A simplified stability analysis method for LV inverter-based microgrids

Abstract

This paper presents a simplified small-signal stability analysis method for low voltage (LV) inverter-based microgrids, in a generalized manner. The simplification is based on a simplified microgrid structure that relies on dominating inverter coupling impedances with respect to interconnecting line impedances of LV distribution networks. The analysis is further simplified by analytically determining equilibrium points of system state variables in terms of known microgrid parameters. And it eliminates the additional analysis required for determination of the equilibrium points of the state variables. Simulation and analysis results show that the proposed method successfully predicts the instability boundaries of microgrid systems for resistive interconnecting lines.