An externally gapped line arrester, EGLA, for transmission lines, the EGLA including a series varistor unit, SVU, having a first end and a second end, the SVU configured to be connected between a transmission line and ground, a primary sparkover gap unit serially connected to the first end of the SVU, a secondary gap arranged between the second end of the SVU and ground, and the secondary gap serially connected to the second end of the SVU, a shorting-link device connected in parallel with the secondary gap, and a disconnecting device arranged in the shorting-link device, the disconnecting device configured to open the shorting-link device when the SVU is overloaded. A method for impulse protection performed by an EGLA is also disclosed.

Power line conductors are normally shielded from direct lightning strikes by appropriately placed overhead ground wires. However, even when such overhead ground wires work as intended and intercept a strike, for a short period of time, typically a few microseconds, the shield wire is exposed to an impulse type potential rise. This could be sufficient to cause flashover of one or more line insulator strings. This is called backflash. The present invention solves this problem by providing a power transmission tower structure with an embedded ground conductor positioned in order to optimize the coupling factors to all conductors and reduce stress on all insulator strings through increased electromagnetic coupling. Use of a streamer-inhibited conductor avoids adverse effects such as radio interference and audible noise due to induced charges and improves electromagnetic coupling as a result of the reduced surge impedance of the conductor.

A lightning rod with an electric double layer and electric dipole moment type discharge amplification function, the lightning rod including: a support member (100) for moving a lightning current to the ground; an emission member (200) fitted to the support member (100) to collect charges of the ground according to the approach of a thundercloud and thus emit a large number of ions with the opposite polarity to the polarity of the thundercloud; ground charge chargers (300) fitted to the support member (100) and having spaces formed therein to charge the charges of the ground; an insulation member (400) disposed on top of the emission member (200); and discharge induction members (500) fixedly disposed on top and underside of the emission member (200) by means of the insulation member (400).

The present apparatus, system and method solves the problems of the prior art by enabling substantial dissipation of an electrical energy surge coming from communications antenna which has been struck by lightning. The apparatus is for mounting to an exterior of a building at or near communications antenna also located at the exterior of the building. The apparatus is connected with incoming coaxial cables extending from exterior mounted antenna and with outgoing coaxial cables which extend from the apparatus to communications equipment housed within a communications center. The lighting strike surge travels from antenna, along the incoming coaxial cable and is redirected within the apparatus by polyphasers which trip at capacity to redirect the surge to three separate grounding bars and prevent the surge from continuing along outgoing coaxial cables leading to communications equipment thus safely dissipating surge and shielding communications equipment.

A lightning current transmission system in a wind turbine between a metal band located at the root of each blade and a metal ring located at the nacelle through a lightning current transmission element comprising a conductive portion, an insulating portion and a supporting unit to be joined to the rotor hub. The metal band and the metal ring are configured with protruding parts extended towards the lightning current transmission element. The conductive portion of the lightning current transmission element comprises first and second receptors mounted on a base plate at different heights and oriented in a direction pointing, respectively, to the protruding parts of the metal band and the metal ring.

An electrically-conductive return mount assembly mountable to an electrically-conductive structure. The assembly has a return mount and a pad. The return mount has a base, and an electrically-conductive portion to conduct electricity to the structure. The pad is positionable between the return mount and the structure, and delimits an internal cavity. The internal cavity is configured to receive therein an adhesive to adhere the base to the structure. The pad is electrically conductive to form a conductive path from the electrically-conductive portion of the return mount, through the pad, and to the structure, upon the base being adhered to the structure. An airframe having such a return mount, as well as a method for mounting same, are also disclosed.

A device for protecting from lightning (30) is intended to form at least a portion of an external surface of a structure to be protected and comprises a ground plane (32), a dielectric substrate (34) arranged on the ground plane, and an array of first metal elements (36) arranged on the dielectric substrate (34) and extending substantially parallel to the ground plane (32) in such a way that any pair of consecutive elements from said first metal elements (36) is separated by a distance comprised between 0.01 millimetres and 10 millimetres, said first metal elements being distributed in juxtaposed similar patterns, each of said patterns including first metal elements of different dimensions corresponding respectively to different electromagnetic resonant frequencies the juxtaposition of which defines an electromagnetic absorption band of the pattern.

An installation device for installing an electrical ground rod into the earth. The electrical ground rod installation device of the present invention may comprise a shaft connecting an upper housing to a base. A user may utilize the installation device to install an electrical ground rod by first sliding the ground rod through the base and into the upper housing. In this arrangement, the base will be adjacent to approximately the middle of the ground rod and thus be at a height that can be engaged by the user from the ground, thereby avoiding the inherent risks associated with using ladders to install ground rods.

A ground rod cap is provided. The cap includes a body that fits around a ground rod, ground rod clamp and ground wire at their point of connection. The body retains a filler material within an internal cavity. In some embodiments, a portion of the body acts as a barrier to retain the filler material. In some such embodiments, the filler material is positioned within the body prior to installation of the cap on the ground rod connection components. In some embodiments, the filler material is located in an airtight cavity until installation. In some such embodiments, a shrink-wrap material is placed around the body to make the cavity airtight. In other embodiments, the filler material is retained within at least a portion of the cap by an internal barrier that breaks as the cap is installed to allow the filler material to flow around the components.

A sparcap for a spar structure inside a wind turbine blade is provided. A down conductor element is integrated on a side of the sparcap such that after assembly of the sparcap into the spar structure, the down conductor element extends along an outer corner of the spar structure.