Current transformer
First Claim
1. A current transformer, comprising:
- a Rogowski coil which detects an alternating current of a main circuit of power distribution equipment or substation main circuits equipment, and outputs a measure of the alternating current as an analog-voltage signal, the Rogowski coil comprising, a printed circuit board of multilayer type comprising four conducting layers of interconnections, having an opening at a center portion which a conductor penetrates, a plurality of metal foils, each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on both sides of surface of the printed circuit board and on two inner conducting layers of the printed circuit board, a first winding formed by electrically connecting metal foils on a first outer side of surface of the printed circuit board and metal foils on a first inner conducting layer of the printed circuit board adjacent to the first outer side of the surfaces of the printed circuit board with first plated through holes penetrating the printed circuit board in a thickness direction, a second winding formed by electrically connecting metal foils on a second outer side of surface of the printed circuit board and metal foils on a second inner conducting layer of the printed circuit board adjacent to the second outer side of the surface of the printed circuit board with second plated through holes penetrating the printed circuit board in a thickness direction; and
the first winding and the second winding connected as mirror images of each other, and connected in series, a sensor unit, comprising, an analog-to-digital converter which converts the analog-voltage signal into a digital electric signal, and an electric-to-optic converter which converts the digital electric signal into a digital optical signal; and
an optic transmission path which transmits the digital optical signal to upstream system.
1 Assignment
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Accused Products
Abstract
A current transformer, includes, a Rogowski coil for detecting an alternating current of a main circuit, and outputting a measure of the alternating current as an analog-voltage signal, includes, a printed circuit board, a sensor unit and an optic transmission path. The printed circuit board with four conducting layers, having an opening at a center portion which a conductor penetrates, comprises metal foils, each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on both sides of surface of the printed circuit board and on two inner conducting layers of the printed circuit board, a first winding formed by electrically connecting metal foils on a first outer side of surface of the printed circuit board and metal foils on a first inner conducting layer of the printed circuit board adjacent to the first outer side of the surfaces of the printed circuit board with first plated through holes penetrating the printed circuit board in a thickness direction, a second winding formed by electrically connecting metal foils on a second outer side of surface of the printed circuit board and metal foils on a second inner conducting layer of the printed circuit board adjacent to the second outer side of the surface of the printed circuit board with second plated through holes penetrating the printed circuit board in a thickness direction, the first winding and the second winding connected as mirror images of each other, and connected in series. The sensor unit comprises an analog-to-digital converter converting the analog-voltage signal into a digital electric signal, and an electric-to-optic converter converting the digital electric signal into a digital optical signal.
70 Citations
23 Claims
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1. A current transformer, comprising:
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a Rogowski coil which detects an alternating current of a main circuit of power distribution equipment or substation main circuits equipment, and outputs a measure of the alternating current as an analog-voltage signal, the Rogowski coil comprising, a printed circuit board of multilayer type comprising four conducting layers of interconnections, having an opening at a center portion which a conductor penetrates, a plurality of metal foils, each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on both sides of surface of the printed circuit board and on two inner conducting layers of the printed circuit board, a first winding formed by electrically connecting metal foils on a first outer side of surface of the printed circuit board and metal foils on a first inner conducting layer of the printed circuit board adjacent to the first outer side of the surfaces of the printed circuit board with first plated through holes penetrating the printed circuit board in a thickness direction, a second winding formed by electrically connecting metal foils on a second outer side of surface of the printed circuit board and metal foils on a second inner conducting layer of the printed circuit board adjacent to the second outer side of the surface of the printed circuit board with second plated through holes penetrating the printed circuit board in a thickness direction; and
the first winding and the second winding connected as mirror images of each other, and connected in series, a sensor unit, comprising, an analog-to-digital converter which converts the analog-voltage signal into a digital electric signal, and an electric-to-optic converter which converts the digital electric signal into a digital optical signal; and
an optic transmission path which transmits the digital optical signal to upstream system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
the Rogowski coil comprises a plurality of the printed circuit boards, arranged so that corresponding center axis openings of respective printed circuit boards are aligned with each other, and the windings formed on the respective printed circuit boards are connected to each other in series.
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3. The current transformer as recited in claim 1, further comprising:
a twisted-pair wire which connects the Rogowski coil and the sensor unit.
