Short circuit sensing device for electromagnetic induction apparatus

Claim 2

An electromagnetic induction apparatus comprising a magnetic circuit, at least one winding having a number of turns placed around said magnetic circuit, said winding being adapted to have current produced therein by a source of electrical power, said current passing through said winding creating a flux pattern which passes predominantly through said magnetic circuit, said flux pattern varying in response to shorted turns within said winding to create a greater proportion of leakage flux, stray flux sensing means responsive only to said flux pattern variation for generating a signal proportional to said flux pattern variation, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said apparatus from further damage.

Claim 3

The apparatus according to claim 1 wherein said flux sensing means includes at least one Hall effect generator.

Claim 4

The combination of a high voltage electromagnetic induction apparatus having at least one magnetic core comprising a series of similar core elements separated by a series of similar electrically insulating layers, at least one magnetic yoke magnetically connecting the ends of said core, and at least one winding surrounding said magnetic core, and adapted to have current produced therein by a source of electrical power, said winding being electrically connected to each of said core elements at respective neighboring portions thereof, said apparatus having a plane on either side of which there is a symmetrical flux pattern during normal condition and wherein under conditions of fault the flux pattern on either side of said plane are not symmetrical, coil means for sensing only the degree of non-symmetry between the flux pattern on either side of said plane, means connected to said coil means for rendering said source inoperative to produce said current thereby protecting said apparatus from further damage.

Claim 5

The combination of a high voltage electromagnetic induction apparatus having at least one magnetic core comprising a series of similar core elements separated by a series of similar electrically insulating layers, at least one magnetic yoke magnetically connecting the ends of said core, and at least one winding surrounding said magnetic core, and adapted to have current produced therein by a source of electrical power, said winding being electrically connected to each of said core elements at respective neighboring portions thereof, said apparatus having a plane on either side of which there is a symmetrical flux pattern during normal condition and wherein under conditions of fault the flux pattern on either side of said plane are not symmetrical, coil means for sensing only the degree of non-symmetry between the flux pattern on either side of said plane, means connected to said coil means for rendering said source inoperative to produce said current thereby protecting said apparatus from further damage.

Claim 6

The combination of a high voltage reactor having at least two magnetic cores, each of said magnetic cores comprising a series of similar core elements separated by a series of similar electrically insulating layers, a pair of yokes connected to the ends of the cores to form a magnetic circuit, at least one winding surrounding each of said cores, said winding being electrically connected to each of said core elements at respective neighboring portions thereof, said windings being adapted to have current produced therein by a source of electrical power, said reactor having symmetrical flux patterns on either side of a plane passing through said yokes under normal conditions and having non-symmetrical flux patterns when portions of said windings become shorted, coil means for sensing only the degree of non-symmetry between the flux patterns on either side of said plane and generating a signal in response thereto and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said reactor from further damage.

Claim 7

The combination of a high voltage reactor having at least two magnetic cores, each of said magnetic cores comprising a series of similar core elements separated by a series of similar electrically insulating layers, a pair of yokes connected to the ends of the cores to form a magnetic circuit, at least one winding surrounding each of said cores, said winding being electrically connected to each of said core elements at respective neighboring portions thereof, said windings being adapted to have current produced therein by a source of electrical power, said reactor having symmetrical flux patterns on either side of a plane passing through said yokes under normal conditions and having non-symmetrical flux patterns when portions of said windings become shorted, coil means for sensing only the degree of non-symmetry between the flux patterns on either side of said plane and generating a signal in response thereto and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said reactor from further damage.

Claim 8

The combination according to claim 4 wherein said coil means includes a coil disposed around the outer periphery of one of said magnetic yokes, said coil having induced thereon voltage proportional to the difference between the flux entering and leaving said yoke.

Claim 9

The combinAtion according to claim 4 wherein said coil means encloses the absolute total value of flux in said magnetic circuit twice.

Claim 10

A transformer comprising a magnetic circuit, a low voltage winding having a number of turns disposed around a portion of said magnetic circuit, a high voltage winding having a number of turns disposed around a portion of said magnetic circuit, both said low voltage and said high voltage windings being adapted to have current produced therein by a source of electrical power, said current passing through said windings creating a flux pattern which passes predominantly through said magnetic circuit, said flux pattern varying in response to shorted turns within said windings to create a greater portion of leakage flux, flux sensing means responsive to said flux pattern variation for generating a signal proportional to said flux pattern variation, said flux sensing means including a pair of sensing coils surrounding a portion of said magnetic circuit and adjacent to respective opposite sides of said windings, said coils being wound in a C configuration around said magnetic circuit and having induced thereon a voltage representing the leakage flux adjacent to said circuit, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said transformer from further damage.

