JPH02242544A - Transient recovery voltage suppressing capacitor apparatus of gas circuit breaker for electric power - Google Patents

Abstract

PURPOSE:To obtain suppressing capacitors apparatus having proper size and withstand voltage and the same electrostatic capacity by decreasing the number of capacitors with the drop of the rated voltage and increasing the number of conductive spacer for compensation thereof. CONSTITUTION:A capacitor unit 12 is composed with an insulating cylinder 13 and a serial unit 16 comprised of a plurality of disk type ceramic capacitors 14 and conductive spacers 15 and placed in the insulating cylinder and the plurality of the capacitors 14 are electrically connected in series through the conductive spacers 15 by applying pressure to the both end planes P of the insulating cylinder 13 by springs. In a serial unit 16 in which the thickness of the conductive spacers 15 is made the same as the thickness of the capacitors 14 and the capacitors 14 and the conductive spacers 15 are alternately placed in order and the number of the capacitors 14 is decreased to half is formed, the withstand voltage of the serial unit 16 can be decreased to half and serial electrostatic capacity can be doubled without altering its length. Thus, the withstand voltage performance and the size of the title apparatus can be decreased correspondingly to lowering rated voltage, without changing the size, withstand voltage and electrostatic capacity of each disk type ceramic capacitor.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is connected between the poles of a gas circuit breaker used in a power system with a system voltage of 72 KV or higher, and suppresses the transient recovery voltage generated by interrupting a large current. Concerning a capacitor device.

[Conventional technology]

When a power gas circuit breaker installed on a power transmission line exceeding several QKV completely cuts off the short-circuit fault current that occurs at a relatively short distance from the power source, a transient recovery voltage determined by the breaking current and line surge impedance occurs, It threatens the insulation between the poles immediately after disconnection. In order to suppress the rate of increase in the transient recovery voltage, a capacitor device is known in which a plurality of rod-shaped capacitor units are connected in parallel between the poles of the interrupting section so as to wrap around the interrupting section nine times.

[Problem to be solved by the invention]

In a gas circuit breaker, its rated breaking current is, for example, 53K.
In the case of A, the rate of increase in the A recovery voltage is the same whether the rated voltage is 600KV or 168KV. This is because the rate of increase in the transient recovery voltage is determined by the breaking current and line impedance, and therefore the capacitance of the transient recovery voltage suppression capacitor device (hereinafter referred to as the suppression capacitor device) is the same regardless of the rated voltage. You will need something with a large capacity.

On the other hand, with gas circuit breakers, when the rated voltage decreases, the insulation distance required to maintain the full withstand voltage is small, so it is recommended to shorten the diameter and length of this segmental tank and make the dimensions of the bushing etc. smaller. Common.

Therefore, it is necessary to keep the capacitance of the suppression capacitor device constant and reduce only its size. Conventionally, as a countermeasure against this problem, a disk-shaped ceramic capacitor constituting a rod-shaped capacitor unit is used with different dielectric strength and dimensions depending on the rated voltage, or the number of ceramic capacitors in series and the number of parallel capacitor units are changed. Efforts have been made to keep the capacitance constant through combinations. However, there is a problem in that the number of types of ceramic capacitors to be prepared increases, and as a result, the assembly work for assembling the ceramic capacitors becomes complicated.

The object of the present invention is to obtain a suppression capacitor device whose withstand voltage performance and thickness are reduced commensurate with the decrease in rated voltage without changing the size, withstand voltage, and capacitance of the disc-shaped capacitor.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, a pair of fixed side collector electrode and a movable side collector electrode are filled with an arc-extinguishing gas and are insulated and supported at both ends in the axial direction of a cylindrical tank; A blocking part provided between the collecting electrodes, and a pair of bushings supported by the cylindrical tank and having a center conductor connected to the pair of collecting electrodes, the movable part of the blocking part being connected to the axis of the cylindrical tank. For a circuit breaker that opens and closes by being driven in the direction, what is the required leg length? It consists of a series body consisting of disc-shaped capacitor mantissas housed almost concentrically in a three-edge cylinder, and disc-shaped conductive spacers with a certain thickness distributed and interposed between the capacitors. A plurality of capacitor units are provided with both ends conductively connected to the pair of collector electrodes, and the capacitor units are supported in parallel to each other between the pair of collector electrodes so as to substantially coaxially surround the cut-off metal. shall be taken as a thing.

