Lecture Notes in Electrical Engineering
The load frequency control (LFC) problem for Isolated Power System is considered from the viewpoint of optimal control theory. However, the practical implementation of the optimal controller requires the measurement of all the state variables. This is a serious limitation because of the difficulties involved in their measurement. Output feedback will allow us to design plant controllers of any desired structure. This is another reason for preferring it over full-state feedback. In the regulator problem, we are interested in obtaining good time responses as well as in the stability of the closed-loop system. Therefore, we shall select a performance criterion in the time domain. The simulation results indicate that the proposed control scheme works well. In addition, they show that the controlled system is robust to bounded input disturbances acting on the system.
