KR101515231B1 - A method of partial discharge diagnosis for gas insulated switchgear - Google Patents

Abstract

The present invention relates to a method of partial discharge diagnosis for gas insulated switchgear which is configured such that: the number of discharged pulse greater than standard value can be counted by each phase by measuring electromagnetic wave using a sensor in time domain; causes of partial discharge is diagnosis by calculating pulse ratio in a straight positive polarity section and a negative polarity section. A method of partial discharge diagnosis for gas insulated switchgear according to the present invention is configured such that when a partial discharge occurs due to an internal electrical defect, a diagnosis is executed on partial discharge signals to be converted into digital signals by detecting partial discharge signals, comprising stages of: (a) calibrating a phase of the detected partial discharge data; (b) generating a pattern signal by analyzing the detected partial discharge data in phase and time areas; (c) counting the number of discharged pulse greater than standard value by each phase; (d) in the partial discharge data, when the number of discharged pulse is greater than standard value diagnosing the case as one of a number of causes according to the ratio of the number of straight and negative phase compared with the number of total discharge; and (e) generating an alarm which informs the occurrence of partial discharge in accordance with a cause of defect among a number of causes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of detecting a partial discharge of a gas insulated apparatus,

The present invention relates to a method of diagnosing a partial discharge of a gas insulated apparatus, and more particularly, to a method of diagnosing a partial discharge of a gas insulated apparatus by using a high-pressure gas as an insulated medium in a power plant or a substation, The number of discharge pulses having a reference value or more is counted in each phase in a time domain in a time domain by measuring an electromagnetic wave with a sensor, and a pulse rate of a positive polarity interval having a phase of 0 to 180 degrees and a negative polarity pulse having a negative polarity of 181 to 360 degrees To a partial discharge diagnosis method for a gas-insulated apparatus that can diagnose seven causes of defects in a partial discharge by calculating a pulse rate of a partial discharge.

Generally, in a power system, insulation deterioration occurs due to mechanical stress, temperature, and the like, and a partial discharge is generated in the internal insulation portion. Such partial discharges can cause the power plant to fail if it occurs for a sustained period of time, even if there is no problem with the performance and operation of the system initially, and in the extreme case, it may lead to an explosion.

Therefore, in order to measure and diagnose the insulation deterioration state in such a power plant in real time, a gas insulation device using a high-pressure gas (SF6) as an insulation medium is used. Gas insulation equipment is widely used in power plants and substations due to its advantages of high insulation strength and compactness due to enclosure, high reliability and easy maintenance.

However, the protrusion of the conductor, the crack of the spacer and the foreign metal of the conductive metal may occur during the gas installation process of the gas-insulated apparatus. Since the electric field concentration phenomenon occurs in the gas insulation device due to such defects, There is a possibility of reaching destruction.

Accordingly, in order to prevent an accident caused by breakage of the power equipment, a method of detecting a partial discharge signal and determining an abnormal symptom from the partial discharge signal has been proposed. However, Is generated.

On the other hand, as a method for diagnosing a partial discharge of a gas insulated apparatus, a spectrum analyzer is used to analyze frequency and phase of an electromagnetic wave to generate a pattern to obtain a partial discharge signal from the measured signal while minimizing sensitivity and measurement error However, since the measurement signal is in the UHF band, it takes a long time to analyze it. In order to shorten the analysis time, the fast sampling method and the FFT (Fast Fourier Transform) analysis are used to perform the analysis relatively quickly. However, since the fast sampling method and the FFT analysis involve complicated signal calculation processing in the system There is a drawback that the equipment is formed at an expensive price for calculation.

In addition, a PRPD (Phase Resolved Partial Discharge) method for analyzing a waveform pattern by accumulating electromagnetic waves in real time and generating a pattern analyzes waveform patterns based on two factors of phase and amplitude. However, when the size of a partial discharge signal is outside noise It is impossible to completely remove the noise from the electromagnetic wave signal due to the partial discharge and when the noise showing a pattern similar to the reference pattern in the frequency region band where the partial discharge occurs is measured, There is a problem that an error is recognized which is recognized as a discharge.

