KR20230086449A - Apparatus for Monitoring Vacumm Status of Vacuum Interrupter - Google Patents

Abstract

The present invention relates to a vacuum state monitoring device of a vacuum interrupter capable of transmitting an output signal to the outside by detecting whether or not a vacuum degree is leaked or a defect occurs in a vacuum interrupter that needs to maintain a vacuum state to ensure blocking performance.
The vacuum state monitoring device of the vacuum interrupter according to the present invention is installed for each phase between the metallic arc shielding plate and the metallic grounding enclosure of the vacuum interrupter in the inner space of the metallic enclosure filled with insulating gas, and is induced when the vacuum state changes. a capacitive sensor electrode that detects a voltage; and integrated monitoring means for diagnosing the vacuum level of each phase vacuum interrupter based on the voltage signal input from the sensor electrode and outputting a control signal for alarm or lockout when the vacuum level is out of the preset safety range. to be characterized

Description

Vacuum status monitoring device of vacuum interrupter {Apparatus for Monitoring Vacumm Status of Vacuum Interrupter}

The present invention relates to a vacuum state monitoring device for a vacuum interrupter, and more particularly, detects whether or not there is a vacuum leak or defect in a vacuum interrupter that needs to maintain a vacuum level to guarantee breaking performance at all times during use, and outputs an output signal to the outside. It relates to a vacuum state monitoring device for a vacuum interrupter that can transmit.

In general, gas insulated switchgear (GIS; Gas Insulated Switchgear) and gas insulated switch (Gas Insulated Switch) are collectively referred to as ground faults and short circuits in power systems that supply electricity such as transmission systems, substation systems, and distribution systems. It refers to a power protection device to prevent damage to related power devices such as generators, transformers, electric lines, etc.

In the case of gas insulated switchgear and gas insulated switchgear of tank type and cubicle type, as all components are housed in an electrically grounded enclosure filled with insulating gas, the safety of the operator is ensured and the insulation performance is maintained at the same time to ensure gas insulation. It is formed in a structure that secures the operation reliability of the switchgear.

As an insulating gas filled inside the enclosure of a _gas insulated switchgear or gas insulated switchgear, SF ₆ gas, which has excellent electrical dielectric strength and arc extinguishing characteristics, has been mainly used in the past. As the use is limited, most of the current insulating gases are replaced with insulating gases such as g3 gas, nitrogen gas, compressed dry air, CO ₂ or mixed insulating gas.

In the case of a gas insulated switchgear or gas insulated switchgear to which a vacuum interrupter is applied to the circuit breaker, the vacuum level of the vacuum interrupter must be maintained at an appropriate pressure to protect the power system by safely performing the shutoff operation in case of a power system failure. During manufacturing and installation, a fixed high vacuum state is maintained, but as it is used for a long time, the degree of vacuum gradually increases due to leakage, air permeation, mechanical defects, etc., and finally becomes equal to the filling pressure of the circuit breaker enclosure of the gas insulated switchgear.

When the fault current generated in the power system is cut off in a state where the vacuum level inside the gas insulated switchgear or the vacuum interrupter of the gas insulated switchgear is leaked and changed to the charging pressure of the insulating gas, the cutoff fails due to the lack of arc extinguishing power of the vacuum and electrically It causes great damage to connected power systems and facilities.

Therefore, it is very important to monitor the vacuum level inside the vacuum interrupter to prevent blocking failure. To this end, various sensors have been developed to predict the status of the interrupter through real-time detection of the vacuum level, but most devices for detecting the vacuum level have been developed. The structure for application to the switchgear is complicated and expensive, so there are many aspects that are not practical.

1. Republic of Korea Patent Registration No. 10-0952686 (April 6, 2010) 2. Republic of Korea Patent Publication No. 10-2020-0129834 (November 18, 2020) 3. Republic of Korea Patent No. 10-1264226 (May 8, 2013)

An object of the present invention is to install a sensing electrode sensor outside the vacuum interrupter, and to monitor the change in the vacuum level of the vacuum interrupter in operation in real time by using the characteristic that the voltage of the sensor varies according to the change in the vacuum level of the vacuum interrupter to measure the vacuum level of the interrupter. It is to provide a vacuum state monitoring device of a vacuum interrupter capable of outputting a control signal for alarming and locking when a sudden change occurs.

