Current sensor

Patent metadata

Field	Value
Publication number	US-12461128-B2
Application number	US-202318343220-A
Country	US
Kind code	B2
Filing date	Jun 28, 2023
Priority date	Jul 7, 2022
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A current sensor includes a magnetic core that can be arranged to surround a conducting wire through which a current to be measured flows, magnetic sensors each configured to detect magnetic flux in a predetermined portion of the magnetic core, amplifiers arranged in correspondence with the magnetic sensors, feedback coils arranged in correspondence with the magnetic sensors, and a current detector that detects the current to be measured based on a current yielded by combining currents flowing through each of the feedback coils. Each of the amplifiers amplifies an output of the corresponding magnetic sensor and outputs a current corresponding to the output of the corresponding magnetic sensor. Each feedback coil is wound around the magnetic core and passes the current outputted by the corresponding amplifier in a direction that cancels the corresponding magnetic flux in the predetermined portion of the magnetic core.

First claim

The invention claimed is:

1 . A current sensor comprising:
a magnetic core that can be arranged to surround a conducting wire through which a current to be measured flows; a plurality of magnetic sensors each configured to detect magnetic flux in a predetermined portion of the magnetic core; a plurality of amplifiers arranged in correspondence with the plurality of magnetic sensors; a plurality of feedback coils arranged in correspondence with the plurality of magnetic sensors; and a current detector configured to detect the current to be measured based on a current yielded by combining currents flowing through each of the plurality of feedback coils, wherein each of the plurality of amplifiers is configured to amplify an output of the corresponding magnetic sensor and output a current corresponding to the output of the corresponding magnetic sensor, each of the plurality of feedback coils is wound around the magnetic core and passes the current outputted by the corresponding amplifier in a direction that cancels the corresponding magnetic flux in the predetermined portion of the magnetic core, the plurality of magnetic sensors is arranged at equal angles as viewed from a center of the magnetic core, and the plurality of feedback coils, which correspond to a plurality of portions of the magnetic core of which the plurality of magnetic sensors detect a magnetic flux, is arranged at equal angles as viewed from the center of the magnetic core.

2 . The current sensor according to claim 1 , further comprising a resistor through which the current yielded by combining the currents flowing through each of the plurality of feedback coils flows, wherein
the current detector is configured to detect the current to be measured based on a voltage at both ends of the resistor.

3 . The current sensor according to claim 1 , further comprising a position detector configured to detect a position of the conducting wire relative to the magnetic core based on the current flowing through each of the plurality of feedback coils.

4 . The current sensor according to claim 1 , wherein the magnetic core is openable and closable.

5 . A current sensor comprising:
a magnetic core that can be arranged to surround a conducting wire through which a current to be measured flows; a plurality of magnetic sensors each configured to detect magnetic flux in a predetermined portion of the magnetic core; a plurality of amplifiers arranged in correspondence with the plurality of magnetic sensors; a plurality of feedback coils arranged in correspondence with the plurality of magnetic sensors; and a current detector configured to detect the current to be measured based on a current yielded by combining currents flowing through each of the plurality of feedback coils, wherein each of the plurality of amplifiers is configured to amplify an output of the corresponding magnetic sensor and output a current corresponding to the output of the corresponding magnetic sensor, and each of the plurality of feedback coils is wound around the magnetic core and passes the current outputted by the corresponding amplifier in a direction that cancels the corresponding magnetic flux in the predetermined portion of the magnetic core, further comprising a position detector configured to detect a position of the conducting wire relative to the magnetic core based on each position of the plurality of magnetic sensors in the magnetic core and ratio of the current flowing through each of the plurality of feedback coils.

Assignees

• Yokogawa Electric Corp
• Yokogawa Test & Measurement Corp

Inventors

• Minami Hiroki
• Ishida Hiroyuki

Classifications

• G01R19/0092 Primary

  Measuring current only · CPC title

• G01R15/207

  Constructional details independent of the type of device used · CPC title

• G01R15/186

  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 title

• G01R15/202 Primary

  using Hall-effect devices (Hall elements in arrangements for measuring electrical power G01R21/08) · CPC title

• G01R15/185 Primary

  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 title