JPS61254011A - Gas insulated switchgear - 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] [Field of Application of the Invention] The present invention relates to a gas insulated switchgear, and in particular to suppressing overvoltage due to a restriking surge that occurs when a disconnector interrupts charging current of a gas insulated bus bar, etc. The present invention relates to a gas insulated switchgear constructed as follows.

[Background of the invention]

In gas-insulated switchgear, a restriking surge occurs when a disconnect switch cuts off the bus charging current, but in the worst case, theoretically, the surge will be tripled at the disconnect switch, and it will be three times that surge at the open end of the bus. Otherwise, a large overvoltage will occur. In order to withstand these overvoltages, it is necessary to increase the size of the disconnector, bus bar, and gas-insulated switchgear, and it is desired to suppress the surges from the economic point of view. Also due to the intrusion of surge voltage through control lines, grounding lines, etc. Surge suppression is also desired from the perspective of preventing operational problems such as dielectric breakdown and malfunction.

From the point of view of surge suppression, when using a interrupting resistor-type disconnect switch, first, when the main contact is opened to interrupt the charging current, the restriking surge is suppressed by the parallel resistance Kl, and then the resistance current flowing through the resistor is suppressed. Method of breaking with resistance contact
Although there is a reference to Publication No. 38031, the structure of the disconnector is complicated and is economical.

There was a problem with reliability. As a means of suppressing the current flowing through the conductor, it has been proposed to provide a magnetic ring on the conductor (see Utility Model Application No. 56-27808 and Utility Model Application No. 58-22808), but In devices with a

[Purpose of the invention]

The present invention eliminates the drawbacks of the prior art, provides a gas insulated switchgear having a simple structure and sufficient surge suppression effect, and aims to improve economy and reliability.

[Summary of the invention]

The present invention relates to suppressing disconnector surge by installing a ferromagnetic ring around the surge propagation conductor of a gas-insulated switchgear, and particularly relates to the installation location of the ferromagnetic ring, and relates to the installation location of the ferromagnetic ring. By installing a ferromagnetic ring on the side of the disconnector from the branch point of the branch busbar that is disconnected by the device, the installation space can be reduced, and by installing it close to the disconnector, the disconnector can be disconnected. This is characterized by improving the efficiency of device surge suppression.

[Embodiments of the invention]

An embodiment of the present invention is shown in FIG. 1, and a switch 6.7 such as a bus 3% disconnector 21, a branch bus A4, and a circuit breaker is connected from a power supply (not shown) to a permeate terminal l such as a bushing. A current is supplied to a load (not shown) via the busbars 8 and 9, and a ferromagnetic ring l is also provided on the power supply side at the branch point 5 of the busbars.
O is installed. The ferromagnetic ring IO has a negligible damping effect on load currents at commercial frequencies, and has a large damping effect on high frequency components of several hundred to several tens of MHg that occur when restarting when charging current is cut off. A ring made of good material, such as 7-elite, is suitable.

For example, when stopping this gas-insulated switchgear, first operate the switch 6.7 such as a circuit breaker, cut off the load current flowing through the mains a8 and 9, and open the switch 6.7. The state is maintained, and then the disconnector 2 is operated to disconnect. At this time, the disconnector 2 connects the high voltage conductors 4a, 4b, 4 of the 1-branch bus 4.
This will cut off the charging current flowing through the capacitance between the capacitance c and the grounded container 4d. As is well known, the disconnector shuts off while repeating restriking, but the ferromagnetic ring lO suppresses the sassage.

As for the installation location of the ferromagnetic ring, if it is installed on the load side of the branch point 5, it may be necessary to install the ferromagnetic ring 11 and 12 as shown in Figure 2, which may cause a surge in the SC1 disconnector. There is a risk that the point will separate from the disconnector 2, and the surge suppression effect will not be effective. On the other hand, if the ferromagnetic ring 1O is installed on the power supply side from the branch point 5, it is only necessary to install the ferromagnetic ring 1O in one place as shown in Fig. 1, and since it is close to the disconnector 2, which is the point where the surge occurs, the surge suppression effect can be improved. Effective.

A more detailed study shows that if the conductor 4a of the branch bus bar is short, the surge suppression effect is great even if it is installed in the ferromagnetic ring 10 near the first branch point 5.

If the conductor 4a of the branch bus bar is long, the surge suppression effect will be small even if it is installed in the ferromagnetic ring lO near the first branch point 5. Therefore, from the standpoint of suppressing surges and mechanically holding the ferromagnetic magnetic ring, the movable contacts 2a and 9 of the disconnector are installed near the insulators 13 and 14 that support the fixed contacts 2b. It is preferable to do so. In particular, as shown in FIG. 2, when ferromagnetic rings 15 and 16 are provided between the contacts of the disconnector and the insulator that supports the contacts, the effect of suppressing surges on the insulator is great.