Korean Registered Patent No. 10-0853725 (Registered Date: Aug. 18, 2008)

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a method of detecting an insulated deterioration state in a power plant using a high-pressure gas as an insulated medium in a power plant or a substation, The number of discharge pulses having a reference value or more is counted for each phase in the time domain to calculate the pulse rate of the positive polarity interval having a phase of 0 to 180 degrees and the pulse rate of the negative polarity interval of 181 to 360 degrees The present invention also provides a partial discharge diagnosis method for a gas-insulated apparatus capable of diagnosing a plurality of causes of defects in partial discharge.

According to an aspect of the present invention, there is provided a method of detecting a partial discharge signal by detecting a partial discharge signal by using a physical phenomenon generated by synchronizing a pressurized voltage frequency when a partial discharge by an internal electrical defect occurs, A method of diagnosing partial discharge of a gas-insulated apparatus that diagnoses partial discharge data obtained by converting a partial discharge signal into a digital signal, comprising the steps of: (a) counting the number of discharge pulses of a reference value or more in each pattern; (b) diagnosing one of a plurality of causes according to the ratio of the positive polarity and the negative polarity phase to the total number of discharges when the number of discharge counts of the number of discharge pulses in the partial discharge data exceeds a reference value; And (c) outputting an alarm indicating that a partial discharge has occurred in accordance with a cause of a defect of one of the plurality of causes.

The step (a) may further include: (a-1) correcting a phase of the detected partial discharge data; And (a-2) analyzing the detected partial discharge data in the phase and time domain to generate a pattern signal, and removing a noise signal of each phase from the pattern signal of the partial discharge data.

In the step (a), the partial discharge data is divided into a positive polarity having a phase of 0 degrees to 180 degrees and a negative polarity having a phase of 181 degrees to 360 degrees, and the number of discharge pulses having a reference value or more is counted for each phase .

In the step (a), even if the partial discharge data exceeds a reference value for a predetermined time after counting the first discharge pulse, the next discharge pulse is counted without counting.

In the step (a), the partial discharge data is divided into a positive polarity having a phase of 0 degrees to 180 degrees and a negative polarity having a phase of 181 degrees to 360 degrees. And the number of discharge pulses equal to or more than the reference value for each window is counted.

In the step (b), the positive phase number ratio may be calculated according to the following equation.

In the step (b), the negative phase number ratio may be calculated according to the following equation.

In the step (b), the cause of the partial discharge may be a POC (Protrusion On Conductor), a POS (Particle On Surface), a POE (Protrusion On Enclosure) depending on the ratio of the positive polarity and the negative polarity to the total number of discharges. ), Floating, Void, Crack, and FP (Free Particle).

In the step (c), the partial discharge is alarmed when the power value of the partial discharge data is larger than the threshold value and the count number of the discharge pulse is larger than the reference value.

In the step (b), the ratio of the positive polarity and the negative polarity phase counts the number of discharge pulses having a threshold value or more with respect to the pattern signal of the partial discharge data by positive and negative phases, Wherein the ratio of the number of phases of the positive polarity and the negative polarity is calculated in accordance with the number of times, and when the ratio of the number of phases of the positive polarity and the negative polarity exceeds the specific reference value, And calculates the phase number ratio of each divided window area.

According to the present invention, it is possible to count the number of discharge pulses having a value greater than or equal to the reference value among the signals having detected the partial discharge by each phase, and calculate the coefficient ratio of the positive polarity (0 to 180 ㅀ) and the negative polarity (181 to 360 을) It is possible to diagnose the cause of the defect for the partial discharge.

In addition, it is possible to prevent a plurality of partial discharge pulses from being counted by the output characteristic of the power detector included in the analog processing section.

In addition, the pulse signal of the measured partial discharge can be processed by a power detector to correct the count after analog-to-digital conversion.

In addition, an accurate phase can be input to correct the phase in the time domain for the partial discharge.

In addition, noise can be removed at the firmware level before the pattern data of the partial discharge is compressed, thereby enhancing the noise removing accuracy.

