two paths of optical signals of three pulse lights with different pulse widths, so that the differential detection is carried out on the two paths of optical signals, the detection sensitivity is further improved, the probability of missing report and false report of detection data is also reduced, and the monitoring reliability is improved; the combined detection of multiple pulse widths is realized, and the richness and the anti-interference capability of the detected optical signals are improved; the technical problems of poor anti-interference capability and low detection sensitivity in the existing cable discharge monitoring technology are solved. The cable partial discharge monitoring method based on multipath optical fiber difference is more suitable for detecting micro signals, and meanwhile, the influence of integral aging of the cable optical fibers is reduced.
In one embodiment of the present application, if the cable is a three-core cable, the three-core cable includes a first core optical fiber, a second core optical fiber, and a third core optical fiber, and the area of the cable is detected by partial discharge using three pulse lights with different pulse widths, so as to obtain N groups of pulse data, where the N groups of pulse data include 3N pulse signals including:
acquiring interval time of time sequence pulse signals, and taking pulse lights with three different pulse widths as a group of detection signals;
carrying out partial discharge detection on the area of the cable through a group of detection signals according to a cycle detection rule to obtain N groups of pulse data;
the loop detection rule includes:
partial discharge detection is carried out on the first core optical fiber and the second core optical fiber of the cable area by adopting two paths of optical signals of a group of detection signals, so as to obtain a first group of pulse data;
after the interval time interval of 2 times, carrying out partial discharge detection on the first core optical fiber and the third core optical fiber of the cable area by adopting two paths of optical signals of a group of detection signals to obtain a second group of pulse data;
wherein the N sets of pulse data include N/2 first sets of pulse data and N/2 second sets of pulse data.
As shown in fig. 2, pulse signals with pulse widths of 100 ns, 200 ns, 400 ns are used as a set of detection signals, a set of detection signals are first used to perform partial discharge detection on the first core optical fiber and the second core optical fiber in the cable area, a set of pulse data is obtained as a first set of pulse data, after an interval of 2T, a set of detection signals are used to perform partial discharge detection on the first core optical fiber and the third core optical fiber in the cable area, a set of pulse data is obtained as a second set of pulse data, and the partial discharge detection is performed on the cable according to the cycle detection rule until N sets of pulse data are obtained. In this embodiment, the value of N is preferably an even number greater than 0, for example, the value of N may be selected to be 100. The interval time duration T of each time sequence pulse signal is determined by the length of the cable, and the interval time duration T is larger than the back and forth time of the detection signal in the optical fiber of the cable.
In the embodiment of the application, denoising, phase extraction and smoothing classification processing are sequentially performed on N groups of pulse data, and three groups of phase data corresponding to three different pulse widths are obtained, wherein the steps comprise:
wavelet denoising is adopted for each group of pulse data, so as to obtain processing data corresponding to each group of pulse data;
extracting phases from each group of processing data by adopting an IQ demodulation mode to obtain phase information corresponding to each group of pulse data;
and processing the phase of each group of phase information by adopting a mean cancellation method to obtain phase processing data corresponding to each group of pulse data:
and extracting phases corresponding to the three different pulse widths from the three groups of phase processing data to obtain three groups of phase data corresponding to the three different pulse widths, wherein each group of phase data comprises N phases.
The N groups of pulse data obtained in step S2 are first subjected to wavelet denoising to remove white noise, gaussian noise and other interference, so as to obtain processing data corresponding to the N groups. And then extracting the phase of each group of processed data signals through an IQ demodulation algorithm to obtain phase information of corresponding N groups. Under the condition of no disturbance, the phase curve of each cable optical fiber is relatively fixed, namely the difference of each group of phase information is smaller; when disturbance occurs, the phase information of the corresponding length (converted to the moment) changes, and then the phase information of each group needs to be processed by a homogeneous cancellation method, so that local disturbance is avoided, and phase processing data of each group is obtained; finally, the phase processing data are divided into three groups of phase data according to the pulse width, and each group of phase data comprises 100 phases of phase processing data. In this embodiment, it is obtained that certain noise and transient fluctuation still exist in each group of phase information, and each group of phase information can be smoothed by a moving window least square polynomial, and smoothing processing is performed on each group of phase information. The IQ-demodulation algorithm is a conventional data processing method in the art, and the content of the IQ-demodulation algorithm is not described in detail here. The moving window length of the moving window least squares polynomial is the pulse width.
