JPS5922663Y2 - Shield device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a shield device that employs a snow melting structure.

For example, the insulation performance of a gas bushing is determined mainly by controlling the electric field by a grounding shield 5 in the gas and a grounding shield ring 6 in the atmosphere, as shown in FIG.

The shield ring 6 is usually made of a relatively large-diameter tube in a toroidal shape, and if a large amount of snow adheres to it when a large amount of wet snow falls, the state of the electric field will change and the required insulation performance may not be maintained. There is sex.

Also, when a large amount of snow falls all at once, it can cause damage to structures below.

In order to prevent these problems, it is possible to embed, for example, a sheathed wire heater in the shield ring 6 and heat it to melt the snow, but this requires sufficient consideration regarding the heater's heat resistance, insulation, and disconnection, and is relatively expensive. I have no choice but to become

An object of the present invention is to provide a shield device that has a snow melting structure by directly passing an electric current through the shield ring.

The present invention will be described below with reference to an embodiment shown in FIG.

In FIG. 2, the shielding device of the present invention has a structure in which a current is passed directly through the shield ring 6 to generate heat.

The legs 11 of the shield ring must be installed insulated, but as will be described later, the voltage is at most several volts, so insulation is easy.

12 is a copper strip, 13 is an insulating spacer for fixing the copper strip 12, 14 is an iron core, and 15 is a coil.

If the shield ring 6 is made of non-magnetic stainless steel, for example, it is convenient because it has a relatively high electrical resistance, there is no difference in heat generation depending on whether or not the bushing is energized, and it has excellent corrosion resistance.

As an example, to explain the shield ring 6 of a bushing for 300 KV, as with a stainless steel shield, the lighting equipment of this invention has a resistance of about 2 to 4 million ohms and a reactance of about 1 million ohms, When connected to a 1 volt, 300 A power source, it generates a moderate amount of heat.

In FIG. 2, the shield ring 6 is connected to a power supply section 16 via a copper strip 12.

As a power source, if a so-called current transformer consisting of an iron core 14 and a coil 15 is used as shown in the figure, the required electric power can be easily obtained, and even with human power, an appropriate value such as 100 volts and 3 amperes can be obtained.

As is clear from the above description, according to the present invention, the overall structure is simple and strong, most parts only require insulation of a few volts, and only the power supply section 16 has a waterproof structure. This has many advantages in terms of flexibility in the mounting position of the shield ring and overall reliability.

In addition, it can be applied not only to shield rings for gas bushings, but also to any ground shield or snow melting of structures such as handrails.

As described above, according to the present invention, since the current is passed directly to the shield ring, the overall structure is simple and strong, and there are many advantages in terms of safety (the working voltage is extremely low) and reliability, and maintenance and inspection are also easy. It is possible to provide a shielding device with many advantages that requires only a power source at hand.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a gas bushing, and FIG. 2 is a perspective view showing an embodiment of the shielding device of the present invention. 1... Main circuit terminal, 2... Insulator tube, 3
...Conductor, 4...SF6 gas filled part,
5...Internal grounding shield, 6...External grounding shield ring, 7...Mounting nozzle holder, 11.
...Shield ring leg, 12...Copper strip, 13...Insulating spacer, 14...Iron core, 15...Coil, 16... ·····Power supply part.

Claims (1)

[Scope of utility model registration request] A shield device in which the shield ring is made of a conductor with high specific resistance, and a current is passed through the shield ring.