Multi-area robust decentralized Load Frequency Controller design in a restructured power system using Quantitative Feedback Theory

In this paper a novel robust decentralized controller using quantitative feedback theory (QFT) is proposed to solve the load frequency control (LFC) problem in a restructured power system that operates under deregulation based on bilateral policy scheme. The load frequency control has been a major subject in electrical power system throughout the years to keep the frequency and tie-line power as close as to their scheduled values. Because of various load changes and wide range of operation conditions scenarios in a multi-area restructured power system, conventional PI controllers for LFC systems are incapable of obtaining good dynamical performance. In this study, a new approach using quantitative feedback theory is presented to design a robust controller for a sample two area power system containing four GENCOs and four DISCOs with system parametric uncertainties under different contracted scenarios. In each control area of this modified traditional dynamical model, the effects of the possible contracts are treated as a set of new input signals. To validate the effectiveness of QFT method, the simulation has been performed using proposed controller and comparison has been done with conventional integral type controller. The simulation results substantiate the robustness and high performance of QFT controller.