Recursive Constrained Algorithms for Short Circuit and Earth Fault Protection of Generator-Transformer Unit

Abstract

Recursive constrained algorithms for short circuit and earth fault protection of generator/transformer unit 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 used for detecting internal short circuit and earth fault conditions of the combined unit. The proposed algorithms were satisfactorily tested for various simulated conditions of the system.