In-situ wound current transformer core

Patent metadata

Field	Value
Publication number	US-10902997-B2
Application number	US-201715645507-A
Country	US
Kind code	B2
Filing date	Jul 10, 2017
Priority date	Jul 12, 2016
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A current transformer includes first and second bobbins, and a secondary winding. The first bobbin includes a first tube defining a first longitudinal axis. First and second flanges are disposed on first and second ends of the first tube. The first tube, the first and second flanges collectively define a first slit along the first longitudinal axis. The first slit allows receipt of a primary conductor into the first tube. The second bobbin includes a second tube rotatably received about the first tube. The second tube defines a second slit along the second longitudinal axis. The second slit allows receipt of the primary conductor into the first and second tubes. The secondary winding is wound about the first bobbin and extends along the first longitudinal axis, passing through the first tube and over the first and second flanges. The second tube rotates about the second longitudinal axis relative to the first tube.

First claim

What is claimed is:

1. A method of installing a current transformer, the method comprising:
disposing a first bobbin on an electric line, the first bobbin comprising:
a first tube having first and second ends and defining a first longitudinal axis;
a first flange disposed on the first end of the first tube;
a second flange disposed on the second end of the first tube, wherein the first tube, the first flange, and the second flange collectively define a first slit along the first longitudinal axis, the first slit configured to allow receipt of the electric line into the first tube; and
a secondary winding wound about the first bobbin, the secondary winding extending along the first longitudinal axis, passing through the first tube and over the first and second flanges;

disposing a second bobbin on the first bobbin disposed on the electric line, the second bobbin comprising:
a second tube having first and second ends, the second tube defining:
a second longitudinal axis; and
a second slit along the second longitudinal axis, the second slit configured to receive the first tube into the second tube, wherein when the first tube is received into the second tube, the first longitudinal axis is substantially coincident with the second longitudinal axis and the second bobbin can spin about the second longitudinal axis relative to the first bobbin; and

winding a core wrap about the second bobbin disposed on the first bobbin in a direction substantially perpendicular to the second longitudinal axis by rotating the second bobbin relative to the first bobbin while feeding the core wrap onto the second bobbin.

2. The method of claim 1 , wherein the second bobbin is sized for receipt over the first tube and between the first and second flanges.

3. The method of claim 2 , wherein the second bobbin comprises:
a third flange disposed on the first end of the second tube; and
a fourth flange disposed on the second end of the second tube,
wherein the second tube, the third flange, and the fourth flange collectively define the second slit.

4. The method of claim 1 , wherein the secondary winding passes through the first flange and/or the second flange.

Assignees

• Google Inc
• Google Llc

Inventors

• Yogeeswaran Karthik
• Mass James A

Classifications

• Y10T29/4902

  Electromagnet, transformer or inductor · CPC title

• H01F2038/305

  with toroidal magnetic core · CPC title

• H01F41/096

  Dispensing or feeding devices · CPC title

• H01F38/30

  Constructions · CPC title

• Y10T29/49071

  by winding or coiling · CPC title