[Effect]

In the above means, a plurality of disc-shaped capacitors are installed inside the insulating cylinder of a capacitor unit which is connected in parallel between the poles so as to surround the interrupting part of the gas circuit breaker, and the capacitors are interposed in a distributed manner between the capacitors. By accommodating a series body with a disc-shaped conductive spacer, in a gas circuit breaker with the highest rated voltage, all series bodies are composed of capacitors, and as the rated voltage decreases, capacitors are By reducing the number of spacers and increasing the number of conductive spacers, the withstand voltage performance of the series body decreases commensurate with the decrease in rated voltage, and at the same time, the capacitance of the series body increases, so the capacitor unit By reducing the number of cylindrical tanks in parallel, the outer diameter of the suppression capacitor device can be reduced in accordance with the reduction in the diameter of the cylindrical tank. Furthermore, the length of the series body can be reduced in proportion to the reduction in the rated voltage by changing the number or thickness of the conductive spacers. Therefore, by preparing one type of capacitor, a conductive spacer with approximately the same dimensions, and a large number of insulating tubes with the same inner and outer diameters, the dimensions and withstand voltage performance can be adjusted to suit each gas circuit breaker with a different rated voltage. A rich and equal capacitance suppression capacitor arrangement can be obtained.

〔Example〕

The following description will be made based on all the embodiments of this invention.

FIG. 1 is a sectional view showing a state in which a device according to an embodiment of the present invention is attached to a gas circuit breaker. In the figure, in a cylindrical tank 1 of a gas circuit breaker, a fixed side collector electrode 2A and a movable side collector electrode 2B are insulated and supported by supporting insulating tubes 8A and 8B, one end of which is fixed on the tank side. The central conductors of bushings 10A and 10B, whose insulator tube portions are flange-bonded to branch holes 1A and IB of the cylindrical tank 1, are conductively connected to 2A and 2B. Moreover, the interrupting part 6 includes a fixed contact 4A and an arc contact 6 provided on the side of the two collector electrodes.
A, a movable contact 4B provided on the collecting electrode 2B side,
It is composed of a movable arc contact 6B, an arc-extinguishing gas compression section consisting of a yohibanofer cylinder 5A and a fixed piston 5B, and a nozzle 9 made of an insulating material.
The buffer cylinder 5A is biased to the right side by being connected to the hydraulic cylinder of the drive device via the operation rod 8C, whose @ part is made of an insulated phase, and the arc extinguishing gas in the buffer cylinder 5B is compressed, causing a pair of arc contactors) 6A. , 6B is opened, arc-extinguishing gas is blown out between the poles and blows out the interruption arc generated in the nozzle 9A, thereby blocking the stain flow.

On the other hand, the capacitor device 11 that suppresses the rate of increase in the transient recovery voltage is composed of a plurality of rod-shaped capacitor units 12 in parallel, and both ends of the rod-shaped capacitor units 12 are connected and supported by a pair of collector electrodes 2A and 2B. Conductively coupled.

FIG. 2 is a sectional view taken along the line A-A in FIG. They are arranged coaxially with the blocking portion 6 and at approximately equal intervals on the circumference having a center radius R so as to maintain G2.

FIG. 3 is a cross-sectional view showing the main parts of the capacitor unit in the device of the embodiment. Series body 1 with spacer 15
A plurality of capacitors 1 are housed in the series body 16, and a surface pressure Pi is applied to both ends of the insulating cylinder 16 via a spring (not shown) by a pair of end fittings screwed together, for example.
4 are electrically connected in series via a conductive spacer 15. Further, for example, by making the outer diameter of the metal conductive spacer 15 approximately equal to that of the capacitor 14 and making the inner diameter of the insulating tube 13 slightly larger, assembly of the capacitor unit 12 can be facilitated. can.

On the other hand, if the thickness of the conductive spacer 15 is made equal to that of all capacitors 14 and the capacitors 14 and conductive spacers 15 are arranged alternately to form a series body 16 in which the number of capacitors 14 is halved, the length of the series body 16 is It is possible to halve the withstand voltage and double the series capacitance without changing the voltage, so this can be suppressed by reducing the number of parallel capacitor units 12 (12) shown in Fig. 2 to half that, that is, six. Capacitance partial pressure of the entire capacitor device can be kept constant. For example, in a gas circuit breaker where the series body 16 must be composed entirely of capacitors 14, in a gas circuit breaker whose rated voltage is half of that, the number of capacitors 14 used can be reduced to several kK, and the length of one gas gap Gl,
The average radius R that needs to be reduced in response to the shortening of G2
The number of capacitor units 12 reduced to six can be easily arranged at equal intervals on the circumference. Furthermore, when the rated voltage is halved, the axial length of the interrupting part 3 is also somewhat shortened, but this can be done by reducing the number of conductive spacers 15 or by changing the thickness of the conductive spacers and the total thickness of the capacitor 14. This can be easily accommodated by reducing the length of the insulating tube 13 to some extent, and the length of the insulating tube 13 can also be accommodated by truncating the end portion thereof.

Further, the suppression capacitor device 11 includes a plurality of capacitors 1
Since the potential of each series capacitor is substantially fixed by the capacitance division voltage of 4, it has the function of controlling the electric field distribution between the poles when the interrupting part 3 is in an open state.

In conventional devices that do not use conductive spacers, determining the thickness of the capacitor and the length of its laminate were important points in order to control the electric field between the electrodes, but in this invention, by introducing the conductive spacer 15, It is possible to freely control the potential in the longitudinal direction of the series body 16 by changing the thickness and the manner of dispersion. Therefore, by improving the electric field distribution, secondary effects can be obtained that can contribute to shortening the distance between shields and improving the insulation recovery voltage immediately after interruption.

〔Effect of the invention〕

As described above, the present invention uses a capacitor unit as a loose body consisting of a plurality of disc-shaped capacitors and disc-shaped conductive spacers distributed between the capacitors, and a surface pressure is applied within an insulating cylinder. The capacitor units are stored in a fully loaded state, and the capacitor units are connected in parallel between the poles so as to surround all the cut-off parts. As a result, the number of capacitors can be reduced in inverse proportion to the rated voltage of the target circuit breaker, and its replacement υ
By increasing the number of conductive spacers, it is possible to form capacitor units suitable for different rated voltages using one type of capacitor, and the series capacitance is increased by reducing the number of series capacitors.The total number of parallel capacitor units can be reduced. By reducing the capacitance, the capacitance of the entire suppression capacitor device can be kept constant regardless of the rated voltage, and the rate of increase in transient recovery voltage can be suppressed, so capacitors with different sizes and capacitances are used depending on the rated voltage. This eliminates the problems that occurred with conventional equipment, such as the large number of capacitors that must be prepared, the size of the insulating tube that houses them all, and the complicated assembly process. The gas circuit breaker is equipped with a complete HJ control capacitor device, which has voltage resistance performance and transient recovery voltage control performance that match the rated voltage in combination with the number of conductive spacers.The entire labor-saving assembly process It can be provided economically. In addition, the number of capacitor units can be reduced in line with the reduction in rated voltage, and the length of the capacitor unit can be fully adjusted by changing the number and thickness of conductive spacers, so the entire capacitor device can be easily downsized in response to shortened insulation distances/JS. This has the advantage of being able to reduce costs and reduce costs. Furthermore, the introduction of the conductive spacer has the advantage of further improving the electric field control performance between the circuit breaker poles.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line A--A in FIG. 1... Cylindrical tank, 2A, 2B... Collector electrode, 6...
・Shutoff part, 4A, 4B...Contactor, 5A...Buffer cylinder-5B...Fixed piston, 6A, 6B...
・Arc contactor, 8A, 8B...Support wheel cylinder, 11・
... Suppression capacitor if, 12... Capacitor unit, 13... Insulating cylinder, 14... Disc-shaped capacitor, 15... Conductive spacer, 16... Series body, R.
...Average diameter, G1. G2...gap length, P...
・Tightening load. (y (Go feast V' mouth

Claims (1)

[Claims] 1) A pair of fixed side collector electrodes and a movable side collector electrode that are insulated and supported at both axial ends of a cylindrical tank filled with arc-extinguishing gas, and one interrupting part provided between the pair of collector electrodes. ,
a pair of bushings supported by the cylindrical tank and having a center conductor connected to a pair of collector electrodes, and a movable part of the interrupting part is driven in the axial direction of the cylindrical tank to open and close the circuit breaker in a predetermined manner. A series body consisting of a plurality of disc-shaped capacitors housed almost concentrically in a long insulating tube, and disc-shaped conductive spacers having a predetermined thickness distributed between the capacitors. comprising a plurality of capacitor units each having both ends conductively connected to the pair of collector electrodes, and the capacitor units are supported in parallel to each other between the pair of collector electrodes so as to substantially coaxially surround the cutoff portion. A transient recovery voltage suppression capacitor device for a power gas circuit breaker, characterized in that: