JPH07262886A - Disconnector with resistor - Google Patents

Abstract

PURPOSE:To judge functional quality of a resistor from the outside of a disconnector without stop of operation of a switch device by arranging a capacitance type electrode in part of a sealed container faced to a resistor shield, and further arranging a DC voltage generator and an ammeter on the outside of the sealed container. CONSTITUTION:Capacitance of several pF order exists between resistor shields 16, 17 and conductive plates 20, 21. Capacitance C of the resistor shields 16, 17 and resistance R of the resistor 18 exist in parallel to form a series-parallel circuit. A switch is connected to one end of the capacitance and an ammeter 27 is connected to one end of a DC power source 26. When the switch is turned off, a charge introduced into the capacitance is discharged by a time constant dependent on the resistance through the resistor 18. When the resistance of the resistor 18 varies, a current wave form varies. Since the wave form is distinctly different from that in a terminal resistor, the abnormality of the resistor 18 can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance disconnecting switch, and more particularly to a resistance disconnecting switch used in a substation or the like.

[0002]

In general, gas insulated switchgear, in a sealed container filled with SF ₆ gas of about 3-6 atmospheres, breakers,
It houses equipment necessary for opening and closing operations such as disconnecting switches, grounding switches, current transformers, and instrument transformers. Among these, the disconnector is
Normally, the opening and closing operation is performed with the circuit breaker open. A steep-wave surge called a disconnector surge accompanying the switching operation of the disconnector is generated between the poles of the disconnector and propagates in the gas-insulated switchgear. In the UHV class, this surge is a gas-insulated switchgear. Since it threatens the insulation of the

A conventional disconnector for suppressing the voltage level of such disconnector surge will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a tank filled with SF ₆ gas of about 3 to 6 atm.
And the fixed side contact portion 3 are provided so as to face each other, and the movable contact 4 linearly slides between them to open and close the electric circuit. The movable contact 2 is attached to the tank 1 via an insulating cylinder 5, and the fixed contact 3 is connected to the tank 1 via an insulating cylinder 6.
Attached to. The driving force of the operating device 7 fixed to the upper part of the tank 1 is converted from the rotary motion to the linear motion via the opening / closing mechanism 8, and the converted driving force is transmitted via the insulating operation rod 9 to make a movable contact. The child 4 is driven.
Further, the movable side contact portion 2 is provided with a finger 11 that contacts the conductor 10 and the movable contactor 4, and the conductor 10 is drawn out through the insulating spacer 12. The fixed-side contact portion 3 is provided with a finger 14 that contacts the conductor 13 and the movable contactor 4, and the conductor 13 is pulled out to the outside via the insulating spacer 12.

The above is the basic configuration of the disconnecting switch. The characteristic of this disconnecting switch is the resistor shield device 15 arranged around the fixed side contact portion 3. The resistor shield device 15 has a pair of resistor shields 16 and 17 which are vertically separated from each other, an upper end of which is fixed to an inner surface of the upper resistor shield 16, and a lower end of which is fixed to a lower resistor shield 17. It is composed of a plurality of resistors 18. The resistor shield 16 is electrically connected to the fixed-side contact portion 3 via the resistor 18 and the resistor shield 17.

Reference numeral 19 is a resistance contact located at the tip of the resistor shield 16, and is made of a material having particularly excellent arc resistance. The resistance contact 19 is configured to have a gap g with the movable contactor 4 when the disconnector is turned on. This gap g is set during the opening / closing operation of the disconnector.
If re-ignition occurs between the disconnector poles when the tip of the movable contactor 4 is located near the resistance contact 19, the resistance contact 19 and the movable contactor 4 are energized by flashover, and at this time point. The movable contactor 4 and the fixed side contact portion 3 and the tank 1 are determined by conducting examination from the viewpoint of insulation coordination so as not to cause dielectric breakdown. The re-ignition occurs a plurality of times between the movable contact 4 and the resistance contact 19 during the opening and closing of the disconnector, but the resistor that electrically mediates between the resistance contact 19 and the fixed-side contact portion 3. Since the resistance value of 18 is sufficiently large, the disconnector surge level can be sufficiently suppressed.

In the disconnecting switch with resistance as described above, the resistor 18 has a structure in which a resistance wire is non-inductively wound around an insulating rod of epoxy or the like and then all or part of the resistance wire is cast with epoxy resin or the like. . The resistor 18 must have a sufficient withstand voltage so as not to cause dielectric breakdown or the like along its creeping surface even if a voltage such as a disconnector surge is applied to both ends thereof.

However, if a voltage such as a disconnecting switch surge is applied due to deterioration of the resistance wire over time, there is a probability that dielectric breakdown will occur and the resistor 18 will lose its function and continue to be used as it is. For example, an excessive surge of the disconnecting switch may occur, and the gas-insulated switchgear (hereinafter, simply referred to as switchgear) may have a dielectric breakdown.

[0008]

By the way, in the disconnector with resistance, if the resistor should lose its function,
The resistance value of the resistor changes. Therefore, for the safety of the switchgear, it becomes necessary to measure the resistance value of the resistor after the operation of the disconnector. However, in order to directly measure its resistance, the operation of the switchgear must be stopped and the disconnector with resistance disassembled, which is virtually impossible.

The present invention has been made in order to solve the problems of the prior art as described above, and its purpose is to determine whether the function of the resistor is good or bad from the outside of the disconnector without stopping the operation of the switchgear. It is to provide a disconnecting switch with a resistance that can be discriminated.