An object of the present invention is to provide a vacuum state monitoring device for a vacuum interrupter that can easily monitor and control the vacuum level of the vacuum interrupter even at a remote location as a communication module is mounted thereon and communication with an external computer at a remote location is possible.

The vacuum state monitoring device of the vacuum interrupter according to the present invention is installed for each phase between the metallic arc shielding plate and the metallic grounding enclosure of the vacuum interrupter in the inner space of the metallic enclosure filled with insulating gas, and is induced when the vacuum state changes. a capacitive sensor electrode that detects a voltage; and integrated monitoring means for diagnosing the vacuum level of each phase vacuum interrupter based on the voltage signal input from the sensor electrode and outputting a control signal for alarm or lockout when the vacuum level is out of the preset safety range. to be characterized

The vacuum state monitoring device of the vacuum interrupter according to the present invention can diagnose the vacuum state inside the vacuum interrupter by installing a vacuum degree state sensor electrode having a simple structure inside the gas insulated switchgear or the circuit breaker of the gas insulated switchgear.

The vacuum state monitoring device of the vacuum interrupter according to the present invention outputs a control signal for alarming and locking when the vacuum degree of the vacuum interrupter in operation is changed so that the vacuum interrupter can be replaced and maintained, so that the power system and power equipment It is possible to secure the operation reliability of the power system by preventing accidents and their spread in advance.

The vacuum state monitoring device of the vacuum interrupter according to the present invention can display the internal vacuum state of the vacuum interrupter as a digital value, and the gas insulated switchgear at a remote location without the inspector moving to the gas insulated switchgear or the installation site of the gas insulated switchgear. Alternatively, it is possible to monitor and control the vacuum state of a gas insulated switchgear.

1 is a structural diagram of a general three-phase integrated gas insulated switchgear.
2 is a detailed structural diagram of a circuit breaker of a general gas insulated switchgear or gas insulated switchgear.
3 is a schematic structural diagram of a vacuum interrupter.
4 is a schematic structural diagram of a vacuum state monitoring device of a vacuum interrupter for a gas insulated switchgear according to the present invention.
5a, 5b, and 5c are application examples of the capacitance type vacuum degree sensor electrode of the gas insulated switchgear or the vacuum interrupter for the gas insulated switchgear according to the present invention.
6 is a graph showing the change in the induced voltage of the capacitive sensor electrode according to the leakage of the gas insulated switchgear or the vacuum interrupter for the gas insulated switchgear according to the present invention.
7 is a schematic structural diagram showing the configuration of a monitoring means for monitoring the vacuum state of a gas insulated switchgear or a vacuum interrupter for a gas insulated switchgear according to the present invention.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms.

In this specification, this embodiment is provided to complete the disclosure of the present invention, and to completely inform those skilled in the art of the scope of the invention to which the present invention belongs. And the invention is only defined by the scope of the claims. Thus, in some embodiments, well-known components, well-known operations and well-known techniques have not been described in detail in order to avoid obscuring the interpretation of the present invention.

Like reference numbers designate like elements throughout the specification. And, the terms used (mentioned) in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. Also, elements and operations referred to as 'include (or include)' do not exclude the presence or addition of one or more other elements and operations.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless they are defined. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 4 is a structural diagram of a vacuum state monitoring device for a three-phase integrated gas insulated switchgear or a vacuum interrupter for a gas insulated switchgear according to the present invention, Figure 5 is a blackout of a gas insulated switchgear or a vacuum interrupter for a gas insulated switchgear according to the present invention An example of the arrangement structure of a capacitive vacuum degree sensor electrode, Figure 6 is a graph showing the change in sensor electrode induced voltage according to the leakage of the gas insulated switchgear or vacuum interrupter for gas insulated switchgear according to the present invention, Figure 7 is the present invention It is a schematic structural diagram showing the configuration of a monitoring means for monitoring the vacuum state of a gas insulated switchgear or a vacuum interrupter for a gas insulated switchgear.

