KR20200033536A - Apparatus for detecting fault location of underground cable and method thereof - Google Patents

Abstract

Disclosed are an apparatus for detecting a fault location of an underground cable and a method therefor. The apparatus for detecting a fault location of an underground cable, of the present invention, comprises: a trigger monitoring unit detecting a trigger signal, which exceeds a reference level, from a current measured through trigger sensors at both ends of a power cable; a real-time monitoring unit detecting, in real time, the current measured through current sensors at both ends of the power cable; a GPS reception unit receiving time information from a GPS satellite; a DB storing trigger data detected by the trigger monitoring unit and real-time current data detected by the real-time monitoring unit; a fault detection server synchronizing the time on the basis of the time information received through the GPS reception unit, and then storing the trigger signal monitored by the trigger monitoring unit in the DB, detecting a fault location on the basis of the trigger signal, storing, in the DB in real time, the current data detected by the real-time monitoring unit, and detecting the fault location on the basis of a transient signal so as to output fault location information according to priority when the fault location is determined; a communication unit sharing system information and measurement data through a network between the fault detection servers; and an output unit displaying the operating state of the fault detection server, and the fault location information. The present invention can improve accuracy of fault location.

Description

Fault location detection device of underground cable and its method {APPARATUS FOR DETECTING FAULT LOCATION OF UNDERGROUND CABLE AND METHOD THEREOF}

The present invention relates to an apparatus for detecting a fault location of an underground cable and a method thereof. More specifically, a real-time load current and a fault current at both ends of the underground cable are simultaneously monitored by a trigger monitoring measurement method and a real-time monitoring measurement method, and a failure occurs. Fault location detection device and method of underground cable to detect fault location and determine complementary fault location by applying fault signal filter to remove noise by using multi-scale wavelet analysis for transient signal It is about.

In general, electric power cables are being installed in place of overhead lines in terms of improving the reliability of power supply to urban areas and load-closed areas such as factories, and in terms of beautification of urban environments.

Since the power cable is buried in the ground, if an abnormality occurs in the power cable due to an insulation failure, it takes a long time to recover due to a failure point detection and replacement process, resulting in economic loss due to a delay in recovery.

Therefore, a preventive diagnosis technique that can prevent a failure in advance is important, but an accurate failure point expression technique in parallel with such a technique is also important for maintenance of an underground line.

Looking at the failure point expression technology of such a power cable, an offline method such as Murray Loop method using Timestone Bridge principle and Time Domain Reflectometry (TDR) method is used.

Such a bridge method is known as an impedance measurement method for expressing a failure point and a traveling wave measurement method for expressing a failure point using reflection characteristics of a traveling wave input or generated in a cable.

However, although this impedance measurement method is a relatively stable technique, it is difficult to detect a failure in the case of a high-resistance failure of several hundreds of kilohertz or more, and there is a disadvantage in that the error of the measurement distance may be increased due to the passage of the line and the installation conditions. .

In addition, the traveling wave measurement method has an advantage that can be expressed as a failure point without being influenced by the impedance or lapse of the line, and the installation conditions, but the traveling wave measurement method is a pulse reflected from the failure point after applying a pulsed voltage to the failure line The difference between and the applied pulse is obtained, and the failure point is expressed by the relationship between the time difference and the pulse speed. This has the disadvantage of detecting the failure point after the failure as in the impedance method.

In addition, various methods such as using the ARM (Arc Reflection Method), Pin pointing method, Searching coil method, etc. are applied to detect the failure point, but all of these methods are performed offline and the line is completely removed from the system after the failure. It is applied after separation, and it takes a relatively long time to detect a failure point, and it is pointed out as a problem in practical application since the skill of the measuring person can also affect the measurement error.

To overcome this problem, a method of detecting a real-time failure point has been proposed in recent years. Such a real-time failure point detection method is known to express a failure point using the principle of pulse reflection and the progress and reflection of a transient traveling wave generated by high arc resistance in the event of a cable failure.