[0010]

In order to solve the above-mentioned problems, the first aspect of the present invention is that the movable side contact portion and the fixed side contact portion are coaxially arranged in a hermetically sealed container containing an insulating / dissipating medium. A resistor shield device comprising a resistor formed by non-inductively winding a resistance wire around an insulating rod around the fixed contact portion, and a resistor shield joined to this resistor is disposed. In a disconnecting switch with resistance adapted to perform an electrical opening / closing operation by operating a movable contactor, a conductive plate is disposed in the vicinity of the closed container wall facing the resistor shield, and further, the conductive material is provided outside the sealed container. By arranging a DC voltage generator and a current measuring device which are hermetically connected to the plate, it is possible to discriminate the characteristic change of the resistor.

[0011]

According to the present invention, it is possible to determine whether the function of the resistor of the disconnector with resistance is good or bad without stopping the operation of the switchgear.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. (Structure of Embodiment) FIG. 1 is a sectional view of an embodiment of the present invention.

As shown in the figure, the resistor shield device 1
Reference numeral 5 denotes a pair of resistor shields 1 which are vertically separated from each other.
6 and 17, and a plurality of resistors 18 whose upper ends are fixed to the inner surface of the upper resistor shield 16 and whose lower ends are fixed to the lower resistor shield 17. Disc-shaped conductor plates 20 and 22 are arranged in a part of the closed container 1 facing the resistor shields 16 and 17. Conductor plates 20, 2
The connection lines 22 and 23 are connected to one side of 1. The connection lines 22 and 23 are electrically insulated from the closed container 1 by the penetration type insulators 24 and 25, and are connected to the connection lines 22 and 23. There is. A DC voltage generator 26 is connected to the connection line 22, and a minute (DC) ammeter 27 is connected to the connection line 23.

Next, the operation of this embodiment will be qualitatively described with reference to FIGS. Between the resistor shields 16 and 17 and the conductor plates 20 and 21, there is electrostatic (floating) capacitance, which is on the order of several picofarads (pF). The electrostatic capacitance C _O of the resistor shields 16 and 17 and the resistor R of the resistor in parallel therewith form a series-parallel circuit. Furthermore,
A switch (SW) is connected to one end of the electrostatic capacity C _S , and an ammeter (μA) meter is connected to one end of the DC power supply C _S ′.

When the switch is turned on, electric charges are induced in the electrostatic capacitance C _O through the electrostatic capacitance C _S and reach a certain constant potential. In this case, the current i _CS ′ flows through the capacitance C _S ′.
Flows, but eventually becomes O (A).

Next, when the switch is turned off, the capacitance C
_The electric charge induced in _O is discharged through the resistor 18 with a time constant that depends on the resistance R. Also at this time, the current i _CS ′ flows through the ammeter through the electrostatic capacitance C _S ′ as shown by the solid line in FIG. 3, but this waveform shows the voltage value of the DC power supply, the resistance value of the resistor 18, and the disconnection. It is uniquely determined by the open / closed state of the vessel.

Now, if the winding forming the resistor 18 changes for some reason and the resistance value becomes larger than that in the normal state, the current (i _CS ) will be in the normal state as shown by the broken line in FIG. The waveform is different from. On the contrary, when the resistance value is smaller than that in the normal state, the waveform becomes different from that in the normal state. Therefore,
When the resistance value of the resistor 18 changes for some reason, the current ( _iCS ') waveform also changes. The degree of change varies depending on the resistance value, but since the waveform is clearly different from that in the normal state, it is possible to detect the abnormality of the resistor.

[0018]

As described above, according to the present invention,
By placing two capacitance-type electrodes in a part of the closed container facing the resistor shield and by arranging a DC voltage generator and an ammeter outside the closed container, the resistance in the operating state of the switchgear can be improved. It is possible to provide a disconnecting switch with resistance capable of determining deterioration of body function.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a circuit diagram for explaining the operation of FIG.

FIG. 3 is a characteristic diagram of FIG.

FIG. 4 is a cross-sectional view of a conventional disconnector with resistance.

[Explanation of symbols]

1 ... Tank, 2 ... Movable side contact part, 3 ... Fixed side contact part, 4
... movable contacts, 5, 6 ... insulating cylinder, 7 ... operating device, 8 ... opening / closing mechanism, 9 ... insulating rod, 10, 13 ... conductor, 11, 1
4 ... Finger, 12 ... Insulating spacer, 15 ... Resistor shield device, 16, 17 ... Resistor shield, 18 ... Resistor, 19 ... Resistive contact, 20, 21 ... Conductor plate, 24, 25
... Penetration type insulator, 22, 23 ... Connection line, 26 ... DC voltage generator, 27 ... Ammeter.

Claims (1)

[Claims] 1. A movable-side contact portion and a fixed-side contact portion are coaxially arranged in an airtight container in which an insulating / dissipating medium is sealed, and a resistance wire is not provided on an insulating rod around the fixed-side contact portion. A disconnector with a resistor, in which a resistor shield device composed of a resistor formed by induction winding and a resistor shield joined to the resistor is arranged, and a movable contactor is operated to perform an electrical switching operation. In the container, a conductive plate is arranged in the vicinity of the closed container wall facing the resistor shield, and a DC voltage generator and a current measuring device that are hermetically connected to the conductive plate are arranged outside the sealed container. A disconnector with a resistor, wherein the characteristic change of the resistor can be discriminated by means of.