Current detection structure

Patent metadata

Field	Value
Publication number	US-9513317-B2
Application number	US-201514600716-A
Country	US
Kind code	B2
Filing date	Jan 20, 2015
Priority date	Jan 21, 2014
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A current detection structure includes a busbar to flow a current therethrough, a magnetic detection element to detect a strength of a magnetic field generated by the current flowing through the busbar, and a current detecting portion to determine the current flowing through the busbar based on the magnetic field detected by the magnetic detection element. A through-hole is formed penetrating the busbar such that a current path is formed on both sides of the through-hole. The magnetic detection element is disposed in the through-hole. The current detecting portion determines the current flowing through the busbar based on a strength of a synthetic magnetic field detected by the magnetic detection element. The synthetic magnetic field is produced by combining a magnetic field that is generated by a current flowing through the current path on the both sides of the through-hole.

First claim

What is claimed is:

1. A current detection structure, comprising:
a busbar to flow a current therethrough;
a magnetic detection element to detect a strength of a magnetic field generated by the current flowing through the busbar; and
a current detecting portion to determine the current flowing through the busbar based on the magnetic field detected by the magnetic detection element,
wherein a through-hole is formed penetrating the busbar such that a current path is formed on both sides of the through-hole,
wherein the magnetic detection element is disposed in the through-hole,
wherein the current detecting portion determines the current flowing through the busbar based on a strength of a synthetic magnetic field detected by the magnetic detection element,
wherein the synthetic magnetic field is produced by combining a magnetic field that is generated by a current flowing through the current path on the both sides of the through-hole,
wherein the magnetic detection element includes a portion which is not accommodated in the through-hole in a thickness direction of the busbar, and
wherein a central axis in a length direction of the busbar overlaps the magnetic detection element in a plan view.

2. The current detection structure according to claim 1 , wherein the magnetic detection element is arranged such that a detection axis thereof is along a thickness direction of the busbar.

3. The current detection structure according to claim 1 , wherein the magnetic detection element comprises a GMR sensor.

4. The current detection structure according to claim 3 , wherein the magnetic detection element is arranged at a position where a magnetic flux density of the synthetic magnetic field is more than 0 and not more than 5 mT.

5. The current detection structure according to claim 3 , wherein the magnetic detection element is arranged at a position where a magnetic flux density of the synthetic magnetic field is more than 0 and not more than 2 mT.

6. The current detection structure according to claim 1 , wherein the though-hole is formed to have a symmetrical shape with respect to a central axis of the busbar, wherein the current path is formed symmetrically on the both sides of the though-hole, and the magnetic detection element is arranged off the central axis of the busbar.

7. The current detection structure according to claim 1 , wherein the magnetic detection element is arranged at a center of the through-hole in a longitudinal direction of the busbar.

8. The current detection structure according to claim 1 , wherein the current path on the both sides of the through-hole is linearly formed along a longitudinal direction of the busbar.

9. The current detection structure according to claim 8 , wherein the current flowing through the busbar has a frequency of not more than 100 kHz, wherein the busbar comprises copper or a copper alloy, and wherein the current path on the both sides of the through-hole has a width and a thickness of not more than 0.5 mm to suppress the influence of the skin effect.

10. The current detection structure according to claim 1 , wherein the magnetic detection element comprises a GMR sensor, and wherein a center of the magnetic detection element in a thickness direction of the busbar coincides with a center of the busbar in the thickness direction thereof.

11. The current detection structure according to claim 1 , wherein the magnetic detection element disposed in the through-hole is a single magnetic detection element.

Assignees

• Hitachi Metals Ltd

Inventors

• Okuyama Ken
• Chiwata Naofumi
• Akimoto Katsuya
• Futakuchi Naoki
• Ikeda Yukio
• Takahashi Kazuhisa

Classifications

• G01R15/205

  using magneto-resistance devices, e.g. field plates · CPC title

• G01R15/207 Primary

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

• G01R19/0092 Primary

  Measuring current only · CPC title

• G01R33/093

  using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00) · CPC title