DEVELOPMENT OF STATIC RELAYS FOR 25 KVr SINGLE PHASE, 50 C/S ELECTRIC TRACTION

Abstract

The dissertation deals with the details of the work being done by the author on the development of static distance relays for the protection of single phase, 25 KV, 54 C/S traction overhead systems. A description of 25 KY, industrial frequency traction supply systems its present protection scheme (provided by a set of electromechanical relays), and general comparison of static relays with their electromechanical counterparts is done. Single step to relay with one extended setting for earth fault protection and offset Rho (second quadrant) for wrong phase coupling protection have been developed# Experimentl verif&cation of the characteristics have been donee. This relay is based on direct phase c k arisen technique using semiconductor devices and the angle of maximum reach and impedance setting of o and offset *0 units is provided by shunt and series transactors respect .v►ely# Some suggestions are also given to modify the relay characteristics to avoid meloperations exper- • ienced with the present protective scheme.