CN115951181A - Method and device for positioning local discharge of distribution cable in electrified mode under condition of no GPS - Google Patents
Method and device for positioning local discharge of distribution cable in electrified mode under condition of no GPS Download PDFInfo
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- CN115951181A CN115951181A CN202211709192.4A CN202211709192A CN115951181A CN 115951181 A CN115951181 A CN 115951181A CN 202211709192 A CN202211709192 A CN 202211709192A CN 115951181 A CN115951181 A CN 115951181A
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Abstract
The invention discloses a method and a device for positioning local discharge electrification of a distribution cable under the condition of no GPS, which comprises the following steps: s1: pre-synchronizing the double-end detection device; s2: carrying out depth sampling on partial discharge signals at two ends of the cable; s3: extracting partial discharge pulse sequences with time correlation in partial discharge signals at two ends of the cable; s4: judging the position source of each partial discharge pulse sequence by utilizing a traveling wave direction criterion, and removing a pulse noise interference sequence; s5: and realizing partial discharge prepositioning according to the attenuation characteristic of the partial discharge pulse sequence peak value after the noise is removed. The invention does not need expensive atomic clock precise timer or GPS synchronizer, and only needs cheap timing circuit. The invention has the advantages of low cost, convenience, high efficiency, strong anti-interference capability and the like, is suitable for the field of cable partial discharge live detection, can accurately distinguish the cable with partial discharge, and can pre-position a partial discharge source.
Description
Technical Field
The invention belongs to the field of cable partial discharge live detection and operation and maintenance, and particularly relates to a distribution cable partial discharge live positioning method and device under the condition of no GPS.
Background
The distribution cable is power equipment for realizing long-distance transmission of distribution network energy, and the reliability of the distribution cable directly influences the power utilization condition of an area. Due to the reasons of service life increase, improper construction department, external force damage and the like, cable faults and even explosion are often caused, and more than 90% of faults of the cable are insulation faults according to incomplete statistics. Therefore, development of cable insulation state detection is very important for ensuring the operation stability and reliability of the distribution network.
Partial discharge detection is currently one of the most common and effective means of cable insulation state assessment. The partial discharge detection of the cable mainly comprises off-line detection and live detection/on-line monitoring, the off-line detection technology at home and abroad is mature at present, and an oscillatory wave partial discharge detection device, an ultralow frequency partial discharge detection device, a cosine square wave partial discharge detection device and the like appear in succession, however, with the increasing requirements on the reliability and the continuity of power supply of a distribution network, the cable cannot be subjected to power failure maintenance, and the off-line detection method has obvious limitations. Therefore, the development of a live detection/online monitoring method for a distribution cable is a hot direction at present.
The local discharge live detection/online monitoring method of the distribution cable is divided into a single-end detection method and a double-end detection method. The single-end detection method positions a partial discharge point by calculating the time difference between a partial discharge pulse and a reflected wave of the partial discharge pulse at a terminal, but is not suitable for a long cable or a short cable due to the problems of reflection superposition and attenuation, so that the application is limited; the double-end detection method can overcome the attenuation and reflection superposition problems of single-end detection by calculating the time difference of reaching two ends of a cable through partial discharge to position the position of the partial discharge, but has the defect of requiring the accurate synchronization of clocks at two ends. The existing synchronization mode comprises optical fibers and a GPS, but most distribution cables are buried directly and cannot be laid with the optical fibers, and a GPS chip which is commercialized in the synchronization grade of ns grade is high in price and poor in signal stability or even has no signal in a transformer substation or an underground transformer room (a common position where a distribution cable terminal is located), so that the technology cannot be further applied to distribution cable detection. In addition, a number of field applications have shown that the greatest challenge facing live detection/online monitoring of distribution cables is the problem of noise interference. When the cable runs on line, the cable is electrically connected with other power equipment (a switch cabinet, a ring main unit, an overhead line, a transformer and the like) of a distribution network, once the other power equipment is coupled with high-frequency interference or a discharge phenomenon occurs, the interference spreads a line into the cable, and the partial discharge detection effect is greatly influenced.