When the size of the pattern signal of the partial discharge whose noise has been removed and the number of discharges exceed the reference value, the partial discharge alarm signal may be output to inform the user of the partial discharge.

1 is a block diagram showing a functional block of a partial discharge diagnosis apparatus of a gas insulated apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method of diagnosing a partial discharge of a gas insulated apparatus according to an embodiment of the present invention. Referring to FIG.
3 is a diagram illustrating an example of internal partial discharge generation according to an embodiment of the present invention.
4 is a diagram illustrating an example of analyzing partial discharge data according to an embodiment of the present invention in phase and time domains.
5 is a diagram showing an example of counting the number of discharge pulses by dividing the partial discharge data according to the embodiment of the present invention into positive and negative polarities.
6 is a diagram illustrating an example of counting discharge pulses for partial discharge data according to an embodiment of the present invention.
FIG. 7 is a flowchart illustrating a process of diagnosing the causes of seven partial discharges according to the ratio of the positive / negative phase number to the total number of discharges based on the result of counting the number of discharge pulses according to the embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to be limited to the particular embodiments of the invention but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a partial discharge diagnosis method of a gas insulated apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the accompanying drawings, the same or corresponding components will be denoted by the same reference numerals, and redundant description thereof will be omitted.

1 is a block diagram showing a functional block of a partial discharge diagnosis apparatus of a gas insulated apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a partial discharge diagnosis apparatus 100 of a gas insulated apparatus according to an embodiment of the present invention includes a partial discharge detection unit 110, a signal processing unit 120, a phase correction unit 130, A pulse counting unit 150, a noise removing unit 160, a control unit 170, a partial discharge alarm unit 180, and a data compression unit 190.

The partial discharge detecting section 110 detects a partial discharge caused by an internal electrical defect.

The signal processing unit 120 converts the analog signal of the detected partial discharge into a digital signal and processes it as partial discharge data.

The phase corrector 130 corrects the phase of the partial discharge data. At this time, the phase correction unit 130 may receive the phase correction value from the user and correct the phase.

The partial discharge analysis unit 140 analyzes the partial discharge data in the phase and time domain.

The pulse counting unit 150 counts the number of discharge pulses equal to or more than the reference value for each phase in the partial discharge data. Here, the pulse counting unit 150 divides the partial discharge data into a positive phase having a phase of 0 degrees to 180 degrees and a negative phase having a phase of 181 degrees to 360 degrees, and counts the number of discharge pulses having a reference value or more in each phase . The pulse counting section 150 counts discharge pulses in the next sequence without counting even after the first discharge pulse count for a certain period of time, for example, 4 占 퐏, over the reference value for the partial discharge data.

The noise removing unit 160 removes the noise signal of each phase from the partial discharge data.

The control unit 170 calculates the ratio of the number of positive phases and the number of negative phases to the total number of discharges based on the result of counting the number of discharge pulses by the pulse count unit 150, On Conductor, POS (Particle On Surface), POE (Protrusion On Enclosure), Floating, Void, Crack and FP (Free Particle).

In addition, the controller 170 determines whether the size of the pattern signal of the partial discharge data and the number of discharges exceed the reference value as a result of analysis of the partial discharge data, and controls the partial discharge to alarm when the pattern signal exceeds the reference value.

According to the control of the controller 170, the partial discharge alarm unit 180 alarms that the partial discharge has occurred. The partial discharge alarm unit 180 also alerts the partial discharge when the power value of the partial discharge data is larger than the threshold value and the count number of the discharge pulse is larger than the reference value.

The data compression unit 190 compresses the partial discharge data. Accordingly, the control unit 170 compresses the partial discharge data through the data compression unit 190 and controls to generate 128 pieces of sampling data.

FIG. 2 is a flowchart illustrating a method of diagnosing a partial discharge of a gas insulated apparatus according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 2, the apparatus 100 for diagnosing partial discharge of a gas insulation device according to an embodiment of the present invention may be configured such that the partial discharge detector 110 detects a partial discharge generated by an internal electrical defect (S210).