As shown in FIGS. 1 and 2, a general gas insulated switchgear or gas insulated switchgear 100 includes an enclosure 10 forming a case and an incoming line provided at the upper end of the inner enclosure 10 and through which a large current flows. The bus part 20 including the main bus line 21 for connection and the support insulator 23 supporting it, and the main bus line ( 21), the ground electrode 33 connected to the ground, and the movable electrode 35 selectively connected to the ground electrode 31 connected to the ground, enabling separation and connection of the line in a non-operating state. A switch unit 30 that plays the role of a disconnector and a grounding switch used for ground switching operation for maintenance and inspection, and a short circuit that is formed in the inner central part of the enclosure 110 and can occur in the circuit, A circuit breaker unit 40 that protects load devices and lines from large fault currents such as ground faults, a cable connection unit 50 partitioned at the lower inside of the enclosure 10 and connected to distribution lines, and installed within the enclosure 10 and includes a control panel 60 that controls the entire operation.

In the gas insulated switchgear or gas insulated switchgear 100, all electrically charged conductors located in the sealed enclosure 10 are electrically insulated by the insulating gas 70 filled therein, and each component is an insulating partition wall spacer ( 80), the gas compartment is divided, so that the spread of an accident in an arbitrary component to other components can be minimized. In addition, the enclosure 10 made of metal is connected to an external ground and electrically maintained in a grounded state, so that the operator's safety can be ensured during equipment inspection and maintenance.

The circuit breaker unit 40 of the gas insulated switchgear or gas insulated switchgear 100 is partitioned in the enclosure 10 of the gas insulated switchgear or gas insulated switchgear 100 filled with the insulating gas 70, and the switchgear unit 30 ) and the cable connection part 50 to protect load devices and lines from fault current, and are classified into vacuum circuit breakers and gas circuit breakers according to the arc extinguishing medium. A gas circuit breaker using sulfur (SF ₆ ) gas as an arc extinguishing medium is mainly used, and a vacuum interrupter having excellent arc extinguishing and insulation performance is mainly used in a distribution voltage class having a voltage rating below that.

As shown in FIG. 2, a vacuum interrupter used as a blocking element in an operation state in which a commercial frequency voltage is applied to a single-phase or three-phase batch switchgear using gas such as SF ₆ , CO ₂ , g3, and dry air as an insulating medium (40) is responsible for blocking the fault current in the power system or opening and closing the current flowing in the load, and the inside of the vacuum interrupter is a cylindrical ceramic insulating tube 41 sealed in a vacuum state, and a ceramic insulating tube ( 41) seals the open lower end of the lower conductive plate 42 on which the fixed outgoing electrode 42a is formed and the open upper end of the ceramic insulating tube 41 is sealed and the movable outgoing electrode 43a is formed thereon. The formed upper conductive plate 43, the fixed contact 44 installed in the ceramic insulating tube 41 and electrically connected to the fixed lead-out electrode 42a, the fixed contact 44 in the ceramic insulating tube 41, A movable contact 45 arranged coaxially and electrically connected to the movable lead electrode 43a by means of a metallic bellows 45a, and a movable conductor 46 connected to the movable lead electrode 43a at the top of the ceramic insulating tube 41 ) is composed of.

Depending on the embodiment, the arc shielding plate 49 is attached to the inner wall of the ceramic insulating tube 41 and prevents metallic ions emitted by the arc generation by the switching operation of the contact from being attached to the inner wall of the ceramic insulating tube 41. ) may be further included.

The movable conductor 46 is connected to the upper switchgear 30 by a conductor, and the fixed lead-out electrode 42a of the lower conductive plate 42 is connected to the lower cable connection part 50 by a conductor.

