KR20210107437A - Apparatus for determining artial discharge - Google Patents

Abstract

The present invention relates to a partial discharge determination apparatus. The partial discharge determination apparatus includes: a plurality of sensing parts individually mounted to be spaced apart from each other in a power facility and sensing partial discharge to output a sensing signal; and a partial discharge determination unit outputting a plurality of pieces of sensing signal data which is time axis data by sampling sensing signals, outputted from the plurality of sensing parts respectively, at different moments, outputting a plurality of sensing signal integration waveforms by converting each of the pieces of sensing signal data into a sensing signal waveform which is each piece of frequency axis data, and then, sequentially integrating the same by sensing signal waveform, outputting an integration waveform with a totaled sensing signal by totaling the plurality of sensing signal waveforms into one single sensing signal waveform, and then, sequentially integrating the same, and determining a partial discharge condition using a statistical numeric value and a characteristic value in regard to each of the sensing signal integration waveforms and the integration waveform with a totaled sensing signal. Therefore, the present invention is capable of determining whether partial discharge has occurred by converting each sensing signal into frequency axis data.

Description

Partial discharge determination device {APPARATUS FOR DETERMINING ARTIAL DISCHARGE}

The present invention relates to a partial discharge determination device, and more particularly, to a partial discharge determination device for determining whether a partial discharge generated in a high voltage generating device is generated.

As the industry advances and the facilities become large-capacity, electricity consumption is skyrocketing, and the demand for electricity also increases accordingly.

However, the reality is that the lifespan of the electrical equipment cannot be predicted, so it is being replaced periodically.

Accordingly, power equipment such as a power transmitter and a distributor may generate a lot of mechanical and electrical stress in the process of transmitting and receiving high-voltage power, and local partial discharge occurs due to a change in the surrounding natural environment. .

If such partial discharge occurs continuously or frequently, the performance or operation of the corresponding power facility will be adversely affected, and the insulation state will be destroyed due to the magnetic field generated during partial discharge. stop and cause a fire or explosion hazard.

Republic of Korea Patent No. 10-0482305 (Announcement date: April 13, 2005, title of invention: Ultrasonic constant monitoring device for measuring partial discharge in transformer) Republic of Korea Patent No. 10-1167918 (Announcement Date: July 30, 2012, Title of Invention: Ultra-high voltage equipment partial discharge diagnostic device using ultrasonic sensor) Republic of Korea Patent No. 10-1791421 (Announcement Date: October 31, 2017, Title: Partial Discharge Monitoring Diagnostic System and Method by Ultrasonic Signal Detection)

The problem to be solved by the present invention is to measure the partial discharge at low cost.

Another problem to be solved by the present invention is to improve the reliability of the partial discharge measurement.

A partial discharge determination device according to one aspect of the present invention for solving the above problems is a plurality of detection units that are respectively mounted to be spaced apart from each other in a power facility and detect a partial discharge and output a detection signal, and output from the plurality of detection units, respectively A plurality of detection signal data is output by sampling the detection signal to be detected at different time points, each detection signal data is converted into a detection signal waveform that is each frequency axis data, and then a plurality of detection signals are integrated by sequentially integrating each detection signal waveform Outputs a waveform, sums a plurality of detection signal waveforms into one detection signal waveform, and then sequentially integrates them to output an integrated waveform with the sum of the detection signals and a partial discharge determination unit that determines a partial discharge state by using the value and the statistical numerical value.

The characteristic value may be at least one of an RMS value, an average value, a maximum value, a waveform rate, and a crest factor for each of the sensing signal integrated waveform and the sensing signal integrated waveform, and the statistical numerical value is at least one of variance and standard deviation. can be one

The partial discharge determination unit may determine whether a partial discharge has occurred and the intensity of the generated partial discharge using the characteristic value and the threshold value of each of the detection signal waveforms.

The partial discharge determination unit may determine the time difference between partial discharges and the generation direction of the partial discharges by using the characteristic values of the integrated waveform summed with the detection signals.

The partial discharge determination unit is connected to each sensing unit, a plurality of sampling units sampling and outputting a detection signal output from each sensing unit at a predetermined sampling time, and connected to each of the plurality of sampling units, each sampling unit A plurality of Fourier transform units for fast Fourier transforming the sampled detection signal data output from the to output a corresponding detection signal waveform, each connected to the plurality of Fourier transform units, and each detection signal waveform output from each Fourier transform unit A plurality of accumulators each integrating and outputting each sensing signal integration waveform, each connected to the plurality of Fourier transform units, summing the sensing signal waveforms output from each Fourier transform unit into one sensing signal waveform and then integrating An integrator for outputting an integrated waveform with the sum of the sensing signals, a plurality of accumulators for outputting each of the sensing signal integrated waveforms, and an integrator for outputting the integrated waveform with the sum of the sensing signals are connected to each other, and the characteristic value of each of the sensing signal integrated waveforms and a calculation unit for generating a statistical numeric value and outputting a calculation unit generating a characteristic value and a statistical numeric value of the integrated waveform summed with the detection signal.