Here, the partial discharge detector 110 includes one or more detection sensors, and detects partial discharge signals generated by the insulation deterioration as electrical, acoustical, and RF signals through the detection sensor. For example, the partial discharge detecting section 110 may include seven sensors for detecting the internal partial discharge signal of the gas-insulated apparatus, and one noise sensor for detecting electromagnetic signals outside the gas-insulated apparatus have. Of course, the number of measurement points can be further increased depending on the number of points of interest. Accordingly, the partial discharge detecting unit 110 detects the internal partial discharge generated as shown in FIG. 3 through the plurality of sensors. 3 is a diagram illustrating an example of internal partial discharge generation according to an embodiment of the present invention.

In this case, a plurality of sensors are external electromagnetic sensors having a detection band of 500 to 1,500 MHz and have a sensitivity to detect an apparent partial discharge of 5 pC or less according to IEC 60270. In order to minimize external noise, And a gasket is inserted into the sensor mounting surface.

The frequency detection band through the plurality of sensors is in the range of 500 to 1,500 MHz in the UHF band (300 to 3,000 MHz). Since the frequency band of 500 MHz or less is a strong frequency band with strong external noise, So that the frequency band can be detected.

Next, the signal processing unit 120 processes the detected analog signal of the partial discharge into partial discharge data of the digital signal (S220).

Here, the signal processing unit 120 may be constituted by, for example, an analog signal processing unit, an A / D (Analog-to-Digital) converter, and a digital signal processing unit. The analog signal processing section can be composed of a low noise amplifier, a digital control attenuator, a filter matrix, an image detector, and a peak detector. The low noise amplifier amplifies the minute signal detected by the sensor part and adjusts the signal size through the digital control attenuator. The filter matrix acts to filter out multiple frequency bands and pass only the required frequency bands. The image detector can be a circuit using a commercial power detector and a logarithmic amplifier and can convert a broadband microwave signal into a low frequency (bandwidth <200 MHz) which is easy to process the signal. When the applied voltage is 60 Hz, the sine wave repeats 60 times per second to form 60 cycles. Each unit cell, which has 128 cycles of a sine wave, is binary )to be. In other words, the binary means a resolution indicating how precisely the signal can be decomposed in one cycle (cycle). When the applied voltage is 60 Hz and decomposes into 128 binary, one cycle is 1/60 second and 1/60 second is divided into 128 again, so one binary (resolution) becomes 0.13 ms. The peak detector receives a signal from the image detector and detects and outputs the highest value in each binary. The A / D converter converts the maximum value per binary output from the peak detector into a digital value. The digital signal processing unit receives digital data from the A / D converter and converts the digital data into an easy form for signal processing. Generally, when a partial discharge is detected, a PRPD (Phase Resolved Partial Discharge) method in which partial discharge signals over several cycles of an applied voltage are accumulated in one cycle is used. However, in the embodiment of the present invention, And a phase resolved pulse sequence (PRPS) method in which data on a magnitude and a phase are represented in a continuous sequence with respect to time so that a discharge occurring inside the actual gas-insulated apparatus can be discriminated.

On the other hand, the phase corrector 130 corrects the phase of the partial discharge data (S230). At this time, the phase correction unit 130 may receive the phase correction value from the user and correct the phase.

Next, the partial discharge analyzer 140 analyzes the detected partial discharge data in the phase and time domain as shown in FIG. 4 to generate a pattern signal (S240). 4 is a diagram illustrating an example of analyzing partial discharge data according to an embodiment of the present invention in phase and time domains.

Next, the pulse counting unit 150 counts the number of discharge pulses equal to or more than the reference value for each phase in the partial discharge data (S250).

5, the pulse counting unit 150 divides the partial discharge data into a positive polarity having a phase of 0 degrees to 180 degrees and a negative polarity having a phase of 181 degrees to 360 degrees, The number of pulses is counted. 5 is a diagram showing an example of counting the number of discharge pulses by dividing the partial discharge data according to the embodiment of the present invention into positive and negative polarities.

