KR20220089422A - Partial discharge monitoring system and patial discharge monitoring method - Google Patents

Abstract

An embodiment provides a partial discharge system, comprising: a plurality of sensors for detecting a plurality of signals generated inside and outside of a transformer and generating a plurality of detection signals; a signal processing unit that distinguishes a partial discharge signal inside the transformer from a plurality of detection signals, generates a partial discharge pulse signal corresponding to the divided partial discharge signal, and generates a digital signal by using the partial discharge pulse signal; and a diagnostic unit for displaying the degree of partial discharge risk inside the transformer using a digital signal, wherein the plurality of sensors are respectively disposed at different positions in the transformer to generate a plurality of detection signals corresponding to the different positions, The processing unit compares a partial discharge signal generated inside the transformer with a noise signal generated outside the transformer among the plurality of detection signals, and extracts the partial discharge pulse signal according to the comparison result.

Description

Partial discharge monitoring system and partial monitoring method

The embodiment relates to a partial discharge monitoring system and a partial monitoring method, and more particularly, to a partial discharge monitoring system and a partial discharge monitoring method for monitoring partial discharge occurring inside a transformer.

In general, the biggest causes of failure of high-voltage power equipment are insulator defects and equipment aging, accounting for 31% of all failure causes (based on KESCO 2012 data). Since such a fault can be detected through partial discharge, the demand for an online partial discharge monitoring system for a high voltage transformer for power is increasing.

Partial discharge refers to any part of the power equipment system, such as power reception facilities and high-voltage switchgear, high-voltage cables, transformers, GIS (Gas Insulated Switchgear, gas insulated switchgear), switchgear, and power reception facilities installed in various industries and power system substations. As a generic term for generated discharges, corona discharges generated near the tip of an electrode, creepage discharges generated along the surface of an insulator, void discharges generated in voids in an insulator, etc. are mentioned.

It was found that about 20% of electrical equipment accidents with known causes are due to insulation deterioration in Korea. Therefore, it is very important to check the insulation status of electrical equipment on a regular basis in order to prevent accidents.

A conventional technique for checking the health condition of a transformer is a Dissolved Gas Analysis (DGA) method. This method analyzes the gas components generated inside the transformer and identifies the symptoms, and the DGA method can also monitor the partial discharge inside the transformer.

However, the conventional partial discharge monitoring method has a problem in that the partial discharge signal generated in the transformer cannot be accurately detected because the partial discharge signal generated in the transformer cannot be accurately distinguished from the noise around the transformer.

The embodiment is intended to overcome the above-described problems, a partial discharge monitoring system and partial discharge monitoring, capable of accurately monitoring a partial discharge signal generated in a transformer by accurately distinguishing a partial discharge signal generated in the transformer from noise around the transformer to provide a way

In addition, it is to provide a partial discharge monitoring system and a partial discharge monitoring method that can detect only the partial discharge signal generated inside the transformer by distinguishing the partial discharge signal generated inside the transformer from the partial discharge signal generated around the transformer. .

The technical problems to be achieved by the embodiment are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art from the description of the embodiment.

According to an embodiment, there is provided a partial discharge monitoring system, the partial discharge monitoring system comprising: a plurality of sensors for detecting a plurality of signals generated inside and outside of a transformer and generating a plurality of detection signals; a signal processing unit for discriminating a partial discharge signal inside the transformer from the plurality of detection signals, generating a partial discharge pulse signal corresponding to the divided partial discharge signal, and generating a digital signal using the partial discharge pulse signal; and a diagnostic unit for displaying the degree of partial discharge risk inside the transformer using the digital signal, wherein the plurality of sensors are respectively disposed at different positions in the transformer to generate a plurality of detection signals corresponding to the different positions and the signal processing unit compares a partial discharge signal generated inside the transformer with a noise signal generated outside the transformer among the plurality of detection signals, and generates the partial discharge pulse signal according to a comparison result.

In addition, in the partial discharge monitoring system according to the embodiment, the plurality of sensors may include: a first sensor coupled to a drain valve of the transformer to generate a first detection signal using the plurality of detection signals; a second sensor attached to the outside of the transformer to detect a first noise signal generated outside the transformer and generate a second detection signal; and a third sensor configured to sense a ground voltage flowing from the transformer to a ground of the transformer to generate a third detection signal, wherein the first detection signal includes the partial discharge signal, the first detection signal, and the second Includes a sensing signal.

In addition, in the partial discharge monitoring system according to the embodiment, the signal processing unit time-synchronizes the first detection signal, the first detection signal, and the second detection signal, and the second detection in the first detection signal The partial discharge pulse signal is generated by excluding the signal and the third detection signal.

In addition, in the partial discharge monitoring system according to the embodiment, the signal processing unit is further configured to time-synchronize the first detection signal, the first detection signal, and the second detection signal, and the first detection signal and the second detection signal A signal and a third detection signal are generated as a first pulse signal, a second pulse signal, and a third pulse signal, and the first pulse signal, the second pulse signal, and the third pulse signal are respectively gated. .

