Device for measuring electric currents in electrical conductors

Patent metadata

Field	Value
Publication number	US-10732205-B2
Application number	US-201715590378-A
Country	US
Kind code	B2
Filing date	May 9, 2017
Priority date	Jul 8, 2016
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A device for measuring electric currents includes multiple current sensors of Rogowski type, each suitable for measuring an electric current flowing through an electrical conductor, these current sensors being in adjacent pairs and each including coils for measuring the current and a central aperture for receiving the corresponding electrical conductor. Each current sensor includes two of the coils, which coils are positioned in parallel and facing one another on opposite edges of the central aperture and two ferromagnetic bars extending between ends of the coils, perpendicularly to a longitudinal axis of the coils.

First claim

The invention claimed is:

1. A measuring device for measuring electric currents in an electrical circuit, said measuring device comprising:
multiple Rogowski current sensors, each adapted to measure an electric current in an electrical conductor, said current sensors being adjacent in pairs and each having:
coils adapted to be electrically connected together to form a current measuring circuit,
a central opening for receiving the corresponding electrical conductor, and the coils being arranged on the periphery of the central opening;

a plurality of ferromagnetic bars; and
a first armature and a second armature arranged parallel to each other,
wherein each current sensor comprises two of said coils arranged in parallel and face to face on opposite edges of the central opening and two of said ferromagnetic bars extending between the ends of the coils, perpendicularly to a longitudinal axis of the coils,
wherein the first and second armatures extend along the longitudinal axis of the coils and the first and second armatures both comprise housings that are each adapted to receive one end of one of the ferromagnetic bars, and
the first and second armatures are secured together by fasteners, the fasteners being included in some of the housings, but not all of the housings, and holding the ferromagnetic bars in position.

2. The measuring device according to claim 1 , wherein each current sensor has a ferromagnetic bar in common with the immediately adjacent current sensor.

3. The measuring device according to claim 1 , wherein the first and second armatures are common to all the current sensors of the device, the two coils of each current sensor being arranged on the first and second armatures, respectively.

4. The measuring device according to claim 3 , wherein each of the first and second armatures have a rectilinear part, and coils being arranged on these first and second armatures by winding about this rectilinear part.

5. The measuring device according to claim 4 , wherein the first and second armatures are identical.

6. The measuring device according to claim 3 , wherein the first and second armatures each comprise a main part of rectilinear shape and secondary parts which protrude from the main part perpendicularly to the main part, and coils being formed by winding on the first and second armatures at the secondary parts.

7. The measuring device according to claim 1 , wherein the ferromagnetic bars are made of an iron alloy, including soft iron or NiFe or FeSi.

8. An assembly comprising:
an electrical device, electrically powered by electrical conductors; and
a measuring device, adapted to measure electric current flowing through each of the electrical conductors,
wherein the measuring device includes
multiple Rogowski current sensors, each adapted to measure the electric current in an electrical conductor of the electric conductors, said current sensors being adjacent in pairs and each having:
coils adapted to be electrically connected together to form a current measuring circuit,
a central opening for receiving the corresponding electrical conductor, and the coils being arranged on the periphery of the central opening,

a plurality of ferromagnetic bars, and
a first armature and a second armature arranged parallel to each other,

wherein each current sensor comprises two of said coils arranged in parallel and face to face on opposite edges of the central opening and two of said ferromagnetic bars extending between the ends of the coils, perpendicularly to a longitudinal axis of the coils,
wherein the first and second armatures extend along the longitudinal axis of the coils and the first and second armatures both comprise housings that are each adapted to receive one end of one of the ferromagnetic bars, and
the first and second armatures are secured together by fasteners, the fasteners being included in some of the housings, but not all of the housings, and holding the ferromagnetic bars in position.

9. The measuring device according to claim 1 , wherein the housings include four housings, two of the housings include the fasteners that secure the first and second armatures together and hold the ferromagnetic bars in position, and two of the housings do not include the fasteners.

10. The measuring device according to claim 1 , wherein the four housings are spaced apart by spacings therebetween.

11. The measuring device according to claim 1 , wherein the fasteners are connectable elements of complimentary shape.

12. The measuring device according to claim 1 , wherein the first and second armatures include connection pins, the connections pins being positioned on distal ends of the housings.

13. The measuring device according to claim 12 , wherein each of the connection pins is in a form of a straight rod made of an electrically conductive material, one end of which is configured to be received inside an electronic board.

14. The measuring device according to claim 13 , wherein the first and second armatures include fastening studs projecting from the measuring device and configured to be received by corresponding holes of the electronic board, the fastening studs being different from the connection pins.

Assignees

• Schneider Electric Ind Sas

Inventors

• Houbre Pascal
• Larcher Patrick

Classifications

• G01R15/16

  using capacitive devices · CPC title

• G01R15/142

  Arrangements for simultaneous measurements of several parameters employing techniques covered by groups G01R15/14 - G01R15/26 · CPC title

• G01R15/181 Primary

  using coils without a magnetic core, e.g. Rogowski coils · CPC title

• G01R19/0092

  Measuring current only · CPC title

• G01R15/205

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