JPH03182016A - Lightning arrester for power-transmission line - Google Patents

Abstract

PURPOSE:To get rid of effects of vibration of a power line and make maintenance and inspection easy and safe by fixing gaps in series on a steel tower and installing a circuit breaker between the serial gaps and a lightning conductor. CONSTITUTION:When a power line 4 or a steel tower 7 is hit by lightning, electric discharge is caused among gaps in series 5 and lightning current runs to a lightning arrester 1 through a lead wire 2. If the period from the starting of said current running to the returning of a reflected wave to the power line 4 after it reaches the lightning arrester 1 is short enough, for example at most 0.1mus, the power line 4 is protected from the lightning. Since the lead wire 2 is drawn out of the power line 4 and connected with one end of gaps 5 fixed to the steel tower 7 with a supporting insulator 3, the gaps 5 are not affected by vibration of the power line 4. A circuit breaker 11 connected with the other end of the gaps 5 is always turned on and when the circuit breaker 11 is released at the time of maintenance and inspection, the gaps 5 do not cause electric discharge and thus maintenance and inspection are carried out easily and safely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lightning arrester used to prevent snow damage accidents on power transmission lines.

[Conventional technology]

Figure 2 shows, for example, the conventional lightning arrester for power transmission lines shown in NGK Review No. 49 Separate Volume 13 published in March 1989. In Figure 0, l is the lightning arrester, 4 is the power line, and 41 is an electrode protruding from the power line 4, 5 is a series gap formed between the lightning arrester 1 and the electrode 41, 6 is a suspension insulator that supports the power line 4, 7 is a steel tower, and 8 is a suspension insulator 6 and lightning arrester extending from the steel tower 7. This is an arm that supports 1.

Next, the operation will be explained. When the steel tower 7 or the power line 4 is struck by lightning, a large voltage is generated between the power line 4 and the arm 8. The part of the power line 4 that has the weakest dielectric strength against lightning voltage is set to be the part of the series gap 5, and the series gap 5 is discharged, the lightning current flows to the arrester 1, and the voltage drop of the arrester 1 is transferred to the power line. 4 and the arm 8, but the voltage drop mentioned above is sufficiently lower than the voltage that discharges the suspension insulator 6, etc., so when the lightning voltage that occurs on the power line 4, which is not directly discharged between the power line 4 and the arm 8, becomes smaller, Since the lightning arrester 1 blocks the current flowing through the series gap 5,
Lightning strike voltage can be quickly removed without flowing alternating current due to the commercial frequency voltage that is constantly applied to the power line 4 and without stopping power transmission.

Furthermore, the electrodes 41 in the series gap 5 are arc-shaped so that the discharge voltage can be kept constant even if the power line 4 is swayed by wind or the like.

[Problem to be solved by the invention]

Conventional lightning arresters for power transmission lines are configured as described above, so even if the power line sways due to wind, etc., the discharge voltage in the series gap must not change, which makes the device complicated. When maintaining and inspecting the lightning arrester, it is necessary to get close to the power line and it is necessary to shut off the power.Furthermore, since the lightning arrester is located at the end of the arm, maintenance and inspection of the lightning arrester is inconvenient.

This invention was made to solve the above-mentioned problems, and it is possible to obtain a series gap that optimizes discharge with a simple device without taking into account the swing of the power line, and also to eliminate the need for maintenance and inspection of lightning arresters during power outages. The purpose of the present invention is to obtain a lightning arrester for power transmission lines that can be easily made without the need for

[Means to solve the problem]

A lightning arrester for a power transmission line according to the present invention has a lead wire connected to a power line, a firmly supported series gap in the middle of the lead wire guiding electricity to the lightning arrester, and a disconnector.

[Effect]

In the lightning arrester for power transmission lines according to the present invention, the series gap is firmly supported by an independent support and is not affected by the vibration of the power line, and the operation of the series gap is suppressed by opening the disconnector. Avoid conducting electricity.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a layout diagram showing the configuration of a power transmission line lightning arrester, in which 1 is a lightning arrester, 11 is a disconnector, 5 is a series gap, and 2 is drawn out from the power line 4 and connects the series gap 5, the disconnector 11, and the lightning arrester 1. Lead wires connected in series, 3 are the above-mentioned disconnector 11
, a support insulator that supports the lead 1!2 and the series gap 5, 9 is a pedestal mounted on the steel tower 7 and on which the lightning arrester 1 is installed, and 4 and 6 to 8 are equivalent to the conventional device.

Next, the operation will be explained. When a power line 4 or a steel tower 7 is struck by lightning, a discharge occurs in the series gap 5 as in the conventional device, and a lightning current flows through the lead wire 2 to the arrester 1. The time from when the current starts flowing through the lead wire 2 until it reaches the lightning arrester a1 and the reflected wave returns to the power line 14 is the power line 4.
not protect.

However, although the above time depends on the discharge voltage of the suspension insulator 6,
For example, if it is short, such as 0.14 or less, the power M4 can be protected from lightning without any problem, and therefore the power line 4 can be
The allowable length of the board I12 is about 15 m.

Lead wire 2 is pulled out from power line 4, and support insulator 3 is attached to steel tower 7.
Since the series gap 5 is connected to one end of the series gap 5 fixed at , the series gap 5 is not affected by the vibration of the power line 4, and therefore, the optimal gap shape for discharge can be selected. Connected to the other end of series gap 5! The lfr switch 11 is always closed, so that the series gap 5 is discharged by the lightning voltage, but if the disconnect switch I is opened during maintenance and inspection, the series gap 5 will no longer be discharged, making it safe and easy. Able to perform maintenance and inspection.

〔Effect of the invention〕

As described above, according to the present invention, since the series gap is fixed to the steel tower, an excellent series gap can be obtained without being affected by the vibration of the power line, and a disconnector can be placed between the series gap and the lightning arrester. Therefore, maintenance and inspection can be carried out safely and easily.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a route showing the configuration of an embodiment of the present invention;
FIG. 2 is a perspective view of a conventional power transmission line lightning arrester. In the figure, 1 is a lightning arrester, 2 is a lead wire, 3 is a support insulator, 4 is a power line, 5 is a series gap, 6 is a suspension insulator, 7 is a steel tower, 8 is an arm, 9 is a frame, and 11 is a disconnector. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] In a device in which a lightning arrester is installed on a power transmission line tower through a power line and a discharge gap, a lead wire is drawn out from the power line, the lead wire is supported by a support insulator, and the lightning arrester is connected to the lightning arrester. A lightning arrester for a power transmission line, characterized in that the lightning arrester is provided with a disconnector between the discharge gap and the lightning arrester.