JP2002214278A - Apparatus for diagnosing high voltage machinery and diagnostic method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for diagnosing high voltage machinery, capable of quantitatively judging the safety to the deterioration degree of insulating capacity and excellent in reliability, and a diagnostic method using the same. SOLUTION: A digital oscillogram 1 for measuring a corona pulse is connected to both ends of the detection resistor R of a disconnector DS for measuring a leak current. A personal computer 3 realizing a processing part, a display and a recording part for the data related to a corona pulse waveform is connected to the digital oscillogram 1 through a GPIB cable 2. The experimental data related to the corona deterioration characteristics instrinsic to a lightning arrester LA with a 500 kV gap is preliminarily calculated, and this experimental data is compared with the corona pulse observation data calculated by the personal computer 3 to diagnose the corona deterioration of the lightning arrester LA with the 500 kV gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for diagnosing the degree of deterioration of high-voltage equipment, and more particularly, to the degree of deterioration of insulation performance of high-voltage equipment by detecting and analyzing corona pulses generated in high-voltage equipment. And a method for diagnosing the problem.

[0002]

2. Description of the Related Art Hitherto, with respect to high-voltage equipment installed in a system or a power facility, a periodic deterioration degree diagnosis is performed for the purpose of preventing occurrence of an accident. For example, when diagnosing the degree of deterioration of a lightning arrester with a gap, this is performed by managing the leakage current bandwidth and insulation resistance. At present, the capacity of high-voltage equipment is increasing with the increase in power demand,
The importance of diagnostic techniques in high-voltage equipment is increasing, and clear degradation diagnostic criteria have been set.

[0003]

However, there is an example in which an accident has occurred despite satisfying the conventional criteria for diagnosing deterioration. Recent studies have shown that the insulation performance degradation of the insulators incorporated in high-voltage equipment accounts for most of the causes of the accident. Therefore, the degree of deterioration of insulation performance in high-voltage equipment is accurately and in real time grasped,
There is a need to ensure that accidents do not occur.

[0004] The present invention has been proposed to meet such a need, and an object of the present invention is to provide a highly reliable diagnosis of high-voltage equipment capable of quantitatively determining the safety against the degree of deterioration of insulation performance. An apparatus and a method thereof are provided.

[0005]

According to one aspect of the present invention, there is provided a diagnostic apparatus for a high-voltage device, comprising: a digital oscillogram for measuring a corona pulse generated in the high-voltage device; A data processing unit that calculates corona pulse observation data consisting of quantitative information and waveform information including period and arrival time difference as digital information, a data display unit that displays the corona pulse observation data, and the corona pulse observation data. A data recording unit for recording is provided. Claim 1 as described above
According to the invention, the corona pulse observation data is obtained from the corona pulse measured by the digital oscillogram, and the corona pulse can be accurately analyzed by examining the displayed data. For this reason, a corona pulse pattern can be derived from corona pulse observation data accumulated as digital information, and the safety against the degree of deterioration of insulation performance in high-voltage equipment can be quantitatively determined with high accuracy. According to the first aspect of the invention, a corona pulse, which is an extremely fast phenomenon such as the nanosecond order, can be directly measured by a digital oscillogram. Therefore, it is not necessary to use a filter technique or waveform shaping by an integrating circuit and an amplifying circuit, and the configuration of the device can be simplified.

In the method for diagnosing a high-voltage device according to the second aspect of the present invention, a corona deterioration characteristic determining step for previously obtaining a corona deterioration characteristic unique to the high-voltage device, the corona deterioration characteristic and the corona pulse And a data comparison step of comparing the observation data with the observation data, and it is possible to quantitatively determine the corona deterioration of the high-voltage equipment, that is, the deterioration of the insulation performance, based on the comparison result.