Fig. 3 is a phase diagram of phase processing data in a cable partial discharge monitoring method based on multi-path optical fiber difference according to an embodiment of the present application.
In the embodiment of the application, the average cancellation method is a function of time variation for phase information at a certain pulse width, assuming thatS i （t) Is the firstiThe phase information, the phase processing data after the average offset method is:
；
in the method, in the process of the application,Nindicating how many phase information in total participates in the average calculation,S i ' （t) Is the firstiThe data is processed in phase. Because of the non-disturbance part, the phase value fluctuates less, and the value is close to zero after subtracting the average value. The phase change of the disturbance part is irregular, and the average value after cancellation is still larger.
The method has the advantages that the phase information participating in the average cancellation comes from two paths of optical signals in the three-core cable, so that the probability of pulse data acquisition can be guaranteed to a greater extent. At the same time, an extreme situation may occur, that is, partial discharge signals appear on the mirror symmetry planes of the two optical fibers, which may cause the two optical signals to be relatively close, and the signals cancel after difference. Therefore, the three-core cable is adopted for two paths of optical signals, and the problems can be thoroughly avoided. Meanwhile, under the condition of no disturbance, the phases of the two paths of optical signals are fixed but different, the fixed value can be eliminated by average cancellation, and the phase curve obtained after average cancellation is approximately shown in fig. 3.
Fig. 4 is a three-group one-dimensional array diagram of a cable partial discharge monitoring method based on multi-path optical fiber difference according to an embodiment of the present application.
In one embodiment of the present application, performing discrete and variable dimension processing on each set of phase data to obtain a one-dimensional array corresponding to each set of phase data includes:
taking the pulse width corresponding to each group of phase data as a window length; performing discrete and variable-dimension processing on each group of phase data by taking the window length as a moving unit of a moving window to obtain one-dimensional data corresponding to each group of phase data;
multiplying the two-phase numerical values corresponding to the three groups of one-dimensional data to obtain three groups of one-dimensional arrays.
It should be noted that, three sets of phase data correspond to data with pulse width of 100 ns, 200 ns and 400ns respectively, and for each set of phase data, a window length is taken as a moving unit of a moving window, and an average value of each moving window is calculated to obtain one-dimensional data; and then multiplying the three discrete groups of one-dimensional data by corresponding data of every two one-dimensional data to form a new one-dimensional array, as shown in fig. 4. For example, the window unit is 400ns, that is, the window unit is dispersed into a one-dimensional array, it can be understood that the phase curve of fig. 3 is dispersed according to a section of 400ns, and the average value of each section of data is calculated, so that the final one-dimensional array is obtained.
In one embodiment of the present application, determining whether partial discharge has occurred in an area of a cable based on three one-dimensional arrays comprises: if the number of at least two one-dimensional arrays in the three one-dimensional arrays is larger than the threshold value data and the number is not smaller than the number threshold value, partial discharge occurs in the area of the cable; otherwise, no partial discharge occurs in the region of the cable.
If there is no disturbance in the cable, the phase fluctuation of the optical signal is small, the average cancellation processing is performed after the phase difference detection, the three groups of values are small, and the values are near zero after the multiplication of the three groups of values. If disturbance such as partial discharge occurs in the cable and is captured by pulse light with 2 pulse widths, 2 groups in the finally obtained 3 groups of one-dimensional arrays have larger values and are close to each other; if captured by 3 pulses of pulsed light, then there are 3 groups where larger values occur. And (3) taking 1000ns as a moving window (namely, continuously 5 numbers), comparing the data in the arrays, and if 2 or more arrays have data values larger than threshold data, determining that partial discharge occurs in the area of the cable. In this embodiment, the threshold data may be selected to be 10. In other embodiments, the threshold data may be set as desired.
In the embodiment of the application, the cable partial discharge monitoring method based on multipath optical fiber difference is used for carrying out joint test by adopting a plurality of groups of pulse signals with different pulse widths through adjusting pulse light pulse width, so that the interference influence is reduced. When the pulse light propagates in the optical fiber, the back scattered light is excited, and the signal received by the receiving end can be regarded as the electric field sum of all scattered signals in the pulse light width. When a narrow-band light source is adopted, the corresponding coherence length is longer, interference effect can occur on different Rayleigh scattering signals, and the total power of signals received by a receiving end is not only superposition of power, but also has relatively stable, but random phase relation. Because the phase relation of signal superposition is random, random fluctuation can be displayed on a terminal measurement curve, random waveforms under different pulse widths are different, the longer the pulse width is, the smaller the overall fluctuation is, and the spatial resolution is also reduced. So that the combined detection of a plurality of groups of pulse signals with different pulse widths is adopted, and the influence of random interference is eliminated.