In addition, in the partial discharge monitoring system according to the embodiment, the signal processing unit further extracts the partial discharge pulse signal by excluding the second pulse signal and the third pulse signal from the first pulse signal, and The comparison result is generated by comparing a first time point at which one pulse signal is generated, a second time point at which the second pulse signal is generated, and a third time point at which the third pulse signal is generated.

In addition, in the partial discharge monitoring system according to the embodiment, the signal processing unit further calculates the first magnitude of the first pulse signal, the second magnitude of the second pulse signal, and the third magnitude of the third pulse signal. generating the comparison result by comparing, extracting the partial discharge pulse signal by excluding the second pulse signal and the third pulse signal from the first pulse signal using the comparison result, and using the partial discharge pulse signal to generate the digital signal.

In addition, in the partial discharge monitoring system according to the embodiment, the diagnosis unit further displays a time point at which the partial discharge occurs and a signal level of the partial discharge using the digital signal.

In addition, when the diagnostic unit of the partial discharge monitoring system according to the embodiment compares the signal level of the partial discharge with a preset first threshold and determines that the signal level of the partial discharge is equal to or less than the first threshold , it is determined that the risk of the partial discharge is the first level.

In addition, in the partial discharge monitoring system according to the embodiment, the diagnosis unit may further compare the signal level of the partial discharge, the first threshold, and a preset second threshold, so that the signal level of the partial discharge is determined to be the first When it is determined that it is between the threshold value and the second threshold value, it is determined that the risk of the partial discharge is a second level, and the first threshold value is smaller than the second threshold value.

In addition, the diagnostic unit of the partial discharge monitoring system according to the embodiment further determines that the risk of the partial discharge is a third level when the signal level of the partial discharge exceeds the second threshold, and the first level , in the order of the second level and the third level, the risk of the partial discharge is high.

The partial discharge monitoring system and partial discharge monitoring method according to the embodiment have an effect of accurately distinguishing a partial discharge signal generated in a transformer and noise around the transformer.

In addition, the partial discharge monitoring system and the partial discharge monitoring method according to the embodiment have the effect of accurately monitoring the partial discharge signal generated in the transformer.

In addition, the partial discharge monitoring system and partial discharge monitoring method according to the embodiment have the effect of distinguishing the partial discharge signal generated inside the transformer and the partial discharge signal generated around the transformer.

In addition, the partial discharge monitoring system and the partial discharge monitoring method according to the embodiment have an effect of detecting only the partial discharge signal generated inside the transformer.

1 is a block diagram showing the configuration of a partial discharge monitoring system according to an embodiment.
2 is a diagram illustrating a position of a sensor unit according to an embodiment.
3A is a graph illustrating a first pulse signal according to an embodiment.
3B is a graph illustrating a second pulse signal according to an embodiment.
3C is a graph illustrating a third pulse signal according to an embodiment.
3D is a partial discharge pulse signal extracted from the partial monitoring system according to the embodiment.
4 is a diagram illustrating a partial discharge signal displayed on a display unit of a diagnosis unit according to an exemplary embodiment.
5 is a diagram illustrating a second sensor according to an embodiment;
6A and 6B are diagrams illustrating a third sensor according to an embodiment.
7 is a flowchart illustrating a method for detecting partial discharge according to an embodiment.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar reference numerals are assigned to the same or similar components, and overlapping descriptions thereof will be omitted. The suffixes "module" and "part" for components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have distinct meanings or roles by themselves. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the present specification is not limited by the accompanying drawings, and all changes included in the spirit and scope of the embodiments; It should be understood to include equivalents and substitutes.

Terms including an ordinal number such as 1st, 2nd, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “comprises” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, a partial discharge monitoring system according to an embodiment will be described with reference to FIGS. 1 to 4 .

1 is a diagram showing the configuration of a partial discharge monitoring system according to an embodiment.

2 is a view showing a position where a sensor of the partial discharge detection system according to the embodiment is attached.

3A is a graph illustrating a first pulse signal according to an embodiment.

3B is a graph illustrating a second pulse signal according to an embodiment.

3C is a graph illustrating a third pulse signal according to an embodiment.

3D is a partial discharge pulse signal corresponding to the partial discharge signal detected by the partial monitoring system according to the embodiment.

4 is a diagram illustrating a partial discharge signal displayed on a display unit of a diagnosis unit according to an exemplary embodiment.

Referring to FIG. 1 , the partial discharge monitoring system according to the embodiment includes a transformer 10 , a sensor unit 20 , a signal processing unit 30 , and a diagnosis unit 40 .

