公开(公告)号：US20180067147A1

公开(公告)日：2018-03-08

申请号：US15695858

申请日：2017-09-05

Applicant: ABB Schweiz AG

Inventor： XUN GU ,  Klaus Bohnert ,  Sergio Vincenzo Marchese

IPC: G01R15/24 ,  G01R19/00 ,  G01R35/00

CPC classification number: G01R15/241 ,  G01R15/246 ,  G01R19/0084 ,  G01R35/005

Abstract: In order to measure a voltage, an electro-optic element is placed in an electrical field generated by the voltage, and light is passed from a light source through a Faraday rotator and the electro-optic element onto a reflector and from there back through the electro-optic element and the Faraday rotator, thereby generating a voltage-dependent phase shift between two polarizations of the light. The interference contrast as well as a principal value of the total phase shift between said polarizations are measured and converted to a complex value having an absolute value equal to the contrast and a phase equal to the principal value. This complex value is offset and scaled using calibration values in order to calculate a compensated complex value. The voltage is derived from the compensated complex value.