Embodiment two:
fig. 5 is a schematic diagram of an optical path of a cable partial discharge monitoring system based on multi-path optical fiber differential in an embodiment of the application.
As shown in fig. 5, an embodiment of the present application provides a cable partial discharge monitoring system based on multi-path optical fiber difference, which includes a light source 10, an acousto-optic modulation unit 20, a coupling unit 30, a first optical signal detection unit 40, a second optical signal detection unit 50, a photoelectric detection unit 60 and a signal processing unit 70, wherein the acousto-optic modulation unit 20 is respectively connected with the light source 10, the coupling unit 30 and the signal processing unit 70, the coupling unit 30 is respectively connected with the first optical signal detection unit 40 and the second optical signal detection unit 50, the first optical signal detection unit 40 and the second optical signal detection unit 50 are both connected with a cable 101 to be tested, and the signal processing unit 70 is respectively connected with the first optical signal detection unit 40 and the second optical signal detection unit 50 through the photoelectric detection unit 60.
In an embodiment of the application, the light source 10 is used to provide coherent light.
The light source 10 may be a narrow-linewidth laser that generates coherent light having a center wavelength of 1550nm, a linewidth of 15kHz, and an optical power of 20 mW.
In the embodiment of the present application, the acousto-optic modulation unit 20 is used for modulating the coherent light into the pulse light with three different pulse widths according to the time sequence pulse signal.
The acousto-optic modulation unit 20 may be an acousto-optic modulator, which modulates continuous coherent light into pulse light, and the pulse light width is related to the detection spatial resolution. To improve signal richness and reduce signal interference and randomness, the pulse light width is not fixed, and is modulated into three different widths (100 ns, 200 ns, 400 ns).
In the embodiment of the present application, the coupling unit 30 is used to split the pulse light into two optical signals.
It should be noted that, the coupling unit 30 may be a coupler, and the coupler may divide one light beam into two light signals.
In the embodiment of the present application, the first optical signal detecting unit 40 is configured to detect an area of the cable to be detected by one path of optical signal, and transmit the optical signal fed back by the detection to the photoelectric detecting unit 60; the second optical signal detecting unit 50 detects the cable to be detected through another path of optical signal, and transmits the optical signal fed back by the detection to the photoelectric detecting unit 60.
It should be noted that, the first optical signal detecting unit 40 and the second optical signal detecting unit 50 amplify each path of optical signal and input the amplified optical signal into a core optical fiber of the cable to be tested. The first optical signal detecting unit 40 and the second optical signal detecting unit 50 each include a first amplifier connected to the coupling unit 30, a second amplifier connected to the first amplifier, and a circulator connected to the second amplifier, the circulator of the second optical signal detecting unit 50 is connected to the cable 101 to be tested through an optical switch, and the circulators of the first optical signal detecting unit 40 and the second optical signal detecting unit 50 are each connected to the photodetecting unit 60. The first amplifier is a first-stage EDFA amplifier, and the second amplifier is a first-stage Raman amplifier. The first optical signal detecting unit 40 and the second optical signal detecting unit 50 operate on the principle that: each path of optical signal is amplified into 500 mW pulse light by the first-stage EDFA amplifier and the first-stage Raman amplifier. One path of optical signal is input to the first core optical fiber of the cable 101 to be tested through the port 1 of the circulator 1. The other path of optical signal is connected with a 2 path of optical switch after passing through a port 1 of the circulator 2, and is tapped to the remaining second core optical fiber and third core optical fiber of the cable 101 to be tested.
Fig. 6 is a graph of light intensity versus distance for a typical prior art optical signal, fig. 7 is a graph of phase versus time for a typical prior art phase sensitive coherent light, and fig. 8 is a graph of a typical Φ -OTDR for a prior art optical signal.
In the embodiment of the present application, the photo-detecting unit 60 is configured to perform differential processing on the two paths of fed-back optical signals to obtain a pulse signal, and transmit the pulse signal to the signal processing unit 70.