The transformer 10 changes and outputs the voltage value of the input AC voltage or the current value of the input current. The transformer 10 may be a gas insulated transformer or an oil immersed transformer, but the embodiment is not limited thereto. The transformer 10 is formed of a body 11 forming an exterior, and a partial discharge may occur inside the body 11 .

The partial discharge gradually increases in magnitude and number of occurrences as the input voltage of the transformer 10 rises, and disappears after the input voltage reaches the maximum value, and as the polarity of the input voltage changes, the discharge starts again in the negative region. There may be a characteristic that disappears after reaching a maximum value. The partial discharge may be classified into an internal discharge, a surface discharge, a corona discharge, an internal discharge in an electrical tree, and the like. Hereinafter, the partial discharge generated inside the body 11 is referred to as an internal discharge.

The sensor unit 20 includes a first sensor 21 , a second sensor 22 , and a third sensor 23 , respectively disposed at different positions in the transformer 10 , and A plurality of signals generated inside and outside the transformer 10 may be sensed and a plurality of detection signals Sr1 , Sr2 , and Sr3 may be generated. Each of the plurality of detection signals Sr1 , Sr2 , and Sr3 generated by the sensor unit 20 may be a radio frequency signal. For example, the sensor unit 20 detects a partial discharge signal generated inside the transformer 10 and a noise signal generated outside the transformer 10 , and generates a plurality of corresponding detection signals Sr1 , Sr2 , Sr3 . can do.

The first sensor 21 is inserted into the transformer 10 through the drain valve 12 of the transformer 10 to detect an internal signal generated inside the transformer 10 and generate a first detection signal Sr1. can The first detection signal Sr1 includes a partial discharge signal, a noise signal generated outside the transformer 10 and sensed inside the transformer 10 , and a signal corresponding to a ground voltage flowing through the ground G of the transformer 10 . may include The first sensor 21 may be installed during an overhaul period of the transformer 10 . The first sensor 21 may detect a partial discharge signal generated in a band of 100 MHz to 3,000 MHz. The first sensor 21 may be an ultra high frequency (UHF) sensor, and the first detection signal Sr1 may be a UHF signal, but the embodiment is not limited thereto. A plurality of first sensors 21 may be installed in the transformer 10 to detect partial discharge and/or noise.

The second sensor 22 may measure a noise signal generated outside the transformer. That is, the second sensor 22 may be attached to the body 11 of the transformer 10 . The second sensor 22 may be attached to the outer surface and/or the inner surface of the body 11 using magnetic force, but the embodiment is not limited thereto, and the second sensor 22 may be attached to the body 11 . It can be attached in any way as long as it is possible. At least one second sensor 22 may be attached to the body 11 to measure a noise signal.

In addition, the second sensor 22 may detect a change in a minute magnetic field generated in the body 11 and generate a second detection signal Sr2 in response to noise generated according to a change in the sensed magnetic field. The second sensor 22 may be an inductive sensor, but the embodiment is not limited thereto. It may be designed based on a capacitance value formed between the second sensor 22 and the body 11 . The second sensor 22 can be installed even during operation of the transformer 10 . The first sensor 22 may sense a voltage in a band of 3 MHz to 300 MHz, but may mainly sense a ground voltage within 100 MHz. The second sensor 22 may be installed even in a live state of the transformer 10 . The second sensor 22 may be a TEV (Transient Earth Voltage) sensor, and the second detection signal Sr2 may be a VHF signal (very high frequency signal), but the embodiment is not limited thereto. A specific shape of the second sensor 22 will be described later.

The third sensor 23 may measure a noise signal generated outside the transformer 10 . That is, the third sensor 23 is a sensor that detects a ground voltage (discharge signal) flowing to the ground G of the transformer 10 and generates a third detection signal Sr3 corresponding to the sensed ground voltage. The third sensor 23 may be installed on the ground wire gl. In addition, the third sensor 23 may be connected to a connection part (not shown) of a cable connected to the transformer 10 , but the embodiment is not limited thereto.

In addition, the third sensor 23 may include a ferromagnetic material such as ferrite to convert a current signal of a high frequency band into a voltage. The third sensor 23 can be installed even during operation of the transformer 10 . The third sensor 23 may be a High Frequency Current Transformer (HFCT) sensor, and the third detection signal Sr3 may be a VHF signal (very high frequency signal), but the embodiment is not limited thereto. A specific shape of the third sensor 23 will be described later.

