Digital protective scheme for large generators based on summation principles

A distinct element in the integrated protective scheme of thegenerator is the differential relay. This unit relay which is employed todepict internal faults; is an essential stage and may be considered the coreof generator protection. This stage is characterized with minimumoperating time. Needless to mention that such relays do not cover theentire length of the generator windings. The unprotected length of thewinding is a point of concern to the protective supervising group in thefield.This work highlights an analog differential relay with amicroprocessor at the output stage, to cater for full coverage of thewinding. This arrangement has been built in the laboratory and the resultsfor set up will be illustrated.So, this work claims the presentation of a differential relay for largegenerators which is based on the summation technique, capable ofcovering the entire length of the winding which is a viable achievement inthe protective scheme of large generators .