Lightning arrester spark gap for HV DC power lines - with active quuecnnching or arc starting at currents below predetermined value

摘要

A lightning arrester spark gap comprises an arc interrupting chamber with at least two electrodes the working surfaces whereof extend in the direction of stretching the arc. The gap also comprises two additional electrodes one of which is shaped as a split ring encompassing the chamber over most of its perimeter. This additional electrode is an extension of one of the electrodes of the chamber. The other additional electrode is a solid ring coaxial with the first additional ring, forming an annular gap therewith, and has a portion, in direct proximity to the free end of the first additional electrode, at which flashover occurs. The second additional electrode is connected to the second electrode of the arc interrupting chamber so that the arc periodically appearing determines the moment at which active quenching of the arc starts at currents below a preset value.