A positive sequence directional element for numerical distance relays

The technique proposed in this paper uses the ratio of the incremental positive sequence voltage and current phasors to decide direction. This impedance lies in the third quadrant for forward faults and in the first quadrant (not including the origin) for reverse faults. This paper outlines the principle of operation of the new element, describes the integration of the element into a distance relay, then gives results of tests on the relay. The relay was tested first of all on the RTDS, then on-line in two different locations in the Manitoba Hydro network. Finally an off-line model of the relay was tested in a complex series compensation application