Scalable Adaptive Fuzzy Voltage Control for DC Microgrids With Plug-and-Play Operations and Constant Power Loads.

Abstract

Voltage stability in DC microgrids (DCMGs) is challenged by the concurrent effects of topological variations arising from plug-and-play (PnP) operations of distributed generation units (DGUs) and nonlinear destabilization induced by constant power loads (CPLs). This article proposes a scalable adaptive fuzzy voltage control (SAFVC) strategy for multibus DCMGs with unknown CPL dynamics and changing electrical interconnection configurations. Afuzzy logic system (FLS) approximates the physical CPL current online without requiring prior CPL information. Because the CPL and converter-voltage input act through unmatched channels, a command-filtered adaptive backstepping architecture first constructs a virtual filter-current command and then realizes it through the converter voltage. Acommon voltage-energy weighting decomposes the aggregate line contribution into a nonpositive Laplacian term and an explicit bounded bias induced by nonuniform voltage references while preserving fully decentralized implementation. Explicit local gain and filter conditions provide an admissibility test for PnP requests and guarantee practical finite-time stability without redesigning unaffected controllers. Numerical simulations demonstrate the performance of the proposed strategy.