The shape of the ferromagnetic material is other than the shape shown in the figure.
A cylindrical shape and various other configurations are possible.

Note that if one of the branch busbars 4b and 4c is extremely long compared to the other, it is also a part of the present invention to separately provide a ferromagnetic ring on the longer busbar at the branch point and the load side. It can be applied as a modification.

Although there are various actual substation configurations, FIG. 4 shows an example of the double busbar shown in FIG. 3.

lK3'1AKj? Ite, 2fffillLt,
L2. In the case of two banks of transformers Tt+T2, there are connections from a power transmission line (not shown) to a current terminal Lt, a bus bar 20, a disconnector 22. Mother a23° circuit breaker 21, mother #I28, 29, 30. It consists of disconnectors 24 and 25, busbars 26 and 27, and main busbars 18 and 19. From current terminal L1 to bus bar 20, disconnector 2
2, bus bar 23, gIAvfr device 21. Mother I! 1128°30, lFr line unit 2 {, main bus 18 via bus $26
The disconnector 25 is operated in an open state.

When disconnecting the hL1 line from this state, first
1 t-! Then, the charging current of the mother @23 is dialyzed by the disconnector 22%, and the charging current of the mother @28.29.30 is dialyzed by the disconnector 24.

When the charging current of the bus bar 23 is cut off by the disconnector 22, a ferromagnetic ring 31 may be provided at the location shown in the figure, for example, as shown in FIG.

In the case where the charging current of the bus bars 28, 29, 30 is connected or disconnected by the disconnector 24, for example, the connection between the branch point 5 of the busbar and the disconnector 24 is performed.
If the ferromagnetic ring 32 between the two is provided at the location shown in the figure, a score surge suppression effect can also be expected for the busbars 29 and 30. In addition, the 9th line may be operated by connecting to bus 19,
In this case, a ferromagnetic ring must also be installed on the disconnector 25 side! There is. Although FIG. 4 shows an example in which the ferromagnetic ring is provided on the load side of the disconnector, it can also be installed on the main bus bar 26 or 27 between the main bus stops having a branch section on the power supply side.

The present invention describes an example of only a gas-insulated busbar;
The same effect can be obtained even if overhead wires or cables are connected to part of the power supply side and load side.

〔Effect of the invention〕

According to the present invention, in a gas insulated switchgear, by providing one ferromagnetic ring closer to the power source than the branch point of the branch ea that is cut off by the disconnector, the ferromagnetic ring It is possible to reduce the number of disconnectors, and by installing them close to the disconnector, it is possible to effectively suppress surges.
A gas-insulated switchgear with simple structure, economy, and reliability can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram showing one embodiment of the gas insulated switchgear of the present invention, Fig. 2 is an explanatory diagram of another embodiment of the gas insulated switchgear of the present invention, and Fig. 3 is a double bus type single wire The wiring diagram in FIG. 4 shows another embodiment in which the present invention is applied to a double bus type gas insulated switchgear. 1...Current terminal, 2.22, 24, 25...Disconnector, 2a, 2b---Contact of disconnector, 3,4,8,9゜2
0.23, 26, 27, 28, 29.30... Bus line,
4a, 4b, 4c...branch busbar, 4d...ground tank, 5...branch point, 6.7...switch, 8.9...
・Bus line! 0,11.12.15.16...Ferromagnetic ring, 13.14...Insulator, 18.19...Main bus bar, 21...Blocker.

Claims (1)

[Claims] 1. A disconnector having at least a pair of contacts that are supported by an insulating support and can be relatively connected and separated is provided in a container filled with an insulating gas, and one contact of the disconnector is The other contact is connected to a current terminal attached to the end of the container and connected to a power source, and the other contact is connected to a bus bar in which a conductor is insulated and supported in a container filled with insulating gas, and the bus bar has a branch part and at least A device connected to two or more busbars, each connected to another circuit breaker or disconnector, characterized in that a ferromagnetic ring is provided on the outer periphery of the conductor between the branch part of the busbar and the current terminal. gas insulated switchgear. 2. The gas insulated switchgear according to claim 1, wherein the ferromagnetic ring is provided near an insulating support that supports the contact of the disconnector. 3. A gas insulated switchgear according to claim 1 or 2, wherein the ferromagnetic ring is provided between a contact of the disconnector and an insulating support.