Current detector and meter

• US 10,670,635 B2
• Filed: 06/28/2018
• Issued: 06/02/2020
• Est. Priority Date: 06/30/2017
• Status: Active Grant

• Current Assignee: Hioki Denki Kabushiki Kaisha
• Original Assignee: Hioki Denki Kabushiki Kaisha
• Inventors: Hayashi, Kazunobu, Seki, Kenichi, Yoda, Hajime
• Primary Examiner(s): Sanghera, Jas A
• Application Number:
  US16/021,304
• Publication Number:
  US 20190004095A1
• Time in Patent Office: 705 Days
• Field of Search: None
• CPC Class Codes: G01R 15/185 with compensation or feedback windings or interacting coils, e.g. 0-flux sensors using galvano-magnetic field sensors G01R15/20; conversion of DC into AC using transductors G01R19/20
• CPC Class Codes: G01R 15/186 using current transformers with a core consisting of two or more parts, e.g. clamp-on type G01R15/142 - G01R15/16 take precedence; tong testers G01R1/22
• CPC Class Codes: G01R 15/202 using Hall-effect devices Hall elements in arrangements for measuring electrical power G01R21/08
• CPC Class Codes: G01R 19/15 Indicating the presence of current

Abstract

A current detector includes a ring-shaped core for inserting a wire; a detection winding on the core; and resistor connectors for connecting a resistor in series to the detection winding. The detection winding has a first winding at a first end and a second winding at a second end that are connected in series. The first winding and second winding each have n (where n is three or higher) first or second unit windings in series. The core surface is partitioned into 2n regions around the core. The first unit windings are formed in odd-numbered regions and the second unit windings are formed in even-numbered regions. A j^th (where j is 1 to n) first unit winding from the first end and a j^th second unit winding from the second end are not adjacent and are formed with an equal number of turns.

Claims

1. A current detector comprising:

a ring-shaped magnetic core through which a measured wire is inserted;

a detection winding formed on an outer surface of the magnetic core; and

a pair of resistor connecting terminals disposed on the detection winding for connecting a detection resistor, which converts a current flowing in the detection winding due to a measured current flowing on the measured wire that has been inserted through the magnetic core to a voltage, in series to the detection winding,

wherein the detection winding is composed of a first winding at a first end side and a second winding at a second end side that is connected in series to the first winding,

the first winding is constructed by connecting n (where n is an integer that is three or higher) first unit windings in series,

the second winding is constructed by connecting n second unit windings in series,

the outer surface is partitioned into 2n formation regions along a circumferential direction of the magnetic core, and

the n first unit windings are formed in odd-numbered formation regions along the circumferential direction with one out of the 2n formation regions as a first formation region, the n second unit windings are formed in even-numbered formation regions out of the 2n formation regions along the circumferential direction, and a j^th (where j is an arbitrary integer in a range of 1 to n, inclusive) first unit winding from the first end side of the detection winding out of the first unit windings and a j^th second unit winding from the second end side of the detection winding out of the second unit windings are not adjacent and are formed with an equal number of turns.

2. The current detector according to claim 1,

wherein the detection resistor is connected between the pair of resistor connecting terminals.

4. The current detector according to claim 1,

wherein the j^th second unit winding is formed in a formation region that is most distant along the circumferential direction from the formation region of the j^th first unit winding.

5. The current detector according to claim 2,

wherein the j^th second unit winding is formed in a formation region that is most distant along the circumferential direction from the formation region of the j^th first unit winding.

7. The current detector according to claim 1,

wherein the 2n formation regions are produced by partitioning into equal lengths,

the n first unit windings are formed of an equal number of turns in order from the first unit winding on the first end side of the detection winding with the first formation region as a starting formation region,

the n second unit windings are formed of an equal number of turns in order from the second unit winding on the second end side of the detection winding in the same direction as the first unit windings, with an even-numbered formation region that is most distant along the circumferential direction from the first formation region out of the 2n formation regions as a starting formation region.

8. The current detector according to claim 2,

wherein the 2n formation regions are produced by partitioning into equal lengths,

the n first unit windings are formed of an equal number of turns in order from the first unit winding on the first end side of the detection winding with the first formation region as a starting formation region,

the n second unit windings are formed of an equal number of turns in order from the second unit winding on the second end side of the detection winding in the same direction as the first unit windings, with an even-numbered formation region that is most distant along the circumferential direction from the first formation region out of the 2n formation regions as a starting formation region.

10. The current detector according to claim 4,

wherein the 2n formation regions are produced by partitioning into equal lengths,

the n first unit windings are formed of an equal number of turns in order from the first unit winding on the first end side of the detection winding with the first formation region as a starting formation region,

the n second unit windings are formed of an equal number of turns in order from the second unit winding on the second end side of the detection winding in the same direction as the first unit windings, with an even-numbered formation region that is most distant along the circumferential direction from the first formation region out of the 2n formation regions as a starting formation region.

