Optical current transformer for 245 kV integrated air insulated switchgear

Applying an optical current transformer (optical CT) to substations has several advantages, e.g. high accuracy and reduction of the cost. In particular, in the case of a digitally controlled substation, the optical CT assures the insulation performance and is free from network damage caused by dielectric breakdown. We made the optical CT for 245 kV integrated air insulated switchgear, Toshiba´s intelligent AIS substation, using a digital control system and demonstrated its characteristics. The optical CT shows excellent performance within IEC 0.5 class accuracy.