MODELLING, DESIGN AND STABILITY ANALYSIS OF MULTI-INPUT MULTI-OUTPUT DC-DC CONVERTERS TO INTEGRATE RENEWABLE ENERGY SOURCES

Abstract

Multiple-input multiple-output (MIMO) converters are emerging as a cost-effective and efficient solution for energy harvesting and distribution in hybrid power systems, including applications such as smart homes and DC microgrids. Unlike traditional single-input single-output (SISO) converters, which often require complex setups involving multiple units interconnected at a common DC bus, MIMO converters simplify the system architecture by integrating multiple energy sources and loads within a single converter. This results in several advantages, including reduced component count, increased power density, and the ability to implement centralized control, making MIMO converters an attractive choice for modern energy systems. This thesis explores various aspects of MIMO converter development, addressing both theoretical and practical challenges. It introduces both non-isolated and isolated MIMO converter topologies designed to handle the diverse demands of hybrid power systems. The non-isolated MIMO converters, such as isolated converters, like flyback topologies, multiport boost converter and high gain z-source converter topologies, are thoroughly analyzed. Steady-state performance and dynamic behavior are examined in detail, providing insights into their operational efficiency and reliability. One of the key contributions of this research is the development of innovative switching strategies and control algorithms tailored to MIMO converters. These strategies enable precise power distribution among multiple energy sources and loads while maintaining stable output voltages. The ability to dynamically allocate power based on load requirements and source availability ensures optimal utilization of resources, enhancing system efficiency. A novel method for designing non-isolated MIMO converters featuring Single inductors (SI) is proposed. By applying a simple set of synthesis rules, this method facilitates the systematic derivation of MIMO converter topologies. The design approach leverages the concept of time-sharing, wherein multiple energy sources supply power during one phase of operation, and multiple loads consume power during the subsequent phase. This time-sharing mechanism allows for effective power management while minimizing interference between sources and loads. vi The thesis also provides general guidelines for transforming conventional SISO converters into MIMO configurations. This is achieved by replacing specific components in SISO topologies with multiport structures, enabling seamless integration of multiple inputs and outputs. The proposed framework not only extends the functionality of existing converter designs but also opens new avenues for customization and optimization in various applications. This thesis demonstrates the potential of MIMO converters to revolutionize power management in hybrid systems. By addressing critical design, modeling, and control aspects, it lays the foundation for the widespread adoption of MIMO converters in future DC distribution systems. The proposed topologies and methodologies are expected to find applications in emerging technologies such as renewable energy systems, electric vehicles, and smart grids. As the demand for efficient and sustainable energy solutions grows, the integration of MIMO converters into industrial and residential energy systems offers a promising pathway toward achieving energy efficiency and sustainability. This thesis provides valuable contributions to the field, bridging the gap between theoretical advancements and practical implementations of MIMO converters in modern energy systems.