Prescribed-Time Control of a DC Microgrid With a Hybrid Energy Storage System

This article addresses the prescribed-time control of a direct current (DC) microgrid equipped with a hybrid energy storage system (HESS) comprising multiple storage batteries and supercapacitors. First, a novel droop control algorithm is proposed to mitigate constant power load (CPL) fluctuations and enable efficient power distribution among the energy storage components. Next, a prescribed-time extended state observer (PTESO) is developed to estimate the lumped perturbations, including both matched and mismatched components, arising from parameter uncertainties in capacitors and inductors of an HESS. Based on the PTESO, a prescribed-time control strategy is designed to guarantee that the dc microgrid bus voltage accurately tracks its reference value within a prescribed time, irrespective of system initial states. Finally, simulation cases under CPL fluctuations verify the effectiveness of the proposed strategy in improving the performance of a dc microgrid with an HESS.