The signal processing unit 30 converts a plurality of radio frequency (RF) signals detected by the sensor unit 20 into analog signals, then extracts a pulse signal corresponding to the partial discharge signal, and uses the extracted pulse signal to generate the digital signal Sd. For example, the signal processing unit 30 may convert the first detection signal Sr1 , the second detection signal Sr2 , and the third detection signal Sr3 detected by the sensor unit 20 to a plurality of analog signals Sa1 , respectively. , Sa2, Sa3) and output. The signal processing unit 30 pulses the plurality of analog signals Sa1, Sa2, and Sa3 to time-synchronize them. The signal processing unit 30 may perform comparison analysis by gating each time-synchronized pulse signal. The signal processing unit 30 may extract only the pulse signal corresponding to the partial discharge signal according to the comparison analysis result. The signal processing unit 30 may generate a digital signal Sd by using the extracted pulse signal. That is, the signal processing unit 30 pulse-gates the plurality of detection signals Sr1, Sr2, and Sr3, and then compares and analyzes the plurality of pulses to correspond to the partial discharge signal among the plurality of detection signals Sr1, Sr2, and Sr3. By extracting only the pulse, a digital signal Sd corresponding to the extracted pulse may be generated.

Hereinafter, a specific configuration of the signal processing unit 30 will be described. It includes a first signal processing device 31 , a second signal processing device 32 , a third signal processing device 33 , and a data generating device 34 .

The first signal processing device 31 converts the first detection signal Sr1 detected by the first sensor 21 into a first analog signal Sa1 and outputs the converted signal. Specifically, the first signal processing apparatus 31 may convert the first detection signal Sr1 of the UHF band into the first analog signal Sa1 and output the converted signal.

The second signal processing device 32 converts the second detection signal Sr2 sensed by the second sensor 22 into a second analog signal Sa2 and outputs it. Specifically, the second signal processing apparatus 32 may convert the second detection signal Sr2 of the VHF band into the second analog signal Sa2 and output the converted signal.

The third signal processing device 33 converts the third detection signal Sr3 sensed by the third sensor 23 into a third analog signal Sa3 and outputs it. Specifically, the third signal processing apparatus 33 may convert the third detection signal Sr3 of the VHF band into the third analog signal Sa3 and output the converted signal.

The data generating device 34 samples each of the plurality of analog signals Sa1, Sa2, and Sa3 to obtain a digital signal including Phase Resolved Pulse Sequence (PRPS) data and/or Phase Resolved Partial Discharge (PRPD) data. (Sd) can be created. For example, the data generating device 34 may pulse the first analog signal Sa1 , the second analog signal Sa2 , and the third analog signal Sa3 , respectively, and then time-synchronize them. The data generating device 34 may gate each time-synchronized pulse signal. The data generating apparatus may compare and analyze each gated pulse signal. The data generating device 34 may compare a pulse signal corresponding to a partial discharge signal generated inside the transformer 10 with a pulse signal corresponding to a noise signal generated outside the transformer 10 using the plurality of pulse signals. . The data generating device 34 excludes the pulse signal corresponding to the noise signal generated outside the transformer 10 from the pulse signal corresponding to the first detection signal Sr1 by using the comparison result, thereby Only pulse signals can be extracted. The data generating device 34 may generate a digital signal Sd by using the extracted pulse signal.

The data generating device 34 is included in the main board (MainBoard) of the partial discharge monitoring system 1 and may include an analog-digital converter (ADC), but the embodiment is not limited thereto.

The diagnostic unit 40 may analyze a partial discharge signal trend using the digital signal Sd and display the partial discharge analysis result so as to display the degree of risk of partial discharge. A detailed method for the diagnosis unit 40 to display the partial discharge analysis result using the digital signal Sd will be described later.

The partial discharge analysis of the diagnostic unit 40 may be performed in a computer program stored in a server, but the embodiment is not limited thereto.

Hereinafter, a specific method of extracting only the noise signal from the partial discharge signal in the data generating device 34 will be described with reference to FIGS. 3A to 3D .

3A is a graph illustrating a first pulse signal according to an embodiment.

3B is a graph illustrating a second pulse signal according to an embodiment.

3C is a graph illustrating a third pulse signal according to an embodiment.

3D is a partial discharge pulse signal extracted from the partial monitoring system according to the embodiment.

Referring to FIG. 3A , the data generating apparatus 34 time-synchronizes the first analog signal Sa1 in a plurality of sections P1 , P2 , and P3 and generates a pulse signal Sp.

The pulse signal Sp includes a first pulse signal Sp1 , a second pulse signal Sp2 , and a third pulse signal Sp3 .

In detail, the data generating device 34 generates a first pulse signal Sp1 at a first time point T1 by using the first analog signal Sa1 in a first period P1 and a second time point T2 . ), the second pulse signal Sp2 may be generated, and the third pulse signal Sp3 may be generated at the third time point T3 . Also, the data generating device 34 generates the first pulse signal Sp1 at the fourth time point T4 by using the first analog signal Sa1 in the second period P2 and at the fifth time point T5 . may generate the second pulse signal Sp2 and generate the third pulse signal Sp3 at the sixth time point T6. Also, the data generating device 34 generates the first pulse signal Sp1 at the seventh time point T7 by using the first analog signal Sa1 in the third period P3 and at the eighth time point T8 . may generate the second pulse signal Sp2 and generate the third pulse signal Sp3 at the ninth time point T9.