A circuit breaker 48 is connected to the movable conductor 46 of the vacuum interrupter 40, and the circuit breaker 48 moves the movable contact 45 up and down to connect the fixed contact 44 and the movable contact of the vacuum interrupter 40. By determining whether to connect 45, the drive rod 47 connected to the movable conductor 46 of the vacuum interrupter 40 and the drive rod 47 connected to the drive rod 47 operate. It comprises a blocking operator 20 for controlling. The operation of the circuit breaker 48 can be performed manually or automatically by manipulating the control panel 60 .

In the vacuum state monitoring device of the vacuum interrupter according to the present invention, in the inner space of the metallic enclosure 10 filled with insulating gas, each phase between the metallic arc shielding plate 49 of the vacuum interrupter 40 and the metallic enclosure 10 Sensor electrodes installed for each (R, S, T) and having a characteristic of changing the voltage induced when the vacuum state changes; an annular silicon or through-type insulating spacer for positioning the sensor electrode in the space of the breaker unit; And an integrated monitoring means 200 that outputs a control signal for alarm or lockdown when the output value is out of the set vacuum level safety range, real-time monitoring of the vacuum level inside the vacuum interrupter to replace and maintain the vacuum interrupter at the right time to prevent accidents in the power system and power devices in advance to secure the reliability of system operation.

As shown in FIG. 4, the capacitive sensor electrode of the vacuum interrupter is electrically connected to the main body of the vacuum interrupter 40, the arc shield plate ( 49), and a composite circuit of capacitive elements (C1, C2, C3) sequentially connected between the metallic enclosure (10).

In addition, as shown in FIG. 5, each capacitive sensor electrode in an electrically floating state may be arranged in three types according to the magnitude of the induced voltage of the electrode determined according to the operating voltage.

That is, when the induced voltage of the sensor electrode is low, a method of directly using the arc shielding plate 49 of the vacuum interrupter as the sensor electrode is taken as shown in FIG. 5(a).

In addition, when the system operating voltage or sensor electrode induced voltage is high, a separate additional electrode module having a simple structure and low cost may be formed between the arc shielding plate and the metal enclosure. Here, the shape of the electrode module is composed of a form in which electrodes are attached to the outer surface of a solid insulator such as silicon or epoxy on the outer surface of the arc shield plate 49 of the vacuum interrupter 40 in a non-contact manner as shown in FIG. , as shown in FIG. 5(c), a separate insulator for potential sensing is additionally installed in the enclosure 10 of the circuit breaker unit 40, and an annular or prismatic conductor is impregnated into the insulator. At this time, a plurality of holes are drilled in the additional insulator so that the insulating gas in the inner space of the circuit breaker unit constitutes the same gas compartment through circulation.

The degree of vacuum of the gas insulated switchgear or gas insulated switchgear 100 is determined by the voltage value in which the voltage between the main conductor and the enclosure 10 is divided to the capacitive sensor electrode by the principle of electrostatic voltage division between the conductors inside the circuit breaker 48. The state is monitored. If the vacuum-tight structure of the interrupter is damaged due to leaks, air permeation, mechanical defects, etc. due to long-term use, the external insulation gas starts to flow into the vacuum interrupter due to the pressure difference and is finally blocked. The base 40 equals the filling pressure of the enclosure 10. In this way, when the insulating gas is mixed inside the vacuum interrupter, as shown in FIG. 6, the relative dielectric constant inside the vacuum interrupter 40, that is, ε _r =ε/ε _0, (where ε is the permittivity of the mixed state, and ε ₀ is the vacuum permittivity) changes, and the internal capacitance characteristics of the electric circuit change, ultimately changing the voltage value induced in the arc shielding plate 49, and through this, the vacuum degree You can monitor that the state has changed.

As such, the vacuum interrupter that maintains the internal vacuum level can be applied not only as a gas insulated switchgear blocker but also to vacuum circuit breakers and various gas insulated switchgear.