Each sensing unit may be a microphone, an ultrasonic sensor, or an acceleration sensor, and when each sensing unit is a microphone, the microphone may be a condenser microphone or a Micro Electro Mechanical System (MEMS) microphone.

The plurality of sensing units may be located in the same power equipment, and the power equipment may be a power cable, a transformer, a current transformer (CT), a potential transformer (PT), or an electronic voltage and current transformer (eVCT).

The partial discharge determination apparatus according to the above feature may further include a power supply unit for supplying power necessary for an operation of the partial discharge determination apparatus.

The power supply unit may be a primary battery, a secondary battery, CT or PT.

According to an embodiment of the present invention, after spatially dividing and attaching a low-cost sensing unit having a low resolution to a desired power facility using a plurality of sensing units, the sampling time of each sensing signal output from each sensing unit does not overlap with each other. It is sampled and converted into frequency-axis data to determine whether partial discharge has occurred.

Due to this, the resolution of each detection signal is improved, and the detection of the partial discharge is performed accurately.

In addition, since the partial discharge is sensed using a low-cost sensing unit, the manufacturing cost is greatly reduced.

1 is a schematic block diagram of a partial discharge measuring apparatus according to an embodiment of the present invention.
2 is a schematic block diagram of a partial discharge determination unit according to an embodiment of the present invention.
3 (a) to (e) are views illustrating various examples in which a plurality of sensing units are attached to power equipment, respectively, according to an embodiment of the present invention.
4 (a) to (c) are each exemplarily illustrating a sampling time of each detection signal and a sampling time of a detection signal to which a plurality of detection signals are summed in the partial discharge determination unit according to an embodiment of the present invention. It is a waveform diagram shown as .
5 is a diagram conceptually illustrating an example in which two sensing units are mounted on a power facility and partial discharge occurs according to an apparatus for determining partial discharge according to an embodiment of the present invention.
6 (a) and (b) show an example of the first detection signal integration waveform and the second detection signal integration waveform generated by the partial discharge determination unit of the partial discharge determination apparatus according to an embodiment of the present invention, respectively; it is one drawing
6C is a first detection signal waveform and a second detection signal waveform shown in FIGS. 6A and 6B in the partial discharge determination unit of the partial discharge determination apparatus according to an embodiment of the present invention. It is a diagram showing an example of the summation waveform of the sensing signal accumulated after summing the .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that adding a detailed description of a technique or configuration already known in the relevant field may make the gist of the present invention unclear, some of these will be omitted from the detailed description. In addition, the terms used in this specification are terms used to properly express the embodiments of the present invention, which may vary according to a person or custom in the relevant field. Accordingly, definitions of these terms should be made based on the content throughout this specification.

The terminology used herein is for the purpose of referring to specific embodiments only, and is not intended to limit the invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of 'comprising' specifies a particular characteristic, region, integer, step, operation, element and/or component, and other specific characteristic, region, integer, step, operation, element, component, and/or group. It does not exclude the existence or addition of

Hereinafter, a partial discharge determination apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, an apparatus for determining partial discharge according to an embodiment of the present invention will be described with reference to FIG. 1 .

As shown in FIG. 1 , the partial discharge determination device of this example is connected to a plurality of detection units 11 and 12 , and connected to a plurality of detection units 11 and 12 , and is connected to the signal processing unit 20 and the signal processing unit 20 . a partial discharge determination unit 30 , a communication unit 40 connected to the partial discharge determination unit 30 , an information output unit 50 connected to the partial discharge determination unit 30 , and a power supply unit 60 . do.

The plurality of sensing units 11 and 12 all have the same structure, and are for detecting whether partial discharge has occurred.

As shown in FIG. 3, the plurality of sensing units 11 and 12 are power cables of various cross-sectional shapes such as circles or polygons [FIG. 3 (a) and (b)], transformers, current transformers (CTs), instruments current transformer), PT (Potential Transformer, instrument transformer) or eVCT (electronic voltage and current transformer) may be mounted on power equipment (FIG. 3(c) and (d)), respectively. Hereinafter, the power cable and the power equipment may be collectively referred to as a single term 'power equipment 100'.

When the plurality of sensing units 11 and 12 are mounted on the power cable 100, as shown in (a) and (b) of FIG. can

In addition, when the plurality of sensing units 11 and 12 are mounted on the power equipment 100 , as shown in (c), (d) and (e) of FIG. 3 , on the outer peripheral surface of the corresponding power equipment 100 . They may be mounted to be spaced apart from each other.