11. The current detector according to claim 5,

wherein the 2n formation regions are produced by partitioning into equal lengths,

the n first unit windings are formed of an equal number of turns in order from the first unit winding on the first end side of the detection winding with the first formation region as a starting formation region,

the n second unit windings are formed of an equal number of turns in order from the second unit winding on the second end side of the detection winding in the same direction as the first unit windings, with an even-numbered formation region that is most distant along the circumferential direction from the first formation region out of the 2n formation regions as a starting formation region.

3. A current detector comprising:

a ring-shaped magnetic core through which a measured wire is inserted;

a detection winding formed on an outer surface of the magnetic core; and

a detection resistor that is connected in series to the detection winding and converts a current flowing in the detection winding due to a measured current flowing on the measured wire that has been inserted through the magnetic core to a voltage,

wherein the detection winding is composed of a first winding at a first end side and a second winding at a second end side that is connected in series to the first winding,

the first winding is constructed by connecting n (where n is an integer that is three or higher) first unit windings in series,

the second winding is constructed by connecting n second unit windings in series,

the outer surface is partitioned into 2n formation regions along a circumferential direction of the magnetic core, and

the n first unit windings are formed in odd-numbered formation regions along the circumferential direction with one out of the 2n formation regions as a first formation region, the n second unit windings are formed in even-numbered formation regions out of the 2n formation regions along the circumferential direction, and a j^th (where j is an arbitrary integer in a range of 1 to n, inclusive) first unit winding from the first end side of the detection winding out of the first unit windings and a j^th second unit winding from the second end side of the detection winding out of the second unit windings are not adjacent and are formed with an equal number of turns.

6. The current detector according to claim 3,

wherein the j^th second unit winding is formed in a formation region that is most distant along the circumferential direction from the formation region of the j^th first unit winding.

9. The current detector according to claim 3,

wherein the 2n formation regions are produced by partitioning into equal lengths,

the n first unit windings are formed of an equal number of turns in order from the first unit winding on the first end side of the detection winding with the first formation region as a starting formation region,

the n second unit windings are formed of an equal number of turns in order from the second unit winding on the second end side of the detection winding in the same direction as the first unit windings, with an even-numbered formation region that is most distant along the circumferential direction from the first formation region out of the 2n formation regions as a starting formation region.

12. The current detector according to claim 6,

wherein the 2n formation regions are produced by partitioning into equal lengths,

the n first unit windings are formed of an equal number of turns in order from the first unit winding on the first end side of the detection winding with the first formation region as a starting formation region,

the n second unit windings are formed of an equal number of turns in order from the second unit winding on the second end side of the detection winding in the same direction as the first unit windings, with an even-numbered formation region that is most distant along the circumferential direction from the first formation region out of the 2n formation regions as a starting formation region.

13. A meter comprising;

a current detector including a ring-shaped magnetic core through which a measured wire is inserted, a detection winding formed on an outer surface of the magnetic core, and a pair of resistor connecting terminals disposed on the detection winding for connecting a detection resistor, which converts a current flowing in the detection winding due to a measured current flowing on the measured wire that has been inserted through the magnetic core to a voltage, in series to the detection winding, wherein the detection winding is composed of a first winding at a first end side and a second winding at a second end side that is connected in series to the first winding, the first winding is constructed by connecting n (where n is an integer that is three or higher) first unit windings in series, the second winding is constructed by connecting n second unit windings in series,

the outer surface is partitioned into 2n formation regions along a circumferential direction of the magnetic core, and the n first unit windings are formed in odd-numbered formation regions along the circumferential direction with one out of the 2n formation regions as a first formation region, the n second unit windings are formed in even-numbered formation regions out of the 2n formation regions along the circumferential direction, and a j^th (where j is an arbitrary integer in a range of 1 to n, inclusive) first unit winding from the first end side of the detection winding out of the first unit windings and a j^th second unit winding from the second end side of the detection winding out of the second unit windings are not adjacent and are formed with an equal number of turns;

a processor that measures a current value of the measured current based on the voltage converted by the detection resistor; and

an outputter that outputs the measured current value.

14. A meter comprising;

a current detector including a ring-shaped magnetic core through which a measured wire is inserted, a detection winding formed on an outer surface of the magnetic core; and

a detection resistor that is connected in series to the detection winding and converts a current flowing in the detection winding due to a measured current flowing on the measured wire that has been inserted through the magnetic core to a voltage, wherein the detection winding is composed of a first winding at a first end side and a second winding at a second end side that is connected in series to the first winding, the first winding is constructed by connecting n (where n is an integer that is three or higher) first unit windings in series, the second winding is constructed by connecting n second unit windings in series, the outer surface is partitioned into 2n formation regions along a circumferential direction of the magnetic core, and the n first unit windings are formed in odd-numbered formation regions along the circumferential direction with one out of the 2n formation regions as a first formation region, the n second unit windings are formed in even-numbered formation regions out of the 2n formation regions along the circumferential direction, and a j^th (where j is an arbitrary integer in a range of 1 to n, inclusive) first unit winding from the first end side of the detection winding out of the first unit windings and a j^t second unit winding from the second end side of the detection winding out of the second unit windings are not adjacent and are formed with an equal number of turns;

a processor that measures a current value of the measured current based on the voltage converted by the detection resistor; and

an outputter that outputs the measured current value.