6, the pulse counting unit 150 does not count even a reference value for a certain period of time, for example, 4 [mu] s after counting the first discharge pulse, and counts the discharge pulses appearing in the following order . 6 is a diagram illustrating an example of counting discharge pulses for partial discharge data according to an embodiment of the present invention.

Next, the noise removing unit 160 removes the noise signal of each phase from the pattern signal of the partial discharge data (S260). At this time, the noise removing unit 160 may increase the accuracy of noise removal by removing noise at the firmware level before compressing the partial discharge data. For example, the noise removing unit 160 may subtract the signal measured by the sensor from the signal measured by the noise sensor. The sensor extracts the partial discharge signal inside the gas-insulated device by subtracting the signal of the noise sensor which measures the external noise since the signal is mixed according to the measurement of not only the signal inside the gas-insulated apparatus but also the electromagnetic wave which floats from the outside.

Next, the control unit 170 determines whether the number of discharge pulses counted by the pulse count unit 150 is positive or negative with respect to the partial discharge data, (S280). &Lt; / RTI &gt; That is, the control unit 170 calculates the ratio of the number of positive phases and the number of negative phases to the total number of discharges based on the result of counting the number of discharge pulses by the pulse count unit 150, In the same process, the cause of the partial discharge is diagnosed as one of 7 kinds such as POC (Protective On Conductor), POS (Particle On Surface), POE (Protrusion On Enclosure), Floating, Void, Crack and FP (Free Particle).

If the size of the pattern signal of the partial discharge data and the number of discharges exceed the reference value (S270: Yes), the partial discharge alarm unit 180 alerts the user that the partial discharge has occurred (S280).

At this time, the partial discharge alarm unit 180 alerts the partial discharge when the power value of the partial discharge data is larger than the threshold value and the count number of the discharge pulse is larger than the reference value.

The control unit 170 compresses the partial discharge data through the data compression unit 190 to generate and store 128 pieces of sampling data.

FIG. 7 is a flowchart illustrating a process of diagnosing the cause of the partial discharge according to the ratio of the positive / negative phase number to the total number of discharges based on the result of counting the number of discharge pulses according to the embodiment of the present invention.

Referring to FIG. 7, in the partial discharge diagnosis apparatus 100 of the gas insulated apparatus according to the embodiment of the present invention, the controller 170 divides the partial discharge data into positive and negative polarities, The ratio of the positive / negative phase number to the total number of discharges is calculated based on one discharge pulse number (S702).

That is, the controller 170 calculates the ratio of the positive phase number and the negative number of phases according to the following equation (1) and the ratio of the negative phase number according to the following equation (2) And calculates the phase number ratio on each window by dividing into 18 window regions.

In FIG. 7, for example, the first angle range is 0 to 40 degrees, the second angle range is 40 to 120 degrees, the third angle range is 20 to 100 degrees, the fourth angle range is 80 to 180 degrees, The angular range is 120 to 180 占, the sixth angular range is 140 to 180 占, the seventh angular range is 180 to 220 占, the eighth angular range is 200 to 280 占, the ninth angular range is 220 to 240 占, The region is assumed to be 260 to 360 degrees, the eleventh angle region to 300 to 360 degrees, and the twelfth angle region to be 320 to 360 degrees.

The controller 170 then determines whether the phase number ratio of the second angular region in the positive polarity phase range (R: Range) is equal to or greater than b1 when the positive phase number frequency ratio Np / Nt is a1 or more (S704 - YES) (Step S706). If the phase number ratio of the second angle area is b1 or more (S706-Yes), it is determined whether the positive phase range R is the phase number ratio of the first angle and the sixth angle area is c1 or less (S708).

If the ratio of the phases of the positive first phase angle R and the sixth angular phase is less than or equal to c1 (S708), the control unit 170 determines that the cause of the partial discharge is POC (Protrusion On Conductor) (S710).

However, if the phase number ratio of the positive phase range second angle region is less than b1 (S706-No) and the phase number ratio of the first and sixth angular regions is c1 or more (S708- Is diagnosed and processed as noise rather than the cause of the partial discharge (S712).

