Am. Basha et J. Jayachandran, RECURSIVE CONSTRAINED ALGORITHMS FOR SHORT-CIRCUIT AND EARTH FAULT PROTECTION OF GENERATOR-TRANSFORMER UNIT, International Journal of Electrical Engineering Education, 32(1), 1995, pp. 75-82
Recursive constrained protective relaying algorithms are developed for
extracting 50 Hz and 150 Hz components of voltage and current signals
of the generator-transformer unit. These frequency components are use
d for detecting internal short circuit and earth fault conditions of t
he combined unit. The proposed algorithms were satisfactorily tested f
or various simulated conditions of the system.