Performance Evaluation of the Adaptive Loss of Field Protection in Synchronous Generators by means of the Positive Offset Method

This paper aims to evaluate the performance of the adaptive loss-of-field protection in synchronous generator based on the rate of change of the apparent reactance. It was accomplished by considering the well known Positive Offset method. Comparisons were made by means of computer simulations. The qualitative analysis is carried out to point out the advantages and disadvantages of each method according to different generators parameters. In this way, it was identified circumstances in which one method is better than other, in order to aid the protection engineers in choosing the more appropriate.