KR20150051707A - Diagnosis apparatus of partial discharge for completion test of underground transmission cable - Google Patents

Abstract

The present invention relates to a diagnosis apparatus of partial discharge for completion test of an underground transmission cable comprising: a PD detection sensor for detecting a partial discharge (PD) signal; an amplifier for amplifying the PD signal sensed by the PD detection sensor; a filter for removing noise from the amplified PD signal; an analog-digital conversion module for converting the PD signal having the noise removed therefrom into a digital signal; a signal processing module for processing the PD signal converted into the digital signal; and a control part for accumulatively storing the PD signal in the case of generation of a PD signal equal to or higher than a predetermined reference value via the signal processing and outputting alarm via a predetermined method.

Description

TECHNICAL FIELD [0001] The present invention relates to a partial discharge diagnostic apparatus for underground transmission cable construction test,

More particularly, the present invention relates to a partial discharge diagnostic apparatus for testing the completion of an underground transmission cable for diagnosing a partial discharge for a complete test of an underground transmission cable.

Since the failure of ultra-high voltage underground transmission cables causes great social and economic losses, the demand for reliability of cable systems is increasing.

As a result, transmission cable manufacturers are testing and shipping finished cable products according to strict standards.

However, since the cable installed, stored, assembled and installed in the cable and installed in the field environment contains the possibility of the defect due to internal and external factors, it is possible to detect the initial defect after the cable is laid, The completion test is carried out.

Accordingly, in the conventional high voltage cable completing test, the partial discharge (PD) is moved from the operation voltage (Uo) to the portable partial discharge (PD) diagnostic tester (or diagnostic device) Respectively.

However, in the conventional portable partial discharge diagnostic tester, since the device for frequency analysis, PD pulse shape analysis and time difference analysis is constituted by a separate device, it is very difficult to apply in the field and is bulky and complicated (refer to FIG. 5A) .

That is, the apparatus for frequency analysis is a PD diagnostic apparatus based on a frequency spectrum analyzer, for example, a device developed by manufacturers in Japan and Europe, and a device for analyzing pulse waveforms includes an oscilloscope- For example, a device developed by an Italian manufacturer, and an oscilloscope is generally used as a device for analyzing the time difference, or a PD diagnostic device with the function is separately used.

In addition, the conventional PD diagnosis apparatus is not linked to the transmission operation system, and when the PD is diagnosed by using the conventional PD diagnosis apparatus, the portable PD diagnosis apparatus is used in a state in which the reliability of the ultra high voltage cable is not verified There is a risk that a safety accident is present and a PD signal is repeatedly generated and extinguished repeatedly with irregular time delay, so that diagnosis reliability of a portable PD diagnostic test is very low. That is, in the case of the PD signal, generation and destruction are repeated. Therefore, when the PD diagnosis test is performed when the PD signal is destroyed, defects can not be detected. Therefore, diagnosis reliability of the PD diagnosis test is very low.

In addition, since the conventional PD diagnostic apparatus requires a separate PD diagnostic apparatus for performing each of the three functions necessary for PD diagnosis, the configuration of the apparatus is very large and complicated. In general, the AC withstand voltage test is performed for 1 hour. During this time, several PD diagnoses were virtually impossible, and the PD diagnosis test and the AC withstand voltage test could not be performed at the same time.

Conventional domestic and overseas PD diagnostic apparatuses exist separately for portable and monitoring purposes, but in the case of a portable PD diagnostic apparatus, a measurement person (user, manager) must measure the PD adjacent to the PD diagnostic apparatus, And it is very difficult to install the equipment developed for monitoring without having the same performance as the portable one. Therefore, it is necessary to develop a compact PD diagnostic device that can perform mobility and telemetry while satisfying the specifications in order to perform PD diagnosis in the completion test.

In addition, since the AC withstand voltage test is performed for a short time (1 h), it is necessary to determine whether or not to replace the cable by accurately judging the abnormality of the cable during the test time. Therefore, it is necessary to develop a compact PD diagnostic device that can perform three main functions at the same time, because frequency analysis technology, pulse shape analysis technology and defect location estimation technology are required for accurate judgment.

