Hardware-in-loop simulation for hybrid AC/DC microgrids

This research develops a photovoltaic-based AC-DC hybrid microgrid to meet growing energy demands and enhance renewable energy utilization. The system configuration employs PV as the primary generation source with a battery-supercapacitor hybrid energy storage system (HESS), addressing the intermittent nature of distributed generation and challenges in microgrid stabilization. Key investigations focus on maintaining voltage stability, implementing effective energy management, and ensuring power balance during dynamic operations. Using a systematic Matlab/Simulink simulation platform, this work develops control schemes, including conductance increment-based MPPT for photovoltaic systems, dual-loop voltage-current regulation for the battery, dynamic compensation with supercapacitors, and PQ/Vf dual-mode switching for bidirectional AC-DC conversion. The research demonstrates that the proposed control method maintains DC bus voltage stability, achieves balanced power allocation across the hybrid energy storage units, and enables seamless transitions for the microgrid between grid-connected and islanding operations. The real-time HIL tests performed on an OPAL-RT platform provided further confirmation of the efficacy of the control strategy. The system demonstrated excellent dynamic performance and operational stability under disturbances such as irradiance variations. This study establishes a valuable framework and practical methodology for resolving microgrid operational challenges under high renewable energy penetration. The outcomes significantly contribute to energy structure transformation and the development of sustainable power supply systems.