KR101333178B1 - Method for diagnosing partial discharge using technique of oil immersed transformer - Google Patents

Abstract

The present invention relates to a partial discharge diagnostic method using an oil-immersed transformer. According to the embodiment of the present invention, the partial discharge diagnostic method using an oil-immersed transformer comprises a signal conversion step, a measured value coincidence step, and a detection signal output step. [Reference numerals] (AA) Start;(BB) No;(CC) Yes;(DD) End;(S10) AE sensor unit, mounted on the external wall of a transformer of a incoming and distributing panel, detects those sound signals ranging from 20kHz to 40kHz within the transformer;(S20) Signal conversion unit converts the sound signals approved by the AE sensor unit into electronic signals;(S30) Size of the electronic signals and pulse count = Pre-measured partial discharge measurement values ?;(S40) Detection and analysis unit determines that partial discharge has occurred in the incoming transformer inside the incoming and distributing panel and outputs a partial discharge detection signal

Description

Partial Discharge Diagnosis Method Using Inflow Transformer Diagnosis Technique {METHOD FOR DIAGNOSING PARTIAL DISCHARGE USING TECHNIQUE OF OIL IMMERSED TRANSFORMER}

The present invention relates to a method of diagnosing partial discharge using an inflow transformer diagnosis technique. More particularly, partial discharge in a switchgear is generated by converting an acoustic signal detected through an acoustic emission (AE) sensor provided in an outer wall of a transformer into an electrical signal. It relates to a technique for diagnosing whether or not.

The switchgear is a device for stepping down the high voltage power supplied from the substation to commercial voltage and supplying it to the customer. Specifically, the switchgear is a power supply facility for receiving the high voltage power supplied from the substation, a substation facility for stepping down the high voltage power received from the substation to a commercial voltage, and for supplying the stepped electricity to the electric devices of each part of the building. Distribution equipment, switchgear and other safety devices.

The closed switchgear applied to such a switchgear receives a high-voltage electricity, depressurizes it appropriately for each consumer's load, and then measures instruments, relays, transformers, and vacuum circuit breakers (VCBs) to monitor and control electrical devices or circuits for distribution. ) It is a facility that centralizes switchgear, busbar, etc. such as a disconnecting device (DS) in one place, and is divided by a metal or an insulating partition wall grounded so as to be isolated and stored in each unit circuit, or having a separate space. Various forms are used, such as those consisting of compartment structures.

On the other hand, Korean Patent Registration No. 10-0876586 relates to an air insulated high-low pressure compartment metal clad insulation insulated closed switchgear, a wall through-type bushing is installed in a closed switchgear consisting of a plurality of partitions, the connection portion as an insulating material A technique for constructing an air insulation type switchboard by covering a configured cover has been disclosed.

In addition, a technique for measuring a partial discharge of a switchgear using an electromagnetic measurement has been disclosed, and related patents related thereto are disclosed in Korean Patent Application No. 20-0278981 (Partial Discharge Detection Device of Power Equipment Using Radiated Electromagnetic Wave). A technique for calculating a partial discharge amount by transmitting an electromagnetic wave signal detected from a closed switchgear, a power cable, and a gas insulated switchgear (GIS) to a control unit is disclosed.

However, in the case of the inlet transformer in which the outside of the distribution panel is surrounded by an iron plate and grounded, there is a problem in that partial discharge occurring in the inlet transformer cannot be detected through electromagnetic wave measurement.

Patent Registration No. 10-0876586 (2008.12.23) Registered Room No. 20-0278981 (2002.06.20)

An object of the present invention is to convert the acoustic signal detected through the AE (Acoustic Emission) sensor provided on the transformer outer wall into an electrical signal, and by measuring and analyzing the converted electrical signal, the outside of the switchboard is surrounded by a steel plate to the ground inflow The purpose is to diagnose whether a partial discharge of a transformer occurs.

