The Devevolpment of a New High Speed 3-Terminal Line Protection Scheme

A new high speed Current Differential protection scheme for application to three-terminal transmission lines is described. The scheme utilises a wide-band Fibre Optic Link and the results show that the special filtering and signal processing techniques developed provide a performance which satisfies the requirements for reliable and secure protection of Teed feeders. The protection was developed using CAD techniques and the methods proposed are readily implemented using present generation signal processing hardware.