In (a) and (c) of Fig. 3, three sensing units 11-13 are mounted on the corresponding power facility 100, and in Figs. 3 (b) and (d), four sensing units 11- 14) is installed in the corresponding power facility 100 .

In FIG. 3E , four sensing units 11-14 are mounted on a CT or PT, which are a type of the power facility 100 .

In (e) of FIG. 3, the center hole H100 is a portion through which the power cable is inserted, and the CT or PT body may be divided into a body for facilitating insertion of the power cable into the corresponding hole.

In this example, for convenience of explanation, the two sensing units 11 and 12 will be exemplified, but the present invention is not limited thereto, and three or more sensing units may be attached to the corresponding power equipment to detect whether or not partial discharge occurs. In this case, as the number of sensing units mounted on the power equipment increases, the accuracy of the measurement of the partial discharge is further improved.

In this example, each of the sensing units 11 and 12 is at least one of vibration, sound waves, and ultrasonic waves of a specific frequency that are generated due to the partial discharge when partial discharge occurs in the corresponding region due to a failure of the installed power equipment, etc. is detected and output as sensing signals SI11 and SI12. In this example, each of the sensing units 11 and 12 receives a microphone such as a condenser microphone or a MEMS (Micro Electro Mechanical System) microphone, and ultrasonic waves. It may be an ultrasonic sensor or an acceleration sensor that senses.

In addition, each of the sensing units 11 and 12 may have a horn shape in order to more efficiently collect a sound of a specific frequency generated during partial discharge.

Each of these sensing units 11 and 12 may be mounted on at least one of a portion in which the waveform of the detection signals SI11 and SI12 is similarly generated and a portion in which the occurrence of partial discharge occurs better than other portions when mounted on the corresponding power facility. and may be positioned to be spaced apart from each other by a predetermined distance.

Accordingly, each of the sensing units 11 and 12 may be mounted at a position where it is easy to detect a specific frequency generated during partial discharge.

For example, when the power facility 100 is a single power cable, the plurality of sensing units 11 and 12 may be spaced apart from each other at the end of the cable, that is, at a junction where coupling with another power cable is made.

In addition, when the power equipment 100 is a single CT or PT, since a lot of partial discharge is mainly generated in the power cable mounted therein, the plurality of sensing units 11 and 12 are located in the vicinity of the inner hole H00. It may be located and surround the power cable inserted into the inner hole (H100).

In the case of one transformer of the power facility 100 , the plurality of sensing units 11 and 12 may be mounted at a portion where the transformer and the cable are connected.

When the plurality of sensing units 11 and 12 are mounted to be spaced apart from each other, the sensing range of each sensing unit 11, 12 overlaps with the sensing range of at least one other sensing unit (that is, in the plurality of sensing units) The plurality of output detection signals SI11 and SI12 may be located within a range in which a portion of a signal detected at a portion overlapping each other exists).

The partial discharge determination apparatus of this example shown in FIG. 1 may be mounted in one power facility, that is, one power cable, one transformer, one CT, one PT or eVCT, and thereby, one partial discharge determination The plurality of sensing units 11 and 12 provided in the device may be located in the same power facility.

For example, some of the plurality of detection units 11 and 12 provided in the same partial discharge determination device 11 are mounted on a high-voltage cable, and the other detection unit 12 is mounted on a transformer connected to the high-voltage cable. Rather, all of the plurality of sensing units 11 and 12 may be all mounted on the high-voltage cable or all of the transformers connected to the high-voltage cable.

The signal processing unit 20 receives the detection signals SI11 and SI12 applied from the respective detection units 11 and 12 , and includes a noise removal operation and a signal amplification operation included in the received detection signals SI11 and SI12 . and the like to output to the partial discharge determination unit 30 .

The signal processing unit 20 may be omitted if necessary. In this case, the detection signals SI11 and SI12 output from the respective detection units 11 and 12 are directly applied to the partial discharge determination unit 30 .

The partial discharge determination unit 30 receives the first and second detection signals SF11 and SF12 signal-processed by the signal processing unit 20 , and after receiving the signals of the respective detection units 11 and 12 , each detection Partial discharge in a power facility equipped with a plurality of sensing units 11 and 12 using a signal applied from the units 11 and 12, specifically, a power cable, a transformer, a CT or PT, or a single power facility such as eVCT occurrence can be determined.

Hereinafter, the first detection signal SF11 and the second detection signal SF12 signal-processed by the signal processing unit 20 will also be omitted, and the term 'signal-processed' will be omitted and the first detection signal SF11 and the second detection signal SF12, respectively. It is referred to as a detection signal SF12.

