Adaptive distance relay setting for hybrid power transmission networks

This paper investigates on distance relay characteristic for hybrid line; an overhead transmission line combined with a cable. Introducing ABCD parameter approach to sequence network the apparent impedance equation is derived that includes line capacitance. For a 400 kV hybrid transmission system results show that shunt capacitance has significant effect on settings for adaptive relaying. It is observed that the trip characteristic for hybrid line is unique. An adaptive setting method using local information is proposed and tested using simulated data obtained through EMTDC-PSCAD.