A composite technique for obtaining the desirable shapes of first zone distance relays.

This paper describes briefly the ideal characteristics required for tripping for faults within the first zone of a distance relay adapted to the protection of a transmission line. The quadrilateral characteristic on an R-X diagram, which is the ideal characteristic, is obtained using a new hybrid comparison technique. This technique possesses the flexibility of conforming to any desired characteristic by a simple change in the selection of current inputs. The relays are described in their block schematic form.
In this paper the first zone distance relay is considered and the desirable shapes of its characteristics are discussed. A new hybrid comparison technique is used to obtain these desirable characteristics. The comparator models are described in their block schematic form. [ABSTRACT FROM AUTHOR]