Comparison of adaptive UFLS schemes in modern power systems

In recent decades, the advantages of a fast development in the communication and computer technology have been successfully harvested in the majority of technological areas for updating various mechanisms and processes. Power system control and protection is no exception. However, actual implementation of modern technologies into power system control and protection mechanisms depends on a country. In case of a sudden underfrequency conditions appearance in the power system only a centralized gathering of measurements and global actions (e.g. use of WAMS and GPS technology) can represent an appropriate approach to a global problem. In such circumstances, underfrequency load shedding is often the last resort tool for avoiding a total power system blackout. Its appropriate actions are of great importance both from technological and economical point of view. In this paper several different adaptive approaches are compared in their efficiency via testing on different dynamic power system models.