The operation of the partial discharge determination unit 30 will be described in more detail as follows.

The partial discharge determination unit 30 of this example first samples the detection signals respectively output from the plurality of detection units 11 and 12 at different time points and outputs a plurality of detection signal data that is time domain data, , It is possible to output a plurality of integrated detection signal waveforms by sequentially integrating each detection signal data into a detection signal waveform, which is frequency domain data, and then sequentially integrating each detection signal waveform into a detection signal waveform for each detection signal waveform. have.

Also, the partial discharge determination unit 30 may sum a plurality of detection signal waveforms, which are data of each frequency axis, into one detection signal waveform, and then sequentially integrate to output an integrated waveform of the detection signal. In this case, it is natural that one detection signal waveform in which a plurality of detection signal waveforms are summed is also frequency axis data.

Then, the partial discharge determination unit 30 may determine the partial discharge state by using the characteristic values and statistical numerical values of the integrated waveforms of the detection signals and the integrated waveforms of the detection signals.

Also, the partial discharge determination unit 30 may determine the partial discharge state by using a characteristic value and a statistical numerical value for each of the detection signal integrated waveform and the detection signal integrated waveform.

As shown in FIG. 1, the partial discharge determination unit 30 includes a signal operation unit 301, a storage unit 302 connected to the signal operation unit 301, and a partial discharge determination unit connected to the storage unit 302 ( 303) may be provided.

The signal operation unit 301 samples the first detection signal SF11 output from the first detection unit 11 at a predetermined time, and then converts the sampled time-axis data, which is the detection signal data, by fast Fourier transform into frequency-axis data. , and integrating the Fourier-transformed sensing signal waveform whenever the fast Fourier transform is performed (ie, every sampling time), a first sensing signal integrated waveform in which the fast Fourier-transformed waveform is sequentially integrated may be generated.

The signal operation unit 301 samples the second detection signal SF12 output from the second detection unit 12 at a different time from that of the first detection unit 11, and then the corresponding detection signal which is the sampled time axis data. The data is converted into frequency-axis data by fast Fourier transform, and whenever the fast Fourier transform is performed, the Fourier-transformed sensing signal waveform is integrated to generate a second sensing signal integrated waveform in which the fast Fourier-transformed waveform is sequentially integrated. .

In addition, the signal operation unit 301 includes a plurality of sensing units, for example, a plurality of sensing signals SF11 and SF12 output from the first and second sensing units 11 and 12, that is, the first and After combining the second detection signal waveforms into one waveform, the integrated waveforms in which the detection signals are summed may be generated by sequentially integrating (that is, whenever the fast Fourier transform is performed).

As described above, the frequency resolution is increased by the operation of summing the plurality of detection signals, that is, the plurality of Fourier-transformed detection signal waveforms into one waveform, thereby increasing the frequency accuracy.

As shown in FIG. 2 , the signal operation unit 301 includes a plurality of signal-processed detection signals output from the signal processing unit 20 , for example, a first detection signal SF11 and a second detection signal SF12 . A first sampling unit 311 and a second sampling unit 312 respectively connected to 321 and 322 , first and second accumulators 331 and 332 respectively connected to the first and second Fourier transform units 321 and 322 , a first Fourier transform unit 321 and a second Fourier transform unit A filter unit 341 connected to 322, a third integrator 342 connected to the filter unit 341, and an operation unit connected to the first to third integrators 331, 332, 342 ( 35) can be provided.

In FIG. 2 , the first and second sensing signals SF11 and SF12 sampled by the first and second sampling units 311 and 312, respectively, are Fourier transformed through the respective Fourier transform units 321 and 322, but this Alternatively, each of the sampled detection signals SF11 and SF12 may be Fourier-transformed using one Fourier transform unit. In this case, each sampled plurality of sensing signals SF11 and SF12 may be stored in a storage unit such as a buffer or a memory, and then may be Fourier transformed by a single Fourier transform unit.

In addition, the signal operation unit 301 further includes a k-mean operation unit, performs k-mean operation on each Fourier-transformed detection signal, and uses each detection signal to determine trends, for example, partial discharge frequency, etc. can

The first and second sampling units 31 sample the first and second detection signals SF11 and SF12 input from the corresponding detection units 11 and 12, respectively, at a predetermined sampling time, that is, at a sampling time. Then, the corresponding detection signal data, which is the sampled time-axis data, are output to the first and second Fourier transform units 321 and 322, respectively.

As shown in (a) and (b) of FIG. 4 , the sampling times of the respective sensing units 11 and 12 are different from each other, and the first and second sensing signals output from the plurality of sensing units 11 and 12 are different from each other. (SF11, SF12) outputs the sampled detection signal data sampled at different times instead of being sampled at the same time, that is, at the same time.