Therefore, further improving and promoting the local discharge live detection technology of the cable, and realizing the high-efficiency, accurate, stable and strong anti-interference local discharge live detection/online monitoring is an important and urgent research topic in the technical research, product design and application fields.
Disclosure of Invention
In order to solve the problems, the invention provides a method and a device for positioning the partial discharge of a distribution cable in an electrified way under the condition without a GPS (global positioning system), which can accurately distinguish the cable with partial discharge and carry out pre-positioning on a partial discharge source.
In order to achieve the purpose, the invention provides a distribution cable partial discharge live positioning method under the condition of no GPS, which comprises the following steps:
s1: pre-synchronizing the double-end detection device;
s2: based on the pre-synchronized double-end detection device, deep sampling is carried out on partial discharge signals at two ends of the cable;
s3: extracting partial discharge pulse sequences with time correlation in partial discharge signals at two ends of the cable;
s4: judging the position source of each partial discharge pulse sequence by using a traveling wave direction criterion, and removing a pulse noise interference sequence;
s5: and realizing partial discharge prepositioning according to the attenuation characteristic of the partial discharge pulse sequence peak value after the noise is removed.
Preferably, in S1, before polling is started each time, clocks of the two detection units are presynchronized by injecting external pulses simultaneously, and a synchronization error of the two detection units in one day does not exceed several milliseconds, so that the two detection units can acquire the same partial discharge pulse.
Preferably, in S2, deep sampling is performed on the partial discharge signal through high-frequency current transformers installed at two ends of the cable, the sampling time is at least longer than one power frequency cycle, and it is ensured that a partial discharge pulse signal meeting a preset threshold is collected, where the power frequency cycle is 20ms; the data collected each time has a time stamp, so that the corresponding data of the detection units at the two ends are matched with each other under the condition of no communication network.
Preferably, in S3, a partial discharge pulse signal with a fixed time difference in the signal sequences detected at the two ends of the cable is separated from the noise signal by a time correlation statistical method, so as to extract a partial discharge pulse under a strong pulse interference condition.
Preferably, in S4, the signal sources are distinguished by determining the current directions of the pulse signals at the two ends of the cable: the partial discharge pulse signals are from the cable, when the partial discharge pulse signals reach two ends of the cable, the traveling wave propagation directions point to two sides, the directions are opposite, and the detected pulse polarities are opposite; on the contrary, the interference pulse comes from other electric equipment except the cable, the traveling wave propagation directions at the two ends of the cable all point to one side, the directions are the same, and the detected pulse polarity is the same.
Preferably, in S5, the partial discharge pulse may exhibit an exponential decay characteristic in the cable, and the position of the partial discharge is reversely deduced through the peak ratio of the partial discharge pulse detected at both ends.
Preferably, the calculation formula of the position of the partial discharge is as follows:
where α is the high frequency attenuation coefficient of the cable, L is the total length of the cable, and PA and PB are the A-side and B-side measurements of the partial discharge pulses, respectively.
The invention also provides a distribution cable partial discharge live positioning device under the condition of no GPS, which comprises two detection units: each detection unit consists of a high-frequency current transformer, a signal conditioning circuit, a data acquisition unit, a timing circuit unit and an ARM microprocessor unit;
the high-frequency current transformers are arranged at the linear position of a cable terminal after a shielding wire is stripped, the high-frequency current transformers are respectively arranged on three-phase cables, the sensitivity of each high-frequency current transformer is 5mV/mA, and the bandwidth is 1-80MHz;
the gain of the signal conditioning circuit is 20dB, the bandwidth is 1-80MHz, the dynamic range is 0-5V, and the number of channels is 3;
the sampling rate of the data acquisition unit is 125MS/s, the sampling bit number is 14 bits, the storage depth is 2G, the dynamic range is 0-5V, and the channel number is 3 channels;
the timing circuit unit is realized by adopting a crystal oscillator and a counter, the crystal oscillator adopts a common quartz crystal oscillator, the clock error of each day is not more than 50ms, and the requirement of 1s sampling time on the synchronization precision is met;
the ARM microprocessor unit is composed of an embedded ARM microprocessor, an SD card memory, a display screen and a 4G communication module, and is used for finishing processing, analyzing, storing and uploading of partial discharge detection data.
