Influence of Optical Path Structure and Parameter on Operating Stability of Optical Current Transformer
Zhou Jianxin · Power System Technology · 2008
The poor operating stability is one of the primal problems of the optical current transformers(OCT) based on Faraday magnetic optic effect,which behave as the step-by-step breakdown of DC operating light intensity.The structural feature of the optical current sensing head with closed light path and that with straight through light path are analyzed;from the viewpoint of optical path coupling efficiency,the influence of coupling loss caused by optical path length of optical current sensing head on DC operating light intensity is researched,thus the straight through light path structure possesses better temperature stability is demonstrated theoretically.The application instances of the straight through light path structure are presented in this paper and it is proposed that the solenoid collecting magnetic field optical path structure based on the straight through light path possesses such advantages as high measuring sensitivity and strong ability of resisting external electromagnet interference as well as simple and stable structure,etc.,therefore this kind of optical path structure possesses good prospect of practicality.