Claim 11

A transformer comprising a magnetic circuit, a low voltage winding having a number of turns disposed around a portion of said magnetic circuit, a high voltage winding having a number of turns disposed around a portion of said magnetic circuit, both said low voltage and said high voltage windings being adapted to have current produced therein by a source of electrical power, said current passing through said windings creating a flux pattern which passes predominantly through said magnetic circuit, said flux pattern varying in response to shorted turns within said windings to create a greater portion of leakage flux, flux sensing means responsive to said flux pattern variation for generating a signal proportional to said flux pattern variation, said flux sensing means including a pair of sensing coils surrounding a portion of said magnetic circuit and adjacent to respective opposite sides of said windings, said coils being wound in a C configuration around said magnetic circuit and having induced thereon a voltage representing the leakage flux adjacent to said circuit, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said transformer from further damage.

Claim 12

The apparatus according to claim 7 wherein said coils are connected in series opposition.

Claim 13

A three phase reactor comprising three gapped magnetic cores, a winding having a number of turns disposed around each of said cores, said windings being adapted to have current produced therein by a source of electrical power, said current passing through each of said windings creating flux patterns which pass predominantly through said magnetic cores, said flux patterns varying in response to shorted turns within said windings to create a greater portion of leakage flux, a first return yoke connecting one of the ends of said cores, a second return yoke connecting the other end of said cores, flux sensing means responsive to said flux pattern variation for generating a signal proportional to said flux pattern variation, said flux sensing means including a first sensing coil disposed around said cores between said first yoke and said windings, and a second sensing coil disposed around said cores between said second yoke and said windings, said coils being connected in a series differential configuration, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said apparatus from further damage.

Claim 14

A three phase reactor comprising three gapped magnetic cores, a winding having a number of turns disposed around each of said cores, said windings being adapted to have current produced therein by a source of electrical power, said current passing through each of said windings creating flux patterns which pass predominantly through said magnetic cores, said flux patterns varying in response to shorted turns within said windings to create a greater portion of leakage flux, a first return yoke connecting one of the ends of said cores, a second return yoke connecting the other end of said cores, flux sensing means responsive to said flux pattern variation for generating a signal proportional to said flux pattern variation, said flux sensing means including a first sensing coil disposed around said cores between said first yoke and said windings, and a second sensing coil disposed around said cores between said second yoke and said windings, said coils being connected in a series differential configuration, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said apparatus from further damage.

Claim 15

The combination of a high voltage reactor having at least two magnetic cores, each of said magnetic cores comprising a series of similar core elements separated by a series of similar electrically insulating layers, a pair of yokes connected to the ends of the cores to form a magnetic circuit, at least one winding surrounding each of said cores, said winding being electrically connected to each of said core elements at respective neighboring portions thereof, said windings being adapted to have current produced therein by a source of electrical power, said reactor having symmetrical flux patterns on either side of a plane passing through said yokes under normal conditions and having non-symmetrical flux patterns when portions of said windings become shorted, coil means for sensing only the degree of non-symmetry between the flux patterns on either side of said plane and generating a signal in response thereto, said coil means including a first coil disposed around the outer periphery of one of said magnetic yokes, a second coil disposed around the outer periphery of the other of said magnetic yokes, each of said coils having induced thereon voltage proportional to the difference between the flux entering and leaving its respective yoke, said coils being connected in series to form a single output, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said reactor from further damage.

Claim 16

The combination of a high voltage reactor having at least two magnetic cores, each of said magnetic cores comprising a series of similar core elements separated by a series of similar electrically insulating layers, a pair of yokes connected to the ends of the cores to form a magnetic circuit, at least one winding surrounding each of said cores, said winding being electrically connected to each of said core elements at respective neighboring portions thereof, said windings being adapted to have current produced therein by a source of electrical power, said reactor having symmetrical flux patterns on either side of a plane passing through said yokes under normal conditions and having non-symmetrical flux patterns when portions of said windings become shorted, coil means for sensing only the degree of non-symmetry between the flux patterns on either side of said plane and generating a signal in response thereto, said coil means including a first coil disposed around the outer periphery of one of said magnetic yokes, a second coil disposed around the outer periphery of the other of said magnetic yokes, each of said coils having induced thereon voltage proportional to the difference between the flux entering and leaving its respective yoke, said coils being connected in series to form a single output, and means responsive to said signal for rendering said source inoperative to produce said current, thereby protecting said reactor from further damage.

Claim 17

The combination according to claim 10 wherein said coils are series connected in an additive mode.

Claim 18

The combination according to claim 10 wherein said coils are series connected in a subtractive mode.