FAULT CURRENT PROTECTION SWITCH, RESPONSE TO FAULT CURRENT WITH CURRENT CURRENT COMPONENTS

摘要

1. Fault current protective switch (1) which responds to fault currents having d.c. components, where the magnetic core of the summing current transformer (2) possesses an induction of sufficient magnitude to induce in the secondary winding (4) a voltage necessary to actuate the release magnet by its release winding (5) when a pulsating d.c. fault current flows in its primary winding (3), and wherein a capacitor (9) is connected between the secondary winding (4) and the release winding (5) to form an oscillatory circuit tuned to the frequency of the voltage induced in the secondary winding (4) by a pulsating d.c. fault current flowing in the primary windings (3) of the summing current transformer (2), characterised in that the magnetic core (13) possesses a dynamic differential induction DELTA Bdyn between the maximum induction Bmax and the dynamic remanence induction Brdyn of : DELTA Bdyn = 0.1 T and that the ratio of the static differential induction DELTA Bstat, between the maximum induction Bmax and the static remanence induction Brstat, to the dynamic differential induction DELTA Bdyn fulfils the equation : DELTA Bstat/DELTA Bdyn = 1.3.