4 (a) and (b) are for illustrating an example of each sampling time for the first and second detection signals output from the first detection unit 11 and the second detection unit 12, respectively. , The first and second sensing signals SF11 and SF12 output from the first sensing unit 11 and the second sensing unit 12 may have different waveform shapes.

4 (a) and (b), the sampling frequency of the first sampling unit 311 and the second sampling unit 312 is 3 kHz (1 kHz period × 3 times), respectively, but each sampling time is different from each other. Able to know.

Accordingly, the plurality of detection signals SF11, SF12, SF13, ? -> the third detection signal SF13 ->, ?, -> the (n-1)th detection signal SFn-1 -> the sampling operation for the corresponding detection signal is performed in the order of -> the nth detection signal SFn can

The first and second sampling units 311 and 312 of this example determine each sampling time of the first detection signal SF11 and the second detection signal SF12 using a clock unit (not shown), and then store them in the storage unit 302 . can be saved

The first and second Fourier transform units 321 and 322 perform fast Fourier transform on the sensing signal data sampled at the corresponding point in time applied from the corresponding sampling units 311 and 312, respectively, and transform it into frequency axis data. It may output to the first and second accumulators 331 and 332, respectively.

The first and second integrating units 331 and 332 sequentially integrate the Fourier-transformed first sensing signal data and the second sensing signal data applied from the first and second Fourier transform units 321 and 322, respectively, respectively. The integrated waveform of the first detection signal and the integrated waveform of the second detection signal may be output.

As shown in FIG. 5 , the first sensing unit 11 and the second sensing unit 12 are positioned to be spaced apart from each other on the outer circumferential surface of the power facility 100 , and at different time points near the first sensing unit 11 and the second sensing unit 12 . 2 It is assumed that partial discharges PD1 and PD2 occur near the sensing unit 12 .

At this time, as already described, the sensing ranges AR1 and AR2 of the first sensing unit 11 and the second sensing unit 12 are mounted adjacent to each other and spaced apart from each other to overlap the plurality of sensing units 11 and 12 . ) so that the waveform of the detection signal outputted from it can have a similar shape.

In this state, an example of the first detection signal integration waveform accumulated during the corresponding sampling time after Fourier transforming the first detection signal data sampled at each sampling point during the sampling time may be (a) of FIG. , an example of the second detection signal integration waveform accumulated during the corresponding sampling time after Fourier transforming the second detection signal data sampled at each sampling point during the sampling time may be illustrated in FIG. 6B .

At this time, although the sampling time in (a) of FIG. 6 and the sampling time in (b) of FIG. 6 may be the same, the sampling time (ie, sampling time) of the first detection signal data and the sampling time of the second detection signal data Sampling time points are different from each other.

Referring to the waveforms of FIGS. 6A and 6B , the partial discharge PD1 sensed by the first sensing unit 11 and the partial discharge PD2 sensed by the second sensing unit 12 are mutually It can be seen that they occur at different times. Accordingly, in the graph of FIG. 6 in which the first detection signal data and the second detection signal data are converted into frequency axis data at different time points, it can be seen that each of the partial discharges PD1 and PD2 occurs in different frequency bands.

In this way, the first detection signal ( SF11) and the second detection signal SF12 are sampled at different times, and the detection signal data sampled at each point in time is subjected to a fast Fourier transform to be sequentially integrated, and then applied to the operation unit 35 .

In addition, the corresponding first and second detection signal waveforms, each fast Fourier-transformed by the first and second Fourier transform units 321 and 322 , are applied to the filter unit 341 .

The filter unit 341 may include a decimation filter, and may appropriately adjust the sampling ratio of each Fourier-transformed sensing signal waveform to a desired size by performing a decimation process, for example, sampling Wealth can be lowered to a desired size.

Accordingly, at least one of unnecessary signal removal, unnecessary frequency band signal removal, and signal amplification and attenuation operations can be performed by the filter unit 341, thereby reducing the amount of data to be processed and shortening the signal processing time can be

However, the filter unit 341 may be omitted if necessary. In this case, the corresponding sensing signal waveforms output from the first Fourier transform unit 321 and the second Fourier transform unit 322 are directly integrated with the third. may be applied to the unit 342 .

The third accumulator 342 sums the Fourier-transformed first sensing signal waveform and the second sensing signal waveform applied at the time through the filter unit 341 into one waveform, and then sequentially integrating the sensing signal. An integrated waveform is generated, and the integrated waveform obtained by summing the generated sensing signals is output to the calculator 35 .

