Polynomial based H∞ robust governor for load frequency control in steam turbine power systems

• Conventional governors cannot withstand parameter and load changes.
• Load frequency control LFC is a crucial problem with parameter uncertainties.
• Robust controllers are essential for LCF.
• H∞ robust controller based on polynomial approaches is designed.
• Simulations show the robust stability and performance against parameter changes.

This work presents an approach to design a load frequency controller (LFC) for power systems with steam turbines. The goal is to damp the oscillations of the output frequency deviations as fast as possible. The design is based on the polynomial H∞ robust control theory. The robust governor is synthesized by assuming parameter’s variations, negligible dynamics, and a constant main steam pressure. The proposed controller will adequately ensure the internal stability and the robust performance of the closed-loop system. The closed-loop control system is tested by subjecting the system to different disturbance signals to show the robustness characteristics, and the well damping of the output frequency under parametric perturbations. The simulation results point out that the system performance is substantially improved.