JPH0253886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hanging insulator used for insulating and supporting a power transmission line in an overhead power transmission line.

(Prior Art) A conventional suspension insulator that supports a power transmission line in an overhead power transmission line has an insulator body 2 as shown in FIG.
A cap fitting 22 is provided at the upper end of the insulator 1, and a pin fitting 24 is attached to the lower end thereof with cement 23, and a cap 25 is provided protruding from the outer periphery of the insulator body 21 to support the high voltage power transmission line. In some cases, an insulator chain consisting of a number of suspended insulators connected in series was used to ensure sufficient voltage resistance.
However, in the conventional suspension insulator shown in Fig. 5, half of its total height is occupied by the cap fitting 22, which does not contribute to improving the withstand voltage characteristics, so when a large number of insulators are connected, There was a problem in that the total length of the transmission line became significantly longer, and the tower had to be made larger due to the clearance with the tower, raising the cost of constructing the transmission line.

(Problems to be solved by the invention) The present invention solves these conventional problems,
It was completed with the aim of producing a multi-suspended insulator that can obtain high withstand voltage characteristics without significantly increasing the overall length of the insulator chain.

(Means for Solving the Problems) The present invention provides two or more hats integrally protruding from the outer periphery of an insulator body having a cap fitting at the upper end and a pin fitting at the lower end, and It is characterized in that the ratio of the surface leakage distance to the shade pitch between the lowest shade is set in the range of 5≦L/P≦9.

(Embodiment) Next, the present invention will be explained in detail with reference to the illustrated embodiment. In FIG. 1, 1 is a porcelain insulator body;
2 is a cap metal fitting connected to one end thereof with cement 3; 4 is a cap metal fitting connected to the lower end of the insulator body 1 with cement 5;
It is a pin fitting connected by. Insulator body 1
is elongated as shown in the figure, and the pin fitting 4 is deeply inserted into the inside thereof. Two shades 6 and 7 are integrally provided on the outer periphery of the insulator body 1 and project therefrom. The number of hats may be any suitable number such as 2, 3, or 4, and a small shade 8 may be provided in the center as shown in FIG. These hats 6, 7, 8
The shade pitch between the top shade 6 and the bottom shade 7 is P, and the surface leakage distance of the insulator (lower end A of the cap metal fitting 2 and lower end B of the insulator body 1 shown in Figs. 1 to 3) is When L is the shortest distance measured along the surface of the insulator body 1 and the shade 6, 7, 8, the design is such that the ratio L/P is in the range of 5≦L/P≦9. has been done. The reason for setting the L/P value to 5 to 9 here is the graph of the relationship between the L/P value and the required leakage distance per 1KV of contamination withstand voltage in Figure 4 and the L/P value in Figure 5. As shown in the graph showing the relationship between the height of the insulator and the contamination withstand voltage of 1KV, when L/P is 5
This is because it has been confirmed through experiments that the maximum withstand voltage characteristics can be obtained with the minimum insulator height when the insulator height is .about.9. If L/P is less than 5, its pollution withstand voltage
The required leakage distance per 1KV is not much different from the L/P range of 5 to 9 as shown in Figure 4, but on the other hand, the required insulator height per 1KV of contamination withstand voltage is much wider as shown in Figure 5. increases, and therefore its pitch becomes longer for an equivalent surface leakage distance. As a result, the length of each insulator becomes long, so when considering a chain of insulators, the length of the connection becomes long, which becomes uneconomical.

Also, generally speaking, if you increase the surface leakage distance of the insulator,
The contamination withstand voltage per insulator increases, but even if you unnecessarily increase only the surface leakage distance, if L/P exceeds 9, the cap pitch (P) will be relatively insufficient and the Arcs are more likely to occur between the
As a result, the contamination withstand voltage efficiency deteriorates, and the required surface leakage distance per 1 KV of contamination withstand voltage becomes longer as shown in FIG. The shape of the hat is not only a regular hat with many folds 9 protruding from the bottom surface as shown in Figure 1, but also an aerodynamic type hat as shown in Figures 2 and 3. good.

(Function) With this structure, the tip of the pin fitting 4 at the lower end of the insulator body 1 is engaged with the cap fitting 2 of the lower insulator, thereby connecting a large number of insulators in series to insulate the power transmission line. Although the support is the same as in conventional suspension insulators, in the present invention, the ratio of the cap metal fitting 2 to the total height of the insulator is small, and the ratio of the insulating insulator body 1, which effectively contributes to insulation, is large. Moreover, since the L/P value is set to the most preferable range of 5 to 9 in terms of withstand voltage characteristics, the withstand voltage value for the entire length of the insulator chain is 15 to 9, which is the most preferable range from the viewpoint of withstand voltage characteristics.
It can be improved by about 20%, and conversely, the total length of the insulator chain required to obtain the same withstand voltage value can be reduced by 15%.
It can be shortened by ~20%.

For example, in the multiple hanging insulator of the present invention shown in FIG. 1, the height (H) is 235 mm, the diameter (D) is 254 mmφ,
If the cap pitch (P) is 85mm, the surface leakage distance (L)
is 635mm, L/P is 7.47, and pollution withstand voltage is 1KV.
The required leakage distance is 23 as shown in Figure 4.
mm/KV. Therefore, this Takasa suspension insulator
When used on a 400KV power transmission line, the design pollution withstand voltage is 400 x 1/√3 x 1.1 (safety factor) = 254KV, and the required surface leakage distance of the insulator chain is 23 x 254 = 5842
mm, and the number of required insulators is 5842/635 = 10, so the total length of the insulator chain is 235 x 10 = 2350 mm. In contrast, the conventional standard suspension insulator shown in Figure 5 has a height (H) of 146 mm, a shade diameter (D) of 254 mmφ, and a surface leakage distance (L) of 292 mm, under the same contamination conditions. The required leakage distance per 1KV of pollution withstand voltage is 21mm/
It is KV. Therefore, the number of insulators and the total length of the insulator chain required to support the 400KV transmission line are determined to be 19, 2774 mm, using the same method as above. in this way,
According to the present invention, the total length of the insulator chain required to obtain the same withstand voltage characteristics as a standard type suspended insulator can be reduced to 85 mm.
%, resulting in a reduction of approximately 15%. Furthermore, the weight of the insulator chain in this case is 99 kg for the conventional one and 88 kg for the one of the present invention, which means that the weight can be reduced by about 11%.

(Effects of the Invention) As is clear from the above description, the present invention is capable of obtaining high withstand voltage characteristics without increasing the overall length of the insulator chain. In this case, there is no need to unnecessarily increase the size of the iron tower, and the cost of constructing power transmission lines can be reduced, so its practical value is extremely great as it eliminates the problems of the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing the first embodiment of the present invention, FIG. 2 is a partially cutaway front view showing the second embodiment, and FIG. 3 is a partially cutaway front view showing the third embodiment. A cutaway front view, Figure 4 is a graph showing the relationship between the L/P value and the required leakage distance per 1KV of contamination withstand voltage, and Figure 5 is a graph showing the relationship between the L/P value and the required insulator height per 1KV of contamination withstand voltage. FIG. 6 is a partially cutaway front view showing a conventional example. 1: Insulator body, 2: Cap metal fittings, 4: Pin metal fittings, 6, 7, 8: Shade.

Claims (1)

[Claims] 1. Two or more caps 6,
7 and 8 are integrally protruded, and the ratio (L/P) of the surface leakage distance (L) to the shade pitch (P) between the top shade 6 and the bottom shade 7 is 5≦L. /P
A Takasa suspension insulator characterized in that the range is ≦9.