Accordingly, when the integration waveforms for the Fourier-transformed first detection signal waveform and the second detection signal waveform are the same as those illustrated in FIGS. 6A and 6B , respectively, the detection signal generated by the integration unit 342 is summed The integrated waveform may be as shown in (c) of FIG. 6 .

The calculating unit 35 includes each of the sensing signal waveforms output from the first and second Fourier transform units 321 and 322, for example, the first sensing signal integrated waveform and the second sensing signal integrated waveform, and the third integrated unit ( Feature values and statistical values for each of the integrated waveforms in which the plurality of detection signals output from 342 are summed, for example, the integrated waveforms in which the first and second sensing signals are summed (ie, the integrated waveform in which the sensing signals are summed) is calculated and then stored in the storage unit 302 .

In this example, the calculating unit 35 may calculate and accumulate characteristic values and statistical numerical values for each waveform at a predetermined time period.

In this case, the feature value may be at least one of an rms value, an average value, a maximum value, a waveform rate, and a crest factor in each corresponding waveform, and the statistical numerical value may be at least one of a variance and a standard deviation. .

As described above, when the characteristic values and statistical numerical values for the first and second detection detection signals SF11 and SF12 and the first and second sum detection signals SF11+SF12 are calculated and stored in the storage unit 302, the partial The discharge determination unit 303 may determine the partial discharge state using a feature value, a statistical value, a sampling time, and a set value of the plurality of detection signal integration waveforms stored in the storage unit 302 for each detection signal determined. .

The storage unit 302 connected to the signal operation unit 301 may be a storage medium such as a memory that stores data necessary for the operation of the partial discharge determination unit 301 or data generated during the operation, as already described. can

Accordingly, the storage unit 302 stores the sampling time for the data applied from the signal operation unit 301 and the first and second detection signals SF11 and SF12 obtained by the first and second sampling units 311 and 312 . and at least one set value for determining the partial discharge state.

The partial discharge determination unit 303 connected to the storage unit 302 generates partial discharge in a power facility equipped with a plurality of detection units 11 and 12 using data stored in the storage unit 302 . At least one of whether or not the partial discharge has occurred and the characteristics of the generated partial discharge may be determined.

Accordingly, the partial discharge determination unit 303 includes the first detection signal SF11 (ie, the first detection signal integration waveform) and the second detection signal SF12 (ie, the second detection signal) stored in the storage unit 302 . signal integration waveform) and the first and second summed detection signals (SF11+SF12) (ie, the integrated waveform with the sum of the detection signals) using characteristic values and statistical numerical values to determine whether partial discharge, intensity of partial discharge, and proximity A partial discharge characteristic such as at least one of a time difference between the partial discharges and a direction in which the partial discharges occur is determined.

To this end, the partial discharge determination unit 303 includes at least one of an RMS value, an average value, a maximum value, a waveform rate, and a crest factor for each integrated waveform of the first sensing signal acquired after a predetermined sampling time and subjected to fast Fourier transform, and a storage unit It is determined whether the partial discharge PD1 detected by the first detection unit 11 exists using a plurality of threshold values preset and stored in 302 .

In this case, the sizes of the plurality of threshold values stored in the storage unit 302 may be different from each other.

Therefore, the partial discharge determination unit 303 first, a threshold value (eg, a first threshold value) having at least one of an RMS value, an average value, a maximum value, a waveform rate, and a crest factor for the integrated waveform of the first detection signal and the smallest value. ), if at least one of the corresponding rms value, average value, maximum value, waveform rate, and crest factor is greater than the first threshold value, it is determined that partial discharge has occurred, otherwise it can be determined that partial discharge does not occur. have.

In addition, when it is determined that the partial discharge has occurred, the partial discharge determination unit 303 determines whether at least one of the rms value, average value, maximum value, waveform rate, and crest factor of the sensing signal integration waveform exists between two threshold values. It is possible to determine the intensity of the generated partial discharge depending on whether or not there is.

For example, it is assumed that first to third threshold values exist, and in this case, the first threshold value is the lowest and the third threshold value is the largest.

In this case, the partial discharge (eg, the first partial discharge) in which at least one of the rms value, average value, maximum value, waveform rate, and crest factor of the first sensing signal integration waveform exists between the first threshold value and the second threshold value. ) and a partial discharge (eg, a second partial discharge) existing between the second threshold value and the third threshold value, it can be determined that the intensity of the discharge is lower in the first partial discharge than the second partial discharge, Due to the size of each threshold, the value of the intensity of the corresponding partial discharge PD1 sensed by the first sensing unit 11 may also be determined.

In the same way, the partial discharge determination unit 303 uses at least one of an rms value, an average value, a maximum value, a waveform rate, and a crest factor for the second sensing signal integrated waveform and one threshold value to the second sensing unit 12 . ), it is determined whether the partial discharge PD2 is present, and the intensity of the generated partial discharge PD2 can be determined using a plurality of threshold values having different values.

