JP2000069624A - Control circuit for gas insulation switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a control circuit, wherein a surge current at the time of accident current breaking of a control cable of a gas insulation switchgear and at switching of a disconnector, and an induction voltage by a surge voltage are restrained, and an electronic apparatus using semiconductor elements can be applied. SOLUTION: As a control cable connected with an electronic apparatus constituted of semiconductor elements which is the constituent apparatus of a gas insulation switchgear, a twisted pair shielded cable where twist pair lines 37a are shielded 37b is used. The shield is grounded constitution. Surge currents at breaking of an accident current and at switching of a disconnector, electromagnetic induction through surge voltage, and an induction voltage by electrostatic induction are restrained, thereby enabling the use of an electronic apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for a gas insulated switchgear installed in a substation or the like.

[0002]

2. Description of the Related Art A general configuration of a gas insulated switchgear installed in a substation or the like includes a plurality of main buses, a line unit connected to a transmission line, a transformer unit connected to a transformer,
A plurality of units such as a bus unit that opens and closes between main buses are arranged in parallel and connected to the main bus. For example, the configuration of a line unit portion connected to a transmission line in the configuration is as shown in FIG. Has become. In the figure, 1 is a gas insulated switchgear, 2 is a first main bus, 3 is a second main bus,
4 and 5 are main bus disconnectors, 4a and 5a are control boxes thereof,
6 is a ground switch, 6a is its control box, 7 is a circuit breaker, 7a is its control box, 8 is a current transformer, 8a is its terminal box, 9 is a ground switch of the line portion, and 9a is The control box, 10 is a line disconnector, and 10a is the control box, 11
Denotes a cable head. 12 is a branch bus, 13 is an arrester, 13a is its terminal box, 14 is a voltage transformer, 14a is its terminal box, 15 is the operation panel of the gas insulated switchgear, 16 is the control box or terminal box of each device. A control cable for connecting between the terminal and the terminal of the operation panel 15 is a power receiving cable. Reference numeral 20 denotes an installation base of the gas insulated switchgear 1, and a laying duct for laying a control cable 16 is provided between a control box and a terminal box of each device and an operation panel 15 of the gas insulated switchgear.

FIG. 9 is a diagram showing a state of laying a control cable 16 between a terminal of a terminal box 8a of a current transformer 8 and a terminal of an operation panel 15, for example. 15a is a terminal plate, 16a is a core of the control cable 16, 16b is an insulating layer, 16c is a metal sheath, 16d is an insulating jacket, and 17 is a metal tube. 18a,
18b is a non-linear resistor. FIG. 9 shows the distance between the control box or terminal box of each device of the gas insulated switchgear 1 and the terminal of the operation panel 15
It is laid in the same way.

The control cable 16 is laid in such a manner that the main bus of the gas insulated switchgear or each device is laid about 1 m in proximity to each other. Around the device 1, a magnetic field is formed by the current flowing through the main bus and each device, and the load current, the fault current is cut off, or each disconnector 4,
When the switch 5 or 10 is opened or closed, an induced voltage is induced between the control cable 16 and between the ground by the induction by the surge voltage and the surge current accompanying the opening and closing. Especially the track disconnector 10
When opening and closing, the charging current of the capacitance between the conductor and the container is opened and closed, and a steep surge current containing many high-frequency components flows through the container, causing the potential of the container to float, generating a surge voltage and causing a surge around the container. High-frequency electromagnetic wave noise is generated, and an induced voltage is generated in the control cable 16 arranged close to the electromagnetic wave. The induced voltage of the control cable 16 arranged close to the component equipment varies depending on the situation, but the peak value is several thousand volts.
For this purpose, the control cable 16 is configured to have a withstand voltage of 2 kV AC voltage and 7 kV impulse voltage.

[0005] If electronic equipment (hereinafter referred to as electronic equipment) such as a relay using a semiconductor element and various detection sensors is used in the control circuit of the gas insulated switchgear, the gas insulated switchgear can be made compact. In a conventional configuration, as a method of suppressing an induced voltage for using an electronic device, a method of grounding both ends using a control cable with a sheath, and a method of connecting the control cable in a direction as perpendicular to the direction of the current of the device as possible. Measures such as a method of arranging and a method of making the ground mesh fine are performed. Further, as shown in FIG. 9, the non-linear resistors 18a and 18b for absorbing surge voltage are provided between the lines at the end of the control cable 16 and between the ground. Surge voltage suppression measures such as connecting to suppress induced voltage have been taken, and specific electronic devices with a certain withstand voltage have been applied,
It is not sufficient for electronic devices that cannot withstand high voltage values.When applying electronic devices, convert them to optical signals using an optical fiber cable that is not affected by surge voltage and surge current when switching. An optical signal system for transmission is applied. However, in the optical signal system, since the cost of the optical-electrical signal converter and the optical fiber cable increases, it is not the situation that the electronic devices are actively applied.