It should be noted that, the photo-detecting unit 60 may be a balanced photo-detector, and the ports of the circulators 1 and 2 are connected to two input ends of the balanced photo-detector to perform differential measurement. The differential signal is passed through the balanced photodetector and then converted into an electrical signal. When light propagates in an optical fiber, back-scattered light is excited, including rayleigh scattering, brillouin scattering, raman scattering, etc., where the rayleigh scattering signal is strongest. The propagation medium in the optical fiber is discontinuous due to the influence of partial discharge, vibration, etc., that is, scattered light when light propagates to the point is changed (light intensity and phase) compared with normal conditions. The back-scattered light intensity (ODTR) is measured directly, and a typical signal is shown in fig. 6, which also allows for detection and localization of medium discontinuities. Because small disturbance signals such as partial discharge are weak, the reaction on the light intensity is not obvious, and the method is not suitable for small disturbance measurement. Phase sensitive coherent light is used for measurement (phi-OTDR) to obtain phase information therein, and a typical phase curve is shown in FIG. 7. If a disturbance occurs, fluctuations in light intensity and phase may occur. If one path of optical signal is adopted, direct detection is carried out through a photoelectric detector, an obtained typical phi-OTDR curve is shown in fig. 8, and phase information is obtained through subsequent phase demodulation; such signals are superimposed with random attenuation on the dc signal, which if weak, would be buried in the dc signal. Particularly, the problem of integral aging of the submarine cable optical fiber is considered, the signal-to-noise ratio of the signal obtained by direct detection is not high, and the balanced photoelectric detector is used for differential detection of two paths of optical signals, so that the sensitivity of signal detection is improved. The balanced light is a photoelectric detector based on a differential technology, the principle of the balanced light is similar to that of a balanced bridge, and the sensitivity and the anti-interference capability of the photoelectric detector can be improved.
In the embodiment of the present application, the balance photo detector used by the photo detection unit 60 is composed of a beam splitter, two photodiodes connected to the beam splitter, and a differential amplifier connected to the two photodiodes. The optical signal is first divided into two paths by an optical beam splitter and is respectively input into two photodiodes, the two photodiodes have the same working mode, but the phases of the input optical signals are opposite. When two photodiodes receive the same intensity, opposite phase optical signals, their output currents are also opposite, so that their output signals can be subtracted to obtain a differential signal. The differential signals are amplified by the differential amplifier, and the working points of the two photodiodes are adjusted through the feedback loop, so that the output signals of the two photodiodes are always equal, thereby eliminating the non-uniformity and the difference in the aspects of light source intensity, photodiode performance and the like, and improving the sensitivity and the anti-interference capability of the photoelectric detection unit 60 for collecting pulse signals.
It should be noted that, the cable partial discharge monitoring system based on multipath optical fiber difference adopts two paths of optical signals for detection, and carries out differential detection on two groups of back scattered light, namely, outputs the difference value of the two groups of optical signals. Since the three-core fibers of the cable are all uniformly arranged, the back-scattered light difference is fixed under normal conditions, and the fluctuation between the two groups is small. The photoelectric detection unit 60 of the cable partial discharge monitoring system based on the multipath optical fiber difference realizes the differential detection of two paths of optical signals, can improve the detection sensitivity, but has more interference influence.
In the embodiment of the present application, the signal processing unit 70 is configured to process all the collected pulse signals by using the cable partial discharge monitoring method based on multi-path optical fiber differential, so as to determine whether a partial discharge occurs in a cable area.
It should be noted that, the content of the cable partial discharge monitoring method based on the multi-path optical fiber differential has been described in detail in the first embodiment, and the content of the cable partial discharge monitoring method based on the multi-path optical fiber differential is not described in detail in the second embodiment. The cable partial discharge monitoring system based on multipath optical fiber difference adopts two groups of optical fibers for sensing, and two groups of back optical signals are subjected to differential measurement through the photoelectric detection unit 60, so that the detection sensitivity is improved, the pulse width of pulse light is changed, the signal richness and the anti-interference capability are improved, and the multi-core cable partial discharge detection is performed.
In one embodiment of the present application, the cable under test 101 includes a first core optical fiber, a second core optical fiber, and a third core optical fiber, the first core optical fiber is connected to the circulator of the first optical signal detecting unit 40, the optical switch is connected to the second core optical fiber and the third core optical fiber, respectively, and the optical switch is used to switch the circulator of the second optical signal detecting unit 50 to be connected to the second core optical fiber or the third core optical fiber of the cable under test 101.
