Voltage Fluctuation Mitigation in DC Microgrids Through Finite-Time Observer and Distributed Compensation

With the increasing deployment of power electronic converters in dc microgrids, improving transient performance is as crucial as stabilizing systems for practical reliability. This article proposes a novel secondary control method integrating a finite-time observer and jump-based distributed compensation mechanism to enhance voltage regulation and current sharing. The finite-time observer estimates and compensates for small, unpredictable disturbances, such as model uncertainties and minor load fluctuations, improving steady-state accuracy and disturbance rejection. In contrast, the jump-based distributed compensation addresses predictable large, step changes in load, such as sudden load connections or disconnections, by directly adjusting the output voltage reference to suppress transient voltage fluctuations and accelerate stabilization. Extensive simulation and experimental tests under various scenarios verify the effectiveness of the proposed control scheme in reducing bus voltage sags and swells without compromising asymptotic stability.