Modeling power inverter interactions in a low voltage grid

This paper presents a modeling technique for the study of power inverter interactions when operating in parallel in a low voltage grid. A generalized model of a droop-controlled voltage source inverter is presented, which can be modified to represent traditional rotating generators as well as external conditions imposed at the point of coupling to the grid. A nonlinear model for the power flow through the grid is derived with both static impedances and dynamic phasors, studying the frequency range of its eigenvalues. Finally, a connected model is derived and validated through simulations, comparing with other modeling techniques found in the literature.