Patent ID: 6191673
Filing Date: 2001-02-20
Classification: H01F

Abstract:
A current transformer for measuring current flowing in a first bus conductor of a multi-phase electrical apparatus including multiple bus conductors, the current transformer comprising:a plurality of current transformer units combined into a bundle, each of said transformer units directly contacting another of said transformer units within said bundle and includingan annular iron core for surrounding a first bus conductor through which an electrical current to be measured flows; anda secondary winding wound around said annular iron core for measuring the electrical current flowing through the first bus conductor; anda shield winding wound around an outside of said bundle of said current transformer units, wherein the first bus conductor and another of the bus conductors of the multiple bus conductors are arranged in a common plane, and at least one of said current transformer units includes a first air gap, where no secondary winding and no shield winding are present, at a portion of said current transformer unit symmetrically located relative to a line perpendicular to the common plane.