KR101456137B1 - High voltage distributing board, low voltage distributing board, motor contorl board, distributing board for detecting arc or corona discharge using transient earth voltage signal - Google Patents

Abstract

Disclosed are a distributing board for detecting arc and corona discharge by using a surge ground voltage signal (a high-tension panel, a low-tension panel, a motor control board, and a panel board). The present invention comprises a surge ground voltage sensor module which is attached to the outside of a metal housing and senses surge ground voltage according to surface currents generated in the metal housing by using electromagnetic waves generated by the inner discharge, the corona discharge, and the arc discharge of the metal housing and a discharge detection module which detects the arc or corona discharge by using the surge ground voltage sensed in the surge ground voltage sensor module. The present invention is provided to sense the surge ground voltage generated by the arc or corona discharge by using the high-tension panel, the low-tension panel, the motor control board, and the panel board sensing the surge ground voltage, thereby indirectly sensing the generation of the arc or corona discharge which causes fire or explosion and handling danger.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage, low-voltage, motor control panel, and a distribution board for detecting an arc and a corona discharge using an excessive ground voltage signal. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high- USING TRANSIENT EARTH VOLTAGE SIGNAL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric distribution board (a high-voltage unit, a low-voltage unit, a motor control panel, and a distribution board) Distribution board).

The switchgear is one of the electric power facilities, which consists of monitoring and control devices such as relays, instruments, and controllers, and main circuit devices such as breakers and disconnecting switches. Each unit device is mounted on the support structure for easy maintenance and repair.

However, if a problem arises in insulation and circuit durability because a high voltage is formed in the switchgear and a current flows, there is a possibility of leading to a serious accident.

Arc and corona discharges are the main causes of accidents, which can lead to fire or explosion.

The arc or corona discharge is discharged through a gap or a joint of a metal clad, which is a housing of a switchgear. A transient earth voltage (TEV) is applied to the metal clad by an arc or a corona discharge. When this occurs between the metal clad and ground, the ground voltage changes instantly and temporarily.

Therefore, sensing this transient ground voltage results in the indirect sensing of arc or corona discharges, and the main cause of the risk can be an important means of recognizing the risk of an arc or corona.

However, in the past, there has been no example in which such excessive ground voltage is detected and utilized as a means of detecting a danger.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric distribution board (high-voltage unit, low-voltage unit, motor control unit, distribution board) for detecting an arc and a corona discharge using an excessive ground voltage signal.

(High voltage, low voltage, motor control panel, and distribution board) for detecting arc and corona discharge using the transient ground voltage signal according to the object of the present invention is attached to the outer surface of the metal housing, A transient earth voltage sensor module for sensing a transient ground voltage according to a surface current generated in the metal housing by an electromagnetic wave generated by a discharge, a corona discharge, and an arc discharge; And a discharge detection module for detecting an arc discharge or a corona discharge using the transient ground voltage sensed by the transient ground voltage sensor module.

Here, the transient ground voltage sensor module may be provided on the outer surface of the metal housing by a predetermined distance.

The transient ground voltage sensor module includes: a transient ground voltage detection sensor for accumulating and sensing the transient ground voltage; A coupling network for detecting and transmitting a transient ground voltage accumulated in the transient ground voltage detecting sensor; And a low-noise amplifier circuit for amplifying the transient ground voltage transmitted by the coupling network and transmitting the amplified transient ground voltage to the discharge detection module.

Here, the transient ground voltage detection sensor may be a detection electrode composed of a copper plate having a diameter of 105 mm and a thickness of 0.5 mm; A ground electrode composed of a copper plate having a diameter of 105 mm and a thickness of 0.5 mm; A dielectric inserted between the detection electrode and the ground electrode and made of an epoxy resin having a thickness of 0.5 mm; And a BNC connection terminal coupled with the detection electrode protrusion protruding from the center of the detection electrode through the dielectric and the ground electrode.

The detection electrode and the ground electrode may be composed of a flame retardant epoxy resin at the edges so as not to cause electric field concentration.

The low-noise amplifying circuit may be a low-noise amplifying circuit that amplifies the transient ground voltage transmitted by the coupling network and transmits the amplified transient grounding voltage to the discharge detecting module through a coaxial cable having a characteristic impedance of 50 Ω.

