JPS5932848B2 - How to increase the dielectric strength of overhead insulated distribution lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for increasing the dielectric strength of overhead insulated distribution lines.

Induced lightning can destroy the insulation of overhead insulated distribution lines, and sustained arcs can cause the wires to melt.

The reason for this is that conventionally, as shown in Fig. 1, an overhead insulated distribution line 1 is supported by a pin insulator 3 attached using a bind wire 2, and the equivalent circuit at this time is as shown in Fig. 2. As a result, the lightning impulse voltage sharing between the pin insulator 3 and the insulated power distribution line 1 becomes very uneven, and the insulation performance of the pin insulator 3 and the insulated power distribution line 1 is not exhibited, and it is difficult to combine the pin insulator 3 and the insulated power distribution line 1. This is because there is not much difference in dielectric breakdown strength from the case of the insulated distribution line 1 alone. Various methods are currently being considered to solve this problem, but without exception, these require stripping the insulation coating of the insulated distribution line 1, which causes the characteristic of the insulated wire to be lost and new problems to arise. This is expected to occur.

An object of the present invention is to provide a method for increasing the dielectric strength of an overhead insulated power distribution line, which eliminates the drawbacks of the prior art described above and can significantly improve the dielectric strength without peeling off the insulation coating of the insulated wire. be.

A feature of the present invention is that a conductive or semi-conductive member is provided in contact with the outer periphery within a predetermined range on both sides of the insulated power distribution line centering on the pin insulator that supports the overhead insulated power distribution line, The main feature is that a capacitor is connected between the legs and the pins to improve voltage sharing between the insulated distribution line and the pins.

The present invention will be explained in detail below using the embodiments shown in FIGS. 3 to 5. FIG. 3 is an explanatory diagram for explaining the present invention. In FIG. 3, 1 is an overhead insulated distribution line, and 3 is a pin insulator attached to the insulated distribution line 1 with a binding wire 2. is a predetermined range on both sides of the insulated distribution line 1 centered on the pin insulator 3 (10 to 150 on one side)
Wrap a conductive (metal) or semi-conductive grip 4 pre-formed in a spiral shape around the outer circumference of the V7l), then attach the pin insulator 3 using the binding wire 2, and connect the grip 4 and the legs of the pin insulator 3. A capacitor 6 is connected between the pin insulator 5 and the insulator 3 in parallel.

The insulated distribution line 1 wrapped around the grip 4 is equivalent to one capacitor since the grip 4 is conductive. Therefore, the equivalent circuit of FIG. 3 becomes as shown in FIG. 4. That is, the capacitance C1 of the insulated distribution line 1, the capacitance C2 of the pin insulator 3, and the capacitance C3 of the capacitor 6 connected between the grip 4 and the leg 5 of the pin insulator 3 are The connections will be made as shown in the figure. Therefore, the voltage applied between the core wire of the insulated distribution line 1 and the leg of the pin insulator 3 is shared between the insulated distribution line 1 and the pin insulator 13, and if the capacitor 6 is appropriately selected (impulse withstand voltage 10
0 to 150k, capacitance 50 to 200PF), the ratio of the voltage applied to the insulated distribution line 1 and the voltage applied to the pin insulator 3 and capacitor 6 is the impulse breakdown voltage of the insulated distribution line 1 alone and the impulse breakdown voltage of the pin insulator 3 alone. The total impulse breakdown voltage of the insulated power distribution line 1 and the pin insulator 3 can be increased to the sum of the impulse breakdown voltages of each of them individually. As described above, according to the embodiment of the present invention, the voltage sharing between the insulated distribution line 1 and the pin insulator 3 is improved, so the impulse breakdown voltage of the combination insulation system can be improved. 1st
It will look like a table.

Furthermore, since the grip 4 and the capacitor 6 are only added, the present invention can be applied not only to newly installed overhead insulated distribution lines but also to existing overhead insulated distribution lines.

Furthermore, since there is no need to peel off the insulation coating of the insulated wire, there is no problem with stress or corrosion resistance.In addition, in the embodiment shown in FIG.
・Instead of the grip 4, you may also use the binding wire used to attach the pin insulator 3.

Further, a conductive paint may be applied to the outer peripheral surface of the insulated distribution line 1, or a metal plate 7 may be wrapped around the grip 4 instead of the grip 4, as shown in FIG. The effect will not change. As explained above, according to the present invention, it is possible to improve the voltage sharing between the overhead insulated distribution line and the pin insulator without peeling off the insulation coating of the insulated wire, and it is possible to significantly improve the dielectric strength. It has a remarkable effect.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional method for increasing the dielectric strength of an overhead insulated distribution line, Fig. 2 is an equivalent circuit diagram of Fig. 1, and Fig. 3 is an explanatory diagram of a method of increasing the dielectric strength of an overhead insulated distribution line according to the present invention. FIG. 4 is an explanatory diagram showing one embodiment, FIG. 4 is an equivalent circuit diagram of FIG. 3, and FIG. 5 is an explanatory diagram showing another embodiment of the present invention. 1: Overhead insulated distribution line, 2: Bind wire, 3: Pin insulator, 4: Grip, 5: Pin insulator foot, 6: Capacitor.

Claims (1)

[Claims] 1. A conductive or semi-conductive member is provided in contact with the outer periphery within a predetermined range on both sides of the insulated power distribution line around a pin insulator provided to increase the dielectric strength of the overhead insulated power distribution line, and A method for increasing the dielectric strength of an overhead insulated distribution line, characterized in that a capacitor is connected between the legs of the insulator to improve voltage sharing between the insulated distribution line and the insulator.