Microgrid Stability Analysis Considering Current State-Feedback

Abstract

A converter-based microgrid including several distributed generations (DG) and energy storage systems (ESS) embodies a small power system consisting of several synchronous machines and loads. The stability issue and the coordination between generating units is an essential challenge, either in island or in grid-connected microgrids. The instability of individual DGs cause the microgrid instability as a whole. So, the individual unit stability and the microgrid stability both must be ensured simultaneously. The state feedback concept which is considered in control of converters has a substantial effect on the converter stability and microgrid stability, subsequently. This study will introduce a small-signal model for the microgrid including converter-based DGs and loads considering the previous studies in this field. A phase locked loop (PLL) is required for the control strategy. The effect of current state feedback is scrutinized and analyzed in this study as the main contribution. The effectiveness of the proposed control strategy to enhance the microgrid stability using chosen state feedback is examined through simulation studies. The simulation results ensure that the microgrid stability using the proposed control method and state-feedback is strengthened.