This paper will review the sub-synchronous oscillation phenomena and the interactions between the electrical power system and the mechanical turbine generator system. The paper presents captured field data of sub-synchronous and super-synchronous resonance at the generator terminals of a nuclear power plant and at a transmission substation from a field study lasting several years. It describes the relationship between sub- and super-synchronous currents and voltages, such as frequencies, dependencies, duration, time constants and magnitudes. From this study a protection scheme was devised that can easily be incorporated into a numerical relay using standard protection functions and a numerical multi-purpose filter.
File Type:
pdf