As shown in FIG. 7, the integrated monitoring means 200 includes an input conversion unit 230 that compares and converts voltage values input from a potential transformer (PT) and sensor electrodes; an A/D converter 240 that converts the voltage value received from the input conversion unit 230 into a digital signal; a central calculation control unit 250 connected to the A/D converter 240 and calculating and diagnosing vacuum levels of vacuum interrupters of each phase based on digital signals input through the A/D converter 240; A control signal generator 260 connected to the central operation control unit 250 and outputting a control signal for alarm or locking when the vacuum degree calculated by the central operation control unit 250 is out of a preset safety range; ; a display unit 270 connected to the central operation controller 250 and digitally displaying a vacuum level state of the vacuum interrupter of each phase calculated and diagnosed by the central operation controller 250; a key input unit 280 connected to the central operation control unit 250 and enabling setting of an operation mode or a safe vacuum range; It is configured to include a power supply unit 290 that supplies power necessary for operation from an external power source 400.

An A/D converter 240 is connected to the input conversion unit 230, and the A/D converter 240 converts the voltage value received from the input conversion unit 230 into a digital signal and acts as a digital arithmetic device. transmitted to the central operation control unit 250.

The central operation control unit 250 connected to the A/D converter 240 calculates and diagnoses the vacuum level value inside the vacuum interrupter of each phase based on the digital signals input through the A/D converter 240, and displays the display unit 270. ), and if the calculated vacuum level value is out of the preset safe range, the corresponding signal is provided to the control signal generating unit 260, and the operation mode or safe vacuum range according to the input signal input from the key input unit 280 As a kind of central arithmetic processing unit for setting, it is implemented in the form of a printed circuit board on which a predetermined circuit is printed or a chip in which a predetermined circuit is integrated.

The control signal generation unit 260 connected to the central operation control unit 250 alarms or locks when the degree of vacuum calculated and measured by the central operation control unit 250 is out of the preset safe range due to an electrical accident or leakage of insulating gas. By outputting a control signal for, an alarm sound is output to the outside through a predetermined alarm means (not shown) connected to the control signal generator 260 so that the manager can take appropriate action, or the control signal generator ( 60) so that the operation of the circuit breaker 48 can be automatically blocked by a predetermined locking means (not shown).

The control signal generator 260 is installed on the rear surface of the integrated monitoring means 200 and includes a control signal output terminal 261 for outputting a control signal for alarming or locking. The above-mentioned alarming means and locking means are electrically connected.

The display unit 270 displaying the vacuum degree of each phase of the vacuum interrupter connected to the central operation control unit 250 digitally displays the vacuum level inside the vacuum interrupter of each phase calculated and diagnosed by the central operation control unit 250, respectively. As a result, a vacuum level display panel installed in the center of the front side of the integrated monitoring means 200 and displaying the vacuum degree state calculated and diagnosed by the central operation control unit 250 in digital numbers, and an arc shape on the front side of the integrated monitoring means 200. It is installed in a voltage degree display window that displays the degree of the measured voltage inside the vacuum interrupter, and the voltage degree display window on the front side of the integrated monitoring means 200 is installed in a concentric arc shape, and the safety range and the upper and lower risk ranges are continuously It includes a safety range display window and two operation display lamps installed on the front side of the integrated monitoring means 200 and displaying whether a control signal for alarm or lockout by the control signal generator 260 is output, respectively. .

The key input unit 280 connected to the central operation control unit 250 enables setting of an operating mode or a safe vacuum level range, and is installed at the bottom of the vacuum level display panel and includes a mode selection button enabling setting of the operating mode , it is preferable to include a safety range setting button that enables setting of a safe vacuum degree range.

The power supply unit 290 supplies power required for operation from an external power source 400, and includes a power connection terminal to which the external power source 400 is connected. The external power source 400 is preferably a DC voltage for stable operation of the integrated monitoring means 200 .

The communication module 265 connected to the central operation control unit 250 enables communication with an external computer 300 at a remote location so that the degree of vacuum inside the vacuum interrupter 40 can be monitored through the external computer 300 at a remote location. As such, it is preferable to be composed of a known wired communication module such as a modem or a known wireless communication module such as Bluetooth.