The cable 101 to be tested has a three-core optical fiber, which improves the probability of acquiring signals. Wherein the first core optical fiber is directly connected with the circulator 1, and pulse light is continuously input; the second core optical fiber and the third core optical fiber alternately input pulse light through the optical switch, and the generated two groups of back scattered light are detected differentially by the photoelectric detection unit 60, and the incident light is processed at the same time, so as to obtain pulse data with three different pulse widths. As shown in fig. 2, the 3-channel signal sequence is generated by the signal processing unit 70, and is input to the acousto-optic modulation unit 20, and the signal sequence has 3 pulse widths of 400 ns, 200 ns and 100 ns, respectively.
In one embodiment of the present application, a signal generating unit 80 for generating a trigger signal is further connected between the signal processing unit 70 and the acousto-optic modulation unit 20.
It should be noted that, the signal generating unit 80 may be a ROGIL signal generator, and the acousto-optic modulator needs to be externally connected with a pre-modulation signal, and the pre-modulation signal is generated by the signal generating unit 80. At the same time, the modulated signal generated by the signal generating unit 80 is also input to the signal processing unit 70 as a trigger signal for data sampling.
Embodiment III:
the embodiment of the application provides terminal equipment, which comprises a processor and a memory;
A memory for storing program code and transmitting the program code to the processor;
and the processor is used for executing the cable partial discharge monitoring method based on the multipath optical fiber difference according to the instructions in the program codes.
It should be noted that the processor is configured to execute the steps in the above-described embodiment of the cable partial discharge monitoring method based on the multi-path fiber differential according to the instructions in the program code. In the alternative, the processor, when executing the computer program, performs the functions of the modules/units in the system/apparatus embodiments described above.
For example, a computer program may be split into one or more modules/units, which are stored in a memory and executed by a processor to perform the present application. One or more of the modules/units may be a series of computer program instruction segments capable of performing specific functions for describing the execution of the computer program in the terminal device.
The terminal device may be a computing device such as a desktop computer, a notebook computer, a palm computer, a cloud server, etc. The terminal device may include, but is not limited to, a processor, a memory. It will be appreciated by those skilled in the art that the terminal device is not limited and may include more or less components than those illustrated, or may be combined with certain components, or different components, e.g., the terminal device may also include input and output devices, network access devices, buses, etc.
The processor may be a central processing unit (Central Processing Unit, CPU), other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory may be an internal storage unit of the terminal device, such as a hard disk or a memory of the terminal device. The memory may also be an external storage device of the terminal device, such as a plug-in hard disk provided on the terminal device, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like. Further, the memory may also include both an internal storage unit of the terminal device and an external storage device. The memory is used for storing computer programs and other programs and data required by the terminal device. The memory may also be used to temporarily store data that has been output or is to be output.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other forms.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. The cable partial discharge monitoring method based on multipath optical fiber difference is characterized by comprising the following steps of:
acquiring a time sequence pulse signal and coherent light, and modulating the coherent light into pulse light with three different pulse widths according to the time sequence pulse signal;
carrying out partial discharge detection on the area of the cable by adopting two paths of optical signals of the three pulse lights with different pulse widths to obtain N groups of pulse data, wherein the N groups of pulse data comprise 3N pulse signals;
sequentially denoising, phase extraction and smoothing classification processing are carried out on the N groups of pulse data, so that three groups of phase data corresponding to three different pulse widths are obtained;
performing discrete and dimension-changing processing on each group of phase data to obtain three groups of one-dimensional arrays, and judging whether partial discharge occurs in the area of the cable according to the three groups of one-dimensional arrays;
Wherein N is a natural number greater than 100.