Referring to FIG. 3B , the data generating apparatus 34 time-synchronizes the second analog signal Sa2 in a plurality of sections P1 , P2 and P3 and generates a pulse signal Sp. The pulse signal Sp includes the first pulse signal Sp1.

Specifically, the data generating apparatus 34 may generate the first pulse signal Sp1 at the first time point T1 by using the second analog signal Sa2 in the first period P1 . Also, the data generator 34 may generate the first pulse signal Sp1 at the fourth time point T4 by using the second analog signal Sa2 in the second period P2 . Also, the data generator 34 may generate the first pulse signal Sp1 at the seventh time point T7 by using the second analog signal Sa2 in the third period P3 .

Referring to FIG. 3C , the data generating apparatus 34 time-synchronizes the third analog signal Sa3 in a plurality of sections P1 , P2 , and P3 and generates a pulse signal Sp. The pulse signal Sp includes a third pulse signal Sp3.

Specifically, the data generating apparatus 34 may generate the third pulse signal Sp3 at the third time point T3 by using the third analog signal Sa2 in the first period P1 . Also, the data generator 34 may generate the third pulse signal Sp1 at the sixth time point T6 by using the third analog signal Sa3 in the second period P2 . Also, the data generator 34 may generate the third pulse signal Sp3 at the ninth time point T9 by using the third analog signal Sa3 in the third period P3 .

Referring to FIG. 3D , the data generating apparatus 34 includes a plurality of pulse signals generated using the first analog signal Sa1 , a plurality of pulse signals generated using the second analog signal Sa2 , and a third A noise signal generated in the transformer 10 may be identified by comparing a plurality of pulse signals generated using the data signal, and only a pulse signal corresponding to the partial discharge signal may be extracted. The data generating device 34 may generate a digital signal Sd by using the extracted pulse signal.

For example, the data generating device 34 recognizes the second pulse signal Sp2 and the third pulse signal Sp3 as pulse signals corresponding to the noise signal of the transformer 10 . Specifically, the data generating device 34 generates the first pulse signal Sp1 and the second pulse signal Sp2 as a pulse corresponding to the noise signal by using the generation time of the pulse signal corresponding to the noise signal and the magnitude of the signal. recognized as a signal. The data generating device 34 generates using the second analog signal Sa2, a first time point T1 that is a generation time of the second pulse signal Sp2, and a magnitude and a first time point T1 of the first pulse signal Sp1. A first time point T1 , which is a generation time point of the first pulse signal Sp1 , generated using the analog signal Sa1 , and magnitudes of the first pulse signal Sp1 are compared, respectively. The data generating device 34 generates a second pulse signal Sp1 generated by using the first analog signal Sa1 that has a generation time and a signal magnitude using the first analog signal Sa1. When it is determined that the generation time of the pulse signal Sp2 and the magnitude of the signal are identical to each other, the second pulse signal Sp2 at the first time point T1 generated using the first analog signal Sa1 is applied to the noise corresponding to the second pulse signal Sp2. It is recognized as a pulse signal.

In addition, the data generating device 34 generates using the second analog signal Sa2, a fourth time point T4 that is a generation time of the second pulse signal Sp2, and the magnitude of the second pulse signal Sp2 and The magnitude of the second pulse signal Sp2 is compared with the fourth time point T4 , which is the generation time of the second pulse signal Sp2 , generated using the first analog signal Sa1 , respectively. The data generating device 34 is configured to generate a second pulse signal Sp2 generated using the second analog signal Sa2 at a generation time point and signal level using the first analog signal Sa1. When it is determined that the generation time of the pulse signal Sp2 and the magnitude of the signal are the same, the second pulse signal Sp2 of the fourth time point T4 generated using the first analog signal Sa1 is applied to the noise corresponding to the signal. It is recognized as a pulse signal.

In addition, the data generating device 34 generates a seventh time T7 which is a generation time of the second pulse signal Sp2 generated by using the second analog signal Sa2, and a magnitude and a second pulse signal Sp2. A seventh time point T7 , which is a generation time point of the second pulse signal Sp2 generated using the first analog signal Sa1 , and magnitudes of the second pulse signal Sp2 are compared, respectively. The data generating device 34 is configured to generate a second pulse signal Sp2 generated using the second analog signal Sa2 at a generation time point and signal level using the first analog signal Sa1. When it is determined that the generation time of the pulse signal Sp2 and the magnitude of the signal are equal to each other, the second pulse signal Sp2 at the seventh time point T7 generated using the first analog signal Sa1 is applied to the noise. It is recognized as a pulse signal.

