Study On Thin Slice Type High Sensitivity Optical Current Sensor System

Optical current transducer (OCT) has potential benefits over conventional current transducer (CT) such as immunity to electromagnetic interference, enhancement in signal bandwidth and dynamic range, ease of integration into future digital control and will be widely used in power electrical system. This paper introduced the problems on OCT, on the basis of electromagnetic theory and elastic-optic effect theory of light, proposed and designed thin slice type optical current sensor system. This system has simple optical structure in the part of sensor head, small dimension of sensitive element, and selected new type of Magneto-optical materials BiGd:YIG, to reduce the linear birefringence and improve temperature stabilization of the system. The design of the whole experimental system has been completed, including system optical structure, electronic structure and signal processing, etc. The experimental system used a LD as light source, a PIN as detector, and a PC to acquire output signal and data process. Experimental verification and performance test is carried out and the test results prove the feasibility of the system.