A method for the design of UFLS schemes of regional power system using improved frequency response model

Summary Under frequency load shedding (UFLS) is an effective remedy against power system frequency collapses. An optimal approach for designing UFLS schemes of regional power system is presented in this paper. An improved multigenerator frequency response (IMFR) model that incorporates UFLS schemes is built to accurately and quickly evaluate system frequency after generator and load imbalance. Unlike the conventional system frequency response model, IMFR involves a spinning reserve, different types of governors, the static load model, and network influence. The representative operating and contingencies for designing UFLS schemes are selected with the use of IMFR. The optimization object function is defined for minimizing the amount of total load shed and considering UFLS design and performance criteria. Then, the optimal UFLS scheme is designed through IMFR and adaptive simulated annealing algorithm. Finally, the approach is applied to an actual regional power system in China. The effectiveness of the optimal UFLS scheme is investigated through a simulation.