[0006]

As described above, the control cable 16 of the conventional gas insulated switchgear 1 is connected to the electromagnetic induction by the current of the gas insulated switchgear 1, the disconnector 4, 5 or 1.
When a high voltage surge voltage is induced between the terminals of the control cable 16 and between the ground and the ground due to a surge voltage caused by opening / closing of 0 and electrostatic induction by electromagnetic wave noise, the use of the electronic device is restricted, and the electronic device is used. However, there is a problem in that an optical signal system in which an optical signal is converted into an optical signal using an optical fiber cable and transmitted is applied, and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The control circuit has a configuration in which an induced voltage due to electromagnetic induction is suppressed, and a surge voltage and electromagnetic wave noise containing many high-frequency components due to disconnection switch opening and closing are provided. An object of the present invention is to provide a control circuit for a gas insulated switchgear in which an induced voltage is suppressed to a low level.

[0008]

According to a first aspect of the present invention, there is provided a control circuit for a gas insulated switchgear, comprising: a control box or a terminal box connected to an electronic device using a semiconductor element of each component; Is a twisted pair shielded cable in which a twisted pair wire is shielded.

A control circuit for a gas insulated switchgear according to a second aspect of the present invention is a control cable between a control box or a terminal box connected to an electronic device using a semiconductor element of each component and an operation panel. Is a twisted pair shielded cable in which a twisted pair wire is shielded, and a plurality of twisted pair shields connected in parallel are further twisted.

According to a third aspect of the present invention, there is provided a control circuit for a gas insulated switchgear, wherein the twisted pair shielded cable of the first or second aspect is inserted through a metal pipe made of a magnetic material and laid.

According to a fourth aspect of the present invention, there is provided a control circuit for a gas insulated switchgear comprising: a control box or a terminal box connected to an electronic device using a semiconductor element of each component of the gas insulated switchgear; And a control cable between the operation panel and the central control panel of the electric substation is constituted by a twisted pair shielded cable in which a twisted pair wire is shielded.

According to a fifth aspect of the present invention, there is provided a control circuit for a gas insulated switchgear, wherein the twisted pair shielded cable according to the fourth aspect is laid through a grounded magnetic metal tube.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 If you use a twisted pair wire with a pair of wires twisted into a control cable,
As shown in FIG. 1, the magnetic flux interlinks into a small loop formed in the twisted pair wire, and an induced voltage is generated in both electric wires. The induced voltage hardly occurs in the twisted pair wire. Further, by shielding the twisted pair wire, it is possible to shield both the magnetic field due to the current flowing through the gas insulated switchgear and the electromagnetic wave noise generated when the disconnector is opened and closed, and it is possible to reduce the induced voltage generated in the twisted pair wire. .

Using a twisted pair shielded cable in which a twisted pair wire is shielded as a control cable, the disconnector is opened and closed by an actual gas insulated switchgear, and the induced voltage is measured. The result shown in FIG. 2 is obtained. . The result is that the induced voltage of a normally used control cable with a sheath has a maximum peak value of 5000 V, while the twisted pair shielded cable in which a twisted pair wire is shielded has a maximum peak value of about 500 V. When the cable is inserted and laid in the metal tube, the voltage is reduced to 300 V or less. This means that by twisting a pair of wires, the voltage induced for each twist is canceled out, and almost no voltage is induced as a cable, and the shielding effect of electromagnetic noise can be obtained by covering the cable. It indicates that it can be avoided.

In the first embodiment, the control cable for controlling the opening and closing of the gas insulated switchgear is a normal control cable with a sheath based on the results shown in FIG. 2, and the semiconductor device is used as a component device for detecting numerical values such as voltage and current. The electronic device used is a twisted pair shielded cable in which a control cable connected to the electronic device is covered with a twisted pair wire.

FIG. 3 is a single-line diagram of the line unit of the gas insulated switchgear of the first embodiment, and FIG. 4 is a cross-sectional view showing the configuration of the single-line diagram of the line unit of FIG. In the figure, 21 is a gas insulated switchgear, 22 is a first main bus, 23 is a second main bus, 22a and 23a are terminal boxes of partial discharge sensors, 2
4, 25 are main bus disconnectors, 24a and 25a are control boxes thereof, 26 is a grounding switch and 26a is a control box thereof, 2
7 is a circuit breaker, 27a is its control box, 27b is a terminal box of a partial discharge detection sensor, 28 is a current detection sensor section, 28a is a terminal box of a current detection sensor, 29 is a ground switch of a line portion, and 29a Is the control box, 30 is the line disconnector, 30a is the control box, 31 is the cable head, 31a is the terminal box of the partial discharge detection sensor, 32 is the branch bus, 33 is the lightning arrester, and 33a is the terminal box And 34, a voltage detection sensor unit, 34a is its terminal box, 35 is a gas insulated switchgear operation panel, 36 is installed between a terminal of a control box or terminal box of each device and a terminal of the gas insulated switchgear operation panel 35. Control cable for opening and closing each device, 37
Is a twisted pair shielded cable connecting between the terminal of the detection sensor and the electronic device, and 39 is a power receiving cable.
40 is a base on which the gas insulated switchgear 1 is installed,
A control line laying duct is provided between the control panel and the control box and terminal box of each device.