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4. The current transformer as recited in claim 1, wherein:
the printed circuit board is formed in the shape of a regular octagon.
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5. The current transformer as recited in claim 1, wherein a number of the Rogoski coils, a number of the sensor units, and a number of the optic transmission paths are more than one, respectively, and the current transformer further comprises:
an merging unit which merges a plurality of the digital optical signals each outputted from the respective Rogowski coils through the respective sensor units to generate at least one merged transmission signal, and transmits the merged transmission signal to the upstream system.
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6. The current transformer as recited in claim 5, wherein the merging unit comprises:
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a plurality of optic-to-electric converters, each of which converts the respective digital optical signals into a second digital electric signal;
an merging means which merges the respective second digital electric signals to generate at least one electric merged transmission signal; and
a second electric-to-optic converter which converts the electric merged transmission signal into a second digital optical signal.
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7. The current transformer as recited in claim 5, wherein the merging unit and the upstream system are connected through a point-to-point transmission channel.
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8. The current transformer as recited in claim 5, wherein the merging unit and the upstream system are connected through a local area network.
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9. A current transformer, comprising:
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a Rogowski coil which detects an alternating current of a main circuit of power distribution equipment or substation main circuits equipment, and outputs a measure of the alternating current as an analog-voltage signal, the Rogowski coil comprising, a printed circuit board, having an opening at a center portion which a conductor penetrates, including a plurality of stacked layers each having an opening at a center portion which a conductor penetrates, having at least three sheets of first layers formed of core material, and at least two sheets of second layers formed of prepreg material each arranged between respective two of the first layers, a plurality of first metal foils and a plurality of second metal foils, each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on an outer side and an inner side of a first outer layer formed of the core material, respectively, a first winding formed by electrically connecting the first metal foils and the second metal foils with first plated through holes penetrating the first outer layer in a thickness direction, a plurality of third metal foils and a plurality of fourth metal foils, each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on an inner side and an outer side of a second outer layer formed of the core material, respectively, a second winding formed by electrically connecting the third metal foils and the fourth metal foils with second plated through holes penetrating the second outer layer in a thickness direction, the second winding formed as a mirror image of the first winding, one of the second metal foils and one of the third metal foils being electrically connected with a third plated through hole penetrating the plurality of stacked layers of the printed circuit board in a thickness direction, the first metal foils and the fourth metal foils being electrically disconnected with the third plated through hole, and thereby, the first winding and the second winding being electrically connected in series;
a sensor unit, comprising, an analog-to-digital converter which converts the analog-voltage signal into a digital electric signal, and an electric-to-optic converter which converts the digital electric signal into a digital optical signal; and
an optic transmission path which transmits the digital optical signal to upstream system. - View Dependent Claims (10, 11, 12, 13, 14, 15)
a first terminal area in which the analog-voltage signal is extracted, mounted on the outer side of the first outer layer formed of core material, the first terminal area surrounding the third plated through hole and being electrically disconnected with the third plated through hole;
a second terminal area in which the analog-voltage signal is extracted, mounted on the outer side of the second outer layer formed of core material, the second terminal surrounding the third plated through hole and being electrically disconnected with the third plated through hole;
the first terminal and the second terminal arranged symmetrically to each other.
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11. The current transformer as recited in claim 9, wherein:
the Rogowski coil comprises a plurality of the printed circuit boards, arranged so that corresponding center axis openings of respective printed circuit boards are aligned with each other, and the windings formed on the respective printed circuit boards are connected to each other in series.
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12. The current transformer as recited in claim 9, further comprising:
a twisted-pair wire which connects the Rogowski coil and the sensor unit.
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13. The current transformer as recited in claim 9, wherein:
the printed circuit board is formed in the shape of a regular octagon.
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14. The current transformer as recited in claim 9, wherein a number of the Rogoski coils, a number of the sensor units, and a number of the optic transmission paths are more than one, respectively, and the current transformer further comprises:
an merging unit which merges a plurality of the digital optical signals each outputted from the respective Rogowski coils through the respective sensor units to generate at least one merged transmission signal, and transmits the merged transmission signal to the upstream system.
