Study On A New Optoelectronic Current Transformer

Along with the development of EHV power transmission and transformation, serious defects of traditional electromagnetic induction-type current transformer emerge. This paper is aimed to research and realize a new-type optoelectronic current transformer to replace traditional CT. Optical fiber technology is introduced to CT design, advantages and design scheme of OECT are presented, and development of system is particularly discussed. High-accuracy miniature CT and A/D modulation are adopted to realize high-accuracy property; method of phase encoding is presented and hardware is selected to realize low power-consumption property. Digital signal processor calculates ration error, and real-time property of data processing is ensured. Virtual instrument technology is applied to develop a virtual OECT calibrator. By test running in laboratory, design requirements of system are achieved, and error source is analyzed, too.