Prescribed Performance Control Strategy for an Isolated Multi-Agent DC Microgrid

This paper introduces an innovative secondary control strategy to regulate bus voltage and achieve effective current sharing in an isolated multi-agent DC microgrid (MG). This MG operates through a distributed network connection. The control architecture is founded on a prescribed performance (PP) approach, wherein a transformed error algorithm is integrated into the prescribed performance control (PPC) framework to establish a novel sliding mode control (SMC). The proposed strategy is reliant solely on input/output measurement data, rendering it suitable for model-free (MF) systems. The incorporation of fractional calculus enhances the controller’s effectiveness. So, a unique sliding surface is introduced, augmenting the controller’s robustness. Additionally, this paper delves into the intricate stability analysis inherent in the data-driven nature of the controller, which combines prescribed performance sliding mode control (PP-SMC). The secondary control encompasses two distinct controllers that leverage the MF-designed controller to compute reference voltages for each distributed generator (DG). One controller is dedicated to voltage regulation, while the other ensures precise current sharing. The proposed controller proficiently curbs the progression of both bus voltage error and current sharing error within predefined thresholds. Numerous Opal-RT experimental results validate the efficacy of the proposed controller, showcasing bus voltage regulation and appropriate current sharing.