Optimal Tuning of LQR for Load Frequency Control in Deregulated Power System for Given Time Domain Specifications

Present work proposes a two stage process of designing a linear quadratic regulator (LQR) for load frequency control (LFC) in two area deregulated power system. Primary objective of proposed algorithm is to design an optimal state feedback closed loop system which embodies a set of desired time domain specifications. First stage of the algorithm comprises of desired time response model formulation, with aim that it embodies a given set of time domain specifications. In second stage, optimal selection of elements of weighting matrices "Q" and "R", used in standard LQR design procedure are carried out with objective of minimizing the error between designed responses and the desired response models. In present work, optimal selection of weighting matrices elements is formulated in an optimization framework which is solved by the application of a simple, parameter-less population based optimization technique called Jaya algorithm. The proposed algorithm reduces the tedious selection process of LQR weighting matrices elements. Optimal tuning of LQR weighting matrices elements is based on minimization of objective function which is formulated with objective of achieving a designed state feedback closed loop system response as close to that a desired time response model. The proposed algorithm has been illustrated for design of a state feedback load frequency controller (LFC) in two area deregulated power system with aim of achieving a given set of time domain specification. The performance of the proposed method is evaluated by carrying out design and simulation for a bilateral contract scenario in two area deregulated power system. Obtained results show that the designed closed loop system responses closely match with that of the desired time response models with minimum control effort and less computation time.