JPS60163317A - 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] [Technical Field of the Invention] The present invention relates to a gas-insulated switchgear for electric power using SF6 gas as an insulating medium, and in particular to control of a disconnector constituting the gas-insulated switchgear. It is related to circuits.

[Technical Background of the Invention] Gas insulated switchgears are used in various places, and an example of one used when drawing out a line side or bank side line from a pair of main busbars is shown in Fig. 1. That's right. That is, a circuit breaker 5 is connected to the main buses 1 and 2 via a disconnect switch 3.4, and a circuit breaker 6 is further connected to this circuit breaker 5, so that the line is drawn out from the main bus 1.2. ing. Then, the main buses 1 and 2, the circuit breaker 5 and each disconnector 3
, 4゜6 are connected with grounding devices 7 to 11, respectively.
is connected.

In this way, gas-insulated switchgear is an assembly composed of various switchgear devices such as circuit breakers, disconnectors, and grounding devices.
Various improvements have been made to the control circuits of these devices. In particular, the control circuit of the disconnector incorporates an interlock circuit with adjacent equipment to prevent the disconnector from switching on or off a large load current.

The idea behind the disconnector interlocks that have been used so far is that when the disconnector is opened or closed, the adjacent circuit breaker and grounding device must both be in the open state. For example, in the configuration shown in FIG. 1, the opening/closing conditions for the disconnector 3 are that the grounding devices 7, 9, and 10 are in the open state, and the breaker 5 is in the open state.

An example of a circuit for satisfying such interrotter conditions is shown in FIG. Although the diagram is simplified,
The a contact 3a and the b contact 3b of the disconnector 3 are connected to the negative sides of the parallel-connected service coil 12 and closing coil 13, respectively, and the grounding device 7 is connected to these contacts 3a and 3b.
．． The b contacts 7b, 9b, 1ob of 9 and 10 and the b contact 5b of the circuit breaker 5 are connected in series.

[Problems with Background Art] By the way, in gas-insulated switchgear, the main circuit electrode part is housed inside a grounded metal container and cannot be easily seen from the outside. As methods, main circuit resistance measurement and main circuit switching time measurement are being evaluated.

This is a meaningful testing method not only for the initial data at the time of installation, but also for several years after operation begins.

As mentioned above, the main circuit is housed inside the container, so
For this measurement, a grounding device is used. Now, the first
In the figure, in order to measure the opening/closing time of the disconnector 3, the grounding device 7 and the grounding device 9 are turned on, and a measuring device is inserted between the grounding devices. It should be possible. However, in the conventional interlock circuit and path as shown in FIG.
With the input of , the b contacts 7b and 9b become open,
Disconnector 3 could not be operated because the opening/closing conditions were not established, and the opening/closing time could not be measured.

Also, an IC that inserts a measuring device into the grounding wire part of the grounding device.
For this purpose, as shown in FIG. 3, one of the grounding terminals must be constructed so that it can be insulated from the container of the gas-insulated switchgear. That is, the grounding terminal 20 on the grounding device 9 side needs to be insulated from the container 21 of the gas-insulated switchgear.

At this time, for example, in FIG. 1, if the main bus 1 is in operation, electrostatic induction exists due to the interelectrode capacitance even if the disconnector 4 is in an open state. here,
If you attempt to install the measuring instrument 22 shown in Figure 3 with the disconnector 3 open, a large static N-induced voltage will be generated at the ground terminal 20 as soon as the ground wire is removed, which may cause harm to the human body.・
It is very dangerous. However, in a multi-bus type substation,
Normally, at least one of the main buses continues to operate, and cannot be stopped at the same time.

Due to these circumstances, in the conventional technology, once the gas insulated switchgear is put into operation, it has not been possible to adopt a method of checking the performance of the disconnector by measuring it on the main circuit side.

[Object of the Invention] The present invention was proposed in order to solve the problems of the prior art as described above, and its purpose is to prevent the disconnector from opening and closing even when the grounding devices disposed at both poles of the disconnector are closed. An object of the present invention is to provide a gas-insulated switchgear that is operable and that allows the performance of a disconnector to be checked on the main circuit side by safely inserting a measuring instrument into the grounding wire of the grounding device during operation. .

[Summary of the Invention] The gas insulated switchgear of the present invention has two grounding devices installed on one pole side of a disconnector and one grounding device installed on the other pole side in parallel with the conventional interlock condition. By incorporating a condition that allows the disconnector to be opened and closed when the grounding device of both poles is closed, the disconnector can be opened and closed even when the grounding devices of both poles are closed.

