  The interconnected power system presents a great challenge to both system
analyzers and control designers. The load-frequency control (LFC) problem has
gained much importance because of the complexity and size of modern
interconnected power systems. In this work, the original (full) system is
decomposed into subsystems using the overlapping decentralization technique. A
discrete-time output feedback control is then designed using Evolutionary
Programming (EP) technique. EP is selected since it is a good candidate for a
global search for the optimum of a cost function that leads to the optimum
output feedback controller gains in order to achieve the LFC requirements and
improve its performance. The system performance is analyzed through simulating
different disturbances and parameter variations over a wide range. Results from
Dynamic Programming technique are also presented for completeness.
