Patent ID: 8933686
Filing Date: 2015-01-13
Classification: G01R

Abstract:
1. A single-phase optical current transformer comprising: a cylindrical container; an electric conductor being arranged inside the cylindrical container; and a Faraday-effect element being provided on the cylindrical container; the Faraday-effect element having two optical fibers and a mirror, each of the optical fibers being provided outside the cylindrical container, the optical fibers forming a first optical path and a second optical path respectively, each of the optical paths being provided outside the cylindrical container, each of the optical paths being placed so as to intersect with the axial direction of the electric conductor, the optical paths being maintained parallel to each other at a predetermined interval, the second optical path being provided farther from an axis of the electric conductor than the first optical path, the mirror being provided at a respective end surface of each of the optical fibers, the mirror reflecting linearly polarized light, wherein: linearly polarized lights from the same light source are injected respectively into the optical paths formed outside the cylindrical container, and the current flowing through the electric conductor is measured based on each of the Faraday rotation angles of the linearly polarized lights which are reflected by the mirror, a first linearly polarized light from the light source is injected into the first optical path and reflected by the mirror such that the first linearly polarized light returns along the first optical path, and a second linearly polarized light from the light source is injected into the second optical path and reflected by the mirror such that the second linearly polarized light returns along the second optical path.