Cascade controller design via controller synthesis for load frequency control of electrical power systems

The regulation of tie -line electricity flow and frequency of electrical power systems (EPS) is crucial for ensuring their robustness to parameter changes and efficient management of disturbances. To this end, a novel cascade control design approach utilizing a serial Proportional -Integral -Derivative controller with a filter (PIDF) is proposed in this paper. The parameters of the controllers are derived analytically, and it is employed in both loops of the cascade control system to regulate the Load Frequency Control (LFC) of EPS. The implementation of PIDF controllers in both loops is utilized in the cascade control scheme for various power systems featuring different turbine topologies. This approach has been applied to single, and two -area power systems and has exhibited enhanced performance compared to other commonly referenced studies in the literature. To assess the effectiveness of the cascade control approach proposed performance metrics such as settling time, peak value (overshoot), and integral absolute error (IAE) value of frequency and tie -line power variations are utilized to gauge the system's response to a load perturbation. Additionally, the suggested cascade control technique and design process have undergone robustness testing with +/- 50% changes in system parameters to validate their reliability.