An Approach for Modeling and Stability Analysis of Single-phase Microgrids

Usage of grid-forming (GFM) converters to build and control microgrids is growing. Parallel GFM converters improve the system reliability, power rating, and flexibility. Understanding the interaction among converters to guarantee the microgrid stability within various operating conditions is necessary. Stability analysis of a single-phase microgrid containing GFM converters controlled in the stationary frame is particularly challenging due to nonlinearities and mixed dc and ac variables. In this paper, an approach is proposed where this system is modeled in a systematic and accurate way, and the issue with mixed dc/ac variables is addressed. Subsequently, the microgrid stability analysis is performed through linearization and eigenvalue analysis approach. The proposed method is verified using simulations and experimental results.