Preferably, considering the problem that the high-voltage cabin of the distribution cable terminal cannot be opened in a live state, the sensor module is preloaded, and a detector carries a detection host to perform a partial discharge detection strategy of the distribution cable which is regularly patrolled.
Compared with the prior art, the invention has the following advantages and technical effects:
the invention adopts a double-end detection principle and utilizes a time correlation statistical method to separate local discharge and noise signals which are distributed in a staggered way in a time domain and are difficult to distinguish, thereby realizing accurate extraction of a cable local discharge sequence under a noise condition.
The invention utilizes the characteristic that the propagation directions of partial discharge pulse signals in the cable and other noise interference in the line are different, and combines the analysis result of double-end time correlation, and can accurately distinguish whether the pulse signals with time correlation come from the cable, thereby filtering other noise interference and accurately extracting the partial discharge of the cable.
The invention adopts a cheap timing circuit to synchronize the double-end detection system, adopts a local discharge positioning method based on the peak attenuation characteristic, does not need an expensive GPS synchronization system, is not influenced by no signal of a transformer substation or an underground transformer substation, and has better economic effect and practical value.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the application, and the description of the exemplary embodiments of the application are intended to be illustrative of the application and are not intended to limit the application. In the drawings:
FIG. 1 is a schematic flow chart of a method for positioning a distribution cable in a partial discharge live state without a GPS according to the present invention;
FIG. 2 is a schematic diagram of the overall hardware framework of the distribution cable partial discharge live positioning device without GPS according to the present invention;
FIG. 3 is a schematic diagram of the dual end partial discharge detection of the distribution cable partial discharge live positioning apparatus of the present invention without GPS;
FIG. 4 is a schematic diagram of the principle of distinguishing partial discharge from noise of a cable based on the pulse direction determination principle of the distribution cable partial discharge live positioning device without GPS, wherein (a) is a schematic diagram of a double-end detection pulse waveform, and (b) is a schematic diagram of a statistical analysis result based on time difference correlation;
FIG. 5 is a schematic diagram of the double-ended detection waveform and time correlation of the distribution cable partial discharge live positioning apparatus of the present invention without GPS;
FIG. 6 is a block diagram of the operation of the local discharge live positioning device of the distribution cable without GPS according to the present invention;
fig. 7 is a schematic diagram of a field implementation of the distribution cable partial discharge live positioning device in the absence of GPS according to the present invention, wherein (a) is an application example diagram, and (b) is a schematic diagram of a high-frequency current transformer pre-loading.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer-executable instructions and that, although a logical order is illustrated in the flowcharts, in some cases, the steps illustrated or described may be performed in an order different than presented herein.
Example one
As shown in fig. 1, in order to avoid high-frequency interference of power electronic devices and discharge interference of switch cabinets, other cables, overhead lines and transformers along the lines, the invention provides a method for positioning local discharge live of a distribution cable under the condition of no GPS, which comprises the following steps:
s1: before each turn-on of the patrol (e.g. within 24 hours), the clocks of the two detection units are pre-synchronized by injecting external pulses simultaneously. The synchronization error of the two detection units in one day is not more than a few milliseconds, so that the two detection units can acquire the same partial discharge pulse.