In this way, the data generating device 34 generates the third pulse signal Sp3 generated by using the third analog signal Sa3 at the generation times T3, T6, and T9 and the third pulse signal Sp2. The magnitude and the magnitude of the third pulse signal Sp3 are compared with the generation time points T3, T6, and T9 of the third pulse signal Sp2 generated using the first analog signal Sa1. The data generating device 34 generates the third pulse signal Sp3 generated by using the third analog signal Sa3 at generation times T3, T6, and T9, the magnitude of the third pulse signal Sp2, and the first analog signal. It is determined that the generation time points T3, T6, T9 of the third pulse signal Sp2 generated using the signal Sa1 and the magnitude of the third pulse signal Sp3 are the same, respectively, and the first analog signal Sa1 The third pulse signal Sp2 generated by using ? is recognized as a pulse signal corresponding to noise.

Also, referring to FIG. 3D , the data generating device 34 recognizes the second pulse signal Sp2 as a pulse signal due to internal discharge. The data generating device 34 generates a signal corresponding to noise among the first pulse signal Sp1 , the second pulse signal Sp2 , and the third pulse signal Sp2 generated using the first analog signal Sa1 . Data D including only the second pulse signal Sp2 may be generated by removing the first pulse signal Sp1 and the third pulse signal Sp3 . The data D may include PRPS data and/or PRPD data.

Specifically, the data generating apparatus 34 may calculate PRPS data by allocating the phase, magnitude, and period of the second pulse signal Sp2 . Also, the data generating device 34 may calculate the PRPD data by allocating the phase, magnitude, and frequency of the second pulse signal Sp2 .

Hereinafter, a method of displaying a partial discharge analysis result by using the digital signal Sd in the diagnosis unit 40 will be described with reference to FIG. 4 .

4 is a diagram illustrating a partial discharge signal displayed on a display unit of a diagnosis unit according to an exemplary embodiment.

Referring to FIG. 4 , the diagnosis unit 40 may monitor an event in which partial discharge occurs by using a digital signal Sd and analyze and diagnose the partial discharge. The diagnosis unit 40 may display the generation time of the partial discharge signal Spd and the magnitude of the partial discharge signal. The diagnosis unit 40 uses the diagnosis result of the partial discharge to allow the user to visually detect the inside of the transformer 10 . The frequency and size of partial discharge can be displayed so that they can be distinguished intuitively.

For example, when it is determined that the level of the partial discharge signal Spd is less than or equal to the preset first threshold Th1, the diagnosis unit 40 determines that the risk of partial discharge is low and It is possible to display a color as a first color (eg, green) and continuously monitor whether partial discharge occurs.

Also, when it is determined that the level of the partial discharge signal Spd is equal to or greater than the preset first threshold value Th1 or greater than or equal to the preset second threshold value Th2 or less, the diagnostic unit 40 determines that the risk of partial discharge is medium. Then, the color of the partial discharge signal Spd may be displayed as a second color (eg, orange), and the occurrence of partial discharge may be continuously monitored.

Also, when it is determined that the level of the partial discharge signal Spd exceeds a preset third threshold value Th3, the diagnostic unit 40 determines that the risk of partial discharge is high and A color may be displayed as a third color (eg, red) and an alarm may be issued to the user. The alarm may be a warning sound or a warning phrase (eg, “requires analysis immediately after partial discharge”), but the embodiment is not limited thereto.

Hereinafter, a specific shape of the first sensor according to the embodiment will be described with reference to FIG. 5 .

5 is a diagram illustrating a first sensor according to an embodiment.

Referring to FIG. 5 , the first sensor 21 according to the embodiment includes a sensor body 211 , a connection unit 212 , a measurement unit 213 , and a transmission unit 214 . The first sensor 21 is to be coupled with the valve 12 through the connection unit 212 so that the measuring unit 213 is inserted into the transformer 10 to measure the partial discharge generated inside the transformer 10 . can

The connection part 212 may be coupled to the valve 12 with a bolt fastening structure, but the embodiment is not limited thereto. ) may be coupled to the valve 12 .

An antenna Atn capable of detecting a partial discharge may be disposed at an end of the measurement unit 213 .

The transmitter 214 may transmit a signal measured from the antenna Atn to the signal processor 30 . A method for the transmitter 214 to transmit the measurement signal to the signal processor 30 may be wired and/or wireless, but the embodiment is not limited thereto.

Hereinafter, a specific shape of the third sensor according to the embodiment will be described with reference to FIGS. 6A and 6B .

6A and 6B are diagrams illustrating a third sensor according to an embodiment.

6A and 6B , the third sensor 23 includes a first body 231 , a second body 232 , a connecting hinge 235 , a locking part 233 , and a terminal 234 . .

The first body 231 and the second body 232 have one end connected to each other through a connection hinge 235, and the end of the first body 231 and the end of the second body 232 are aligned with each other. It is designed to be reached.

The third sensor 23 may sense a ground voltage flowing through the ground line gl while surrounding the outside of the ground line gl and generate a third detection signal Sr3 corresponding to the sensed ground voltage.