In addition, the integrated monitoring unit 200 is a filter unit 210 that is sequentially connected between the input conversion unit 230 and the A/D converter 240 to remove noise from the voltage value output from the input conversion unit 230. ), and a linear processing unit 220 that linearizes the voltage value that has passed through the filter unit 210 and provides it to the A/D converter 240.

In the high-power gas insulated switchgear or gas insulated switchgear 100 operated with high voltage applied, an abnormal voltage may be generated by a magnetic field and switching surge, so a filter unit 210 is installed to remove it. The unit 210 is preferably composed of a low pass filter.

Claims (8)

Capacitive sensor electrodes installed for each phase between the metallic arc shielding plate of the vacuum interrupter and the metallic ground enclosure in the space inside the metallic ground enclosure filled with insulating gas to detect the voltage induced when the vacuum state changes; and
Integrated monitoring means for diagnosing the vacuum level state of each phase vacuum interrupter based on the voltage signal input from the sensor electrode and outputting a control signal for alarm or lockout when the vacuum level is out of the preset safety range.
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 1,
The voltage induced when the vacuum state changes is the voltage induced according to the change in the relative permittivity (ε _r ) inside the vacuum interrupter when insulating gas is mixed inside the vacuum interrupter, where ε _r =ε/ε ₀ , and ε Is the permittivity in the state where the insulating gas is mixed inside the vacuum interrupter, and ε ₀ is the vacuum permittivity.
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 1,
The capacitive sensor electrode is
A capacitive element electrically connected in sequence between the main conductor of the vacuum interrupter 40, the arc shield plate 49, and the metallic enclosure 10 in the inner space of the circuit breaker compartment filled with insulating gas Characterized in that it consists of a synthesis circuit of (C1, C2, C3)
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 1,
The capacitive sensor electrode is
The arc shield plate 49 of the vacuum interrupter is directly used as a sensor electrode in the space inside the circuit breaker filled with insulating gas (C1+C2),
Characterized in that it is composed of a composite circuit of the main body of the vacuum interrupter 40, the arc shielding plate 49 and the capacitive elements (C1, C2, C3) sequentially connected inside the metal enclosure 10
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 1,
The capacitive sensor electrode is a non-contact method with the arc shielding plate,
It is configured in the form of an electrode on the surface of a solid insulator (insulation material such as silicon, epoxy) surrounding the outside of the arc shielding plate 49 of the vacuum interrupter in an annular shape,
Characterized in that it consists of an annular or prismatic conductor impregnated into the inside of an insulator for potential sensing surrounding the outside of the arc shielding plate 49 of the vacuum interrupter in an annular shape.
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 1,
The integrated monitoring means,
An input conversion unit that compares and converts voltage values input from a potential transformer (PT) and sensor electrodes;
an A/D converter connected to the input conversion unit and converting the voltage value received from the input conversion unit into a digital signal;
a central calculation control unit connected to the A/D converter and calculating and diagnosing the vacuum level of each phase vacuum interrupter based on digital signals input through the A/D converter;
a control signal generator connected to the central operation control unit and outputting a control signal for alarming or locking when the vacuum level calculated by the central operation control unit is out of a preset safety range;
a display unit connected to the central operation control unit and digitally displaying the vacuum degree state of the vacuum interrupter of each phase calculated and diagnosed by the central operation control unit;
a key input unit connected to the central operation control unit and capable of setting an operating mode or a safe vacuum range; and
It is provided in the integrated monitoring means, characterized in that it comprises a power supply for supplying power necessary for the operation of the integrated monitoring means from an external power source
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 6,
The integrated monitoring means,
Further comprising a communication module connected to the central operation control unit and enabling communication with an external computer at a remote location to monitor the vacuum level of the vacuum interrupter of the device through the external computer at a remote location.
Vacuum interrupter's vacuum condition monitoring monitoring device.
According to claim 1,
The vacuum interrupter is characterized in that it is applied to the blocking part of the gas insulated switchgear, the vacuum circuit breaker, and various gas insulated switchgear.
Vacuum interrupter's vacuum condition monitoring monitoring device.

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