Background art of the present invention is disclosed in Republic of Korea Patent Publication No. 0317032 (announced on December 22, 2001, a method and apparatus for detecting a fault point in an underground line).

However, the transient phenomenon occurring in the underground transmission system including the HVDC cable has a problem in that it is very difficult to discriminate the noise and the transient signal because noise in a high frequency region is generated due to interference due to external environmental influences. In addition, even in an offline technique of detecting a failure point by injecting a specific signal, there is a problem in that it is very difficult to determine a time point reflected by a large amount of noise.

The present invention has been devised to improve the above problems, and the object of the present invention according to an aspect is to simultaneously monitor real-time load current and fault current at both ends of an underground cable using a trigger monitoring measurement method and a real-time monitoring measurement method. , Fault location detection device of underground cable that detects the location of a failure and complementarily determines the location of the failure by applying a failure signal filter that removes noise by using multi-scale wavelet analysis on the transient signal that appears when a failure occurs And to provide a method.

A fault location detection device for an underground cable according to an aspect of the present invention includes: a trigger monitoring unit that detects a trigger signal exceeding a reference level from a current measured through a trigger sensor at both ends of a power cable; A real-time monitoring unit that senses the current measured through the current sensor at both ends of the power cable in real time; GPS receiver for receiving time information from a GPS satellite; A DB that stores trigger data sensed by the trigger monitor and real-time current data sensed by the real-time monitor; After synchronizing the time based on the time information received through the GPS receiver, the trigger signal monitored by the trigger monitor is stored in the DB, the fault location is detected based on the trigger signal, and the current data detected from the real-time monitor is DB A fault detection server that stores in real time and detects a fault position based on a transient signal, and outputs fault position information according to priority when the fault position is expressed; A communication unit for sharing system information and measurement data through a network between fault detection servers; And an output unit for displaying the operation status and the location of the failure of the failure detection server.

In the present invention, the trigger sensor is characterized by including a Rogowski sensor.

In the present invention, the real-time monitoring unit is characterized in that noise is removed by using a correlation of signals detected through multi-scale wavelet analysis of a transient signal that appears when a failure occurs.

In the present invention, the failure detection server is characterized in that the real-time current data is divided and stored in units of a set time.

In the present invention, the failure detection server is characterized in that it detects the failure location by calculating the distance to the failure location based on the difference between the traveling wave arrival time at both ends of the power cable.

In the present invention, the failure detection server is characterized in that it first provides a detected failure location based on a trigger signal when the failure location is expressed.

According to another aspect of the present invention, a method for detecting a fault location of an underground cable includes: a fault detection server synchronizing time based on time information received through a GPS receiver; A fault detection server receiving current data measured through a current sensor at both ends of the power cable in real time and storing it in a DB and detecting a fault location based on a transient signal; A fault detection server receiving a trigger signal detected by a trigger sensor from both ends of the power cable, storing it in a DB, and detecting a fault location based on the trigger signal; And when the fault location is expressed, the fault detection server providing the detected fault location information according to the priority.

In the present invention, detecting a fault location based on a transient signal is performed by removing noise by correlating the detected signal through multi-scale wavelet analysis of the transient signal when the failure detection server occurs. It is characterized by detecting the location.

In the present invention, when receiving the current data in real time and storing it in the DB, it is characterized in that the failure detection server classifies and stores the real time current data in units of a set time.

In the present invention, the step of detecting the fault location is characterized in that the fault detection server detects the fault location by calculating the distance to the fault location based on the difference between the traveling wave arrival time at both ends of the power cable.

In the present invention, the step of providing the fault location information is characterized in that the fault detection server first provides the detected fault location based on the trigger signal when the fault location is expressed.

The fault location detecting device and method of the underground cable according to an aspect of the present invention are a trigger monitoring measurement method and a real-time monitoring measurement method, and simultaneously monitor real-time load current and fault current at both ends of the underground cable, and a transient that occurs when a failure occurs By applying a fault signal filter that removes noise using multi-scale wavelet analysis on the signal, it is possible to improve the accuracy of the fault location by detecting the fault location and determining the fault location complementarily.

