Current transformer

Claim 2

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings, said enclosure having a wall portion extending through said window passage so as to cause said enclosure to be electromagnetically linked with said secondary system, and an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned current ranges.

Claim 3

The current transformer of claim 1, said enclosure being a housing enclosing said secondary system and having a shape corresponding to a hollow ring.

Claim 4

The current transformer of claim 1, said enclosure having an end face at said window passage; said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage.

Claim 5

The current transformer of claim 3, comprising a fluid insulating medium filling said enclosure; and an insulating plate for covering said opening fluid-tight, said plate in turn having openings for passing through and holding said compact rod as well as for accommodating said conductors of said windings.

Claim 6

The current transformer of claim 3, comprising an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin.

Claim 7

The current transformer of claim 5, said metal enclosure being a conductive coating applied to said body of casting resin.

Claim 8

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings; an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned curRent ranges; said enclosure having an end face at said window passage, said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage; and, an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin, said primary windings having respective turns disposed in said body of cast resin, said turns being respective rounded metal strips, each of said metal strips having a curvature corresponding to the curvature of said enclosure.

Claim 9

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings; an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned curRent ranges; said enclosure having an end face at said window passage, said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage; and, an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin, said primary windings having respective turns disposed in said body of cast resin, said turns being respective rounded metal strips, each of said metal strips having a curvature corresponding to the curvature of said enclosure.

Claim 10

The current transformer of claim 7, said enclosure having ribs, said turns being accommodated in said ribs.

Claim 11

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings; an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned current ranges; said enclosure having an end face at said window passage, said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage; an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin; and, a housing surrounding said enclosure and said cast resin body containing said secondary system, said enclosure and said housing defining a space therebetween, said primary windings having respective turns disposed in said space.

Claim 12

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings; an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned current ranges; said enclosure having an end face at said window passage, said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage; an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin; and, a housing surrounding said enclosure and said cast resin body containing said secondary system, said enclosure and said housing defining a space therebetween, said primary windings having respective turns disposed in said space.

Claim 13

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings; an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned current ranges; said enclosure having an end face at said window passage, said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage; and, an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin, said primary windings having respective turns mounted on the exterior of said enclosure.

Claim 14

A current transformer switchable at the primary side and operable in an electrical system at high voltage and current for detecting currents in respective current ranges comprising a secondary system defining a window passage therethrough and having an iron core; a plurality of primary windings surrounding said core, said windings including respective conductors having respective cross-sections stepped down in magnitude one with respect to the other in correspondence to respective ones of the current ranges; a metallic enclosure surrounding said secondary system in the manner of a hollow ring and constituting a turn of said primary windings; an elongated conductor member in the form of a compact, short rod extending through said window passage for detecting currents in an additional current range greater than the first-mentioned current ranges; said enclosure having an end face at said window passage, said enclosure having a ring-shaped opening in said end face in surrounding relation to said window passage; and, an insulating body of cast resin disposed inside said enclosure, said secondary system being imbedded in said body of cast resin, said primary windings having respective turns mounted on the exterior of said enclosure.

Claim 15

The current transformer of claim 10 comprising insulating pieces for mounting the conductors of said turns on said exterior of said enclosure.

Claim 16

The current transformer of claim 10, comprising tubes extending along the exterior of said enclosure, the conductors of said turns being run in said tubes.

Claim 17

The current transformer of claim 12, said tubes being made of metal.

Claim 18

The current transformer of claim 12, said tubes being made of insulating material.

Claim 19

The current transformer of claim 12, a portion of each of said tubes extending through said window passage, said portions of said tubes and said elongated conductor member substantially filling said window passage.

Claim 20

The current transformer of claim 10, portiOns of the conductors of said turns extending through said window passage, the current transformer comprising support bodies of insulating material disposed in said window passage for supporting said portions of said conductors and said elongated conductor member therein.

Claim 21

The current transformer of claim 1, one of said windings of said plurality of windings consisting of a single turn, said single turn being formed by said metallic enclosure.

Claim 22

The current transformer of claim 1, said plurality of windings being at least two in number, one of said two windings consisting of at least one turn being run within said metallic enclosure, and said other one of said two windings consisting of at least one turn disposed within said metal enclosure and one further turn, said further turn being formed by said metallic enclosure.