Distributed Secondary Frequency Control in AC Microgrids with Lossy Electrical Networks

This paper presents a distributed control scheme for achieving secondary frequency control in AC microgrids. The control scheme is designed for microgrid electrical networks comprised of distribution lines with equal/unequal resistance to reactance ratio; in other words, it works well even when ohmic losses are taken into account in the electrical network. The control problem is formulated and an overview of the proposed distributed secondary frequency control scheme is provided. A criterion for choosing controller gains that stabilize the system frequency is also provided. Finally, results on the testing of the control scheme on a controller hardware-in-the loop (C-HIL) testbed are provided.