On the other hand, the coupling network includes a composite impedance Rm including a matching resistance Rm of 50 Ω and a compensation resistance Ri, which is equal to the characteristic impedance of the coaxial cable, to eliminate signal distortion due to capacitance caused by the insulator and outer conductor of the coaxial cable Av. ≪ / RTI >

여기서, Rm은 검출 임피던스, fc는 차단 주파수이며, 상기 임피던스 Zs는 다음의 수학식으로 구성되고, [수학식]

여기서, Ld는 유도성 검출 임피던스, Ri는 상기 저잡음 증폭 회로의 입력 임피던스로 구성될 수 있다.Here, the combined impedance Av is formed by the following equation,

Here, Rm is the detection impedance, fc is the cutoff frequency, and the impedance Zs is expressed by the following equation,

Here, Ld may be an inductive detection impedance, and Ri may be an input impedance of the low-noise amplifying circuit.

여기서, S는 유효 검출 면적, Rm은 저항성 검출 임피던스로 구성될 수 있다.On the other hand, the output voltage of the coupling network is expressed by the following equation,

Where S is the effective detection area and Rm is the resistive detection impedance.

The cut-off frequency fc may be 100 kHz.

According to the above-described switchboard (high-voltage, low-voltage, motor control, and distribution board) that detects arc and corona discharge using the transient ground voltage signal, it is configured to detect the transient ground voltage caused by arc discharge or corona discharge, It indirectly recognizes occurrence of an arc discharge or a corona discharge which may lead to a secondary accident such as a fire or an explosion, and can immediately cope with the danger.

FIGS. 1A and 1B are actual layouts of an ASSEMBLY that detects an arc and a corona discharge using a transient ground voltage signal according to an embodiment of the present invention. FIG.
1C is a block diagram of an ASSEMBLY that detects an arc and a corona discharge using a transient ground voltage signal according to an embodiment of the present invention.
2A is a front view of a transient ground voltage detection sensor according to an embodiment of the present invention.
2B is a rear view of a transient ground voltage detection sensor according to an embodiment of the present invention.
2C is a side view of the transient ground voltage detection sensor according to an embodiment of the present invention.
FIG. 2D is a conceptual diagram showing the detection principle of the transient ground voltage detection sensor according to an embodiment of the present invention. FIG.
2E is a Norton equivalent circuit of the transient ground voltage detection sensor according to an embodiment of the present invention.
3 is an equivalent circuit of a coupling network according to an embodiment of the present invention.
4 is a cut-off frequency graph of a coupling network according to an embodiment of the present invention.
5 is a frequency response graph of a coupling network according to an embodiment of the present invention.
6A is a circuit diagram of a low noise amplifier circuit according to an embodiment of the present invention.
6B is a frequency response graph of a low noise amplifier circuit according to an embodiment of the present invention.
7 is a graph of the response of the detected transient ground voltage according to an embodiment of the present invention.
FIG. 8 is a graph showing a magnitude variation of a detected transient ground voltage according to an embodiment of the present invention. FIG.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail to the concrete inventive concept.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, .

On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1A and 1B are actual layouts of an AC and corona discharge detection circuit using an over-ground voltage signal according to an exemplary embodiment of the present invention. FIG. 1C is a schematic diagram of an over-ground voltage signal according to an exemplary embodiment of the present invention. Fig. 2 is a block diagram of an electric distribution board for detecting an arc and a corona discharge.

1A through 1C, an electric distribution board 100 for detecting an arc and a corona discharge using a transient ground voltage signal according to an embodiment of the present invention includes a high voltage side, a low voltage side, a motor control side, .
The switchboard 100 may be configured to include the transient ground voltage sensor module 110 and the discharge detection module 120.

The switchboard 100 is configured to sense an excessive ground voltage which is caused by arc discharge generated therein or high frequency leaking out by a corona discharge.

As shown in FIG. 1B, the transient ground voltage sensor module 110 may be attached to the outer surface of the switchboard panel 200, and the discharge detection module 120 may be remotely connected thereto.

Here, the transient ground voltage sensor module 110 may be attached to the bus bar connecting portion, the bushing connecting portion, the switchgear, the breaker terminal block, etc., in addition to the switchboard panel 200.

The switchboard 100 can recognize the occurrence of an arc discharge or a corona discharge by detecting the excessive ground voltage, and can immediately take measures against it.

Hereinafter, the detailed configuration will be described.

The transient ground voltage sensor module 110 is configured to be attached to the outer surface of the metal housing. The transient ground voltage sensor module 110 includes a transient grounding voltage sensor module 110 according to the surface current generated in the metal housing by electromagnetic waves generated by internal discharge, corona discharge, And is configured to sense a voltage.

Here, the metal housing is connected to ground.

