Decentralized Sliding Mode voltage control in DC microgrids

The present paper deals with the design of a decentralized control scheme that relies on advanced control strategies of Sliding Mode (SM) type to regulate the voltage in islanded Direct Current (DC) microgrids. More specifically, the model of an islanded DC microgrid composed of several Distributed Generation units (DGus) interconnected according to an arbitrary topology including loops, is presented. The model takes into account the power lines dynamics and is affected by unknown load demand and unavoidable modelling uncertainties. First, a Second Order Sliding Mode (SOSM) control algorithm, belonging to the class of Suboptimal SOSM control, is proposed to solve the voltage control problem. Then, in order to obtain a continuous control signal that can be used as duty cycle of the power converter, a third order Sliding Mode (3-SM) control strategy is presented.