Sliding Modes for Voltage Regulation and Current Sharing in DC Microgrids

In this paper a novel distributed control algorithm for voltage regulation and current sharing in Direct Current (DC) microgrids is proposed. The DC microgrid is composed of several Distributed Generation units, interfaced with Buck converters, and unknown current loads. The proposed control strategy exploits a communication network to achieve current sharing using a consensus-like algorithm. Voltage regulation is achieved by constraining the system to a suitable manifold. A third order Sliding Mode controller is developed to reach the desired manifold in a finite time. The proposed control scheme is formally analyzed, proving the achievement of current sharing, while guaranteeing that the average voltage of the microgrid is identical to the average of the voltage references.