Current transformer of air circuit breaker

Patent metadata

Field	Value
Publication number	US-11810709-B2
Application number	US-201917414002-A
Country	US
Kind code	B2
Filing date	Sep 18, 2019
Priority date	Dec 26, 2018
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A current transformer according to the present invention may comprise a magnetic core, a secondary coil, and a magnetic flux compensation member. A main circuit of an air circuit breaker penetrates the magnetic core. In addition, the secondary coil is arranged to be adjacent to the magnetic core, and a secondary current is induced through a current flowing in the main circuit. In addition, the secondary coil supplies the induced secondary current to a relay. The magnetic flux compensation member may be coupled to the magnetic core so as to correct magnetic flux of the secondary coil.

First claim

What is claimed is:

1. A current transformer comprising:
a magnetic core through which a main circuit of an air circuit breaker passes;
a secondary coil disposed adjacent to the magnetic core to induce a secondary current from a current flowing through the main circuit and to supply the secondary current to a relay; and
a magnetic flux compensation member coupled to the magnetic core to compensate for the current induced from the secondary coil,
wherein the magnetic core has a through-hole defined therein through which the main circuit passes, and
wherein the secondary coil is coupled to a first shunt spaced from the magnetic core by a predetermined distance.

2. The current transformer of claim 1 , wherein the magnetic flux compensation member is coupled to both side faces of the magnetic core.

3. The current transformer of claim 1 , wherein the magnetic flux compensation member is embodied as a plate-like member having a predetermined thickness.

4. The current transformer of claim 3 , wherein the magnetic flux compensation member includes a plurality of plate-like members having a predetermined thickness and coupled to the magnetic core and overlapping each other.

5. The current transformer of claim 1 ,
wherein the magnetic flux compensation member extends vertically by a first distance, wherein a virtual connection line having a shortest distance and connecting the secondary coil and the main circuit to other overlaps the magnetic core by the first distance.

6. The current transformer of claim 5 , wherein the magnetic flux compensation member includes a plate-shaped member having a predetermined thickness and having a vertical dimension equal to the first distance.

Assignees

• Ls Electric Co Ltd

Inventors

• Chung Han-Baek

Classifications

• H01F38/30 Primary

  Constructions · CPC title

• G01R15/185

  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 title

• H01F27/427 Primary

  for current transformers · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H01F3/12 Primary

  Magnetic shunt paths · CPC title