JPS60200712A - Ground switch for gas insulated switching device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a grounding switch for gas insulated switchgear.

Gas insulated switchgear (hereinafter referred to as GIS) consists of a circuit breaker body, a disconnector body, a bus conductor, etc. housed in a metal container at ground potential filled with an insulating gas such as SF6 gas. For the purpose of ensuring safety, earthing switches are provided at important points to ground the main circuit, that is, the energized main circuit constituted by the circuit breaker body, the disconnector body, and the connection/disconnection of the bus conductor.

By the way, as mentioned above, the main circuit of GIS is sealed, so measuring the main circuit resistance to check whether it maintains the specified performance is necessary to measure the main circuit resistance at the terminals of each device such as the circuit breaker body and disconnector body. This cannot be done directly from outside the container using For this reason, the voltage drop method is used using two earthing switches.

However, when using a normal grounding switch, there is a problem in that a value that also includes the resistance of the grounding switch is derived.

In contrast, it can be seen that if the main circuit grounding circuit (current injection circuit) and the main circuit voltage measuring circuit are separated, the resistance of the grounding switch will not be included.

A conceivable solution that satisfies this requirement is a circuit for electrical measurement in which the movable part and the voltage measurement terminal are connected by a flexible electric wire. However, according to this configuration,
If the number of openings and closings increases, there are problems in that the connecting portion of the electric wire may break due to fatigue, or the flexible portion may become entangled with other parts, causing operational problems or breakage. It is also conceivable to construct a voltage measuring circuit by making constant sliding contact during the entire stroke of the opening/closing operation instead of using the flexible wire, but this has the drawback of accelerating the wear and tear of the contacts.

The present invention was proposed in view of these points, and its purpose is to provide a grounding switch for GIS that not only enables the main circuit to be grounded but also accurately measures the main circuit resistance and has a simple structure and high reliability. It's about doing.

The inside is filled with an insulating gas 2 such as SF6 gas at a predetermined pressure. Reference numeral 6 denotes an end container that closes the open end of the container 1, and also serves as an operation mechanism container for the earthing switch 4 and the disconnector 5. 6.7.8 are earthing switch fixed contacts, sliding contacts,
It is a movable contact. Is contact 6 the main circuit center conductor? , an insulating spacer 10, and a mounting base 11 for all six phases arranged in a direction perpendicular to the plane of the paper. The sliding contact 7 has a contact base 12 and a mounting plate 16 made of insulating material for 6 phases at once.
It is supported by the container 6 via.

The movable contactor 8 is operated by an operating device (not shown) connected to an operating shaft 17 via a connecting rod 14 made of an insulating material, a mounting hardware 15 for all six phases, and an operating lever 16. Reference numeral 18 denotes a guide for guiding the mounting hardware 15 to move linearly, and is arranged between the phases. 19 is a stopper.

In this embodiment, the movable contactor 8 has a cylindrical shape, and a voltage detection movable conductor 21 is housed therein via an insulating tube 20. The conductor 21 is configured such that its tip 21 a slightly protrudes from the tip of the movable contact 8 and comes into contact with the fixed side voltage detection contact 22 . Reference numeral 26 denotes a spring for pressure contact.An auxiliary movable contact 24 is attached to the other end of the conductor 21 and protrudes from the side surface of the movable contact 8 in a perpendicular direction.

An auxiliary fixed contact 25 that receives this contact 24 is attached to the mounting plate 16. 26 is a grounding conductor, 27 is a voltage detection conductor, and these are placed inside an insulating spacer 28 made of an insulating material such as epoxy resin. is embedded in the . 29 is the conductor 26 and the contact base 1
2, and 60 connects the conductor 27 and the contact 25? This is a connecting conductor for pressure detection.

The grounding terminal 26a of the lead-out conductor 26 is connected to a mounting grounding bar 62 for all six phases via a grounding conductor 61. This bar 62 is secured at a predetermined height by a stand 66.

64 is a shield, 65 is a main circuit lead-in conductor, and 66 is a main circuit lead-in conductor.

Further, each component for six phases is arranged in a direction perpendicular to the plane of the paper, but the explanation is omitted.

