Stochastic Load Frequency Control of Microgrids Including Wind Source Based on Identification Method

Load Frequency Control (LFC) of microgrids has become crucial due to immense deployment of renewable energy, and load variation. Some types of frequency deviations are associated with sustainable energy sources and loads as a result of their stochastic nature. These variations create oscillatory responses which can lead to stability issues with a traditional controller. To better address the microgrid stability, it is required to utilize a robust and reliable controller to manage the energy sources and control the frequency even under heavy oscillations. Thus two-layer linear quadratic regulator (LQR) based controller in conjunction with an improved measurement-based observer is proposed to address this hard frequency control problem in presence of variations. Throughout performing this proposed algorithm, the oscillation signal is dealt with as an unknown input (UI) and affects some of the system states. The first layer identifies UI and actively eliminates that signal; meanwhile, in the second layer, LQR regulates frequency based on the estimated states of the system. Results confirm the efficacy of this control framework based on system parameter identification under varied uncertainties of wind energy and load profiles.