According to a third aspect of the present invention, there is provided a method for diagnosing a high voltage device, wherein a waveform transmission time characteristic determining step for previously obtaining a waveform transmission time characteristic specific to a system configuration including the high voltage device;
The digital oscillogram includes a corona pulse measuring step of simultaneously measuring two or more phases of corona pulses, and a arrival time difference measuring step of measuring an arrival time difference in a corona pulse between the two phases. According to the third aspect of the present invention, it is possible to specify the position where the corona pulse is generated from the arrival time difference in the corona pulse between the two phases and the waveform transmission time characteristic.

Further, the method for diagnosing a high-voltage device according to a fourth aspect of the present invention is characterized in that the method further comprises a polarity discriminating step of discriminating the polarity of the corona pulse from the direction of the first wave of the corona pulse. The analysis accuracy of the corona pulse can be improved by a very simple method such as checking the direction.

A diagnostic method for a high-voltage device according to a fifth aspect is characterized in that the method includes a corona pulse reproducing step of reading out the waveform information of the corona pulse from the data recording section to the digital oscillogram and reproducing the corona pulse. . According to the fifth aspect of the present invention, since the data recorded in the waveform data recording unit is digital information,
It is possible to faithfully reproduce a corona pulse at the time of measurement in a digital oscillogram. Therefore, the corona pulse analysis operation can be easily performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Representative Embodiment Hereinafter, an embodiment of a diagnostic apparatus for a high-voltage device and a method thereof according to the present invention will be specifically described with reference to FIGS. This embodiment includes claims 1 to 5,
A surge arrester with a 500 kV gap is targeted for diagnosis.

[Configuration] FIG. 1 shows a configuration diagram of the present embodiment. A plurality of lightning arresters LA with a 500 kV gap are arranged on the high-voltage line 5, and each lightning arrester LA is provided with a disconnector DS for measuring leakage current. Each disconnector DS
Is connected to a digital oscillogram 1 via a coaxial cable 4 at both ends of the detection resistor R. The digital oscillogram 1 measures the voltage across the detection resistor R in a sufficient band and measures a nanosecond-order waveform. Digital oscillogram 1 is 4c
h can be inputted, and the corona pulse generated in the four-phase lightning arrester LA can be simultaneously measured.

A GPIB cable 2 is connected to the digital oscillogram 1, and a personal computer 3 as a terminal is connected via the GPIB cable 2. The personal computer 3 is a data processing unit according to claim 1,
This implements a data display unit and a data recording unit.
In other words, the CPU calculates corona pulse observation data consisting of quantitative information and waveform information including the charge amount, period and arrival time difference as digital information, displays the corona pulse observation data on a display, and stores the corona pulse observation data in a built-in memory. It records corona pulse observation data.

FIG. 2 and FIG. 3 show examples of corona pulse observation data displayed on the display of the personal computer 3. FIG. 2 shows the corona pulse charge from 21:59 to 22:59 on December 1, 1999 and the accumulated charge over a continuous 24 hours for each lightning arrester LA. FIG. 3 shows a display result of visualizing the histogram of the number of corona pulse occurrences per hour of each lightning arrester LA. The numbers at the bottom of the graph indicate the elapsed time from the start of the measurement, and the items that can be visualized are the number of occurrences,
The total charge amount, average charge amount, maximum charge amount, and minimum charge amount. Note that G in the GPIB cable 2 shown in FIG.
PIB is a general-purpose interface bus.
NSI / IEEE Standards Collection 488.1-1987 and 48
This is the general name of the communication interface system specified in 8.2-1987.

[Measurement of Corona Pulse by Digital Oscillogram 1] In the diagnostic apparatus as described above, the digital oscillogram 1 measures the corona pulse under the following settings. That is, in the digital oscillogram 1, the sampling is set to 100 MHz (10 ns), the trigger is set to the single trigger mode of DC coupling, the trigger level is set to 100 mV, the waveform measurement mode is set to the high resolution mode, and the coupling of each channel is set to the AC coupling. The corona pulse is measured for the required time and continuous unmanned operation by setting each of the rings. At this time, the coaxial cables 4 from the detection resistor R to the digital oscillogram 1 are all 10 cables.
The same cable length of 0 m is used. In the digital oscillogram 1, the memory in the digital oscillogram 1 is divided into a plurality of frames, and continuous measurement for the number of frames is performed, assuming that several corona pulses are generated in one cycle.