1 is a block diagram showing a fault location detecting device of an underground cable according to an embodiment of the present invention.
Figure 2 is a block diagram showing the actual system installation state of the fault location detection device of the underground cable according to an embodiment of the present invention.
Figure 3 is an exemplary screen showing a main screen of the fault location detection device of the underground cable according to an embodiment of the present invention.
Figure 4 is an exemplary screen showing a real-time monitoring screen of the fault location detection device of the underground cable according to an embodiment of the present invention.
Figure 5 is an exemplary screen showing a trigger monitoring load screen of the fault location detection device of the underground cable according to an embodiment of the present invention.
6 is an exemplary screen showing a real-time monitoring log screen of a fault location detecting device of an underground cable according to an embodiment of the present invention.
7 is a flowchart illustrating a method for detecting a fault location of an underground cable according to an embodiment of the present invention.

Hereinafter, an apparatus and method for detecting a fault location of an underground cable according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition of these terms should be made based on the contents throughout the present specification.

1 is a block diagram showing a fault location detecting device of an underground cable according to an embodiment of the present invention, and FIG. 2 shows a real system installation state of a fault location detecting device of an underground cable according to an embodiment of the present invention It is a block diagram. Figure 3 is an exemplary screen showing a main screen of the fault location detection device of the underground cable according to an embodiment of the present invention, Figure 4 is a real-time monitoring screen of the fault location detection device of the underground cable according to an embodiment of the present invention Exemplary screen shown, Figure 5 is an exemplary screen showing a trigger monitoring log screen of the fault location detecting device of the underground cable according to an embodiment of the present invention, Figure 6 is a fault location of the underground cable according to an embodiment of the present invention This is an example screen showing the real-time monitoring log screen of the detection device.

1 and 2, the fault location detecting device of the underground cable according to an embodiment of the present invention includes a trigger monitoring unit 20, a real-time monitoring unit 40, a GPS receiving unit 50, and a DB 90 , It may include a failure detection server 60, the communication unit 70 and the output unit 80.

The trigger monitoring unit 20 triggers exceeding a reference level from current measured by the first to second trigger sensors 11 and 12, which are the trigger sensors 10, at the ends of the substations or converter stations at both ends of the power cable 100 It may include a first trigger monitoring unit 21 and a second trigger monitoring unit 22 for detecting a signal.

Here, the trigger monitoring unit 20 detects the trigger signal at a sampling period of 100 MS / s and transmits it to the failure detection server 60. The transmitted trigger signal is stored in the DB 90, and allows the fault detection server 60 to detect the fault location based on the trigger signal.

At this time, the trigger sensor 10 may include a Rogowski sensor for detecting a trigger signal due to a failure.

The real-time monitoring unit 40 monitors the load current and the fault current measured in real time through the first to second current sensors 31 and 32, which are the current sensors 30, at the ends of the substations or converter stations at both ends of the power cable 100 in real time. It may include a first real-time monitoring unit 41 and the second real-time monitoring unit 42 to detect.

Here, the real-time monitoring unit 40 senses current at a sampling period of 100 MS / s and transmits the sensed current data to the failure detection server 60. The transmitted current data is stored in DB 90 in units of set time, and the failure detection server 60 can detect the location of the failure based on the transient signal caused by the failure current.

In addition, the real-time monitoring unit 40 removes noise by using a correlation of signals detected through multi-scale wavelet analysis of a transient signal that appears when a failure occurs, thereby increasing the detection accuracy of a fault location.

The GPS receiver 50 is provided with a first GPS receiver 51 to synchronize measurement times between the first failure detection server 61 and the second failure detection server 62 provided at both ends of the power cable 100. 2 Measurement time measured at both ends of the power cable 100 by receiving time information from the GPS satellites through the GPS receiver 52 and providing them to the first fault detection server 61 and the second fault detection server 62 Can be synchronized.

