Underfrequency Load Shedding Scheme Using Generator Coherency Approach

In power system operation, frequency issue caused by power imbalance between generation and load can occur in power system. If generation is smaller than load, system frequency will drop. When generation deficiency is too large, system frequency will decrease significantly which can lead to system blackout. To solve this frequency issue, proper underfrequency load shedding and islanding scheme is essential to prevent further deviation of system frequency from its nominal frequency. In this research, conventional underfrequency load shedding and islanding scheme using generator coherency approach are designed for Southern Sulawesi system, one of power system in Sulawesi, Indonesia. Southern Sulawesi system is not too large with peak load of about 800-1000 MW therefore easier to analyze performance of the method used in this research. The simulations were performed using DIgSILENT PowerFactory. Underfrequency load shedding and islanding scheme obtained can be applied to all scenarios simulated in this research with good performance.