2. The method for monitoring partial discharge of a cable based on multi-path optical fiber difference according to claim 1, wherein if the cable is a three-core cable, the three-core cable includes a first core optical fiber, a second core optical fiber, and a third core optical fiber, the partial discharge detection is performed on an area of the cable by using the pulse light with three different pulse widths, so as to obtain N groups of pulse data, the N groups of pulse data include 3N pulse signals including:
acquiring interval time of the time sequence pulse signals, and taking the pulse light with three different pulse widths as a group of detection signals;
carrying out partial discharge detection on the area of the cable through a group of detection signals according to a cycle detection rule to obtain N groups of pulse data;
the loop detection rule includes:
partial discharge detection is carried out on the first core optical fiber and the second core optical fiber of the cable area by adopting two paths of optical signals of a group of detection signals, so as to obtain a first group of pulse data;
after the interval time interval is 2 times, carrying out partial discharge detection on the first core optical fiber and the third core optical fiber of the cable area by adopting two paths of optical signals of a group of detection signals to obtain a second group of pulse data;
Wherein the N groups of pulse data comprise N/2 of the first group of pulse data and N/2 of the second group of pulse data.
3. The method for monitoring partial discharge of a cable based on multi-path optical fiber difference according to claim 1, wherein sequentially performing denoising, phase extraction and smoothing classification on N groups of pulse data to obtain three groups of phase data corresponding to three different pulse widths comprises:
carrying out wavelet denoising treatment on each group of pulse data to obtain treatment data corresponding to each group of pulse data;
extracting phases from each group of processing data by adopting an IQ demodulation mode to obtain phase information corresponding to each group of pulse data;
and processing the phase of each group of phase information by adopting a homogeneous cancellation method to obtain phase processing data corresponding to each group of pulse data:
and extracting phases corresponding to three different pulse widths from the three groups of phase processing data to obtain three groups of phase data corresponding to the three different pulse widths, wherein each group of phase data comprises N phases.
4. The method for monitoring partial discharge of a cable based on multi-path optical fiber difference according to claim 1, wherein performing discrete and variable dimension processing on each set of phase data to obtain a one-dimensional array corresponding to each set of phase data comprises:
Taking the pulse width corresponding to each group of phase data as a window length; performing discrete and variable-dimension processing on each group of phase data by taking the window length as a moving unit of a moving window to obtain one-dimensional data corresponding to each group of phase data;
multiplying the two-phase values corresponding to the three groups of one-dimensional data to obtain three groups of one-dimensional arrays.
5. The method for monitoring partial discharge of a cable based on multi-path optical fiber difference according to claim 1, wherein determining whether partial discharge occurs in a region of the cable according to three sets of the one-dimensional arrays comprises: if the number of at least two one-dimensional arrays in the three one-dimensional arrays is larger than the threshold value data and the number is not smaller than the number threshold value, partial discharge occurs in the area of the cable; otherwise, no partial discharge occurs in the region of the cable.
6. The cable partial discharge monitoring system based on multipath optical fiber difference is characterized by comprising a light source, an acousto-optic modulation unit, a coupling unit, a first optical signal detection unit, a second optical signal detection unit, a photoelectric detection unit and a signal processing unit, wherein the acousto-optic modulation unit is respectively connected with the light source, the coupling unit and the signal processing unit, the coupling unit is respectively connected with the first optical signal detection unit and the second optical signal detection unit, the first optical signal detection unit and the second optical signal detection unit are both connected with a cable to be detected, and the signal processing unit is respectively connected with the first optical signal detection unit and the second optical signal detection unit through the photoelectric detection unit;
The light source is used for providing coherent light;
the acousto-optic modulation unit is used for modulating the coherent light into pulse light with three different pulse widths according to a time sequence pulse signal;
the coupling unit is used for dividing the pulse light into two paths of optical signals;
the first optical signal detection unit is used for detecting the area of the cable to be detected through one path of optical signal and transmitting the optical signal fed back by detection to the photoelectric detection unit;
the second optical signal detection unit is used for detecting the cable to be detected through another path of optical signal and transmitting the optical signal fed back by detection to the photoelectric detection unit;
the photoelectric detection unit is used for carrying out differential processing on the two paths of fed-back optical signals to obtain pulse signals and transmitting the pulse signals to the signal processing unit;
the signal processing unit is used for processing all the collected pulse signals by adopting the cable partial discharge monitoring method based on the multipath fiber difference as claimed in any one of claims 1-5, and determining whether partial discharge occurs in the area of the cable.
7. The multi-path fiber differential based cable partial discharge monitoring system according to claim 6, wherein the first optical signal detection unit and the second optical signal detection unit each comprise a first amplifier connected with the coupling unit, a second amplifier connected with the first amplifier, and a circulator connected with the second amplifier, the circulator of the second optical signal detection unit is connected with a cable to be tested through an optical switch, and the circulators of the first optical signal detection unit and the second optical signal detection unit are connected with the photodetecting unit.