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15. The current transformer as recited in claim 14, wherein the merging unit comprises:
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a plurality of optic-to-electric converters, each of which converts the respective digital optical signals into a second digital electric signal;
an merging means which merges the respective second digital electric signals to generate at least one electric merged transmission signal; and
a second electric-to-optic converter which converts the electric merged transmission signal into a second digital optical signal.
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16. A current transformer, comprising:
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a Rogowski coil which detects an alternating current of a main circuit of power distribution equipment or substation main circuits equipment, and outputs a measure of the alternating current as an analog-voltage signal, the Rogowski coil comprising, a printed board of multilayer type comprising three conducting layers of interconnections, having an opening at a center portion which a conductor penetrates, a plurality of first metal foils each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on a first outer side of surface of the printed circuit board, a plurality of second metal foils each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on a second outer side of surface of the printed circuit board, a winding formed by electrically connecting the first metal foils and the second metal foils with plated through holes penetrating the printed circuit boards in a thickness direction, a return circuit line formed by a circular metal foil with a center that is approximately the center of the opening, mounted on an inner conductive layer of the printed circuit boards, and the winding and the return circuit line being connected in series;
a sensor unit, comprising, an analog-to-digital converter which converts the analog-voltage signal into a digital electric signal, and an electric-to-optic converter which converts the digital electric signal into a digital optical signal; and
an optic transmission path which transmits the digital optical signal to upstream system. - View Dependent Claims (17, 18, 19, 20)
the Rogowski coil comprises a plurality of the printed circuit boards, arranged so that corresponding center axis openings of respective printed circuit boards are aligned with each other, and the windings formed on the respective printed circuit boards are connected to each other in series.
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18. The current transformer as recited in claim 16, further comprising:
a twisted-pair wire which connects the Rogowski coil and the sensor unit.
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19. The current transformer as recited in claim 16, wherein:
the printed circuit board is formed in the shape of a regular octagon.
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20. The current transformer as recited in claim 16, wherein a number of the Rogoski coils, a number of the sensor units, and a number of the optic transmission paths are more than one, respectively, and the current transformer further comprises:
an merging unit which merges a plurality of the digital optical signals each outputted from the respective Rogowski coils through the respective sensor units to generate at least one merged transmission signal, and transmits the merged transmission signal to the upstream system.
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21. A Rogowski coil for a current transformer, which detects an alternating current of a main circuit of power distribution equipment or substation main circuits equipment, and outputs a measure of the alternating current as an analog-voltage signal, comprising:
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a printed circuit board of multilayer type comprising four conducting layers of interconnections, having an opening at a center portion which a conductor penetrates;
a plurality of metal foils, each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on both sides of surface of the printed circuit board and on two inner conducting layers of the printed circuit board;
a first winding formed by electrically connecting metal foils on a first outer side of surface of the printed circuit board and metal foils on a first inner conducting layer of the printed circuit board adjacent to the first outer side of the surfaces of the printed circuit board with first plated through holes penetrating the printed circuit board in a thickness direction;
a second winding formed by electrically connecting metal foils on a second outer side of surface of the printed circuit board and metal foils on a second inner conducting layer of the printed circuit board adjacent to the second outer side of the surface of the printed circuit board with second plated through holes penetrating the printed circuit board in a thickness direction; and
the first winding and the second winding connected as mirror images of each other, and connected in series. - View Dependent Claims (22)
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23. A Rogowski coil for a current transformer, which detects an alternating current of a main circuit of power distribution equipment or substation main circuits equipment, and outputs a measure of the alternating current as an analog-voltage signal, comprising:
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a printed board of multilayer type comprising three conducting layers of interconnections, having an opening at a center portion which a conductor penetrates;
a plurality of first metal foils each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on a first outer side of surface of the printed circuit board;
a plurality of second metal foils each extended in the shape of radiating from a center that is approximately the center of the opening, mounted on a second outer side of surface of the printed circuit board;
a winding formed by electrically connecting the first metal foils and the second metal foils with plated through holes penetrating the printed circuit boards in a thickness direction;
a return circuit line formed by a circular metal foil with a center that is approximately the center of the opening, mounted on an inner conductive layer of the printed circuit boards; and
the winding and the return circuit line being connected in series.
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Specification