Study of impacts on operation of island and frequency based auto load shedding to improve service reliability using CYME PSAF

Formation of island may be inadvertent which is due to system fault or intentional for a purpose of system maintenance. Generally fall of frequency is lead by abnormal condition to a power system and sometimes blackout of an integrated system is occurred due to extreme abnormality. Though traditionally, interconnection standards avoid islanding operation but in case of emergency islands can support local supplies to critical and important loads to improve the service reliability. This paper presents different studies of impact on an island as well as develops a frequency based auto load shedding scheme in case of load addition or generation loss to the island. The scheme has been applied to a seven bus test island to validate the effectiveness of the developed system and various abnormal conditions to the test system have been simulated.