JPH0223050Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial field of application" This invention relates to a gas insulated switchgear equipped with a lightning arrester and a voltage transformer.

"Prior Art" An example of the structure of the lead-in end of a conventional gas insulated switchgear is shown in the single line diagram of FIG. 2a.

In the figure, main bus 1 connected to cable head CH has lightning arrester LA and voltage transformer PT.
are connected via disconnecting portions D1 and D2, respectively.

An example of the arrangement of these devices is shown in FIG. 2b.

The lead-in end of the gas-insulated switchgear includes the cable head CH, which is the cable lead-in part, the lightning arrester LA, and the instrument transformer PT, as well as the branch bus 2, the main bus 1 that connects to other equipment, and the tank 3 that houses these.
It consists of etc. Further, the space inside the tank 3 is filled with an insulating fluid such as SF6.

The lightning arrester LA and the potential transformer PT are arranged on both sides of the cable head CH, and are connected to the main bus 1 with disconnecting sections D1 and D2 provided at their respective tops.

The disconnection sections D1 and D2 are each operated by an arbitrary operating device (not shown).

``Problems that the invention attempts to solve'' In the conventional example described so far, the disconnection parts D1 and D2 are provided at two locations, which not only complicates the structure but also requires two operating devices, which is unnecessary. It's the economy. Moreover, not only is the operation cumbersome as the operation has to be performed twice, but also
If a test voltage is applied with the PT circuit connected, there is a risk of damaging the equipment, and incorrect operation may lead to an accident.Therefore, an interlock device may be installed to prevent operation errors, and in this case, the structure becomes even more complex. .

``Means for solving the problem'' Focusing on the fact that the lightning arrester and voltage transformer can be connected to and removed from the main circuit at the same time, the lightning arrester and the voltage transformer are connected through a common bus. A disconnection section for opening and closing between the main bus bar and the lightning arrester is provided at the top of the surge arrester, and the disconnection section is operated by an operating rod that passes through the center of the surge arrester and is drawn out of the tank. It is characterized by being

"Example" FIG. 1a shows an example of how the devices of the present invention are connected.

In the figure, the lightning arrester LA and the potential transformer PT are connected to a common branch bus 11 via a common disconnection section D3.

FIG. 1b shows an example of the arrangement of the present invention in a front view.
Here, descriptions of common items with the conventional example shown in FIG. 2 will be omitted.

Lightning arrester LA and potential transformer PT are in tank 14
It is located adjacent to the cable head CH within the cable head CH and is connected by a common bus 12. The branch bus 11 connected to the main bus 13 has a disconnection section D that opens and closes between the branch bus 11 and the lightning arrester LA.
3 is installed above the lightning arrester LA.

The operating rod 15 that opens and closes this disconnection section D3 has one end connected to the disconnection section D3 and a lightning arrester.
The other end passes through the center of the LA and is drawn out to the outside of the tank 14, and is connected to the operating device 16.

To open and close the disconnection section D3 during a withstand voltage test, etc.,
If the operating rod 15 is moved downward or upward by the operating device 16, the disconnecting portion D3 is opened or closed, thereby opening or closing the circuit between the main bus bar 13, the lightning arrester LA, and the voltage transformer PT.

In the above embodiment, the branch bus bar 11 is drawn out from the main bus bar 13, and the disconnection section D3 is provided between the branch bus bar 11 and the arrester LA, but the branch bus bar 11 is omitted and the main bus bar 13 and the arrester LA are directly connected. Disconnection section D between
3 may be provided.

Note that the lightning arrester and potential transformer are disconnected from the main circuit in order not to apply the test voltage during the withstand voltage test, and there is no problem even if they are not disconnected independently.

"Effects of the invention" As described above in detail with the embodiments, according to the invention, the number of disconnections is reduced to one, which is one less than in the conventional technology, resulting in improved economic efficiency, downsizing, and reliability. Not only can this be improved, but the disconnecting section only needs to be opened and closed once, so labor can be saved.

In addition, since the operating rod for operating the disconnection section passes through the center of the arrester and is pulled out to the outside of the tank, it takes up less space inside the arrester than when the operating rod is installed outside the arrester inside the tank. can be used effectively, further downsizing becomes possible.

[Brief explanation of the drawing]

1a and 1b are a single line diagram and a front view showing an embodiment of the present invention, and FIGS. 2a and 2
FIG. b is a single line diagram and a front view showing a conventional example. In the figure, LA is a lightning arrester, PT is a voltage transformer, 12 is a common bus, 13 is a main bus, 14 is a tank, and 15 is an operating rod.

Claims (1)

[Scope of utility model registration request] In a gas-insulated switchgear including at least a lightning arrester and a voltage transformer in a tank, the lightning arrester and the voltage transformer are connected by a common bus, and a disconnection section for opening and closing between the main bus and the voltage arrester is provided. A gas insulated switchgear, characterized in that the disconnection section is disposed above the lightning arrester and is operated by an operating rod that passes through the center of the lightning arrester and is pulled out of the tank.