INTEGRATED SOFTWARE FOR OPTIMAL DIRECTIONAL OVERCURRENT RELAY COORDINATION

ABSTRACT

This paper reports the development of fully integrated software for the optimal directional overcurrent relay coordination of interconnected power systems. Different software packages like load flow analysis, fault analysis, determination of backup/primary relay pairs, main relay coordination program, etc. have been integrated. The program could be run as an interactive package or as an off-line package, depending upon the choice of the user. The information needed for the coordination is stored and used by the software. No data base management packages are needed to manage huge data generated by the program. The software uses an efficient method to generate, store and retrieve the data as per the requirements of the coordination. In the Interactive mode, the information about the coordination time interval, range of the relay settings, limits to the maximum and minimum time of operation of the relays, etc., are supplied. All other relevant data needed for coordination are generated by the software package itself. The usage of the program is illustrated by a case study involving the SPC 26-bus power system.