Patent · US Active

Fiber-optic current sensor with sum detection

US7876448B2 · kind B2 · utility

2Cited by

7References

17Claims

0Family size

Assignee

ABB RESEARCH LTD. · CH

Inventors

Lars Andersson · Uppsala, SE
Hubert Braendle · Oberengstringen, CH
Klaus Bohnert · Oberrohrdorf, CH

Key dates

Filing date	Oct 3, 2008
Grant date	Jan 25, 2011
Priority date	—
Expiry date	Jan 14, 2029

Classification

Technology area (CPC G)Physics
CPC primaryG01R19/10
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.