As described above, by using a twisted pair shielded cable for connecting components for detecting numerical values such as voltage and current, current, voltage and partial discharge can be performed without using an expensive optical signal system as in the prior art. Electronic devices using semiconductor elements can be applied to the components such as detection sensors and receivers of components that detect numerical values such as control signals.The cost of control cables is low, the laying of control cables is simple, and gas insulation switching is possible. The device can be made small and inexpensive.

Embodiment 2 FIG. In the first embodiment, the control cable connected to the electronic device is a twisted pair shielded cable. In the second embodiment, the twisted pair shielded cable is further inserted and laid in a magnetic metal tube. FIG. 5 shows a configuration in which a single twisted pair shielded cable is inserted through a magnetic metal tube as a control cable for detecting a current, for example. In the figure, 28s is a current detection sensor, 37 is a twisted pair shielded cable, 37a is a twisted pair wire, 3
7b is a shield, 37c is an insulation jacket, and 38 is a magnetic metal tube. FIG. 6 shows a case where a plurality of control cables needing a plurality of control cables are inserted through one magnetic metal tube and laid as in the case of a plurality of partial discharge sensors provided on a main bus, for example. The configuration is shown. In the figure, 22
s is a partial discharge detection sensor, 37d and 37e are twisted pair wires, 37f is a shield, and one end is grounded.
37 g is an insulating jacket.

When the twisted pair shielded cable is inserted and laid in a metal pipe made of a magnetic material as described above, it is shielded from an external magnetic field and shielded against electromagnetic waves generated when the disconnector is opened and closed, as shown in FIG. The voltage induced by the induction is lower than that of the first embodiment, and the connection can be made so as to hardly affect the electronic device using the semiconductor device. The electronic device using the semiconductor device without using the optical signal method can be used. Can be used stably.

Embodiment 3 In the third embodiment, a plurality of twisted pair shielded cables are further twisted and laid. FIG. 7 shows the configuration. FIG. 7 shows a case where a plurality of partial discharge sensors are connected similarly to the case of FIG. In this case, the twisted pair cables 37d and 37e are further twisted as shown in the figure.
The shield 37f is grounded at one end. Reference numeral 38 denotes a magnetic metal tube.

When a plurality of twisted pair shielded cables are connected in parallel as described above, by further twisting, the induced voltage between the twisted pair shielded cables is further reduced by the twist effect, and the potential difference between the connected circuits is further reduced. Is obtained.
Even if there are three or more sets of twisted pair shielded cables 37, the potential difference between the circuits is reduced by twisting. By inserting a twisted pair of shielded cables through a metal tube made of a magnetic material as shown in the figure, a shielding effect is further obtained and the induced voltage is suppressed.

Embodiment 4 The fourth embodiment has a configuration in which a control cable connected to an electronic device between an operation panel of a gas insulated switchgear and a central control panel of an electric substation is also a twisted pair shielded cable. 22a, 23 of the configuration of FIG.
Reference numerals a, 27a, 28a, 31a, 33a, and 34a denote control cables connected to the electronic device, and the terminal of each control cable and the terminal of the operation panel are connected by a twisted pair shielded cable according to the third embodiment. In addition to,
The control cable between the terminal box or the terminal connected to the terminal box of the operation panel 35 of the gas insulated switchgear and the central control panel is also connected by a twisted pair shielded cable that shields a twisted pair wire.

As described above, the control cable for connecting the operation panel of the gas insulated switchgear of the control circuit in which the electronic device is used and the central control panel is also a twisted pair shielded cable, so that guidance can be provided even after the operation panel. Is suppressed, and the reliability of the operation of the electronic device is increased. If the twisted pair shielded cable is inserted and laid in a magnetic metal tube, the effect of shielding the induced voltage is further improved.

With this configuration, when the control cable route from the operation panel of the gas insulated switchgear to the central control panel is laid in proximity to the gas insulated switchgear, for example, the gas insulated switchgear is installed in an underground substation in the city center. Even when the device is installed in a narrow place, the electromagnetic wave noise is not induced by the surge voltage at the time of opening / closing operation, so that a highly reliable control circuit can be configured.