Corona discharges and arc discharges occur for a very short period of time, and the resulting high frequency is also released in a short time, and the occurrence of transient ground voltage also occurs in a very short time.

Here, since the transient earth voltage generated over a very short time has a large time delay, it is preferable that a large number of transient ground voltage sensor modules 110 are disposed in order to effectively detect the transient earth voltage.

Accordingly, it is preferable that the transient ground voltage sensor module 110 is provided on the outer surface of the metal housing by a predetermined distance.

Meanwhile, the transient ground voltage sensor module 110 may be configured to include an excessive ground voltage detection sensor 111, a coupling network 112, and a low noise amplification circuit 113.

The transient ground voltage detection sensor 111 may be configured to accumulate and sense the transient ground voltage. That is, the excessive ground voltage is temporarily accumulated by the capacitive element and is sensed.

The coupling network 112 may be configured to detect and transmit the transient ground voltage accumulated in the transient ground voltage detection sensor 111. [ The coupling network is configured to match the impedance with the transient ground voltage detection sensor 111 and the low noise amplification circuit 113.

The low noise amplifying circuit 113 may be configured to amplify the transient ground voltage transmitted by the coupling network 112 and transmit it to the discharge detection module 120.

The discharge detection module 120 is configured to detect an arc discharge or a corona discharge using the transient ground voltage sensed by the transient ground voltage sensor module 110.

The discharge detection module 120 may be provided at a remote place from the main body of the switchgear 100 and may be provided in a monitor room that can be checked by the user at any time.

More specifically, the discharge detection module 120 is configured to remove and average noise of the electric field intensity data sensed by the transient ground voltage sensor module 110. Preferably, the background noise is measured in a power-off state. Preferably, the background noise is acquired and averaged periodically once a day or once a month in advance.

The discharge detection module 120 then calculates the difference between the averaged field strength data and the previously averaged background noise to obtain accurate arc discharge and corona discharge.

Then, the discharge detection module 120 calculates field strength data for each frequency band from which noises have been removed by the previously calculated difference. Then, the electric discharge intensity and discharge type are determined and displayed using the electric field intensity data for each frequency band calculated above.

Here, whether or not a discharge is generated and whether a discharge has occurred can be determined by determining whether the discharge is a corona discharge or an arc discharge. Specifically, when electric field intensity data occurs at 10 MHz to 100 MHz and peak value occurs at 18 MHz ± 2 MHz, arc discharge is judged. When electric field strength data occurs at 10 MHz to 250 MHz and peak value is 15 MHz To < RTI ID = 0.0 > 60 MHz. ≪ / RTI > Data on such frequency spectra or peak values are obtained experimentally and can be used to determine the type of discharge. In another method, it is determined whether or not a pulse of the electric field intensity data is generated every 100 ms. If the pulse is not generated, it is determined that no discharge has occurred. If the pulse occurs over three cycles in units of predetermined time, It can be determined that an arc discharge has occurred when the pulse is generated one time.

The above two methods may be used either alone or in combination.

Next, the discharge detection module 120 removes the noise of the electric field intensity data detected before and averages it (S103).

Next, the discharge detection module 120 receives the background noise and averages the input background noise (S104). Preferably, the background noise is measured while the power is off. Preferably, the background noise is acquired and averaged periodically once a day or once a month in advance.

Next, the discharge detection module 120 calculates the difference between the averaged field intensity data and the previously averaged background noise (S105). This is to obtain accurate arc discharge and corona discharge.

Next, the discharge detection module 120 calculates the field intensity data for each frequency band from which noise has been removed by the previously calculated difference (S106).

Next, the discharge detection module 120 determines the discharge status and the discharge type using the calculated electric field intensity data for each frequency band, and displays the result (S107).

Here, whether or not a discharge is generated and whether a discharge has occurred can be determined by determining whether the discharge is a corona discharge or an arc discharge.

Specifically, when electric field intensity data occurs at 10 MHz to 100 MHz and peak value occurs at 18 MHz ± 2 MHz, arc discharge is judged. When electric field strength data occurs at 10 MHz to 250 MHz and peak value is 15 MHz To < RTI ID = 0.0 > 60 MHz. ≪ / RTI >

Data on such frequency spectra or peak values are obtained experimentally and can be used to determine the type of discharge.

In another method, it is determined whether or not a pulse of the electric field intensity data is generated every 100 ms. If the pulse is not generated, it is determined that no discharge has occurred. If the pulse occurs over three cycles in units of predetermined time, It can be determined that an arc discharge has occurred when the pulse is generated one time.