Partial discharge diagnostic method using the inlet transformer diagnostic method of the present invention for achieving the technical problem, the AE sensor unit 100 is installed on the transformer outer wall of the switchgear panel to detect the acoustic signal of 20kHz to 40kHz inside the transformer (a ) step; (B) converting, by the signal conversion unit 200, an acoustic signal received from the AE sensor unit 100 into an electrical signal; The detection analyzing unit 300 measures whether the partial discharge is generated from the electric signal applied from the signal conversion unit 200, and determines whether the magnitude and pulse count of the electric signal match the measured partial discharge measurement value ( c) step; And (c) when the magnitude and pulse count of the electric signal coincide with the measured partial discharge measurement value, the detection analyzing unit 300 determines that the partial discharge has occurred in the inlet transformer inside the switchboard. (D) outputting a discharge detection signal;

In the step (c), the detection analyzer 300 filters the noise included in the electrical signal received from the signal converter 200 to a bandwidth of 70 kHz to 300 kHz through the analog signal processing module 310 (c-1). ) step; Detecting, by the detection analyzer 300, amplifying the filtered electrical signal at an amplification rate of 20 dB to 60 dB through the preamplifier 320; (C-3) the detection analyzing unit 300 converting the amplified electric signal into a digital signal at a processing speed of 50 Ms / s at 16 bits through the digital signal processing module 330; The detection analyzing unit 300 extracts the magnitude and pulse count of the digitally converted signal through the signal analysis module 340, and determines whether the magnitude and pulse count of the extracted signal match the measured partial discharge measurement value. (C-4) doing; And (c-4), when the magnitude of the extracted signal and the pulse count coincide with the measured partial discharge measurement value, the detection analyzer 300 flows into the switchboard through the signal analysis module 340. And determining that the partial discharge has occurred in the transformer and outputting the partial discharge detection signal (c-5).

According to the present invention as described above, by converting the acoustic signal detected by the AE (Acoustic Emission) sensor provided on the transformer outer wall into an electrical signal, by measuring and analyzing the converted electrical signal, the outside of the switchboard is surrounded by a steel plate to ground It is effective to diagnose whether or not partial discharge of the inlet transformer is generated.

1 is a block diagram showing a partial discharge diagnostic apparatus using an inlet transformer diagnostic technique according to the present invention.
Figure 2 is a diagram showing the detailed configuration of the partial discharge diagnostic apparatus using the inlet transformer diagnostic technique according to the present invention.
3 is an exemplary view showing that the AE sensor unit and the signal conversion unit of the partial discharge diagnosis apparatus using the inflow transformer diagnostic technique according to the present invention designed / manufactured.
Figure 4 is an exemplary view showing that the detection analysis unit of the partial discharge diagnostic apparatus using the inlet transformer diagnostic technique according to the present invention designed / manufactured.
5 is a view showing the experimental result signal waveform of the partial discharge diagnostic apparatus using the inlet transformer diagnostic method according to the present invention.
Figure 6 is a flow chart illustrating a partial discharge diagnostic method using the inlet transformer diagnostic method according to the present invention.
Figure 7 is a flow chart showing the detailed process of step S20 of the partial discharge diagnostic method using the inlet transformer diagnostic method according to the present invention.
8 is a flow chart showing the detailed process of step S30 of the partial discharge diagnostic method using the inlet transformer diagnostic method according to the present invention.

Specific features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, terms and words used in the present specification and claims are to be interpreted in accordance with the technical idea of the present invention based on the principle that the inventor can properly define the concept of the term in order to explain his invention in the best way. It should be interpreted in terms of meaning and concept. It is to be noted that the detailed description of known functions and constructions related to the present invention is omitted when it is determined that the gist of the present invention may be unnecessarily blurred.

As shown in FIG. 1, the partial discharge diagnosis apparatus A using the inflow transformer diagnosis technique according to the present invention is installed on the transformer outer wall of the switchgear and detects an acoustic signal inside the transformer 100. ), Whether or not the partial discharge is generated from the electrical signal received from the signal conversion unit 200 and the signal conversion unit 200 for converting the acoustic signal applied from the AE sensor unit 100 into an electrical signal, the magnitude of the electrical signal And a detection analyzer 300 for outputting the partial discharge detection signal by determining that the partial discharge has occurred in the inlet transformer inside the switchgear when the pulse count coincides with the measured partial discharge measurement value.

Hereinafter, referring to FIG. 2, a detailed configuration of the partial discharge diagnosis apparatus A using the inflow transformer diagnosis technique according to the present invention is as follows.

Specifically, the AE sensor unit 100 is installed on the transformer outer wall of the switchgear to detect the acoustic signal of the pulse form propagated by the destruction or deformation of the object provided inside the transformer.