For reference, the AC withstand voltage test is a one-hour short-time test, and the conventional portable PD diagnostic test is a time-consuming test. In order to simultaneously perform the AC withstand voltage test and the PD test, a test procedure and a test technique combining the conventional AC withstand voltage test and the PD diagnosis test are also required. Is required.

Also, in the case of the PD signal, a time delay of several seconds to several days may be generated. Therefore, it is necessary to monitor a period of several days or more in order to detect defects in such a case. That is, it is necessary to detect the PD signal automatically and output an alarm to the user when monitoring PD generation for several days or more. In addition, it is necessary to link with the transmission operation system in Korea for such a function. However, since the conventional portable PD diagnosis device can not be linked with the transmission operation system, it is necessary to connect the optical communication network, alarm server and system. In other words, it is necessary to develop a compact PD diagnostic device capable of remote communication for remote control and measurement.

The background art of the present invention is disclosed in Korean Registered Patent No. 10-0206656 (Registered on April 04, 1999, Underground Power Cable Completion Inspection Apparatus).

It is an object of the present invention to provide a partial discharge diagnostic device for a test for the completion of an underground transmission cable for diagnosing a partial discharge for a complete test of an underground transmission cable.

It is another object of the present invention to provide a partial discharge diagnostic device for a submerged transmission cable construction test which is movable and telemetric to diagnose a partial discharge for a submerged transmission cable of an underground transmission cable.

It is another object of the present invention to provide a partial discharge diagnostic apparatus for a submerged transmission cable completion test which can simultaneously perform frequency analysis, pulse shape analysis, and defect location estimation in the completion test of an underground transmission cable.

Another object of the present invention is to provide a partial discharge diagnostic apparatus for a submerged transmission cable construction test, which enables remote communication for remote control and measurement during the completion test of an underground transmission cable.

According to an aspect of the present invention, there is provided a partial discharge diagnosis apparatus for a subway transmission cable construction test, comprising: a PD detection sensor for detecting a partial discharge (PD) signal; An amplifier for amplifying a PD signal sensed by the PD detection sensor; A filter for removing noise from the amplified PD signal; An analog-to-digital conversion module for converting the noise-removed PD signal into a digital signal; A signal processing module for signal processing the PD signal converted into the digital signal; And a controller for cumulatively storing the PD signals when the PD signal of a predetermined reference value or more is generated through the signal processing and outputting an alarm in a predetermined manner.

The present invention is further characterized by a phase synchronization unit for synchronizing a phase to form a PD pattern by detecting a reference signal of the PD signal.

In the present invention, the signal-processed PD signal is input to the control unit through an SPI bus (Serial Peripheral Interface Bus).

The present invention further includes a storage unit for cumulatively storing all or a part of the signal-processed PD signals.

In the present invention, the controller may combine or simultaneously apply at least one of a frequency analysis method, a PD pulse analysis method, and a time difference analysis method to detect and analyze a PD signal.

The communication unit may further include a communication unit for transmitting the PD signal to an external transmission operating system or for receiving a remote control signal from the transmission operating system, And communication is performed in any one manner.

In the present invention, the controller may also communicate with at least one or more other PDUs to relay a PD signal or a remote control signal.

In the present invention, the PD detection sensor may include a metal foil sensor or a HFCT (High Frequency Current Transformer) sensor, and the signal processing module may be implemented by a field programmable gate array (FPGA) or a digital signal processor .

In the present invention, the partial discharge diagnosis device for the underground transmission cable completion test divides the AC test voltage applied to the underground transmission cable into at least three stages and applies the voltage up to the test maximum voltage. In each step, .

In the present invention, the PD diagnostic device for underground transmission cable completion test may include a PD diagnostic device installed in at least one intermediate connection part of the underground transmission cable for simultaneously performing the AC withstand voltage test and the PD diagnosis, The information related to the PD signal collected by the partial discharge diagnosis device for at least one underground transmission cable completion test installed in the connection part is transmitted to the partial discharge diagnosis device for the subterranean transmission cable completion test or the external transmission operation system.