[Diagnosis method] In the above-described diagnostic apparatus, the following four modes are adopted to diagnose the degree of deterioration of the lightning arrester LA with a 500 kV gap. Corona deterioration diagnosis mode In this mode, a lightning arrester with a 500 kV gap
Experimental data relating to the corona deterioration characteristic peculiar to A is obtained (corona deterioration characteristic determination step), and the experimental data is compared with the corona pulse observation data obtained by the personal computer 3 (data comparison step) to obtain 500 kV. A corona deterioration diagnosis is performed on the lightning arrester LA with a gap.

FIG. 4 is a graph showing the experimental data. The purpose of this experiment is to forcibly generate a partial discharge in the insulator, measure the change in the insulation resistance of that part, and determine the corona degradation characteristics of the insulator from the relationship between the amount of charge of the partial discharge and the insulation resistance. To investigate. The test conditions are as follows.

[0017]

[Table 1] Test device: Upper unit of red phase 5-3-3 section 1 insulator (1.5 kV rating) Partial discharge charge: 1000 pC 5000 pps (half cycle 50 times) 5000 × 10 3 pC / s Container: Φ = 430 1 = 560 FRP sealed container Enclosure Air: Air Marking Applied voltage: 3 kV Partial discharge location: Insulator

A criterion for determining the amount of corona charge is set based on data obtained by performing such an experiment. For example, a criterion for determining a decrease in insulation resistance of an insulator is 1000 MΩ.
(1000 V megger), the charge amount until reaching this reference is 0.68C. Assuming that the time required to reach this charge amount is the life of the insulator, the determination criterion c of the corona charge amount converted into 24 hours is 0.005C. By comparing such a criterion with the actually measured accumulated charge amount (total charge amount) of each phase arrester LA, a primary diagnosis such as the influence on the device and the remaining life is performed.

In this mode, a waveform transmission time characteristic peculiar to the system configuration including the lightning arrester LA is determined in advance (waveform transmission time characteristic determination step), and two or more phases are determined by the digital oscillogram 1. Are measured simultaneously (corona pulse measurement step), and the arrival time difference in the corona pulse between the two phases is measured (arrival time difference measurement step).

By performing the above steps, the corona pulse generation position is specified from the corona pulse arrival time difference and the waveform transmission time characteristic. The graph of FIG. 5 is a four-phase corona pulse waveform diagram, and FIG. 6 is an enlarged view of the first part of the waveform, showing the arrival time difference. The arrival time difference is obtained by detecting the arrival time from the first intersection point between the zero-level reference line and the waveform in one corona pulse waveform and calculating the difference from the arrival time in another corona pulse waveform.

In this mode, it is determined whether the direction of the first wave (see FIG. 7) of the corona pulse waveform is upward or downward, and thereby the polarity of the corona pulse is determined (polarity determination step). . Corona pulse reproduction mode In this mode, corona pulse waveform information is read from the personal computer 3 to the digital oscillogram 1 and reproduced (corona pulse reproduction step).

According to the present embodiment as described above, the personal computer 3 obtains corona pulse observation data from the corona pulse measured by the digital oscillogram 1 and can display it. For this reason,
By displaying the corona pulse observation data integrated as digital information on the corona pului, it is possible to accurately and in real time grasp and analyze the corona pulse to guide the pattern of the corona pulse. Therefore, 500 kV
The degree of corona deterioration in the lightning arrester LA with the gap, that is, the safety related to the degree of deterioration of the insulation performance can be quantitatively determined with high accuracy. Further, the generation of the corona pulse is an extremely fast phenomenon such as the nanosecond order, but in the present embodiment, it can be directly measured only by the digital oscillogram 1. Therefore, there is no need to perform a waveform shaping by a filter technique or an integrating circuit and an amplifying circuit, and the device configuration can be easily simplified.