S2: the high-frequency current transformers arranged at two ends of the cable are used for deeply collecting partial discharge signals, and the sampling time is at least more than one power frequency period (20 ms) so as to ensure that enough partial discharge pulse signals are collected. Each time the data is collected, a time stamp is provided, for example, 12 o' clock 00 min 00 s, so that the corresponding data of the detection devices at the two ends are matched with each other under the condition of no communication network.
S3: when the partial discharge detection is carried out on the cable running on line, the noise interference is inevitable, and particularly, no effective and reliable solution exists at present for pulse type noise similar to partial discharge pulse. When partial discharge occurs, the partial discharge is often accompanied by a series of discharge pulse signals, and the pulse signals have a common characteristic that the time difference of arrival at the two ends of the cable is consistent. According to the characteristic, the cable partial discharge signal and the noise signal can be distinguished, so that the invention provides a statistical analysis method based on time difference correlation, the partial discharge pulse signal with fixed time difference in the signal sequence detected at two ends of the cable is separated from the noise signal, and the partial discharge pulse extraction under the condition of strong pulse interference can be realized.
S4: after a statistical analysis of the time difference correlation of the signal sequences detected at the two ends of the cable, one or more pulse sequences can be obtained in which noise interference sequences may occur, for example high-frequency interference of power electronics in the power equipment connected to the cable or discharge phenomena. In order to judge whether the pulse sequences are partial discharge signals from the cable body, the invention distinguishes signal sources by judging the current directions of the pulse signals at two ends of the cable. If the pulse signal comes from the cable, when the pulse signal reaches the two ends of the cable, the traveling wave propagation direction points to the two sides, the directions are opposite, and the detected pulse polarities are opposite; however, if the pulse is from other electric equipment except the cable, the traveling wave propagation directions of the pulse at the two ends of the cable are all pointed to one side, the directions are the same, and the detected pulse has the same polarity.
S5: the partial discharge pulse can present exponential attenuation characteristics in the cable, wherein the attenuation coefficient can be obtained through the structure and model calculation of the cable, and then the approximate position of the partial discharge is reversely deduced according to the peak value proportion of the partial discharge pulse detected at the two ends. Assuming that the partial discharge occurs x meters away from the a end of the cable, the peak value of the partial discharge pulse detected at both ends (a end and B end) can be expressed as:
P A ＝P PD e -αx (1)
P B ＝P PD e -α(L-x) (2)
wherein P is PD 、P A 、P B The method is characterized in that the method comprises the following steps of respectively obtaining a real peak value, an A-end measured value and a B-end measured value of a partial discharge pulse, wherein L is the total length of a cable, and alpha is a high-frequency attenuation coefficient of the cable, is an inherent characteristic of the cable, and can be obtained through calculation according to the size and the model of the cable. Simultaneous equations (1) and (2) allow the position x of the partial discharge to be calculated:
example two
As shown in fig. 2, the present invention further provides a distribution cable partial discharge live positioning device without GPS, comprising:
the invention adopts a double-end detection method to carry out the partial discharge detection of the cable, two detection units which are respectively arranged at two ends of the cable are required, and the hardware compositions of the two detection units are completely the same, so that the hardware design of only one detection unit is described. Each detection unit mainly comprises three high-frequency current transformers, a three-channel amplification filter circuit (signal conditioning circuit), a three-channel data acquisition card (data acquisition unit), a timing circuit (timing circuit unit) and an ARM microprocessor unit. The sensitivity of the three high-frequency current transformers is 5mV/mA, the bandwidth is 1-80MHz, in order to complete the detection of the propagation direction of partial discharge pulses in the cable, the high-frequency current transformers are arranged at the cable linear position of the cable terminal after the shielding wires are stripped, and the three-phase cable needs one high-frequency current transformer respectively. The gain of the three-channel amplifying and filtering circuit is 20dB, the bandwidth is 1-80MHz, the dynamic range is 0-5V, and the number of channels is 3. The main purpose of signal conditioning and amplification is to suppress power frequency interference, harmonic interference thereof and other high-frequency interference and improve the signal-to-noise ratio of partial discharge signals. A data acquisition unit: the sampling rate is 125MS/s, the sampling bit number is 14 bits, the storage depth is 2G, the dynamic range is 0-5V, and the channel number is 3 channels. In order to ensure the data reliability of the time difference correlation statistical analysis method of claim 2, the sampling time is set to 1s. The timing circuit unit adopts a crystal oscillator and counter implementation method, the crystal oscillator adopts a common quartz crystal oscillator (frequency error is less than 0.5 ppm), and the clock error of each day is not more than 50ms; the ARM microprocessor unit consists of an embedded ARM microprocessor, an SD card memory, a display screen and a 4G communication module, and is used for finishing the processing, analysis, storage and uploading of partial discharge detection data.