The DB 90 is a first failure detection server 61 located at both ends of the power cable 100 to store trigger data sensed by the trigger monitoring unit 20 and real-time current data sensed by the real-time monitoring unit 40. ) And the second failure detection server 62 may be provided with a first DB 91 and a second DB 92, respectively, and an operator may apply and analyze an algorithm by directly applying the stored data.

The failure detection server 60 may be located at a substation or a conversion station at both ends of the power cable 100, and is provided with a first failure detection server 61 and a second failure detection server 62, respectively, to provide a first GPS receiver ( After synchronizing the time based on the time information received from the 51) and the second GPS receiver 52, the trigger signals monitored from the first trigger monitoring unit 21 and the second trigger monitoring unit 22 are first monitored. Stored in the DB 91 and the second DB 92, respectively, detects a fault location based on a trigger signal, and detects current data respectively detected by the first real-time monitoring unit 41 and the second real-time monitoring unit 42. Each of the first DB 91 and the second DB 92 is stored in real time, and a failure location is detected based on a transient signal, and when the failure location is expressed, failure location information may be output according to priority.

In this embodiment, the failure detection server 60 may store the folder in 0.5 second increments when real-time current data transmitted from the real-time monitoring unit 40 is stored in the DB 90.

In addition, the failure detection server 60 may detect the failure location by calculating the distance to the failure location based on the difference between the traveling wave arrival time at both ends of the power cable 100.

As described above, the failure detection server 60 detects the failure location based on the trigger signal input from the trigger monitoring unit 20 and the failure location based on the transient signal input from the real-time monitoring unit 40. When the fault location is expressed, the detected fault location is first provided based on the trigger signal.

For example, when a fault location is simultaneously expressed through the trigger monitoring unit 20 and the real-time monitoring unit 40, the fault location information in which the fault location is expressed through the trigger monitoring unit 20 is first provided. If the fault location is expressed through the trigger monitoring unit 20 but the fault location is not expressed through the real-time monitoring unit 40, the fault location information expressed through the trigger monitoring unit 20 is provided. Conversely, when a fault location is not expressed through the trigger monitoring unit 20 but a fault location is expressed through the real-time monitoring unit 40, by providing the fault location information expressed through the real-time monitoring unit 40, each other It is possible to maintain mutually complementary functions by linking.

However, when the failure location is not expressed in both the trigger monitoring unit 20 and the real-time monitoring unit 40, it is possible to use the data stored in the DB 90 to directly analyze the algorithm by applying an algorithm.

The communication unit 70 is a first communication unit 71 and the second communication unit, respectively, so as to share system information and measurement data through the network 200 between the first failure detection server 61 and the second failure detection server 62 It is provided as (72), the failure detection server 60 can not only be able to express the location of the failure based on the time difference of the traveling wave, but also share the system information with each other to enable mutual confirmation.

Accordingly, when a trigger signal or a transient signal is simultaneously measured at both ends within a time during which the traveling wave proceeds according to the total length of the power cable 100 in the failure detection server 60, the fault location is expressed. However, if the trigger signal is triggered by a time difference exceeding the traveling time of the traveling wave or when the trigger signal is measured on only one side, it is determined as noise and stored in the DB (90) instead of expressing the fault location so that the log can be analyzed.

The output unit 80 is provided with a first output unit 81 and a second output unit 82, respectively, in the first failure detection server 61 and the second failure detection server 62, respectively, the failure detection server 60 ) To indicate the operating status and fault location information so that the operator can recognize them.

As described above, the operation status and location information of the failure detection server 60 display line information, load current, trigger monitoring status, and real-time monitoring status of the power cables between Haenam and Jeju, as shown in the example screen shown in FIG. 3. You can.

In addition, as shown in FIG. 4, the trigger signal measured by the real-time monitoring unit 40 and the trigger monitoring unit 20 at both ends of the power cable and the waveform of the measurement signal can be displayed to monitor the current data in real time. You can.

And, Figure 5 is an example screen showing a trigger monitoring log screen, it is possible to check the distance to the failure location analyzed by the trigger waveform and trigger time difference and the list stored by date in the DB 90.

