Lightning arrester and arrester-triggering system

Claim 2

In a lightning protection system for a high voltage transmission line including a lightning arrester having a number of spark gaps, triggering means including a laser generator disposed to send a laser beam into the interelectrode space of at least one of said spark gaps and a circuit for controlling the triggering of the spark gaps by energization of the laser, the improvement wherein said controlling circuit comprises at least one detector sensitive to electrical and radio disturbances created by electrical storms and means responsive to detector operation for operating said laser.

Claim 3

The system as claimed in claim 1 wherein said control circuit comprises at least one detector sensitive to light emitted by the lightning for creating a control signal for triggering of said laser.

Claim 4

The system as claimed in claim 2, wherein said controlling circuit further comprises computing means connected to said detector for computing the probable time of arrival of the shock wave at the lightning arrester, and a delay element operatively coupled to said detector and said triggering means and responsive to computer operation for delaying the control signal transmitted from said detector to said laser operating means.

Claim 5

The system as claimed in claim 3 wherein said means for operating said laser comprises a device for modulating the intensity of the laser, said device being operatively coupled to said delay means.

Claim 6

The system as claimed in claim 3 wherein said means for operating said laser includes means for deflecting the light beam of said laser to control triggering of the arrester and means for operatively coupling said delay means to said device.

Claim 7

The system as claimed in claim 1 wherein said arrester comprises at least one double spark gap in the form of two series-connected coaxial spark gaps and a coil surrounding said series connected coaxial spark gaps and connected in series therewith to create an axial magnetic field perpendicular to the electric arc.

Claim 8

The system as claimed in claim 6 wherein at least one of said coaxial spark gaps is formed by a central electrode and a cylindrical electrode surrounding the same with the inside surface of said cylindrical electrode comprising a plurality of protuberances facilitating the extinction of the arc.

Claim 9

The system as claimed in claim 1 wherein said lightning arrester comprises a column of axially disposed spark gaps formed of spaced, aligned electrodes each having an axial aperture allowing the passage of the laser beam, an insulating column, said column of axially aligned spark gaps being supported within said insulating column by insulating support means coupled to the intermediate electrode, a coil surrounding said insulating column For the creation of an axial magnetic field, a metal wall surrounding said coil and acting as a screening conductor with the lower part connected to ground and the upper part connected to the lower electrode of the column of spark gaps through said coil.

Claim 10

The system as claimed in claim 8 further comprising resistor means connecting said lower electrode to ground and constituting a pedestal on which the arrester rests.

Claim 11

The system as claimed in claim 9 wherein the lower part of said metal wall is connected to ground through at least a portion of said pedestal.

Claim 12

The system as claimed in claim 9 wherein said pedestal includes a hollow central portion forming a seat for said laser.

Claim 13

The system as claimed in claim 8 further comprising means carried by said electrodes for focusing the laser beam in at least one of the interelectrode spaces.

Claim 14

The system as claimed in claim 8 wherein said coil acts to circulate cooling fluid and is formed of a plurality of hollow conductors as portions of the circle, connected together by hollow conductors extending parallel to the axis of the coil thus formed with ends coupled respectively to said plurality of hollow conductors of circular form.