The disconnector 5 has a fixed contact, a sliding contact, a movable contact that slides into and out of contact with these contacts, and is operated from outside the container 3, but a description thereof will be omitted.

When the disconnector 5 is closed and the main circuit conductors 35, 9.66 are connected, the earthing switch 4 is opened. In this state, the main circuit is energized.

The main circuit conductors 65 and 9 can be grounded by breaking a circuit breaker (not shown), opening the disconnector 5, and then closing the earthing switch 4. As a result, the fixed contact 6, the movable contact 8, the sliding contact 7, the contact base 12, the connection conductor 29, the lead-out conductor 26,
After six phases are short-circuited, grounding is performed through the container 6 through a main circuit grounding circuit formed by a grounding conductor 61 and a grounding bar 62.

The auxiliary contacts 24 and 25 come into contact near the closing position of the earthing switch 4, that is, the area where the movable contact 8 and the solid grass contact 6, and the conductor 21 and the contact 22 come into contact. Therefore, the above-mentioned earthing circuit is Separately, a main circuit voltage measuring circuit is formed which includes the spring 26, the contact 22, the conductor 21, the contacts 24 and 25, the connecting conductor 60, and the conductor 27.

To measure the main circuit resistance, for example, the circuit breaker O
Earthing switches 4, 4' sandwiching the measured sections a and b with B
Close the respective lead-out conductors and ground terminal 2 at 26'.
Remove ground conductor 55.3.5' from 68.268'. Then, connect the measurement power source to flow a current, measure the voltage between the voltage detection conductors 27 and 27' with a voltmeter V, and add a resistance. In this way, the voltage between the conductors 27° and 27' is the same as the voltage between the measured sections a and b, and the resistance of the main circuit can be directly measured, making it possible to check with extremely high accuracy. . That is, only the main circuit resistance can be measured without including the resistance of the contact portions of the grounding devices 4, 4', the lead-out conductors, etc.

In this example, since no flexible wires are used, there will be no fatigue breakage due to opening/closing operations or troubles such as the flexible wires getting entangled with other parts, and the sliding parts are also minimized, reducing wear and tear. few. In addition, less operating force is required.

In the embodiment shown in FIG. 1, the open circuit special voltage detection conductor 21 and the contact 24 are electrically insulated, and it is not inconceivable that a voltage may be induced due to induction from the main circuit voltage. However, in reality, the capacitance to the ground potential section is much larger than the capacitance to the main circuit and does not pose a problem.

However, if you are concerned about this voltage, as shown in Figure 3, provide a contact 67 to connect the conductor 21 to the lead-out conductor 26 when the circuit is open, or use a high resistance that does not interfere with voltage measurement and is always movable. What is necessary is to take measures such as connecting it to the contactor 8.

As explained above, in this study, the main circuit voltage side reverse circuit was provided independently from the main circuit grounding circuit, and the latter was configured so that it was closed only near the closing position of the former, so that the main circuit could be securely connected. Not only can the grounding switch be grounded accurately, but only the main circuit resistance can be accurately measured, and there is no need for flexible wires, etc., making it possible to obtain a highly reliable grounding switch for GIS with a simple structure.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing one embodiment of the present invention, FIG. 2 is an electric circuit diagram explaining the main circuit resistance measuring method according to the method shown in FIG. 1, and FIG. 6 is a side sectional view showing one embodiment of the present invention. FIG. 6: Fixed contact 7: Sliding contact 8: Movable contact 20: Insulating cylinder 21: Voltage detection movable conductor 2: Fixed side voltage detection contact 24: Auxiliary movable contact 25: Auxiliary movable contact 26: Output conductor 27: Voltage detection conductor 29, 30: Connection conductor Patent applicant Nissin Electric Co., Ltd. Representative Ue 1) Hisa - Ke 1 Ino 7 Fig.

Claims (1)

[Claims] A grounding switch for a gas-insulated switchgear, characterized in that a main circuit voltage measuring circuit is provided independently from a main circuit grounding circuit, and the latter is configured to be closed near the closing position of the former.