Scalable PI Voltage Stabilization in DC Microgrids

This paper addresses the problem of decentralized PI-based voltage stabilization in islanded DC microgrids with DC-DC buck converters. We propose a voltage control approach with a decentralized PI control structure. The proposed voltage control design is scalable and does not rely on the global model of the microgrids and parameters of the distribution lines. Moreover, it guarantees the asymptotic stability of the DC microgrid systems. The scalability of the design and asymptotic stability are ensured by the use of a separable quadratic-type Lyapunov function, with a fixed-structure Lyapunov matrix, as well as the LaSalle's invariance principle. The effectiveness of the proposed voltage control strategy is evaluated through simulation case studies. Copyright (C) 2020 The Authors.