A new under-frequency load shedding scheme based on OBDD

Under-frequency load shedding (UFLS) controls are means that usually are taken when generation deficiency occurs and frequencies of power systems are in extreme danger. A new UFLS scheme is designed to maintain the system frequency within an acceptable range for the possible generation deficiencies. The proposed scheme considers the spinning reserve and load models, estimates imbalance power through the rate of change of frequency after a disturbance and calculates the amount of load to be shed. The scheme adopts the way of searching, checking and optimizing. Simulation results are presented to illustrate the validity of the scheme.