In this paper, a new modelling approach based on the equivalent Thevenin circuit is proposed for voltage source converters in islanded microgrids. The proposed method approximate the entire network connected to the voltage source converter with an equivalent Thevenin circuit. The equivalent circuit is first considered with a non-dynamic impedance. This model is simple but does not provide a good transient response. To cope with this issue, a dynamic equivalent Thevenin circuit is considered with dynamic similar to a series resistance and inductance branch. Both non-dynamic and dynamic models are validated using a microgrid test system simulated in MATLAB/SimPowerSystems.
