Dynamic Modeling and Stability Analysis of Converter-based Three-phase AC Microgrids with Active Loads

Presence of active load (AL) in ac microgrids (MG) can induce instabilities due to the interactions between the AL dynamics with the rest of the MG, particularly in the isolated mode of operation. In this paper, the complete state-space model of an ac MG is derived. Then, using small-signal analysis, the influence of integrating an AL in the ac MG on the system stability is investigated under different operating conditions and parameters variations. To verify the small-signal results, a series of large signal simulations is carried out on a 100 kVA ac MG.