A Numerical Study of the Load Frequency Control Scheme for a Steam Plant Integrated with an Islanded Microgrid

The existing power systems suffer from numerous challenges resulting from the imbalance between the supply and the load. Load Frequency Control (LFC) is a mechanism designed to maintain a consistent frequency by regulating the power flow between various components of an interconnected system. The LFC ensures that the frequency deviations in an interconnected power system are minimized to zero. This is achieved by forcing the frequency and tie-line power errors to zero, hence maintaining a balance between the power generated and the demand. This study presents an investigation on the LFC of a steam plant integrated with an islanded microgrid (MG). The proposed MG consists of a hydro plant and a wind farm. The aim of the study is to analyze the effect of frequency variation when integrating a conventional power system with a renewable energy-based system. A comparative study was conducted on the various control strategies to design a simple and effective control technique for the proposed system. Based on the comparative study, a droop controller was proposed for the hydro plant, and a PI controller was proposed for the steam plant. No control scheme was implemented in the wind farm. A numerical model for the proposed system was developed on MATLAB. It was evident that the proposed system requires more time to achieve a steady state, primarily due to the unpredictable fluctuations in the renewable energy resource. Based on the simulation results, the application of the droop and PI controllers in the interconnected system resulted in the reduction of the settling time, and steady state error reduced to zero.