8. The multi-path fiber differential based cable partial discharge monitoring system of claim 7, wherein the cable under test comprises a first core fiber, a second core fiber, and a third core fiber, the first core fiber is connected with a circulator of a first optical signal detection unit, the optical switch is connected with the second core fiber and the third core fiber, respectively, and the optical switch is used for switching the circulator of the second optical signal detection unit to be connected with the second core fiber or the third core fiber of the cable under test.
9. The multi-path fiber differential based cable partial discharge monitoring system of claim 6, wherein a signal generating unit for generating a trigger signal is further connected between the signal processing unit and the acousto-optic modulation unit.
10. A terminal device comprising a processor and a memory;
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is configured to execute the cable partial discharge monitoring method based on multi-path fiber differential according to any one of claims 1-5 according to instructions in the program code.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311014815.0A CN116754910B (en) | 2023-08-14 | 2023-08-14 | Cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311014815.0A CN116754910B (en) | 2023-08-14 | 2023-08-14 | Cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116754910A true CN116754910A (en) | 2023-09-15 |
| CN116754910B CN116754910B (en) | 2024-01-09 |
Family
ID=87948033
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311014815.0A Active CN116754910B (en) | 2023-08-14 | 2023-08-14 | Cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116754910B (en) |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08271573A (en) * | 1995-03-28 | 1996-10-18 | Tokyo Electric Power Co Inc:The | Method for detecting partial discharge |
| JP2001041849A (en) * | 1999-08-02 | 2001-02-16 | Advantest Corp | Otdr measuring instrument |
| JP2015114185A (en) * | 2013-12-11 | 2015-06-22 | 三菱電機株式会社 | Partial discharge detection method, and partial discharge detection device |
| CN105044568A (en) * | 2015-06-30 | 2015-11-11 | 山东微感光电子有限公司 | Optical fiber ultrasonic detection system and detection method with self-adaptive transformer partial discharge |
| CN108303626A (en) * | 2018-03-09 | 2018-07-20 | 广东电网有限责任公司珠海供电局 | A kind of shelf depreciation ultrasound measurement system and method based on distributing optical fiber sensing array |
| CN108802577A (en) * | 2018-04-19 | 2018-11-13 | 沈阳工程学院 | A kind of switch cabinet partial discharge measurement and positioning method |
| CN109085477A (en) * | 2018-09-28 | 2018-12-25 | 国网山东省电力公司济南供电公司 | Signal identification and localization method for power cable distribution partial discharge monitoring system |
| CN111308289A (en) * | 2020-03-06 | 2020-06-19 | 西安交通大学 | Partial discharge multispectral weak light detection device and method |
| WO2021082522A1 (en) * | 2019-11-01 | 2021-05-06 | 华为技术有限公司 | Optical fiber testing method based on optical time-domain reflectometer, and optical time-domain reflectometer |
| JP2021131258A (en) * | 2020-02-18 | 2021-09-09 | アズビル株式会社 | Light detection system and discharge probability calculating method |
| CN113835002A (en) * | 2021-08-19 | 2021-12-24 | 深圳供电局有限公司 | Distributed detection method and detection system for partial discharge of power cable |
| CN115144707A (en) * | 2022-06-29 | 2022-10-04 | 南方电网科学研究院有限责任公司 | Partial discharge positioning method and device based on optical fiber sensing measurement ultrasonic signal |
-
2023
- 2023-08-14 CN CN202311014815.0A patent/CN116754910B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08271573A (en) * | 1995-03-28 | 1996-10-18 | Tokyo Electric Power Co Inc:The | Method for detecting partial discharge |
| JP2001041849A (en) * | 1999-08-02 | 2001-02-16 | Advantest Corp | Otdr measuring instrument |
| JP2015114185A (en) * | 2013-12-11 | 2015-06-22 | 三菱電機株式会社 | Partial discharge detection method, and partial discharge detection device |
| CN105044568A (en) * | 2015-06-30 | 2015-11-11 | 山东微感光电子有限公司 | Optical fiber ultrasonic detection system and detection method with self-adaptive transformer partial discharge |
| CN108303626A (en) * | 2018-03-09 | 2018-07-20 | 广东电网有限责任公司珠海供电局 | A kind of shelf depreciation ultrasound measurement system and method based on distributing optical fiber sensing array |
