Fiber Optical Current Transformers Based on Modulated Light Source
Zhaobi Wei · Xi'an Jiaotong Daxue xuebao · 2008
A structure of an optical current transformer is presented.The output of the system is analyzed theoretically and experimentally.The power-line interference and the linear birefringence effect are pointed out as the key barriers for getting the useful signal from the system,and a way based on modulated light source for depressing the power-line interference is verified,where 2 000 Hz square-wave light is considered as the optic supply.For amelioration,the different information is got from two channels to depress the power-line interference by information fusion.The theoretical analysis and experimental results demonstrate that by the improved method the powerline interference is depressed more efficiently,while the signal-to-noise ratio is enhanced obviously.