Design of Load Frequency Controller for Hydro Power Dynamic System Using PSO-DV Algorithm Based Model Approximation Method

In this paper, the design of load frequency control of a high order hydro power system model is simplified by proposing an optimal model approximation method. The model approximation is executed by minimizing the Integral Square Error (ISEI) between the unit impulse responses of the original system and the approximate model along with the retention of their Impulse Response Energies (IRE), by using a hybrid evolutionary (i.e. PSO-DV) algorithm. The Reduced Order Model (ROM) developed by this method assures the properties of preserving the stability, passivity, and the dynamic behaviour of the original hydro power system. The suitability of ROM is shown by designing a PID controller and the same is used to control load frequency response of the original hydro power system to the desired value. The gains of PID controller are tuned by minimizing the Integral Square error (ISEc) between the desired and actual response of the ROM, by using the same PSO-DV algorithm. The efficacy of the approximate model and the controller designed is shown by comparing some of the performance error indices and the time responses.