Application of the Fiber Optical Current Transformer in the 110kV Smart Substation

This paper describes the application of the Fiber Optical Current Transformer (FOCT) in 110kV smart substation. The authors provide brief introduction to the principle of the FOCT firstly, then the application details of the FOCT in 110kV Jinnan smart substation are described. Generally, the accuracy, polarity and ratio are tested in field, therefore the authors put focus on them. The method of the field accuracy test and the problem existed in the test at present are introduced. The FOCT uses the optical detection method, so the secondary output signal contains optical speckle noise inevitably. The impact on the electric energy metering and protective relay is analyzed. Finally, the other challenges in project application of the FOCT are discussed.