In addition, the present invention enables one of the two grounding devices provided on one pole side of the disconnector and the circuit breaker to be in the closed state, thereby preventing electrostatic induction caused by the main bus during operation. The purpose is to release the voltage from this grounding device and suppress the dangerous voltage generated in the grounding wire portion of the other grounding device installed at both poles of the disconnector.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the circuit diagram of FIG. 4.

An a contact 3a and a b contact 3b of the disconnector 3 are connected to the negative sides of the application coil 12 and the closing coil 13 of the disconnector 3, which are connected in parallel, respectively. These contacts 3a,
3b, the b contacts 7b, 9b, 10b of the grounding devices 7, 9, and 10 and the b contact 5b of the circuit breaker 5 are connected in series so as to satisfy the conventional interlock conditions. at the same time,
Disconnector 3
A contacts 7a, 9a, and 10a of the grounding devices 7, 9, and 10 connected in series are connected in parallel to the b contacts of each of the grounding devices.

The operation of the gas insulated switchgear of the present invention having the control circuit having such a configuration is as follows.

Under normal conditions, the circuit breaker 5, each grounding device 7゜9.10
The disconnector 3 can be opened and closed when it is in the open state and its b contacts are both on, that is, under the same conditions as the conventional interlocker.

On the other hand, when opening/closing the disconnector 3 and checking its performance, it is necessary to turn on each grounding device @7.9.10 installed at both poles of the disconnector 3. In that case, under the conventional interlock conditions, the b contacts of each grounding device are turned off, making it impossible to open and close the disconnector!f). However, in the present invention, the bipolar grounding device A, 9.10 is turned on in parallel with the conventional interlock condition, and when the A contacts 7a, 9a, 10a are turned on, the opening/closing operation of the disconnector 3 is performed. Since it is possible to ground these
! The performance of the disconnector 3 can be measured by operating the disconnector 3 with the A position turned on.

Moreover, in this embodiment, two grounding devices are connected to one pole of the disconnector, one of which is connected to the circuit breaker 5.
Since it is connected to another disconnector 4 facing the main bus 1 in operation, if this earthing device 10 and breaker 5 are connected, other disconnectors may Vessel 4
It is possible to release dangerous voltages due to capacitance occurring in the grounding device 10 from this grounding device 10. As a result, disconnector 3
It is possible to safely insert the measuring instrument 20 into the ground wire portions of the remaining two grounding devices 7.9. Note that the closing of the breaker 5 in this case can be carried out without any restrictions since the breaker does not have an interlock condition built into it.

[Effects of the Invention] As described above, according to the present invention, it is possible to open and close a disconnector even when both earthing devices are connected, so it is not necessary to insert a measuring instrument between the earthing devices. With this simple method, it is possible to measure the opening and closing of a disconnector, which has the effect of making quality diagnosis, which is the initial objective, easier.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing the configuration of a general gas insulated switchgear, Fig. 2 is a circuit diagram of a circuit that controls the interlock conditions of a disconnector used in this gas insulated switchgear, and Fig. 3 is a circuit diagram showing the configuration of a general gas insulated switchgear. The figure is a circuit diagram showing the mounting state of a measuring instrument inserted into a grounding device to measure the opening/closing of a disconnector in a gas-insulated switchgear, and FIG. FIG. 3 is a circuit diagram of a circuit that controls lock conditions. 1.2... Main bus bar, 3, 4.6... Disconnector, 5...
- Breaker, 7.8.9. ．． 10.11... Earthing device, 12... Service coil, 13... Closing coil, 20
... Insulated terminal, 21 ... Gas insulated switchgear container,
22...Side measuring device, 3a, 3b-...Contact point of disconnector, 7
a, 9a. i o a--A contact of grounding device, 7b, 9b, 10
b...B contact of the grounding device. 7317 Agent Patent Attorney Noriyuki Kensuke (1 person) #11 Figure 3 Figure 4

Claims (2)

[Claims] (1) In a gas-insulated switchgear in which a breaker is connected to the main bus through a disconnector, and a grounding device is connected to both poles of the disconnector, the control circuit of the disconnector is connected to both poles of the disconnector. A gas-insulated switchgear characterized by incorporating a condition that enables a disconnector to be opened and closed when a grounding device is in a closed state. (2) The main bus bar is a multi-bus bar, and each main bus bar is connected to a breaker via its own disconnect switch, and one pole of the disconnect switch is connected to the operating main bus bar by another disconnect switch. 2. The gas insulated switchgear according to claim 1, wherein two grounding devices are connected: a grounding device connected via the circuit breaker, and a grounding device for measuring opening/closing of the disconnector.