The present invention enables simultaneous frequency analysis, pulse shape analysis, and fault location estimation in the completion test of the underground transmission cable, and also enables remote communication for remote control and measurement in the completion test of the underground transmission cable. The improved mobility in diagnostic partial discharge diagnostics shortens the diagnostic time and it is convenient to measure remotely using the remote measurement function.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a schematic configuration of a partial discharge diagnosis apparatus according to an embodiment of the present invention; FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for detecting and analyzing a PD signal using a partial discharge diagnosis apparatus.
3 is a diagram illustrating an example of a method of performing an AC withstand voltage test and a PD diagnosis using a partial discharge diagnosis apparatus according to an embodiment of the present invention.
FIG. 4 is an exemplary diagram for explaining a method of applying an AC voltage for an AC withstand voltage test in FIG. 3; FIG.
5 is a photograph for explaining the external volume and complexity of a partial discharge diagnostic apparatus according to an embodiment of the present invention and a conventional partial discharge diagnostic apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, an embodiment of a partial discharge diagnostic apparatus for a subway overhead power transmission cable completing test according to the present invention will be described with reference to the accompanying drawings.

In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

For convenience, the partial discharge diagnosis apparatus for underground transmission cable completion test is briefly described as a partial discharge diagnosis apparatus (or PD diagnosis apparatus) in this embodiment.

FIG. 1 is an exemplary diagram showing a schematic configuration of a partial discharge diagnosis apparatus according to an embodiment of the present invention.

1, the PD diagnostic apparatus 100 includes a PD detection sensor 110, an amplifier 120, a filter 130, an analog-to- A digital conversion module 140, a signal processing module 150, a phase synchronization unit 160, a control unit 170, a communication unit 180, and a storage unit 190.

The PD detection sensor 110 is a sensor for detecting a partial discharge (PD) signal, and is configured to be capable of sensing three-phase inputs, respectively.

For example, the PD detection sensor 110 includes a metal foil sensor and a HFCT (High Frequency Current Transformer) sensor.

The amplifier 120 amplifies the PD signal sensed by each PD detection sensor 110 so that noise can be easily removed.

The filter 130 removes noise (that is, corona noise) from the PD signal amplified through the amplifier 120. The filter 130 may use a specific band filter according to the type of noise included in the PD signal.

The analog-to-digital conversion module 140 converts each of the noise-removed PD signals into a digital signal that is easy to process.

The signal processing module 150 processes the PD signal of each phase converted into the digital signal. The signal processing module 150 may be configured using an FPGA (Field Programmable Gate Array) or a DSP (Digital Signal Processor).

The phase synchronization unit 160 can form a PD pattern by detecting a reference signal of the input PD signal. The phase synchronization unit 160 performs phase synchronization by a trigger signal (or a control signal) output from the controller 170. For reference, the partial discharge diagnosis apparatus 100 according to the present embodiment can input 20 to 300 MHz as an external synchronization signal, and the internal synchronization signal uses an input power source frequency.

The phase synchronization unit 160 synchronizes the phase of the inside and the phase of the outside.

The signal processed PD signals of each phase are input to the controller 170 through a SPI (Serial Peripheral Interface Bus) bus. All or part of the signal-processed PD signals of each phase can be cumulatively stored in the storage unit 190 under the control of the controller 170.

As shown in FIG. 2, the controller 170 may combine or simultaneously apply at least one of a frequency analysis method, a PD pulse analysis method, and a time difference analysis method to detect and analyze a PD signal. That is, the controller 170 may analyze the PD pattern and the PD position by combining or applying at least one of the analysis methods.

The controller 170 may simultaneously receive and process signals through three channels of the PD signal, one channel of the noise input, and one channel of the phase synchronization.

The communication unit 180 may transmit PD signals of each phase stored in the storage unit 190 to an external transmission operating system (not shown). That is, an external transmission operation system (not shown) may remotely monitor whether the underground transmission cable is partially discharged or output an alarm in a pre-designated manner to the user.

The communication unit 180 may be a TCP / IP communication system or an optical communication system. However, it is not necessarily limited to an optical communication system (i.e., a wired system), and it is also possible to apply a wireless system (e.g., WiFi, LTE, 3G, 4G, etc.).

The communication unit 180 can transmit and receive information (i.e., information related to a PD signal) or a remote control signal between the PDUs 100 according to an embodiment of the present invention, (I.e., information related to the PD signal) and a remote control signal with the information (not shown).

