In this paper, a new modeling method based on the equivalent Thevenin circuit is proposed for inverterinterfaced microgrids. The proposed method approximates the entire network connected to each inverter with an equivalent Thevenin circuit. The equivalent circuit is studied in two forms: static impedance and dynamic second-order RL branch. The static impedance equivalent circuit provides a good steady state but not a good transient response. To cope with this issue, the static impedance is replaced with a dynamic second-order RL branch, which results in appropriate transients. Both static and dynamic models are validated using a microgrid test system simulated in MATLAB/SimPowerSystems.