| CN108802577A (en) * | 2018-04-19 | 2018-11-13 | 沈阳工程学院 | A kind of switch cabinet partial discharge measurement and positioning method |
| CN109085477A (en) * | 2018-09-28 | 2018-12-25 | 国网山东省电力公司济南供电公司 | Signal identification and localization method for power cable distribution partial discharge monitoring system |
| WO2021082522A1 (en) * | 2019-11-01 | 2021-05-06 | 华为技术有限公司 | Optical fiber testing method based on optical time-domain reflectometer, and optical time-domain reflectometer |
| JP2021131258A (en) * | 2020-02-18 | 2021-09-09 | アズビル株式会社 | Light detection system and discharge probability calculating method |
| CN111308289A (en) * | 2020-03-06 | 2020-06-19 | 西安交通大学 | Partial discharge multispectral weak light detection device and method |
| CN113835002A (en) * | 2021-08-19 | 2021-12-24 | 深圳供电局有限公司 | Distributed detection method and detection system for partial discharge of power cable |
| CN115144707A (en) * | 2022-06-29 | 2022-10-04 | 南方电网科学研究院有限责任公司 | Partial discharge positioning method and device based on optical fiber sensing measurement ultrasonic signal |
Non-Patent Citations (2)
| Title |
|---|
| REDY MARDIANA ET AL.: "Phase difference method for two-end partial discharge location in power cables", 2011 IEEE GCC CONFERENCE AND EXHIBITION (GCC), pages 597 - 600 * |
| 汪佛池等: "基于有限差分法的变压器局部放电高频信号的传播特性研究", 高压电器, vol. 55, no. 04, pages 72 - 81 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116754910B (en) | 2024-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107505041B (en) | Phase demodulation device and method based on phase sensitive optical time domain reflectometer | |
| JP6698164B2 (en) | Optical frequency domain reflection method and system based on frequency synthesis | |
| CN107907151B (en) | Phi OTDR and sensing method based on optical frequency modulation and direct detection | |
| CN105806465B (en) | A kind of novel Φ-OTDR detection device and its detection method based on fixation reflex point | |
| CN106768277B (en) | A kind of demodulation method of distributed optical fiber vibration sensing device | |
| CN113852416B (en) | Phase demodulation method and device with fading noise identification and elimination function | |
| CN110793558B (en) | Coherent detection type phi-OTDR system and self-checking method | |
| CN112833929A (en) | Disturbance monitoring system of heterodyne phi-OTDR technology based on local optical frequency shift | |
| CN109164300A (en) | Microwave frequency high precision measuring system and method based on harmonic wave amplification | |
| CN111896138A (en) | Long-distance high-spatial-resolution distributed chaotic Raman optical fiber sensing device | |
| CN116754910B (en) | Cable partial discharge monitoring method, system and equipment based on multipath optical fiber difference | |
| CN111637910B (en) | Time domain differential high-speed chaotic Brillouin optical coherent domain monitoring device and method | |
| CN103823175A (en) | Photoelectric detection circuit frequency response characteristic test method based on OTDR | |
| CN111141414B (en) | Temperature and strain simultaneous measurement device and method based on chaos BOCDA | |
| CN109444895B (en) | Vibration information positioning method for eliminating interference fading of distributed vibration sensor | |
| CN116576897A (en) | Multi-parameter optical fiber distributed sensing system and method thereof | |
| CN115900787A (en) | Method and system for realizing spectral domain reflectometer | |
| CN114485748B (en) | Multi-parameter distributed optical fiber sensing method and system | |
| CN111721438B (en) | Exempt from frequency sweep BOTDA device that noise modulation linear array CCD gathered | |
| CN113390449A (en) | Optical fiber sensing device | |
| CN116015428B (en) | DVS-based optical fiber length determination method, device and system | |
| CN113124931A (en) | Method, device and storage medium for improving power optical fiber state monitoring precision | |
| CN207263419U (en) | A kind of Cable's Fault detecting system based on Rayleigh scattering technology | |
| KR20210024830A (en) | Phase Detector and Phase Detection Method for Extracting Vibration Signal in Distributed Acoustic Sensors | |
| CN212752265U (en) | System for detecting Rayleigh scattering signal intensity by adopting EDFA (erbium doped fiber amplifier) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |