JPH01239718A - Vertical cutting type disconnecting switch - Google Patents

Abstract

PURPOSE:To reduce sufficiently the induced voltage generated to a lower terminal when the contact is disconnected by placing a capacitor between the lower terminal plate and a case at the earthing side to make the electrostatic capacity between electrodes much larger. CONSTITUTION:An upper side terminal plate 5 is connected to the current application side, while a lower side terminal plate 3 is connected to the load side. when the circuit and the like of the load side are tested, the shaft 13 in a case 1 is turned to operate a blade 8 together with an insulating rod 11 and the circuit is disconnected. In this case, where the voltage to ground of the terminal plate 5 is made V1, the voltage to ground of the terminal plate 3 is made V2, the electric capacity between the electrodes of the terminal plates 5 and 3 is made C1, and the electrostatic capacity between the terminal plate 3 and the ground is made C2, a formula V2=V1XC1/(C1+C2) is formed. In this case, since a capacitor 17 is provided between the case 1 and the terminal plate 3, the value of C2 can be made much larger than the value of C1. As a result, the induced voltage of the vertical cutting type disconnecting switch can be detected to be sufficiently low even though the terminal plate 3 is detected by a detector after the contact 10 is disconnected.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vertical disconnect switch used in power plants, substations, etc.

(Prior Art) A vertical disconnect switch in which a contact provided between an upper terminal board and a lower terminal board is opened and closed by an insulating rod has been known for a long time, and is useful when, for example, inspecting a circuit. Then, use this disconnector to disconnect the load side circuit from the power supply side connected to the upper terminal board, and then check the voltage at the lower terminal board with a windmill-type voltage detector to confirm that the circuit is interrupted. 6
11 It is stipulated that after tx, a grounding wire should be attached to the lower terminal board and inspection work should be performed. However, when I tried to perform inspection work using the above procedure on a recently developed cut-off type gas disconnector whose contacts were filled with an insulating gas such as SF gas, I found that the circuit was disconnected. However, the windmill of the windmill-type voltage detector rotated, indicating that a voltage of 3,000 V or more was occurring at the lower terminal board, resulting in a problem in which work could not proceed.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and when the circuit is open, a high voltage that can be detected by a windmill-type voltage detector is generated on the lower terminal board. The object of the present invention is to provide a vertical disconnect switch that prevents this from occurring.

(Means for Solving the Problem) As a result of investigating the cause of the above-mentioned high voltage occurring in the lower terminal board, the present inventor found that good gas insulation is particularly important in gas-filled vertical disconnectors. The capacitance between the poles is large because the separation distance of the disconnecting section is made small using the characteristics, and the capacitance to ground is small, so the upper terminal board is in a energized state. The present invention was completed based on this knowledge, and the present invention was completed based on this knowledge. The connected contact extends from the case on the ground side l! In a vertical disconnect switch that opens and closes from an L edge, a capacitor is placed inside the lower insulator tube that insulates and supports the lower terminal board above the case, making the capacitance to ground larger than the capacitance between the poles. It is characterized by:

(Example) The present invention will be explained in more detail below with reference to an example of a gas-filled vertical disconnect switch shown in the figure. The lower insulator tube is erected, (3) is the lower terminal plate, (4) is the upper insulator tube installed above it, and (5) is the upper terminal plate. is included. (6)
is an upper fixed contact fixed in the upper insulator tube (4) by a conductor (7), and (8) is a blade provided through the lower fixed contact (9), and this upper fixed contact ( 6) and play 1'+8) constitute a contact point 0[9. This blade (8) is an insulating rod (11) extending upward from the case (1) inside the lower insulator tube (2).
) is attached to the upper end of the insulating rod (11) via a connecting fitting (12), and when the shaft (13) is rotated, the insulating rod (11) and the blade (8) move up and down via the link (14). Contact Om can be opened and closed. The current flows through the upper terminal board (5), the conductor (7), the upper fixed contact (6), the blade (8), the lower fixed contact (93), and the Ill of the lower terminal board (3), the shield (15), The electric field is relaxed by (16). (17) is this lower insulator tube (2).
) is a capacitor installed inside. The upper end of the capacitor (17) is connected to the lower terminal plate (3) by the 6 bodies (18).
), or its lower end is connected to the case (1) by a conductor (19). Note that the capacitor (
As 17), it is preferable to use a ceramic capacitor with a large capacitance, and if it is shaped like a donut surrounding the insulating rod (11), the capacitance can be made sufficiently large.

(Function) The device configured in this way is used by connecting the upper terminal board (5) to the power supply side and the lower terminal board (3) to the load side, and the circuit etc. on the load side When inspecting the insulating rod (1), rotate the shaft (13) inside the case (1).
The circuit is opened by pulling down the blade (8) together with 1) and separating the blade +81 from the upper fixed contact (6), as in the case of conventional modified disconnectors of this type. In this case, the voltage to ground of the upper terminal plate (5) is V and the voltage to ground of the lower terminal plate (3) is V! , the capacitance between the electrodes of the upper terminal plate (5) and the lower terminal plate (3) is 01, and the lower terminal plate (
Assuming that the capacitance to ground in 3) is 02, the following relationship holds between them.

Vx −V+
However, in the present invention, since the capacitor (17) is provided between the case (1) and the lower terminal plate (3), the value of Ct is
The value of I can be made much larger than the value of I, thereby making the value of V2 sufficiently smaller than the operating voltage of the electroscope, which is 3000 V, even when the value of V is several hundreds of thousands of V. be able to. Therefore, in the vertical disconnection switch of the present invention, even if the voltage of the lower O:i plate (3) is detected using a windmill type voltage detector after the contact O1 is opened, the windmill will not rotate.
Subsequent installation of the grounding wire and inspection of the load-side circuit can be carried out without any problems. Furthermore, in the present invention, since the capacitor (17) is housed inside the lower insulator tube (2), there is no problem with insulation and there is no need to provide extra protrusions on the outside.

(Effects of the Invention) As is clear from the above description, the present invention includes a capacitor between the lower terminal plate and the case on the ground side to increase the capacitance to ground. Since we have succeeded in sufficiently reducing the induced voltage generated on the lower terminal board, the voltage detector will not activate when the lower terminal board is tested for voltage in accordance with safety regulations after the contacts are opened. , inspection work, etc. can be carried out without any hindrance. Therefore, the present invention greatly contributes to the development of industry as a vertical disconnector that eliminates the problems of the conventional art.

[Brief explanation of the drawing]

The drawing is a central vertical sectional view showing an embodiment of the present invention. (1): Case, (2): Lower insulator tube, (3): Lower terminal plate, (5) Two upper terminal plates, OI: Contact, (11): Insulating rod, (17): Capacitor.

Claims (1)

[Claims] A vertical disconnector in which a contact (10) provided between an upper terminal plate (5) and a lower terminal plate (3) is opened and closed by an insulating rod (11) extending from a grounding side case (1),
A capacitor (17) is placed inside the lower insulator tube (2) that insulates and supports the lower terminal board (3) above the case (1), and the capacitance between the ground and the ground is made larger than the capacitance between the poles. Features a vertical disconnect switch.