Patent ID: 9595380
Date: 2017-03-14
CPC Classifications: H01F,H02H

Claim:
1. A fault current limiter having a plurality of cores each one comprising an elongated portion biased magnetically towards saturation by means of a surrounding magnetic field created by at least one DC coil surrounding the cores, and a plurality of AC coils each surrounding the elongated portion of a respective core, the fault current limiter further including: the elongated portion of the core having a variable cross section along the axis of the elongated portion of the core, in the vicinity of the AC coil, wherein the intensity of the magnetic field varies axially along the elongated portion of the core and said axially variable cross section is larger in the vicinity of the larger intensity of the magnetic field, the elongated portion of the core including an enlarged cross sectional area in a first region adjacent the DC coil, a reduced cross sectional area in a second region spaced apart from the DC coil and an enlarged cross sectional area in a third region at the ends of the elongated portion of the core, said variation in cross section aiding the operational characteristics of the fault current limiter and being optimized to reduce the surrounding magnetic field strength around the core required to induce saturation of the core.