In consideration of the problem that the high-voltage cabin of the distribution cable terminal cannot be opened in a charged state, the invention adopts the sensor module for preloading, and the detection personnel carry the detection host machine to carry out the partial discharge detection strategy of the distribution cable for regular inspection.
Fig. 3 shows a schematic diagram of the double-ended partial discharge detection of the present invention. When partial discharge occurs in the cable, high-frequency pulse current generated by the partial discharge propagates to both ends along the cable, so that a high-frequency current transformer is installed at the cable terminal to capture the high-frequency pulse current, thereby realizing the detection of the partial discharge of the cable.
However, for cables running online, noise interference is unavoidable, and among them, impulse noise interference is the main one, and since the waveform characteristics are similar to those of partial discharge pulses (as shown in fig. 4 (a), where P represents partial discharge pulses, solid lines, N represents noise interference, dotted lines, "+" represents positive polarity of pulses, "-" represents negative polarity of pulses, and Tsyn represents synchronization errors), it is difficult to distinguish them by common time-frequency analysis. As shown in fig. 4 (a), assuming that a partial discharge pulse (red) and a noise interference pulse (green) having a similar amplitude appear simultaneously in a detection sequence, the core of the present invention is how to separate the partial discharge pulse and the noise interference pulse and identify the partial discharge pulse.
The basic principle of pulse sequence separation based on time difference correlation statistical analysis provided by the invention is as follows: firstly, synchronizing a double-end detection system through a timing circuit (accurate synchronization is not needed), then calculating the time difference between every two pulse sequences at two ends, wherein due to the fact that local discharge signals and noise interfere the difference of physical positions of respective sources, an obvious time aggregation phenomenon can occur in a spectrogram of a time difference calculation result, then solving the distribution density of the time difference calculation result on a time axis to obtain a time difference statistical analysis density graph, so that the pulse sequences which are difficult to distinguish in a time domain are divided into two pulse sequences with obvious time difference statistical analysis density difference, and as shown in fig. 4 (b), a solid line represents a partial discharge pulse; the dashed line represents noise interference; the pulse polarities measured by the upper half area of the coordinate axis representing two ends are the same, and the pulse polarities measured by the lower half area of the coordinate axis representing two ends are opposite; tsyn represents the synchronization error.
Although the above basic principle can transform the partial discharge pulse and the noise pulse which are difficult to distinguish in the time domain into the time difference layout with obvious distribution difference, it still cannot distinguish which sequence of pulse signals is the real cable partial discharge signal. To solve this problem, the present invention uses the difference in the traveling wave propagation direction of the cable partial discharge pulse and the noise interference at both ends of the cable to distinguish them. As shown in fig. 5, if the pulse signal is from the cable, the traveling wave propagation direction is directed to both sides when reaching both ends of the cable, and the directions are opposite, so the pulse detected by the current transformer has opposite polarity; however, if the pulse originates from other electric equipment except the cable, the traveling wave propagation directions of the pulse at two ends of the cable are all directed to one side and the directions are the same, so that the polarities of the pulses detected by the current transformer are the same, the representation of the polarity difference in the waveform diagram is shown in fig. 4 (a), the pulse polarity factor is considered when the statistical analysis of the time difference is performed, and the obtained time difference calculation result diagram and the time difference statistical analysis density diagram are shown in fig. 4 (b). Therefore, the cable partial discharge pulse sequence can be extracted from the noise pulse sequence by the polarity difference.
