Advanced Modelling and Control of Hybrid AC-DC/DC-DC Conversion Systems in Smart Microgrids: Integrating Offshore Wind Energy with Enhanced Protection Strategies and Battery Storage Management

This research presents a comprehensive framework for smart microgrid systems, focusing on the integration of offshore wind farms through advanced hybrid AC-DC and DC-DC conversion technologies. The study introduces a novel Model Predictive Control (MPC) approach that incorporates detailed wind dynamics, including speed, direction, and turbulence, while addressing critical aspects such as wind farm layout and wake effects. The proposed framework encompasses both AC-DC and DC-DC conversion systems, integrating Battery Energy Storage Systems (BESS) and sophisticated protection mechanisms for enhanced grid stability and reliability. The research addresses power conversion challenges through a multi-layered approach. For AC-DC conversion, it develops advanced control strategies to manage the interface between offshore wind farms and the DC microgrid, ensuring efficient power capture and grid stability. Simultaneously, for DC-DC conversion, it implements Multi-Terminal (MT) topologies with sophisticated state-of-charge (SOC) management strategies for BESS, utilizing integral calculus for precise charge-discharge cycle calculations, thereby extending battery life and improving system performance. Protection systems are integrated across both AC-DC and DC-DC domains, incorporating current-based and voltage-based fault detection schemes, alongside traveling wave techniques for accurate fault location. The study details the coordinated control of AC/DC breakers with both converter types, emphasizing the role of Solid-State Circuit Breakers (SSCB) in rapid fault isolation. Furthermore, the research introduces redundancy measures, fault-tolerant control, and self-healing methodologies to enhance system reliability across the entire conversion chain. The proposed framework prioritizes cost-effectiveness through optimal utilization of solar PV sources and wind energy, while maintaining seamless transitions between grid-connected and islanded operation modes. This comprehensive approach integrates protection systems for both AC and DC faults, coordinated control strategies, and advanced power management techniques, contributing to the development of more resilient, efficient, and sustainable smart microgrid systems. The research outcomes demonstrate significant improvements in grid stability, power quality, and overall system reliability, paving the way for enhanced integration of offshore renewable energy sources through sophisticated power conversion architectures.