A load shedding method based on the power vacancy sensitivity analysis

The loss of a large capacity power plant or extra-high voltage transmission line in weak-connected power system may cause abundant power vacancy of consumer district. As a result, the system frequency will drop sharply. This paper presented a load-shedding method which is based on the power vacancy sensitivity analysis. Refer to the network structure after fault, it first calculates the sensitivity of power vacancy to load power and carries out the load-shedding according to the descending sequence of the sensitivity values, and then determines the load-shedding amount by the time-domain simulation method. As the precaution before the traditional UFLS (Under Frequency Load Shedding) method, this method could effectively raise the system frequency with minimal load-shedding. EPRI-36 system is used to demonstrate the efficiency of the method.