Also, the partial discharge determining unit 303 may calculate a time difference between temporally adjacent partial discharges using the integrated waveform of the first and second sensing signals.

To this end, the partial discharge determining unit 303 may determine whether at least one partial discharge occurs in the integrated waveform in which the first and second sensing signals are summed by the same method as the method described above.

In addition, the partial discharge determination unit 303 generates a plurality of partial discharges and determines the generation time of each partial discharge, that is, the corresponding sampling time stored in the storage unit 302 , and determines two temporally adjacent partial discharges PD2 and PD2 . The time difference between PD1) can be calculated.

In this way, when the generation time of each generated partial discharge is determined, the partial discharge determination unit 303 may determine the generation direction of the partial discharge by arranging the determined generation times of each partial discharge in chronological order.

The determination result of the partial discharge determination unit 303 according to this operation may be stored in the storage unit 302 .

The communication unit 40 connected to the partial discharge determination unit 30 operates under the control of the partial discharge determination unit 303 of the partial discharge determination unit 30 to transmit the determination result stored in the storage unit 302 to the outside. can be sent to the device.

Accordingly, the management server or the like that manages the operation of the corresponding power facility may output the partial discharge state transmitted through the communication unit 40 in real time.

For this reason, the manager of the corresponding power facility uses the judgment result output through the management server to quickly and accurately determine whether or not the power equipment is defective and the signs of an accident in advance.

The information output unit 50 may be an information display device such as a liquid crystal display device or an organic light emitting display device, and the partial discharge determination unit 303 according to the control of the partial discharge determination unit 303 of the partial discharge determination unit 30 . It is possible to output the partial discharge state output from the to the outside in real time.

The power supply unit 60 is a power supply unit for supplying power required for the operation of the partial discharge determination device, and may be a primary battery or a secondary battery.

Alternatively, the power supply unit 60 may use a CT or PT, and in this case, it may generate power through an electromagnetic induction method with a power cable mounted on the CT or PT.

In addition, when the partial discharge determination device of this example is installed outside, all parts exposed to the outside are waterproofed or provided with a separate waterproof structure to prevent failure or damage due to rain or snow. can be protected from the external environment.

The partial discharge determination device includes a plurality of devices in at least one of a series structure and a parallel structure in the same power facility (eg, one transformer) or in a power system having a plurality of power facilities (eg, a power cable and a transformer) through a parallel structure. It is arranged so that it can be determined whether or not partial discharge occurs in the corresponding part. In this case, the plurality of power equipment provided in the plurality of power systems may be the same type of power equipment (eg, a power cable) or at least two different types of power equipment (eg, a high-voltage cable and a transformer).

In this case, each partial discharge determining device may include a separate wired communication unit or a wireless communication unit, thereby enabling communication between adjacent partial discharge determining devices.

Accordingly, at least one of whether a partial discharge has occurred between adjacent partial discharge determination devices, a plurality of detection signal integrated waveforms, a detection signal summed integrated waveform, feature values, and statistical numerical values can be communicated, and a plurality of partial discharge determinations in which communication occurs All data may be collected by the partial discharge determination device of any one of the devices to determine the overall partial discharge occurrence situation.

Alternatively, at least some of these partial discharge determination devices may transmit all result values such as data and waveforms measured by themselves to a management server communicating with the device. In this case, the management server may collect or calculate desired data such as the partial discharge occurrence status and the occurrence pattern by using the result values transmitted from all partial discharge determining devices.

For example, in the case of a three-phase power cable, an example of a power installation. A partial discharge determination device for the power signal of each phase may be installed, and the partial discharge determination devices of each phase located adjacent to each other may be connected to each other through short-distance communication. Therefore, one partial discharge determination device among the three-phase partial discharge determination device may synthesize the partial discharge determination results received from the partial discharge determination devices for the other two phases, that is, aggregate, and transmit the aggregated result to the management server. . However, as described above, in the case of a three-phase power cable, unlike this, each partial discharge determination device for each phase may communicate with each direct management server to transmit a corresponding partial discharge determination result.

As such, according to the present embodiment, in order to detect the partial discharge of the power facility, using a plurality of sensing units 11 and 12 mounted on each part spatially distributed in one power facility, that is, the area is distributed. After generating a plurality of detection signals, it is determined whether partial discharge has occurred using signals sampled at different sampling points, that is, signals sampled through temporal distribution. Accordingly, since the number of sampled signal data increases due to temporal distribution and area distribution, the accuracy of an operation for detecting a partial discharge increases.