The first body 231 and the first body 231 so that the end of the first body 231 and the end of the second body 232 are in contact with each other through the locking part 233 and surround the outside of the ground wire gl can be fixed. The locking part 233 may have a clip shape including a protrusion 2332 and a clasp 2331 , but the embodiment is not limited thereto.

The third detection signal Sr3 may be transmitted to the signal processing unit 30 through the terminal 234 . The third detection signal Sr3 may be transmitted to the signal processing unit 30 in a wired and/or wireless manner, but the embodiment is not limited thereto.

Hereinafter, a partial discharge signal monitoring method according to an embodiment will be described with reference to FIG. 7 .

7 is a flowchart illustrating a partial discharge monitoring method according to an embodiment.

Referring to FIG. 7 , in step Sr10 , the first sensor 21 is inserted into the transformer 10 through the drain valve 12 of the transformer 10 to generate partial discharge ( Hereinafter, a partial discharge is sensed and a first detection signal Sr1 corresponding to the sensed partial discharge is generated. The second sensor 22 may measure a noise signal generated outside the transformer. That is, the second sensor 22 detects a change in the minute magnetic field generated in the body 11 and generates a second detection signal Sr2 corresponding to noise corresponding to the detected change in the magnetic field. The third sensor 23 senses a ground voltage flowing to the ground G of the transformer 10 and generates a third detection signal Sr3 corresponding to the sensed ground voltage.

In step S20 , the signal processing unit 30 may convert the plurality of RF signals detected by the sensor unit 20 into analog signals. For example, the signal processing unit 30 may convert the first detection signal Sr1 , the second detection signal Sr2 , and the third detection signal Sr3 detected by the sensor unit 20 to a plurality of analog signals Sa1 , respectively. , Sa2, Sa3) and output it.

Specifically, the first signal processing device 31 converts the first detection signal Sr1 sensed by the first sensor 21 into the first analog signal Sa1 and outputs it. The second signal processing device 32 converts the second detection signal Sr2 sensed by the second sensor 22 into a second analog signal Sa2 and outputs it. The third signal processing device 33 converts the third detection signal Sr3 sensed by the third sensor 23 into a third analog signal Sa3 and outputs it.

In step S30, the signal processing unit 30 may time-synchronize the plurality of analog signals Sa1, Sa2, and Sa3 and compare and analyze each gated pulse signal by gating each time-synchronized pulse signal. .

Specifically, the data generating device 34 generates a plurality of pulse signals generated using the first analog signal Sa1, a plurality of pulse signals generated using the second analog signal Sa2, and a third data signal. A plurality of pulse signals generated using

For example, as described with reference to FIG. 3D , the generating device 34 generates the second pulse signal Sp2 generated using the second analog signal Sa2 at the seventh time point T7 and the second pulse signal Sp2 . The magnitude of the second pulse signal Sp2 and the magnitude of the second pulse signal Sp2 and the seventh time T7 which are the generation times of the second pulse signal Sp2 generated using the first analog signal Sa1 are respectively Compare.

In step S40 , the signal processing unit 30 extracts only a pulse signal corresponding to the partial discharge signal using the plurality of pulse signals. The signal processing unit 30 generates a digital signal Sd by using a pulse signal corresponding to the partial discharge signal. Specifically, the data generating device 34 samples each of the plurality of analog signals Sa1, Sa2, and Sa3 to include phase resolved pulse sequence (PRPS) data and/or phase resolved partial discharge (PRPD) data. A digital signal Sd may be generated. For example, the data generating device 34 pulses and time-synchronizes the plurality of analog signals Sa1, Sa2, and Sa3. The data generating device 34 may perform comparison analysis by gating each time-synchronized pulse signal. The data generating device 34 compares a pulse signal corresponding to a partial discharge signal generated inside the transformer 10 with a pulse signal corresponding to a noise signal generated outside the transformer 10 using a plurality of pulse signals, Based on the comparison result, only the pulse signal corresponding to the partial discharge signal may be extracted.

In operation S50 , the data generating device 34 may generate a digital signal Sd using a pulse signal corresponding to the partial discharge signal.

In step S60 , the diagnosis unit 40 analyzes the partial discharge signal trend using the digital signal Sd so that the partial discharge signal risk is displayed and displays the partial discharge analysis result. For example, when it is determined that the level of the partial discharge signal Spd is less than or equal to the preset first threshold Th1, the diagnosis unit 40 determines that the risk of partial discharge is low and It is possible to display a color as a first color (eg, green) and continuously monitor whether partial discharge occurs.

Also, when it is determined that the level of the partial discharge signal Spd is equal to or greater than the preset first threshold value Th1 or greater than or equal to the preset second threshold value Th2 or less, the diagnostic unit 40 determines that the risk of partial discharge is medium. Then, the color of the partial discharge signal Spd may be displayed as a second color (eg, orange), and the occurrence of partial discharge may be continuously monitored.

