Interaction of Droop Controllers through Complex Power Network in Microgrids

摘要

The interaction of frequency and voltage droop controllers through power network is the dominant factor affecting dynamic stability of autonomous networked microgrids (ANMGs). The X/R ratio of power lines is low in the low-voltage microgrids (MGs) which makes the interaction/cross-coupling of droop controllers high and raises low/subsynchronous frequency oscillations and thus stability concerns. This issue is investigated in this work by developing new models to support the idea of interaction of droop controllers. To this end, the impacts of power network (mainly the X/R ratio) and the droop rules including the low-pass filter (LPF) are evaluated. The developed models can be used to design sufficient damping to the system by considering the interaction of droop controllers and power network requirements to improve stability margins of ANMGs.