Fig. 6 shows a block diagram of the operation of the distribution cable partial discharge live detection device. Firstly, the cloud server issues a double-end detection instruction, detection time is set, if double-end preparation is finished, the next step is carried out, otherwise, the operation is directly finished, and the next instruction is waited; the double-end data acquisition card enters a waiting triggering state, and an external triggering mode is adopted to wait for the triggering of a timing circuit; the double-end timing circuit simultaneously triggers the data price card to acquire the data at the end at the set detection time; in order to ensure the efficiency of data uploading, the collected data is preprocessed, the pulse arrival time, the peak value and the polarity are extracted, and the original data (with the size of about 500 MByte) is compressed into dozens of kByte; performing time difference correlation analysis on the double-end detection result to obtain a plurality of pulse sequences; judging the pulse polarity condition, if the pulse polarity condition is the same, removing the pulse polarity condition, and if the pulse polarity condition is opposite, reserving the pulse polarity condition; and finally, outputting the reserved partial discharge pulse sequence, and calculating the position of a partial discharge source through a formula (3).
Fig. 7 shows a schematic diagram of a field implementation of the distribution cable partial discharge live detection device. In consideration of the problem that the high-voltage cabin of the distribution cable terminal cannot be opened in a charged state, the invention adopts the sensor module for pre-loading, and a detection personnel carries a detection host to carry out a partial discharge detection strategy of the distribution cable for periodic inspection, as shown in fig. 7 (a). Fig. 7 (b) shows a pre-loading schematic diagram of a high-frequency current sensor in a cable terminal switch cabinet, the high-frequency current transformer is installed on a three-phase cable core at a cable terminal after a shielding layer is peeled off, then a sensor outgoing line is led to an instrument cabin of the switch cabinet (can be opened in a live manner) through a wiring groove of the switch cabinet, and then a through socket is arranged in the instrument cabin so as to detect the connection of a host and the sensor during testing.
The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (9)
1. The method for positioning the local discharge live of the distribution cable under the condition of no GPS is characterized by comprising the following steps:
s1: pre-synchronizing the double-end detection device;
s2: based on the pre-synchronized double-end detection device, deep sampling is carried out on partial discharge signals at two ends of the cable;
s3: extracting partial discharge pulse sequences with time correlation in partial discharge signals at two ends of the cable;
s4: judging the position source of each partial discharge pulse sequence by utilizing a traveling wave direction criterion, and removing a pulse noise interference sequence;
s5: and realizing partial discharge prepositioning according to the attenuation characteristic of the partial discharge pulse sequence peak value after the noise is removed.
2. The method for positioning the partial discharge live line of the distribution cable under the GPS-free condition according to claim 1, wherein in the step S1, before the inspection is started each time, clocks of the two detection units are pre-synchronized by injecting external pulses at the same time, and the synchronization error of the two detection units in one day is not more than a few milliseconds, so that the two detection units can acquire the same partial discharge pulse.
3. The method for locating the partial discharge live of the distribution cable under the GPS-free condition according to claim 1, wherein in S2, the partial discharge signals are deeply sampled by high-frequency current transformers installed at two ends of the cable, the sampling time is at least greater than one power frequency period, and the partial discharge pulse signals meeting a preset threshold value are ensured to be collected, wherein the one power frequency period is 20ms; the data collected each time has a time stamp, so that the corresponding data of the detection units at the two ends are matched with each other under the condition of no communication network.
4. The method as claimed in claim 1, wherein in S3, partial discharge pulse signals with fixed time difference in the signal sequence detected at two ends of the cable are separated from noise signals by a time correlation statistical method, so as to extract partial discharge pulses under strong pulse interference condition.