The controller 170 determines whether the negative phase number ratio Nn / Nt is equal to or greater than a2 (S714) when the positive phase number ratio Np / Nt is less than a1 (S704-No) (S714-YES), it is determined whether the phase number ratio of the negative phase range tenth angle region is b2 or less (S716).

Then, the controller 170 determines whether the phase number ratio of the negative phase range ninth angular range is c2 or more (S716-YES) if the phase number ratio of the negative phase range 10th angle range is b2 or less ).

At this time, if the phase number ratio of the negative phase range ninth angle region is less than c2 (S718-No), the controller 170 diagnoses and processes the noise as noise rather than the cause of the partial discharge (S712) If the ratio of the number of phases of the ninth angular region is equal to or larger than c2 (YES in S718), it is diagnosed that the partial discharge PD is a POS (Particle On Surface) (S720).

If the phase number ratio of the negative phase range 10th angular range is b2 or more (S716-No), the controller 170 determines whether the phase number ratio of the negative phase range seventh angle and the twelfth angle range is b3 or less (S722). If the result of the judgment is negative (NO in S722), the cause of the partial discharge is diagnosed as POE (Protrusion On Enclosure) (S726).

On the other hand, when the negative phase number ratio Nn / Nt is less than a2 (S714: No), the controller 170 divides the phase region from 0 degrees to 360 degrees into 18 windows at intervals of 20 degrees, (S728). If the number of windows having a phase number ratio of 0.05 (5%) or more is a3 or more, it is diagnosed that the cause of the partial discharge is FP (Free Particle) (S730).

However, when the number of windows having a phase number ratio of 0.05 (5%) or more is less than a3 (S728-No), the controller 170 calculates the phase number ratio of the positive phase range fourth angle range and the negative phase range Is equal to or greater than b4 (S732).

If the ratio of the number of phases of the fourth positive angular region to the negative first tenth angular region is b4 or more (S732-Yes), the controller 170 determines whether or not the positive phase range first angular region and the negative phase range seventh angular region It is determined whether the phase number ratio is c3 or more (S734). If the phase number ratio is c3 or more (S734), it is diagnosed that the cause of the partial discharge is Floating (S736).

However, if the ratio of the number of phases in the positive phase range fourth angular region and the negative phase range tenth tangential region is b4 or less (S732-No), the positive phase range first angular region and the negative phase range seventh angular region The controller 170 determines whether the phase number ratio of the positive phase range fifth angle range and the phase number ratio of the negative phase range eleventh angle range are equal to or less than c4 (S734: NO) (S738).

Next, when the phase number ratio of the positive phase range fifth angular range to the negative phase range eleventh angular range is equal to or less than c4 (YES in S738), the controller 170 sets the phase number ratio And the phase number ratio of the negative phase range eighth angle region is c5 or more (S740).

If the phase number ratio between the positive phase range third angle region and the negative phase range eighth angle region is c5 or more (S740- YES), the controller 170 diagnoses that the cause of the partial discharge is Void or Crack (S742).

However, if the phase number ratio of the positive phase range fifth angular range and the negative phase range eleventh angular range is c4 or more (S738-No), the positive phase range third angular range and the negative phase range eighth angle range (S740: No), the controller 170 diagnoses and processes the noise as noise rather than the cause of the partial discharge (S744).

Therefore, according to the embodiment of the present invention, the partial discharge data is detected, and the 360 degree phase range in the time domain is constituted by a window obtained by dividing the phase range by 20 degrees into 18, and the positive polarity region from 0 degrees to 180 degrees, The partial discharge pulse rate and the negative partial discharge pulse ratio can be calculated for the total number of partial discharge pulses by dividing the negative discharge region up to 360 degrees and diagnose a number of causes for the partial discharge. It is possible to alarm the occurrence and the cause of the occurrence.

