Design and Analysis of Voltage Control for Islanded DC Microgrids Based on a Fuzzy-PI Controller

In the transition to clean, cheap, and sustainable energy, microgrid-based renewable energy resources (RES) are widely utilized in islanded or grid-connected modes. However, due to the intermittent nature of RES such as photovoltaic (PV) or wind energy systems, energy storage systems (ESSs) such as batteries are mandated to satisfy load demands and stabilize system operation. For instance, stabilizing the dc bus voltage in islanded microgrids is crucial to keeping the system reliable, dependable, and stable. This paper proposes an adaptive dc bus voltage control technique based on a fuzzy-PI controller. Moreover, a performance comparison between fuzzy-PI and conventional proportional-integrator (PI) controllers is performed based on a MATLAB/Simulink model. The results show that the fuzzy-PI controller has a faster response to any reference voltage variation and less overshoot compared to conventional PI controllers. Additionally, the proposed controller can efficiently stabilize the dc bus voltage during load variation portions.