At this time, the AE sensor unit 100 detects an acoustic signal of 20 kHz to 40 kHz, which is an acoustic wave generated radially and spreading inside the transformer due to partial discharge, arc, crack caused by crack, potential or transformation in crystalline material inside the transformer. do.

In addition, the signal converting unit 200 converts an acoustic signal received by being grounded with the AE sensor unit 100 to an electrical signal through the piezoelectric vibrator 210, the piezoelectric vibrator 210 is configured of a resonant type of 120kHz.

In addition, the piezoelectric vibrator 210 of the signal conversion unit 200 is configured to include, and the (+) charge and (-) generated on each side of the diaphragm in response to the acoustic signal from the AE sensor unit 100 Converts charge into an electrical signal

On the other hand, Figure 3 is an illustration showing the design / fabrication of the AE sensor unit 100 and the signal conversion unit 200 provided on the inside of the partial discharge diagnostic device (A) using the inlet transformer diagnostic method according to the present invention It is also.

In addition, the detection analyzing unit 300 is composed of two channels to filter the noise included in the electrical signal received from the signal converter 200 through the analog signal processing module 310, the preamplifier 320 is filtered Amplifying the electrical signal, the detection analysis unit 300 converts the electrical signal amplified by the digital signal processing module 330 into a digital signal.

At this time, the analog signal processing module 310 filters noise with a bandwidth of 70 kHz to 300 kHz, the preamplifier 320 has an amplification rate of 20 dB to 60 dB, and the digital signal processing module 330 processes 50 Ms / s at 16 bits. It consists of A / D converter that converts speed.

In addition, the signal analysis module 340 of the detection analysis unit 300 extracts the magnitude and pulse count of the digitally converted signal, when the magnitude and pulse count of the extracted signal coincide with the measured partial discharge measurement value, It is determined that partial discharge has occurred in the inlet transformer inside the switchboard and outputs a partial discharge detection signal.

At this time, the signal analysis algorithm is performed by a field programmable gate array (FPGA), but the present invention is not limited thereto.

On the other hand, Figure 4 is an exemplary view showing the design / fabrication of the detection analysis unit 300 of the partial discharge diagnostic device (A) using the inlet transformer diagnostic method according to the present invention.

Hereinafter, referring to FIG. 5, the experimental results of the partial discharge diagnosis apparatus A using the inflow transformer diagnosis method according to the present invention will be described below.

The experiment was performed to check the signal detection capability and performance of the AE sensor unit 100, and was performed according to the 'Pencil Lead Break' technique, which is a signal generation method for signal calibration for AE measurement.

First, an acoustic signal input through the AE sensor unit 100 is converted into an electrical signal through the signal converter 200.

Then, the converted electric signal is downloaded to a PC and the waveform of the signal of the general AE sensor (FIG. 5A) and the waveform of the signal detected from the AE sensor unit 100 of the present invention (FIG. 5B). ) Was compared.

As a result of the comparison, it was confirmed that the signal waveform of the general AE sensor is similar to the signal waveform detected from the AE sensor unit 100 of the present invention.

Hereinafter, a partial discharge diagnosis method using the inlet transformer diagnosis method according to the present invention will be described with reference to FIG. 6.

First, the AE sensor unit 100 is installed on the transformer outer wall of the switchgear to detect a sound signal of 20kHz to 40kHz inside the transformer (S10).

Subsequently, the signal conversion unit 200 converts the sound signal received from the AE sensor unit 100 into an electric signal (S20).

Then, the detection analyzer 300 measures whether the partial discharge is generated from the electric signal applied from the signal converter 200, and determines whether the magnitude and pulse count of the electric signal match the measured partial discharge measurement value. (S30).

As a result of the determination in step S30, when the magnitude of the electric signal and the pulse count coincide with the previously measured partial discharge measurement value, the detection analyzer 300 determines that partial discharge has occurred in the inlet transformer inside the switchboard and detects partial discharge. The signal is output (S40).

Hereinafter, referring to FIG. 7, a detailed process of step S20 of the partial discharge diagnosis method using the inflow transformer diagnosis method according to the present invention will be described below.

After the step S10, the signal conversion unit 200 is grounded with the AE sensor unit 100 receives a sound signal (S21).

