Experimental and theoretical investigations of the high current regime of an interferometric fiber-optic current sensor

The influence of non-perfect circularity of the left and right circular light waves of a reflective interferometric fiber-optic current sensor is theoretically and experimentally investigated for currents up to several 100 kA and temperatures from -40 to 80degC. By control of crucial parameters and appropriate packaging of the sensing fiber accuracy and repeatability within plusmn0.1% is achieved. Applications of the sensor are in high-voltage substations and in the electrolytic production of metals such as aluminum.