Load Frequency Control of an Islanded Microgrid Based on Virtual Inertia Control

The increased integration of renewable energy sources (RESs) and the resulting decrease in total system inertia has made load frequency control (LFC) in current power systems, especially in microgrids, more difficult. When combined with varying load demands, inverter-based RESs like wind and solar can result in continuous frequency fluctuations in microgrids, which in extreme circumstances may create a system instability, power outages, or even complete system blackouts. Secondary control and auxiliary control are suggested for both islanded and non-linear microgrid situations in order to overcome the problems related to the integration of intermittent power sources and the frequency instability that results. Auxiliary control uses a battery energy storage system (BESS) to supply virtual inertia (VI). Here, Proportional Integral (PI) controller is used as the auxiliary controller for the virtual inertia system. In this paper, a thermal system is integrated with wind and solar power sources. The performance of the developed LFC schemes were evaluated under various operating conditions. The simulation result show that the suggested control methods provide better frequency regulation performance even with successive load changes. Thus improves frequency stability when dealing with varying loads and changing RES penetration level.