In the present embodiment, it is also possible to specify the corona pulse generation position from the arrival time difference in the corona pulse between the two phases and the waveform transmission time characteristic peculiar to the system. Further, the polarity of the corona pulse can be determined only by checking the vertical direction of the first wave of the corona pulse, and the analysis accuracy of the corona pulse can be improved.
Moreover, when reading out the corona pulse waveform information from the personal computer 3 to the digital oscillogram 1,
Since the waveform information is digitized, faithful reproduction of the corona pulse during measurement is possible. As a result, highly reliable corona pulse analysis can be easily realized.

(2) Other Embodiments The present invention is not limited to the above embodiments, and the performance of the digital oscillogram and the number of devices to be diagnosed can be changed as appropriate. . Further, the present invention can also be applied to deterioration diagnosis of high-voltage equipment other than the lightning arrester. However, since the corona deterioration characteristics and the waveform transmission time characteristics are unique to each device or each system configuration, they need to be determined after conducting separate experiments.

[0025]

As described above, according to the diagnostic apparatus and method for a high-voltage device according to the present invention, a digital oscillogram for measuring a corona pulse generated in a high-voltage device, a charge amount, a period, and an arrival time are obtained. A data processing unit that calculates corona pulse observation data consisting of quantitative information and waveform information including time difference as digital information, and obtains a corona deterioration characteristic and a corona pulse observation data unique to a high-voltage device obtained in advance. By performing the comparison, the degree of deterioration of the insulation performance of the high-voltage device can be quantitatively determined, and excellent safety and reliability can be secured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a typical embodiment of the present invention.

FIG. 2 is a display example of corona pulse observation data.

FIG. 3 is a display example of corona pulse observation data.

FIG. 4 is a graph of experimental data relating to a corona deterioration characteristic peculiar to a lightning arrester LA with a 500 kV gap.

FIG. 5 is a four-phase corona pulse waveform diagram.

FIG. 6 is a partially enlarged view for explaining an arrival time difference in a corona pulse between two phases.

FIG. 7 is a partially enlarged view for explaining a first wave portion of a corona pulse waveform.

[Description of Signs] 1 ... Digital oscillogram 2 ... GPIB cable 3 ... Personal computer 4 ... Coaxial cable 5 ... High-voltage line DS ... Disconnector for leakage current measurement LA ... 500kV gap arrester R ... Detection resistor

Claims (5)

[Claims] 1. A digital oscillogram for measuring a corona pulse generated in a high-voltage device, and data for calculating, as digital information, corona pulse observation data including quantitative information and waveform information including a charge amount, a cycle, and a time difference of arrival. A diagnostic device for a high-voltage device, comprising: a processing unit; a data display unit for displaying the corona pulse observation data; and a data recording unit for recording the corona pulse observation data. 2. A method for diagnosing a high-voltage device using the apparatus according to claim 1, wherein a corona deterioration characteristic determining step for previously obtaining experimental data on a corona deterioration characteristic specific to the high-voltage device; A data comparing step of comparing the corona pulse observation data with the corona pulse observation data. 3. A method for diagnosing a high-voltage device using the apparatus according to claim 1, wherein a waveform transmission time characteristic determining step for previously obtaining a waveform transmission time characteristic specific to a system configuration including the high-voltage device; A method for diagnosing a high-voltage device, comprising: a corona pulse measuring step of simultaneously measuring two or more phases of corona pulses by a digital oscillogram; and an arrival time difference measuring step of measuring an arrival time difference in a corona pulse between the two phases. . 4. A method for diagnosing a high-voltage device using the apparatus according to claim 1, further comprising a polarity determining step of determining the polarity of the corona pulse from the direction of the first wave of the corona pulse. To diagnose high voltage equipment. 5. A method for diagnosing a high-voltage device using the apparatus according to claim 1, wherein corona pulse reproduction for reading out waveform information of the corona pulse from the data recording section to the digital oscillogram and reproducing the same. A method for diagnosing a high-voltage device, comprising the steps of: