LIGHTNING CURRENT MEASURING DEVICE AND LIGHTNING CURRENT MEASURING METHOD

摘要

A lightning current measuring device is provided with: a polarized light separation element which separates light output from a sensor fiber into horizontal and vertical components having orthogonal planes of polarization, a Faraday rotation angle calculation unit calculating a Faraday rotation angle through arc-sine processing of a digitized signal of the difference between the horizontal and vertical components converted to a signal through photoelectric conversion after separation by the polarized light separation element, amplifiers which amplify the horizontal and vertical components converted to a signal through photoelectric conversion after separation by the polarized light separation element, a Faraday rotation angle calculating unit which calculates a Faraday rotation angle based on a digitized signal of the difference between the amplified horizontal and vertical components, and current value conversion units converting current values based on the calculated Faraday rotation angles.

主权项

1. A lightning current measuring device which is provided with a sensor fiber, inputs linearly polarized light to the sensor fiber, and detects the magnitude of Faraday rotation applied to the linearly polarized light by a magnetic field due to a current to be measured flowing through a conductor provided around the sensor fiber to measure the current to be measured, the lightning current measuring device comprising:
polarized light separation means for separating output light from the sensor fiber into a horizontal component and a vertical component having orthogonal planes of polarization; first calculation means for calculating a Faraday rotation angle through arc-sine processing of a digitized signal of the difference between the horizontal component and the vertical component converted to signals through photoelectric conversion after separation by the polarized light separation means; amplification means for amplifying the horizontal component and the vertical component converted to signals through photoelectric conversion after separation by the polarized light separation means; second calculation means for calculating a Faraday rotation angle based on a digitized signal of the difference between the horizontal component and the vertical component amplified by the amplification means; first conversion means for converting a current value from the Faraday rotation angle calculated by the first calculation means; and second conversion means for converting a current value from the Faraday rotation angle calculated by the second calculation means.