Then, the signal converter 200 applies an acoustic signal to the piezoelectric vibrator 210, and converts the positive and negative charges generated on both surfaces of the diaphragm of the piezoelectric vibrator 210 into electric signals (S22). ).

At this time, the piezoelectric vibrator 210 is configured of a resonant type of 120kHz.

Hereinafter, referring to FIG. 8, a detailed process of step S30 of the partial discharge diagnosis method using the inflow transformer diagnosis method according to the present invention will be described below.

After operation S20, the detection analyzer 300 filters the noise included in the electrical signal applied from the signal converter 200 to the bandwidth of 70 kHz to 300 kHz through the analog signal processing module 310 (S31).

Subsequently, the detection analyzing unit 300 amplifies the filtered electrical signal at an amplification rate of 20 dB to 60 dB through the preamplifier 320 (S32).

Subsequently, the detection analyzing unit 300 converts the amplified electric signal into a digital signal at a processing speed of 50 Ms / s in 16 bits through the digital signal processing module 330 (S33).

Then, the detection analyzer 300 extracts the magnitude and pulse count of the digitally converted signal through the signal analysis module 340, and whether the magnitude and pulse count of the extracted signal match the measured partial discharge measurement value. Determine (S34).

As a result of the determination in step S34, when the magnitude and the pulse count of the extracted signal coincide with the previously measured partial discharge measurement value, the detection analyzing unit 300 partially discharges the inlet transformer inside the switchboard through the signal analysis module 340. It is determined that this has occurred and outputs the partial discharge detection signal (S35).

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, 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 invention as defined by the appended claims. It will be appreciated by those skilled in the art that numerous changes and modifications may be made without departing from the invention. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

A: Partial Discharge Diagnosis Device Using Inlet Transformer Diagnosis Technique
100: AE sensor 200: signal conversion unit
210: piezoelectric vibrator 300: detection and analysis unit
310: analog signal processing module 320: preamplifier
330: digital signal processing module 340: signal analysis module

Claims (2)

(A) the AE sensor unit 100 is installed on the transformer outer wall of the switchgear to detect the sound signal of 20kHz to 40kHz inside the transformer;
(b) the signal conversion unit 200 converting the sound signal received from the AE sensor unit 100 into an electrical signal;
(c) the detection analyzing unit 300 measures whether the partial discharge is generated from the electric signal applied from the signal conversion unit 200, and whether the magnitude and pulse count of the electric signal matches the measured partial discharge measurement value. Determining; And
(d) As a result of the determination in step (c), when the magnitude and pulse count of the electric signal coincide with the previously measured partial discharge measurement value, the detection analyzer 300 indicates that partial discharge has occurred in the inlet transformer inside the switchgear. Determining and outputting the partial discharge detection signal;
The step (c)
(c-1) detecting, by the detection analyzer 300, the noise included in the electrical signal applied from the signal converter 200 to a bandwidth of 70 kHz to 300 kHz through the analog signal processing module 310;
(c-2) amplifying the filtered electrical signal at an amplification rate of 20 dB to 60 dB through the preamplifier 320;
(c-3) converting the amplified electric signal into a digital signal at a processing speed of 50 Ms / s in 16 bits through the digital signal processing module 330;
(c-4) The detection analyzer 300 extracts the magnitude and pulse count of the digitally converted signal through the signal analysis module 340, and the magnitude and pulse count of the extracted signal are measured with the partial discharge measurement value. Determining whether or not a match; And
(c-5) As a result of the determination in step (c-4), when the magnitude and pulse count of the extracted signal coincide with the measured partial discharge measurement value, the detection analyzing unit 300 performs a signal analysis module 340. And determining that a partial discharge has occurred in the inlet transformer inside the switchgear and outputting a partial discharge detection signal. The partial discharge diagnosis method using the inflow transformer diagnosis technique comprising: a partial discharge detection signal. The method of claim 1,
The step (b)
(b-1) receiving a sound signal by grounding the signal conversion unit 200 to the AE sensor unit 100; And
(b-2) The signal converter 200 applies an acoustic signal to the piezoelectric vibrator 210 to convert the positive and negative charges generated on both surfaces of the diaphragm of the piezoelectric vibrator 210 into electrical signals. Partial discharge diagnostic method using an inlet transformer diagnostic method comprising a.

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