In other words, the PD detection sensor 110 is capable of three-phase input, and an independent amplifier 120, a filter 130, an analog-digital conversion module 140, and a signal processing module 150 are connected to independent modules . Therefore, the PD signal of each phase can be independently measured, and when the PD signal (for example, a PD signal with a maximum peak value or more) exceeding a preset reference is generated, the controller 170 can detect the PD signal without delaying each phase.

In the signal processing module 150, firmware for PD frequency analysis, PD pulse shape analysis, and time difference analysis is built in, and the measurement mode can be selected under the control of the controller 170.

Accordingly, one device (i.e., one partial discharge diagnostic apparatus) according to an embodiment of the present invention performs three functions to detect a partial discharge.

1, it may further include a display unit (not shown) and an alarm output unit (not shown) for displaying PD signal analysis results of the respective phases. (PD) signal can be displayed on the field through the display unit (not shown), an alarm signal can be output through the alarm output unit (not shown) when a PD signal is generated, SMS) to a user (administrator) registered in advance. The display unit (not shown) and the alarm output unit (not shown) operate under the control of the controller 170.

Also, in an external transmission operating system (not shown) receiving the PD signals of the respective phases, the PD signal is supplied through a display unit (not shown), which is provided in the same manner as the operation of the partial discharge diagnosis apparatus according to an embodiment of the present invention And can output an alarm signal through an alarm output unit (not shown) provided when the PD signal is generated.

FIG. 3 is a diagram illustrating an example of a method of performing an AC withstand voltage test and a PD diagnosis using a partial discharge diagnosis apparatus according to an embodiment of the present invention.

As shown in FIG. 3, in order to simultaneously apply the PD diagnosis apparatus 100 (PDMS) for testing the completion test of an ultra-high voltage cable (i.e., an underground transmission cable) to the AC withstand voltage test and the PD diagnosis of the ultra high voltage cable, The PD diagnosis apparatus 100 (PDMS) is installed.

Here, the AC voltage booster 300 is means for applying an AC test voltage to the ultra high voltage cable. In the embodiment according to the present invention, the AC test voltage is divided into predetermined steps (for example, three steps) to increase the AC withstand voltage test and the PD diagnosis to the test maximum voltage in order.

A PD diagnostic apparatus 100 (PDMS) installed at an intermediate connection portion of the cable is connected to an external transmission operating system (not shown) or a PD diagnostic apparatus 200 (PDMS) as a master station (M / S) Remote control is possible.

The PD diagnostic apparatus 200 (PDMS), which is an external transmission operating system (not shown) or a master station (M / S), is connected to the PD diagnostic apparatuses 100, (I.e., information related to the PD signal) through the PDMS.

Or the PD diagnostic apparatus 200 (PDMS), which is the master station (M / S), transmits information collected through the PD diagnostic apparatus 100 (PDMS), which is the local station (L / S), to an external transmission operating system , Or may transmit the remote control signal transmitted from an external transmission operating system (not shown) to the PD diagnostic apparatus 100 (PDMS), which is the local station (L / S).

FIG. 4 is an exemplary view for explaining a method of applying an AC voltage for an AC withstand voltage test in FIG.

As shown in FIG. 4, according to an embodiment of the present invention, AC voltage is raised and applied in three stages in order to perform an AC withstand voltage test using the partial discharge diagnosis apparatus 100. FIG. For example, after applying 125 kV to the first step, PD diagnosis is performed concurrently, 200 kV (Uo) is applied to the second step, PD diagnosis is performed concurrently, 250 kV of the test maximum voltage is applied to the third step, Perform PD diagnosis for a period of time (60 minutes).

After the AC withstand voltage and PD diagnosis are performed at the test maximum voltage, the AC applied voltage is gradually lowered (or stepwise).

After the AC withstand voltage (or withstand voltage) test, the system voltage (i.e., the operating voltage Uo) is applied to perform monitoring for about one week (seven days).

At this time, when monitoring is performed by applying the grid voltage (i.e., the operation voltage Uo), the remote monitoring is performed in conjunction with an external transmission operating system (not shown). When the generation of the PD signal is detected during the remote monitoring, an alarm is output through an alarm output unit (not shown) or an alarm message (e.g. SMS) is transmitted to a registered user (administrator) in advance.

As described above, the PD diagnosis apparatus according to an embodiment of the present invention can perform simultaneous measurement in one apparatus by applying a frequency analysis method, a PD pulse analysis method, and a time difference analysis method.