FIG. 2A is a front view of a transient ground voltage detecting sensor according to an embodiment of the present invention, FIG. 2B is a rear view of a transient ground voltage detecting sensor according to an embodiment of the present invention, FIG. FIG. 2 is a side view of an overvoltage detection sensor according to an embodiment of the present invention; FIG.

2A to 2C, the transient ground voltage detecting sensor 111 may include a detecting electrode 111a, a ground electrode 111b, a dielectric 111c, and a BNC connecting terminal 111d.

The detection electrode 111a may be formed of a circular copper plate and may have a diameter of 105 mm and a thickness of 0.5 mm.

The ground electrode 111b may be composed of a circular copper plate, and may have a diameter of 105 mm and a thickness of 0.5 mm.

The dielectric 111c is inserted between the detecting electrode 111a and the ground electrode 111b and can be composed of an epoxy resin having a thickness of 0.5 mm.

That is, the detection electrode 111a and the ground electrode 111b are bonded to both ends of the dielectric 111c.

The BNC connection terminal 111d may be configured to be coupled with the detection electrode protrusion protruding through the dielectric 111c and the ground electrode 111b from the center of the detection electrode 111a.

The detection signal of the transient ground voltage detection sensor 111 is detected through the BNC connection terminal 111d.

Here, the frequency band detected by the transient ground voltage detection sensor 111 is 150 kHz to 16 MHz.

FIG. 2D is a conceptual diagram showing the principle of detection of the transient ground voltage detection sensor according to an embodiment of the present invention, and FIG. 2E is a Norton equivalent circuit of the transient ground voltage detection sensor according to an embodiment of the present invention.

The principle of transient ground voltage detection will be described with reference to FIGS. 2D and 2E.

First, the total current detected by the transient ground voltage detection sensor 111 is expressed by the following equation (1).

Equation (2) can be derived from Equation (1).

Here, the unknown voltage V (t) calculated by Equation (2) depends on the magnitude of the input impedance Z _o of the amplifier as follows. Assuming that the input impedance of the amplifier is 50 OMEGA, and the first term of the right side term in Equation 2 is much smaller than the second term and is neglected, the unknown voltage V (t) to be measured can be approximated as shown in Equation (3).

Here, the magnitude of the sensing voltage V (t) is determined by the area S of the transient ground voltage detection sensor 111 and is sampled by the amount of incident displacement current. In this case, the sensed voltage V (t) of the transient ground voltage detection sensor 111 is proportional to a sub-fraction of the time of the full-speed density.

3 is an equivalent circuit of a coupling network according to an embodiment of the present invention.

3, in order to eliminate signal distortion due to capacitance caused by the insulator and the external conductor of the coaxial cable connecting the low noise amplifier circuit 113 and the discharge detection module 120, a characteristic impedance of 50 Ω Lt; RTI ID = 0.0 > Rm < / RTI > and the compensation resistance Ri.

Here, the composite impedance Av can be expressed by the following equation (4).

Here, Rm is the detection impedance, fc is the cutoff frequency, and the impedance Zs may be expressed by the following equation (5).

Here, Ld is the inductive detection impedance, and Ri is the input impedance of the low noise amplifier circuit 112. [

At this time, the voltage output through the coupling network 112 may be expressed by the following equation (6).

Here, S is the effective detection area and Rm is the resistive detection impedance.

And the cut-off frequency fc can be configured as 100 kHz as the -3 dB frequency.

Meanwhile, the low-noise amplifying circuit 113 may be configured to amplify the transient ground voltage transmitted by the coupling network 112 and transmit the amplified transient ground voltage to the discharge detection module 120 through a coaxial cable having a characteristic impedance of 50 OMEGA.

FIG. 4 is a graph illustrating a cutoff frequency of a coupling network according to an exemplary embodiment of the present invention, and FIG. 5 is a frequency response graph of a coupling network according to an embodiment of the present invention.

Referring to FIGS. 4 and 5, it can be seen that the cut-off frequency fc can be configured to pass a high frequency band of 100 kHz or more at a -3 dB frequency, .

6A is a circuit diagram of a low noise amplifier circuit according to an embodiment of the present invention.

The low-noise amplifier circuit of FIG. 6A is a circuit designed to detect a minute electromagnetic wave signal. The low-noise amplifier circuit is composed of two stages of amplification so as to have a sufficient frequency band and low noise characteristics, and the voltage gain is designed to be 40 dB.

6B is a frequency response graph of a low noise amplifier circuit according to an embodiment of the present invention.

