Decentralized Voltage Control of Boost Converters in DC Microgrids: Feasibility Guarantees

Abstract

This article deals with the design of a decentralized dynamic control scheme to regulate the voltage of a direct current (dc) microgrid composed of boost converters supplying unknown loads. Moreover, the proposed control scheme guarantees that physical system constraints are satisfied at each time instant. Specifically, we guarantee that the voltages evolve in the positive orthant and that the duty cycle of each boost converter remains within specified bounds. The control design is based on Lyapunov theory and, more precisely, we use a Krasovskii Lyapunov function to estimate a feasible domain of attraction of the closed-loop system. Then, we guarantee that for any initial condition inside the estimated domain of attraction, the desired equilibrium point is asymptotically stable and the physical constraints are satisfied at each time instant. Finally, we assess the effectiveness of the proposed control scheme through extensive and realistic simulation scenarios.