As described above, according to the present invention, with respect to a deteriorated portion of a gas-insulated apparatus that uses a high-pressure gas as an insulated medium in a power plant or a substation to measure and diagnose an insulated deterioration state in a power plant in real time, The number of discharge pulses having a reference value or more is counted for each phase in the time domain to calculate the pulse rate of the positive polarity interval having a phase of 0 to 180 degrees and the negative polarity interval of 181 to 360 degrees, It is possible to realize a partial discharge diagnosis method of a gas insulated apparatus which can diagnose a plurality of causes of defects.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

The present invention is applied to a gas insulation device for measuring and diagnosing insulation deterioration in a power plant in real time using a high-pressure gas as an insulation medium in a power plant or a substation, measuring electromagnetic waves with a sensor against a deteriorated part of the gas insulation device, The number of discharge pulses of the reference value or more is counted for each phase in the time domain to diagnose the cause of the partial discharge and to alarm the partial discharge when the number of discharging exceeds the reference value, The present invention can be applied to a partial discharge diagnosis method.

100: partial discharge diagnostic apparatus 110: partial discharge detection unit
120: Signal processor 130: Phase corrector
140: partial discharge analysis unit 150: pulse count unit
160: Noise removing unit 170:
180: partial discharge alarm unit 190: data compression unit

Claims (10)

When a partial discharge due to an internal electrical fault occurs, a partial discharge signal is detected using a physical phenomenon generated by synchronizing the pressurized voltage frequency, and the partial discharge data obtained by converting the detected partial discharge signal into a digital signal is diagnosed A method of diagnosing a partial discharge of a gas insulated apparatus,
(a) counting the number of discharge pulses of a reference value or more from the pattern signal of the partial discharge data for each phase;
(b) diagnosing one of a plurality of causes according to the ratio of the positive polarity and the negative polarity phase to the total number of discharges when the number of discharge counts of the number of discharge pulses in the partial discharge data exceeds a reference value; And
(c) outputting an alarm indicating that a partial discharge has occurred in accordance with a cause of one of the plurality of causes;
Wherein the partial discharge diagnosis method comprises the steps of:
The method according to claim 1,
The step (a) includes the steps of: (a-1) correcting a phase of the partial discharge data; And (a-2) analyzing the partial discharge data in the phase and time domain to generate a pattern signal, and removing a noise signal of each phase from the pattern signal of the partial discharge data. A method of partial discharge diagnosis of a device.
The method according to claim 1,
The step (a) includes the steps of: dividing the partial discharge data into a positive phase having a phase of 0 degrees to 180 degrees and a negative phase having a phase of 181 degrees to 360 degrees, and counting the number of discharge pulses having a reference value or more, A method of diagnosing a partial discharge of a gas insulated apparatus.
The method of claim 3,
Wherein the step (a) counts discharge pulses in the next sequence without counting even after the first discharge pulse count for a predetermined time exceeds the reference value for the partial discharge data.
The method according to claim 1,
In the step (a), the partial discharge data is divided into positive polarity having a phase of 0 degrees to 180 degrees and negative polarity having a phase of 181 degrees to 360 degrees, and 18 windows And counting the number of discharge pulses equal to or more than a reference value for each window.
The method according to claim 1,
Wherein the positive phase number ratio is calculated according to the following equation in the step (b).

The method according to claim 1,
Wherein the negative phase number ratio is calculated according to the following equation in the step (b).

The method according to claim 1,
(PO), a PO (Protrusion On Enclosure), and a PoE (POE) to the cause of the partial discharge according to the ratio of the positive polarity and the negative polarity phase to the total number of discharges. Characterized in that the method is diagnosed as one of causes of floating, void, crack, or FP (Free Particle).
The method according to claim 1,
Wherein the partial discharge is alarmed when the power value of the partial discharge data is larger than the threshold value and the count number of the discharge pulse is larger than the reference value.
The method according to claim 1,
In the step (b), the ratio of the positive polarity and the negative polarity phase counts the number of discharge pulses of a threshold value or more with respect to the pattern signal of the partial discharge data by positive and negative phases, And calculating a proportion of the number of phases of the positive polarity and the negative polarity so as to calculate the ratio of the number of phases of the positive polarity and the negative polarity to the positive polarity and the negative polarity, And calculating the ratio of the phase number of each window region.

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