A Novel Optical Current Transformer Based on Comparative Measurement

A comparative method, which can compensate the material´s Verdet constant and linear birefringence variations of Optical Current Transformer (OCT) due to environmental factors, is proposed. The strategy is based on a novel OCT where a permanent magnet is used as reference source. Theoretic analysis is carried out employing matrix optics theory, and the experiment results are presented to show the validity. The point type sensing head is adopted in designed sensing element. So the OCT is simple in structure and is suitable for applications in the high voltage environment.