5. The method as claimed in claim 1, wherein in step S4, the signal sources are distinguished by determining the current direction of the pulse signal at the two ends of the cable: the partial discharge pulse signals are from the cable, when the partial discharge pulse signals reach two ends of the cable, the traveling wave propagation directions point to two sides, the directions are opposite, and the detected pulse polarities are opposite; on the contrary, the interference pulse comes from other power equipment except the cable, the traveling wave propagation directions at the two ends of the cable point to one side, the directions are the same, and the detected pulse polarity is the same.
6. The method as claimed in claim 1, wherein in step S5, the partial discharge pulse exhibits an exponential decay characteristic in the cable, and the position of the partial discharge is deduced reversely by the peak ratio of the partial discharge pulse detected at both ends.
7. The method as claimed in claim 6, wherein the partial discharge live positioning method for distribution cable without GPS is characterized in that the calculation formula of the partial discharge position is as follows:
where α is the high frequency attenuation coefficient of the cable, L is the total length of the cable, and PA and PB are the A-side and B-side measurements of the partial discharge pulses, respectively.
8. Electrified positioner of distribution cable partial discharge under no GPS condition, its characterized in that includes two detecting element: each detection unit consists of a high-frequency current transformer, a signal conditioning circuit, a data acquisition unit, a timing circuit unit and an ARM microprocessor unit;
the high-frequency current transformers are arranged at the linear position of a cable terminal after a shielding wire is stripped, the high-frequency current transformers are respectively arranged on three-phase cables, the sensitivity of each high-frequency current transformer is 5mV/mA, and the bandwidth is 1-80MHz;
the gain of the signal conditioning circuit is 20dB, the bandwidth is 1-80MHz, the dynamic range is 0-5V, and the number of channels is 3;
the sampling rate of the data acquisition unit is 125MS/s, the sampling bit number is 14 bits, the storage depth is 2G, the dynamic range is 0-5V, and the channel number is 3 channels;
the timing circuit unit is realized by adopting a crystal oscillator and a counter, the crystal oscillator adopts a common quartz crystal oscillator, the clock error of each day is not more than 50ms, and the requirement of 1s sampling time on the synchronization precision is met;
the ARM microprocessor unit consists of an embedded ARM microprocessor, an SD card memory, a display screen and a 4G communication module, and is used for finishing the processing, analysis, storage and uploading of partial discharge detection data.
9. The device for locating the live partial discharge of the distribution cable under the GPS-free condition according to claim 8, wherein the sensor module is preloaded in consideration of the problem that the high-voltage cabin of the distribution cable terminal cannot be opened under the live state, and a detection personnel carries a detection host to carry out a local discharge detection strategy of the distribution cable for periodic inspection.
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| CN202211709192.4A CN115951181A (en) | 2022-12-29 | 2022-12-29 | Method and device for positioning local discharge of distribution cable in electrified mode under condition of no GPS |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117554767A (en) * | 2024-01-10 | 2024-02-13 | 华北电力科学研究院有限责任公司 | High-frequency discharge signal detection device and method based on power frequency current transformer |
| CN117761469A (en) * | 2024-02-22 | 2024-03-26 | 陕西公众电气股份有限公司 | Inspection method and system for diagnosing partial discharge of overhead line of power distribution network |
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2022
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117554767A (en) * | 2024-01-10 | 2024-02-13 | 华北电力科学研究院有限责任公司 | High-frequency discharge signal detection device and method based on power frequency current transformer |
| CN117554767B (en) * | 2024-01-10 | 2024-04-05 | 华北电力科学研究院有限责任公司 | High-frequency discharge signal detection device and method based on power frequency current transformer |
| CN117761469A (en) * | 2024-02-22 | 2024-03-26 | 陕西公众电气股份有限公司 | Inspection method and system for diagnosing partial discharge of overhead line of power distribution network |
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