A new linear model for active loads in islanded inverter-based microgrids

•A new linear state-space model for active loads is proposed.•Islanded inverter-based microgrids with active loads are analyzed using a time-step simulation.•The proposed time-step simulation derives the steady-state operating point as well as the eigenvalues directly.•Large signal-stability analysis is also studied.•The execution time of the proposed simulation is much smaller than others.

Active rectifier loads have major effects on the stability of microgrids, therefore the modeling and analysis of such loads become more popular, recently. In this paper, a new linear state-space model for inverter-based microgrids (IBMGs) as well as active loads is proposed and then the model is corrected using a time-step simulation. The proposed simulation drives the eigenvalues and transient response of such loads and systems directly and quickly which makes the stability analysis of active loads simple. Using these advantages, the load-flow analysis and, moreover, the linearization of equations around an operating point to study small-signal stability are no longer needed. The proposed method can also study large-signal stability analysis as simple and fast as the small one and the execution time of the simulation is much smaller than that of other simulations. The analysis and stability assessment of active loads in IBMGs are easy and fast using the proposed model due to linearity. The validation and comparison of different case studies show the performance of the proposed method.