In addition, FIG. 6 is an example screen showing a real-time monitoring log screen. The real-time measurement data measured by the real-time monitoring unit 40 is formed in a folder in 0.5 second increments, and the list stored in the DB 90 and the measurement data stored in each folder. You can see the waveform.

On the other hand, the failure detection server 60 may store information about whether or not the measurement equipment is abnormal, start and stop measurement as a log in the DB 90 and provide an operator with an analysis based on the log.

As described above, according to the fault location detecting device of the underground cable according to the embodiment of the present invention, the real-time load current and the fault current at both ends of the underground cable are simultaneously monitored by a trigger monitoring measurement method and a real-time monitoring measurement method, and a failure occurs. By applying a fault signal filter that removes noise by using multi-scale wavelet analysis for transient signals that appear when they occur, it is possible to improve the accuracy of the fault location by detecting the fault location and determining the fault location complementarily. .

7 is a flowchart illustrating a method for detecting a fault location of an underground cable according to an embodiment of the present invention.

In the method of detecting a fault location of an underground cable according to an embodiment of the present invention as shown in FIG. 7, first, the fault detection server 60 synchronizes time based on time information received through the GPS receiver 50. (S10).

Since the failure detection server 60 expresses the location of the failure based on the difference in the duration of the trigger signal and the transient signal measured at both ends of the power cable 100, the time is synchronized based on the time information received from the GPS satellite.

After synchronizing the time in step S10, the failure detection server 60 receives the current data measured through the current sensor 30 at both ends of the power cable 100 in real time from the real-time monitoring unit 40, and then DB 90 In addition to the storage, the fault location is detected based on the transient signal (S20).

Here, the failure detection server 60 can detect and store the current real-time current data transmitted from the real-time monitoring unit 40 at a sampling period of 100 MS / s in the DB 90, and store the folder in 0.5 second increments.

At this time, noise is removed using correlation of detected signals through multi-scale wavelet analysis of transient signals that appear when a failure occurs, so that the detection accuracy of a fault location can be improved.

In addition, when detecting a fault location, the fault detection server 60 may detect the fault location by calculating the distance to the fault location based on the difference in the arrival time of the traveling wave from both ends of the power cable 100.

Meanwhile, in step S20, in addition to detecting a fault location based on the transient signal transmitted from the real-time monitoring unit 40, the fault detection server 60 detects through the trigger sensor 10 at both ends of the power cable 100. A trigger signal is received from the trigger monitoring unit 20 and stored in the DB 90, and a fault location is detected based on the trigger signal (S30).

The failure detection server 60 may detect the failure location by calculating the distance to the failure location based on the difference in the arrival time of the trigger signal at both ends of the power cable 100.

At this time, the failure detection server 60 may express the location of the failure when a trigger signal or a transient signal is simultaneously measured at both ends within a time during which the traveling wave proceeds according to the total length of the power cable 100. However, if the trigger signal is triggered by a time difference exceeding the traveling time of the traveling wave or when the trigger signal is measured on only one side, it is determined as noise and stored in the DB (90) instead of expressing the fault location so that the log can be analyzed.

After detecting the failure location in steps S20 and S30, the failure detection server 60 determines whether the failure location is expressed (S40).

When the fault location is expressed in step S40, the fault detection server 60 not only provides the fault location information detected according to the priority through the output unit 80, but also enables mutual inquiry through the communication unit 70. (S50).

For example, when a fault location is simultaneously expressed through the trigger monitoring unit 20 and the real-time monitoring unit 40, the fault location information in which the fault location is expressed through the trigger monitoring unit 20 is first provided. If the fault location is expressed through the trigger monitoring unit 20 but the fault location is not expressed through the real-time monitoring unit 40, the fault location information expressed through the trigger monitoring unit 20 is provided. Conversely, when a fault location is not expressed through the trigger monitoring unit 20 but a fault location is expressed through the real-time monitoring unit 40, by providing the fault location information expressed through the real-time monitoring unit 40, each other It is possible to maintain mutually complementary functions by linking.