5 (a), the PD diagnosis apparatus according to an embodiment of the present invention has the following problems. The PD diagnosis apparatus shown in FIG. 5 As shown in b), since it is mounted on a carrying case and its weight is about 8kg, it is lighter, so it is convenient to move and it is possible to monitor PD generation for a long time in one place.

Also, PD diagnosis apparatus according to an embodiment of the present invention can remotely control and measure an external transmission operation system (not shown) using an optical communication network, and generate PDs through a master station (M / S) Has long-term monitoring and alarm functions and is linked to the transmission operating system.

Also, in order to simultaneously perform the AC withstand voltage test and the PD diagnosis test, the PD diagnostic apparatus according to an embodiment of the present invention performs an AC withstand voltage test by setting an ascending step for applying an AC voltage test voltage to three stages, PD diagnosis test can be performed through the PD diagnosis device according to the application step.

Also, in order to remotely control and monitor the PD diagnostic apparatus during the AC withstand voltage test or the PD long-term monitoring, the PD diagnosis apparatus according to an embodiment of the present invention connects each PD diagnosis apparatus to an optical transmission network, The installation work of the optical cable can be minimized.

In addition, PD signal (or PD detection information) is displayed on the monitoring screen of the transmission operating system by connecting the master station of the power transmission operating system and the master station of the PD diagnosis device during long term monitoring of the PD signal generation, .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand the point. Accordingly, the technical scope of the present invention should be defined by the following claims.

100: partial discharge diagnosis device 110: PD detection sensor
120: Amplifier 130: Filter
140: analog-to-digital conversion module 150: signal processing module
160: phase synchronizer 170:
180: communication unit 190: storage unit

Claims (10)

A PD detection sensor for detecting a partial discharge (PD) signal;
An amplifier for amplifying a PD signal sensed by the PD detection sensor;
A filter for removing noise from the amplified PD signal;
An analog-to-digital conversion module for converting the noise-removed PD signal into a digital signal;
A signal processing module for signal processing the PD signal converted into the digital signal; And
And a controller for cumulatively storing the PD signal when a PD signal of a predetermined reference value or more is generated through the signal processing and outputting an alarm in a predetermined manner. The method according to claim 1,
And a phase synchronization unit for synchronizing a phase to form a PD pattern through detection of the reference signal of the PD signal. 2. The apparatus of claim 1, wherein the signal-
And is input to the control unit through an SPI bus (Serial Peripheral Interface Bus). The method according to claim 1,
And a storage unit for cumulatively storing all or a part of the signal-processed PD signals. The apparatus of claim 1,
Wherein at least one of a frequency analysis method, a PD pulse analysis method, and a time difference analysis method is combined or simultaneously applied to detect and analyze a PD signal. The method according to claim 1,
Further comprising a communication unit for transmitting the PD signal to an external transmission operating system or for communicating a remote control signal from the transmission operating system,
Wherein the communication unit communicates with at least one of a wired optical communication system and a wireless system. The apparatus of claim 1,
Wherein the at least one partial discharge diagnostic device communicates with at least one of the other partial discharge diagnostic devices to relay the PD signal or the remote control signal. The method according to claim 1,
The PD detection sensor includes a metal foil sensor or a HFCT (High Frequency Current Transformer) sensor,
Wherein the signal processing module is implemented by an FPGA (Field Programmable Gate Array) or a DSP (Digital Signal Processor). 2. The partial discharge diagnosis apparatus for underground transmission cable completing test according to claim 1,
Wherein the AC test voltage applied to the underground transmission cable is divided into at least three stages and applied to the test peak voltage and the PD diagnosis is performed for a predetermined time in each step. 10. The partial discharge diagnostic apparatus for underground transmission cable completing test according to claim 9,
To simultaneously perform the AC withstand voltage test and the PD diagnosis,
The PD diagnostic apparatus is installed in at least one intermediate connection section of the underground transmission cable, and information related to the PD signals collected by the partial discharge diagnosis apparatus for at least one underground transmission cable completion test installed in the intermediate connection section is transmitted to the master underground transmission cable completion test Wherein the partial discharge diagnosis apparatus or the external transmission operation system transmits the partial discharge diagnosis apparatus to a partial discharge diagnosis apparatus for underground transmission cable completion test.

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