Investigation of midpoint STATCOM effects on synchronous generator loss of field protection

This paper investigates the impacts of midpoint static synchronous compensator (STATCOM) on the conventional loss of field (LOF) protection of synchronous generator. Simulation studies are conducted by using the phase domain generator model available in the real-time-digital-simulator (RTDS). A realistic field circuit model is considered for the generator, which allows simulating different LOF failures in order to have a more accurate study. Obtained results show that the conventional LOF relay needs more time to detect LOF failures in presence of midpoint STATCOM. The amount of this time delay depends on the generator initial loading and the type of LOF failure.