AN ADAPTIVE-CONTROL SCHEME FOR LOAD FREQUENCY CONTROL OF MULTIAREA POWER-SYSTEMS .1. IDENTIFICATION AND FUNCTIONAL DESIGN

An adaptive hierarchical control scheme for the load frequency control (LFC) of a multiarea power system is presented. The strategy decomposes a given control problem into multilevel-multilayer hierarchical subproblems, and uses the minimum variance stochastic model to represent each subproblem. The key control parameters are monitored on a real-time basis and are used to compute the local control signals adaptively. The actual subsystem control signal at each level is obtained as the algebraic sum of its local and global control signals. The control strategy can handle unpredictable load changes of random magnitude and duration. The technique presented in this paper provides for real-time parallel processing that can use only locally available measurements for each entity controller. A companion paper (A. Rubaai and V. Udo, Electr. Power Syst. Res., 24 (1992) 189-197) discusses and illustrates the practical implementation of the proposed control strategy.