Referring to FIG. 6B, it can be seen that the amplifier satisfies the band for detecting an abnormal signal through the characteristic analysis. Experimental results show that the -3dB frequency band ranges from 50 kHz to 5 MHz.

FIG. 7 is a graph showing the response of a transient ground voltage detected according to an embodiment of the present invention, and FIG. 8 is a graph illustrating a magnitude variation of a transient ground voltage detected according to an embodiment of the present invention.

Referring to FIGS. 7 and 8, the transient ground voltage exhibits characteristics that change with time. It can be seen that the transient ground voltage is generated in a very short time of nanoseconds and gradually disappears. It can be seen that the absolute size thereof is drastically reduced in inverse proportion to time as shown in FIG.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims. There will be.

110: Transient ground voltage sensor module
111: Transient ground voltage detection sensor
111a:
111b: ground electrode
111c: Dielectric
111d: BNC connector
112: coupling network
113: Low Noise Amplification Circuit
120: Discharge detection module
200: Switchboard panel

Claims (10)

A transient ground voltage sensor module attached to an outer surface of the metal housing and sensing an excessive ground voltage according to a surface current generated in the metal housing by an electromagnetic wave generated by internal discharge, corona discharge, and arc discharge in the metal housing;
And a discharge detection module for detecting an arc discharge or a corona discharge by using the transient ground voltage sensed by the transient ground voltage sensor module and for detecting an arc and a corona discharge using a transient ground voltage signal, . 2. The transient ground voltage sensor module according to claim 1,
Wherein a plurality of arc discharge electrodes are arranged on the outer surface of the metal housing to be spaced apart from each other by a predetermined distance, and arc and corona discharges are detected using the ground discharge voltage signal. 3. The transient ground voltage sensor module according to claim 2,
A transient ground voltage detection sensor for accumulating and sensing the transient ground voltage;
A coupling network for detecting and transmitting a transient ground voltage accumulated in the transient ground voltage detecting sensor;
And a low noise amplifying circuit for amplifying a transient ground voltage transmitted by the coupling network and transmitting the amplified transient ground voltage to the discharge detection module, wherein the arc and corona discharges are detected using the transient ground voltage signal. The apparatus of claim 3, wherein the transient ground voltage detecting sensor comprises:
A detection electrode composed of a copper plate having a diameter of 105 mm and a thickness of 0.5 mm;
A ground electrode composed of a copper plate having a diameter of 105 mm and a thickness of 0.5 mm;
A dielectric inserted between the detection electrode and the ground electrode and made of an epoxy resin having a thickness of 0.5 mm;
And a BNC connection terminal connected to the detection electrode protrusion protruding through the dielectric and the ground electrode from the center of the detection electrode. The switchboard of claim 1, wherein the arc and corona discharge are detected using the transient ground voltage signal. The plasma display apparatus according to claim 4,
And an edge is formed of a flame-retardant epoxy resin so as to prevent an electric field concentration from being generated, and an arc and a corona discharge are detected using a transient ground voltage signal. 6. The apparatus of claim 5, wherein the low-
And a low noise amplifying circuit for amplifying the transient ground voltage transmitted by the coupling network and transmitting the amplified transient ground voltage to the discharge detection module through a coaxial cable having a characteristic impedance of 50 OMEGA. A switchboard for detecting discharge. 7. The apparatus of claim 6,
And a composite impedance Av including a matching resistance Rm of 50 Ω and a compensation resistance Ri equal to the characteristic impedance of the coaxial cable in order to eliminate signal distortion due to the capacitance due to the insulator and external conductors of the coaxial cable Which detects an arc and corona discharge using a transient ground voltage signal. 8. The method as claimed in claim 7, wherein the synthetic impedance (Av)
Is constituted by the following equation,
[Mathematical Expression]

Here, Rm is the detection impedance, fc is the cutoff frequency, the impedance Zs is expressed by the following equation,
[Mathematical Expression]

Wherein Ld is an inductive detection impedance, and Ri is an input impedance of the low noise amplifying circuit, wherein an arc and a corona discharge are detected using a transient ground voltage signal. 4. The method of claim 3, wherein the output voltage of the coupling network
Is constituted by the following equation,
[Mathematical Expression]

Wherein S is an effective detection area, Rm is an resistive detection impedance, and fc is a cut-off frequency, and detects an arc and a corona discharge using the transient ground voltage signal. 10. The method of claim 9, wherein the cut-
100 kHz, wherein the arc and corona discharges are detected using the transient ground voltage signal.

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