JPH0745916Y2 - Discharge electrode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a discharge electrode capable of preventing thermal damage to a proximity device due to a generated arc.

(Prior art and its problems) When a power transmission line is supported by a steel tower, for example, as shown in FIG. 1, the conductors (2) (2 ') for power transmission are connected by insulator strings (1) (1').
At the same time that the (2)
(2 ') are connected to each other by jumper conductors (4). By the way, in this case, in order to protect the insulator string (1) (1 ') from an overvoltage caused by a lightning strike or the like, rod-shaped horn electrodes (5) (5') facing the tower supporting part (3) and the jumper conductor (4). And the Vt characteristics thereof are selected so that the rod-shaped horn electrodes (5) and (5 ') when an overvoltage occurs.
Insulators (1)
Protecting (1 ') is done. Further, in this case, the arc generated between the electrodes does not cause a thermal obstacle to the insulator string (1) (1 ') on the steel tower supporting part (3) side, and the arc spot is jumper conductor on the jumper conductor (4) side. (3) The diameter of the rod-shaped horn electrodes (5) and (5 ') is made thin and the tip surface is made flat so as not to damage the electrode by moving it upward, and the movement of the arc spot in the electrode surface state is prevented as much as possible. Therefore, the blowing direction of the arc jet is prevented from swinging.

However, with the thin horn electrode with a flat tip as described above,
Disturbs the electric field and deteriorates corona discharge characteristics during sound power transmission. Therefore, when applied to ultra-high voltage and ultra-high voltage transmission lines that require special consideration for corona discharge, the conventional technology uses a large horn electrode diameter and a hemispherical tip surface to improve corona discharge characteristics. I have no choice but to take the method of making it happen. However, in this case, for example, as shown in FIG. 2, the arc jet (6) blows off on the hemispherical surfaces of the electrodes (5) and (5 ') in a large swing angle .theta. The part will spread over a large area. Therefore, even if the corona discharge characteristics can be improved, the function of eliminating the thermal obstacle due to the generated arc is deteriorated.

(Purpose of the Invention) The present invention provides an electrode structure capable of reliably fixing the arc spot to the center of the electrode tip while preventing the oscillation of the tip surface in the arc jet blowing direction while improving the electric field. Even in high-voltage transmission lines, the corona discharge characteristics are not deteriorated and the insulator series and jumper conductors can be protected from thermal damage due to the generated arc.

(Means of the Present Invention for Solving Problems) The feature of the present invention is, for example, FIG. 3 (a).
As shown in the plan view and the cross-sectional side view of the AA ′ section of one embodiment shown in (b), a hollow rod-shaped outer electrode (7) having a hemispherical tip has a center and an interval (8). A central electrode (9) in the form of a round bar is provided to open the outer electrode (7), and a plurality of slits (10) (4 in the figure) are radially connected to the space (8) in the radial direction. There is a point.

Then, when the arc jet (6) blows off on the surface of the outer electrode (7) as shown in FIG. 3 (b), the current (11) that flows toward the part of the surface of the outer electrode (7) is biased. The electromagnetic force (12) in the direction opposite to the side where the arc jet (6) supplies the current due to (solid arrow in the figure)
(Indicated by a dotted arrow in the figure) so that the arc jet (6) is finally fixed to the central electrode (9). In this way, if the area of the tip of the central electrode (9) is selected so that the arc jet can be reliably fixed, the tip surface of the electrode is not flattened unlike the conventional horn electrode described above. The hemispherical outer electrode (7) fixes the arc jet (6) in the center while improving the electric field. Therefore, it is possible to effectively prevent the swinging of the blowing position of the arc jet while improving the corona discharge characteristics, and to reliably prevent thermal damage to the insulator string and the jumper conductor due to the blowing of the high temperature arc.

In addition, since the arc moves to and is maintained at the central electrode (19), it is possible to prevent the edge portion of the outer electrode (7) having a hollow structure from being melted or deformed by the arc, so that arc discharge for a long time is possible. Is also possible.

One embodiment of the present invention has been described above. As shown in FIG. 4, the effect of fixing the discharge position of the arc jet (6) is further improved by making the tip of the central electrode (9) a flat surface (9a). Can be done.

In the above, an example in which a hollow electrode is used as the outer electrode (7) has been described, but only the tip portion may be hollow or the entire length may be hollow.

Although the case where a plurality of (4) diametrical slits are provided has been described above, for example, two slits may be provided as shown in FIG. 5 (a) and one end may be gathered as shown in FIG. 5 (b). It is also possible to provide three radial slits. However, the fixed effect decreases as the number decreases. Further, the slit may be provided at the substantially hemispherical tip portion.

(Effect of the Invention) As is apparent from the above, according to the present invention, the blowout position of the arc jet can be fixed to the central electrode, so that peripheral equipment can be protected from thermal stress due to the arc. Moreover, since the potential gradient near the electrodes can be reduced, the corona discharge characteristics can be improved. Therefore, it is possible to effectively protect the insulator series of the jumper device in the ultra-high voltage transmission line that requires consideration of the corona discharge characteristics. Further, according to the present invention, the invention can be applied to a discharge electrode which is required to fix the arc spot and prevent the swing position of the arc jet from swinging, for example, to protect the insulator of various high-voltage power equipment from overvoltage.

[Brief description of drawings]

FIG. 1 is an explanatory view of a jumper device in a power transmission line, FIG. 2 is an explanatory view of a swinging state of an arc jet in a conventional electrode, FIG. 3 is an explanatory view of the present invention, and FIGS. It is another Example figure. (1) (1 ') ... Insulator series, (2) (2') ... Power transmission conductor, (3) ... Tower support, (4) ... Jumper conductor, (5) (5 ') ... ... Horn electrode, (6) ... arc jet, (7) ... outer electrode, (8) ... spacing,
(9) …… Center electrode, (9a) …… Flat tip surface, (10)…
… Slit, (11) …… current, (12) …… electromagnetic force.

Claims (2)

[Scope of utility model registration request] 1. A rod-shaped discharge electrode used to face another electrode, wherein the tip of the rod-shaped electrode portion is hemispherical, and a central electrode is provided at the center in the longitudinal direction of the electrode including the hemispherical portion. Is formed, the outer electrode of the portion excluding the central electrode is hollow, and at least the hemispherical portion of the outer electrode in which the hollow is formed is provided on a line extending radially from the center point of the central electrode. A discharge electrode characterized by being divided into a plurality of electrodes by being divided by slits. 2. The discharge electrode according to claim 1, wherein a tip of the central electrode is formed on a flat surface.