Optimal tracking approach to load frequency control in power systems

This paper presents a new optimal tracking approach to the LFC problem. It should be noted that the LFC problem intrinsically has the nature of optimal tracking on the point that generation plant is so special a type of system that the generator automatically supplies its output exactly equal to the load demand. This study proposes the LFC formulation to make the mechanical output of the turbine and the system frequency track the load demand and the desired frequency respectively. With the use of the optimal tracking approach, the optimal feedback gains have been calculated for the new LFC scheme adopting the modified PID controller. The optimality of the calculated gains has been tested for the single machine, which shows that the new LFC scheme with the modified PID controller improves the system damping remarkably and that the feedback of load disturbance signal further reduces the system oscillation. In addition, this study also presents averaged-derivative PID control to get rid of noise from innumerable on-off load operations