However, when the failure location is not expressed in both the trigger monitoring unit 20 and the real-time monitoring unit 40, it is possible to use the data stored in the DB 90 to directly analyze the algorithm by applying an algorithm.

As described above, according to the method for detecting a fault location of an underground cable according to an embodiment of the present invention, a real-time load current and a fault current at both ends of the underground cable are simultaneously monitored by a trigger monitoring measurement method and a real-time monitoring measurement method, and a failure occurs. By applying a fault signal filter that removes noise by using multi-scale wavelet analysis for transient signals that appear when they occur, it is possible to improve the accuracy of the fault location by detecting the fault location and determining the fault location complementarily. .

The present invention has been described with reference to the embodiment shown in the drawings, but this is merely exemplary, and those skilled in the art to which the art belongs can various modifications and equivalent other embodiments from this. Will understand.

Therefore, the true technical protection scope of the present invention should be defined by the following claims.

10: trigger sensor 20: trigger monitoring unit
30: current sensor 40: real-time monitoring unit
50: GPS receiver 60: failure detection server
70: communication unit 80: output unit
90: DB 100: Power cable
200: network

Claims (11)

A trigger monitoring unit detecting a trigger signal exceeding a reference level from a current measured through a trigger sensor at both ends of the power cable;
A real-time monitoring unit that senses current measured through a current sensor at both ends of the power cable in real time;
GPS receiver for receiving time information from a GPS satellite;
A DB for storing trigger data sensed by the trigger monitor and real-time current data sensed by the real-time monitor;
After synchronizing the time based on the time information received through the GPS receiver, the trigger signal monitored by the trigger monitor is stored in a DB, the fault location is detected based on the trigger signal, and the current sensed by the real-time monitor A fault detection server that stores data in real time in the DB and detects a fault location based on a transient signal, and outputs fault location information according to priority when a fault location is expressed;
A communication unit for sharing system information and measurement data through a network between the failure detection servers; And
And an output unit for displaying the operation status and location information of the failure detection server.
The apparatus of claim 1, wherein the trigger sensor comprises a Rogowski sensor.
According to claim 1, The real-time monitoring unit detects the fault location of the underground cable, characterized in that by removing the noise using the correlation (correlation) of the signal detected through the multi-scale wavelet analysis of the transient signal that appears when a failure occurs Device.
The fault location detection device of an underground cable according to claim 1, wherein the fault detection server classifies and stores real-time current data in units of set time.
According to claim 1, The fault detection server, the fault location detection device of the underground cable, characterized in that for detecting the fault location by calculating the distance to the fault location based on the difference between the traveling wave arrival time at both ends of the power cable .
The fault location detection device of an underground cable according to claim 1, wherein the failure detection server first provides a failure location detected based on a trigger signal when the failure location is expressed.
The fault detection server synchronizes the time based on the time information received through the GPS receiver.
The fault detection server receiving current data measured through a current sensor at both ends of the power cable in real time and storing it in a DB and detecting a fault location based on a transient signal;
Receiving, by the fault detection server, a trigger signal detected through a trigger sensor at both ends of the power cable, storing it in the DB, and detecting a fault location based on the trigger signal; And
And when the fault location is expressed, the fault detection server providing fault location information detected according to priority.
The method of claim 7, wherein detecting the location of the failure based on the transient signal, correlation of the detected signal through multi-scale wavelet analysis of the transient signal that the failure detection server appears when a failure occurs. A fault location detection method of an underground cable, characterized in that the noise is removed to detect the failure location.
The fault location detection method of an underground cable according to claim 7, wherein when the current data is input in real time and stored in the DB, the fault detection server classifies and stores the current data in real time by setting units.
The method of claim 7, wherein the step of detecting the failure location, the failure detection server to detect the failure location by calculating the distance to the failure location based on the difference between the traveling wave arrival time at both ends of the power cable. A method for detecting the location of a fault in an underground cable.
The method of claim 7, wherein the step of providing the fault location information, the fault detection server of the underground cable, characterized in that to provide the fault location detected based on the trigger signal when the fault location is expressed first. Fault location detection method.

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