Robust output regulation for voltage control in DC networks with time-varying loads

In this paper, we propose novel control schemes for regulating the voltage in Direct Current (DC) power networks, where the loads are the superposition of time-varying signals and uncertain constants. More precisely, the proposed control schemes are based on the robust output regulation methodology and, differently from the results in the literature, where the loads are assumed to be constant, we consider time-varying loads whose dynamics are described by a class of differential equations with parametric uncertainty. The proposed control schemes achieve voltage regulation and guarantee the local robust stability of the overall network in case of impedance (Z), current (I), and power (P) load types and the global robust stability in case of ZI loads. The simulation results illustrate excellent performance of the proposed control schemes in different scenarios, where real load data are considered.