Also, when it is determined that the level of the partial discharge signal Spd exceeds a preset third threshold value Th3, the diagnostic unit 40 determines that the risk of partial discharge is high and A color may be displayed as a third color (eg, red) and an alarm may be issued to the user. The alarm may be a warning sound or a warning phrase (eg, “requires analysis immediately after partial discharge”), but the embodiment is not limited thereto.

For convenience of explanation, an example in which the partial discharge monitoring system 1 is applied to the transformer 10 has been described, but the embodiment is not limited thereto, and GIS (Gas-Insulated Switch gear), Cable Compartment, Bushing, Partial discharge can be detected by being mounted on a high-voltage or medium-voltage device that requires partial discharge detection, such as a power distribution panel.

Although the embodiment of the embodiment has been described in detail above, the scope of the embodiment is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the embodiment as defined in the claims below are also included in the scope of the embodiment. will be.

Accordingly, the foregoing detailed description should not be construed as limiting in all respects but should be considered as illustrative. The scope of the embodiments should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the embodiments are included in the scope of the embodiments.

10: transformer
20: sensor unit
21: first sensor
22: second sensor
23: third sensor
30: signal processing unit
31: first signal processing device
32: second signal processing device
33: third signal processing device
34: data generating device
40: diagnostic unit

Claims (10)

a plurality of sensors for detecting a plurality of signals generated inside and outside the transformer and generating a plurality of detection signals;
a signal processing unit for discriminating a partial discharge signal inside the transformer from the plurality of detection signals, generating a partial discharge pulse signal corresponding to the divided partial discharge signal, and generating a digital signal using the partial discharge pulse signal; and
and a diagnostic unit for displaying the risk of partial discharge inside the transformer using the digital signal,
The plurality of sensors are respectively disposed at different positions in the transformer to generate a plurality of detection signals corresponding to the different positions,
The signal processing unit compares a partial discharge signal generated inside the transformer with a noise signal generated outside the transformer among the plurality of detection signals, and generates the partial discharge pulse signal according to a comparison result. surveillance system. According to claim 1,
The plurality of sensors,
a first sensor coupled to the drain valve of the transformer and configured to generate a first detection signal using the plurality of detection signals;
a second sensor attached to the outside of the transformer to detect a first noise signal generated outside the transformer and generate a second detection signal; and
A third sensor for generating a third detection signal by sensing a ground voltage flowing from the transformer to the ground of the transformer
including,
The first detection signal includes the partial discharge signal, the first detection signal, and the second detection signal. 3. The method of claim 2,
The signal processing unit,
The first detection signal, the first detection signal, and the second detection signal are time-synchronized, and the partial discharge pulse signal is generated by excluding the second detection signal and the third detection signal from the first detection signal which, partial discharge detection system. 4. The method of claim 3,
The signal processing unit further,
The first detection signal, the first detection signal, and the second detection signal are time-synchronized, and the first detection signal, the second detection signal, and the third detection signal are combined with a first pulse signal, a second pulse signal, and a second detection signal. A partial discharge detection system for generating a three-pulse signal and gating the first pulse signal, the second pulse signal, and the third pulse signal, respectively. 5. The method of claim 4,
The signal processing unit further,
extracting the partial discharge pulse signal by excluding the second pulse signal and the third pulse signal from the first pulse signal;
and generating the comparison result by comparing a first time point at which the first pulse signal is generated, a second time point at which the second pulse signal is generated, and a third time point at which the third pulse signal is generated. 6. The method of claim 5,
The signal processing unit further,
The comparison result is generated by comparing the first magnitude of the first pulse signal, the second magnitude of the second pulse signal, and the third magnitude of the third pulse signal, and using the comparison result, a first pulse signal extracting the partial discharge pulse signal by excluding the second pulse signal and the third pulse signal, and generating the digital signal by using the partial discharge pulse signal. 7. The method of claim 6,
The diagnostic unit additionally,
A partial discharge system for displaying a time point at which the partial discharge occurs and a signal level of the partial discharge by using the digital signal. 8. The method of claim 7,
The diagnostic unit additionally,
Comparing the signal level of the partial discharge with a preset first threshold and determining that the signal level of the partial discharge is equal to or less than the first threshold, determining that the risk of the partial discharge is the first level . 9. The method of claim 8,
The diagnostic unit additionally,
When it is determined that the signal level of the partial discharge is between the first threshold and the second threshold by comparing the signal level of the partial discharge with the first threshold value and the second preset threshold, the risk of the partial discharge is Determined to be the second level,
wherein the first threshold is less than the second threshold. 10. The method of claim 9,
The diagnostic unit additionally,
When the signal level of the partial discharge exceeds the second threshold, it is determined that the risk of the partial discharge is a third level;
The partial discharge system, wherein the risk of the partial discharge is high in the order of the first level, the second level, and the third level.

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