[0025]

According to a first aspect of the present invention, there is provided a control circuit for a gas insulated switchgear comprising a control box or a terminal box connected to an electronic device using a semiconductor element of each component and an operation panel. The control cable is a twisted pair shielded cable with twisted pair wires shielded, so the detection sensor and the receiving side of component devices that detect numerical values such as current, voltage, partial discharge, etc. without using an expensive optical signal system as in the past. A control circuit of a gas insulated switchgear, to which an electronic device using a semiconductor element can be applied to a component device such as an amplifier, can be configured at low cost.

According to a second aspect of the present invention, there is provided a control circuit for a gas insulated switchgear, wherein a control cable between a control box or a terminal box connected to an electronic device using a semiconductor element of each component device and an operation panel. Is a twisted pair shielded cable that shields twisted pair wires, and twisted pair shielded cables that are connected in parallel are further twisted, so when multiple cables are used in parallel, induced voltage between cables is also suppressed it can.

In the control circuit for a gas insulated switchgear according to a third aspect of the present invention, the twisted pair shielded cable of the first or second aspect is inserted and laid in a metal pipe made of a magnetic material. The shielding effect is further enhanced, and the induced voltage is further suppressed.

According to a fourth aspect of the present invention, there is provided a control circuit for a gas insulated switchgear comprising: a control box or terminal box connected to an electronic device using a semiconductor element of each component of the gas insulated switchgear; The control cable between the control panel and the central control panel of the electric substation is composed of twisted-pair shielded cables that shield the twisted-pair wires, so that guidance after the control panel is also suppressed and installed in a narrow space. Even if the control cable route after the operation panel is close to the gas insulated switchgear, electromagnetic induction during switching operation,
A highly reliable control circuit that hardly receives electromagnetic wave noise induced by surge voltage can be configured.

In the control circuit for a gas insulated switchgear according to a fifth aspect of the present invention, the twisted pair shielded cable according to the fourth aspect is laid through a grounded magnetic metal tube, so that the induced voltage is further reduced. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of electromagnetic induction of a twisted pair wire.

FIG. 2 is a graph showing measured data of an induced voltage of a control cable and a twisted pair shielded cable.

FIG. 3 is a single line diagram of a line unit of the gas insulated switchgear.

FIG. 4 is a side view showing a configuration of a line unit of the gas insulated switchgear according to the first embodiment.

FIG. 5 is a laying configuration diagram in the case of one twisted pair shielded cable.

FIG. 6 is a laying configuration diagram in the case of two twisted pair shielded cables.

FIG. 7 is a laying configuration diagram in a case where two twisted pair shielded cables are further twisted.

FIG. 8 is a side view showing a configuration of a line unit of a conventional gas insulated switchgear.

FIG. 9 is a configuration diagram of a conventional control cable.

[Explanation of symbols]

21 gas-insulated switchgear, 22 first main bus, 23
Second main bus, 24, 25 main bus disconnector, 26 ground switch, 27 circuit breaker, 28 current detection sensor unit, 29
Ground switch, 30 line disconnector, 31 cable head, 32 branch bus, 33 arrester, 34 voltage detection sensor, 35 operation panel, 36 control cable, 37
Twisted pair shielded cable, 38 metal tube, 40
base.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsuhito Kamei 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 5G017 AA04 AA06 FF01

Claims (5)

[Claims] A control cable between a control box or a terminal box connected to an electronic device using a semiconductor element of each component device of the gas insulated switchgear and an operation panel and a twisted pair shielded cable in which a twisted pair wire is shielded. A control circuit for a gas-insulated switchgear, characterized in that: 2. A control cable between a control box or a terminal box connected to an electronic device using a semiconductor element of each component device of the gas insulated switchgear and an operation panel, and a twisted pair shielded cable in which a twisted pair wire is shielded. The control circuit for a gas insulated switchgear, wherein a plurality of twisted pair shielded cables connected in parallel are further twisted. 3. The control circuit for a gas insulated switchgear according to claim 1, wherein the twisted pair shielded cable is laid so as to pass through a grounded magnetic metal pipe. 4. Between a control box or a terminal box connected to an electronic device using a semiconductor element of each component of the gas insulated switchgear and an operation panel and between an operation panel and a central control panel of an electric substation. The control circuit of the gas insulated switchgear, wherein the control cables are twisted pair shielded cables each of which shields a twisted pair wire. 5. The gas insulated switchgear according to claim 4, wherein the twisted pair shielded cable connected to the electronic device using the semiconductor element is laid by passing through a grounded magnetic metal tube. Control circuit.