Differential current detecting toroid for switchgear, has magnetic band, whose end part has unit homogenizing magnetic flux to gradually reduce magnetic coupling between end part and turn towards ends of band

摘要

The toroid (2) has a band made of magnetic material, provided with a constant sensible section and winded in a manner to form a succession of turns. The band has two triangular end parts (18) extended on a predetermined length from ends (8) of the band. Each end part is equipped with a magnetic flow homogenization unit that is formed by a non magnetic shim, a reduction element and a recess for homogenizing magnetic flux to gradually reduce magnetic coupling between the end part and a turn (6-2) towards the ends of the band. An independent claim is also included for a switchgear comprising primary conductors.