In addition, each of the sampled detection signal data collected from the detection signals of the detection units 11 and 12 is individually divided and fast Fourier transform is performed to calculate the characteristic values of the detection signals and the collected plurality of sampled detections. The precision of judgment is improved by the operation of calculating the characteristic values of the sensing signal after summing the signal data into one, and the signal amplification effect is generated by summing the plurality of sampled signal data.

In this case, as the number of sensing units increases, the sampling time interval becomes narrower, so that the frequency resolution of the fast Fourier transform increases and the precision of judgment is improved.

In addition, since the operation of the filter unit removes a noise component or an unnecessary frequency band signal, and amplifies and attenuates the signal, the structure of the partial discharge determination unit is simplified.

The technical features disclosed in each embodiment of the present invention are not limited only to the embodiment, and unless they are incompatible with each other, the technical features disclosed in each embodiment may be combined and applied to different embodiments.

In the above, embodiments of the partial discharge determination apparatus of the present invention have been described. The present invention is not limited to the above-described embodiments and the accompanying drawings, and various modifications and variations will be possible from the point of view of those of ordinary skill in the art to which the present invention pertains. Accordingly, the scope of the present invention should be defined not only by the claims of the present specification, but also by those claims and their equivalents.

11: first detection unit 12: second detection unit
20: signal processing unit 30: partial discharge determination unit
301: signal operation unit 302: storage unit
303: partial discharge determination unit 40: communication unit
50: information output unit 311: first sampling unit
312: second sampling unit 321: first Fourier transform unit
322: second Fourier transform unit 33: filter unit
34: accumulator 35: arithmetic unit
SF11: first detection signal SF12: second detection signal

Claims (8)

a plurality of sensing units mounted to be spaced apart from each other in the power equipment and configured to detect a partial discharge and output a detection signal; and
The detection signals output from the plurality of detection units are sampled at different times to output a plurality of detection signal data that is time-axis data, and each detection signal data is converted into a detection signal waveform that is frequency-axis data. Sequentially integrating for each signal waveform to output a plurality of detection signal integration waveforms, summing the plurality of detection signal waveforms into one detection signal waveform and then sequentially integrating them to output the detection signal summed integration waveform, and each detection signal A partial discharge determination unit that judges the partial discharge state by using the characteristic values and statistical numerical values of the integrated waveform and the detection signal summed with the integrated waveform
Partial discharge determination device comprising a. According to claim 1,
The characteristic value is at least one of an RMS value, an average value, a maximum value, a waveform rate, and a crest factor for each of the sensing signal integrated waveform and the sensing signal integrated waveform,
The statistical numerical value is at least one of variance and standard deviation. According to claim 1,
The partial discharge determination unit determines whether a partial discharge has occurred and the intensity of the generated partial discharge by using a characteristic value and a threshold value of each of the detection signal waveforms. According to claim 1,
The partial discharge determination unit determines a time difference between partial discharges and a generation direction of the partial discharges using a feature value of the integrated waveform summed with the detection signals. According to claim 1,
The partial discharge determination unit,
a plurality of sampling units connected to each sensing unit and sampling and outputting a sensing signal output from each sensing unit at a predetermined sampling time;
a plurality of Fourier transform units connected to each of the plurality of sampling units and configured to perform fast Fourier transform on the sampled sensing signal data output from each sampling unit to output a corresponding sensing signal waveform;
a plurality of accumulators respectively connected to the plurality of Fourier transform units, each integrating each sensing signal waveform output from each Fourier transform unit, and outputting each sensing signal integrated waveform;
an integrating unit connected to the plurality of Fourier transform units, respectively, summing the sensing signal waveforms output from each of the Fourier transform units into a single sensing signal waveform and integrating the summation unit to output the summed sensing signal waveform; and
A plurality of accumulators for outputting each of the sensing signal integrated waveforms and an integrator for outputting the summed waveform of the sensing signals are connected to generate characteristic values and statistical numerical values of each of the sensing signal integrated waveforms, and the sensing signals are summed An arithmetic unit that outputs the arithmetic unit that generates the characteristic values and statistical numerical values of the integrated waveform
Partial discharge determination device comprising a. According to claim 1,
Each sensing unit is a microphone, an ultrasonic sensor, or an acceleration sensor, and when each sensing unit is a microphone, the microphone is a condenser microphone or a MEMS (Micro Electro Mechanical System) microphone. According to claim 1,
A plurality of sensing units are located in the same power equipment, and the electric power equipment is a partial discharge determination device of a power cable, a transformer, a current transformer (CT), a potential transformer (PT), or an electronic voltage and current transformer (eVCT). 8. The method of claim 7,
A power supply unit for supplying power necessary for the operation of the partial discharge determination device
further comprising,
The power supply unit is a primary battery, a secondary battery, CT or PT partial discharge determination device.

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