Gravitational Search Algorithm Optimized State Feedback Load Frequency Controller

To maintain reliable and stable operation in a power system, maintaining the value of frequency variation within a desired limit is important. In this paper, a state feedback controller is designed for a load frequency control (LFC) system. This process of defining each state will help the operator to understand the cumulative behavior of different states on the system performance in presence of external disturbances. A generalized range for stability is derived depending on the physical parameters of the system. Instead of manually selecting the controller gain values from stable range, an optimization algorithm is used. In this paper, gravitational search algorithm (GSA) is used as an optimization algorithm. GSA minimizes the effect of external disturbance on system frequency and gives a set of controller values satisfying system stability criterion. A set of results is presented to show the improved closed-loop performance of the system. A comparative study with the previous work of the authors and with a few existing works is also presented to highlight the advantages of the proposed method.