Design of high-performance controller for load frequency control in electrical energy generation systems

In this thesis study, firstly, a proportional integral – proportional derivative (PI-PD) controller design is presented for single–area electric power systems with single and multi-source structures consisting of different thermal turbines. This controller is robust against parameter variations and has the capability to suppress load disturbances for LFC. The parameters of the PI-PD controller are calculated using a graphical method based on calculating the weighted geometric centers of the stability boundary locus. In the study, LFC of single, two, and four-area electric power systems with different thermal turbines is also proposed a cascade control design approach utilizing a series proportional integral derivative controller with filter (PIDF). PIDF controller is used in the cascade control structure's inner and outer loops. The PIDF controller parameters used in the inner and outer loops are analytically designed using the controller synthesis approach. Finally, within the scope of the study, the control of electric power systems for LFC using a proportional-integral-derivative plus second order derivative (PIDD2) controller is presented. The parameters of the proposed controller are determined by the direct synthesis (DS) method, which is an analytical tuning method. This method is based on firstly developing a suitable reference model and then matching the desired dynamic behaviour model with the closed-loop system model. The proposed PIDD2 controller design is realized separately for both load disturbance rejection and disturbance rejection. The design approaches are designed for single, two, three, and four area power systems hosting various thermal turbines. The optimal values of the PIDD2 controller parameters are determined using a novel objective function that includes criteria such as integral of the absolute error (IAE) and settling time. In this thesis study, the effectiveness of the proposed approaches for LFC is demonstrated using different performance criteria such as settling time, peak value, and IAE in response to load variations for frequency and tie-line power deviations in all three proposed design approaches. In addition, simulations are also carried out considering the variations in system parameters and random load variations. It is observed that all three controller design approaches proposed in this thesis can provide significant advantages when compared with the studies in the literature.