Research Projects

This project targets the rising demand for efficient, high-performance, isolated bidirectional DC-DC converters in applications like electric vehicles (EVs), energy storage systems, and DC microgrids. With the shift toward renewable energy and sustainable power systems, there is a need for converters supporting bidirectional power flow, wide voltage ranges, and high efficiency. The Dual Active Bridge (DAB) converter is favored for its high power density, galvanic isolation, soft-switching, and simple design. However, conventional DABs struggle under wide voltage and load variations, facing issues such as increased circulating current, reactive power losses, and higher conduction and switching losses—especially when port voltage ratios deviate from unity. Moreover, their limited Zero Voltage Switching (ZVS) range compromises efficiency and reliability across operating conditions. State of the Art and Innovation: Recent research has focused on enhancing DAB performance through resonant structures, topology reconfigurations, and advanced modulation strategies. Innovations such as LCL resonant elements, neutral point clamped and flying capacitor DABs, and transformer winding reconfigurations have extended ZVS regions and operating voltage ranges. However, these solutions often introduce greater structural and control complexity. Traditional modulation methods like Single Phase Shift (SPS) are simple but lack the flexibility needed for wide-range applications. More advanced strategies—Extended Phase Shift (EPS), Dual Phase Shift (DPS), and Triple Phase Shift (TPS)—offer additional control degrees of freedom, reducing losses and improving soft-switching, but at the cost of increased control algorithm complexity. There is a pressing need for hybrid or optimized modulation strategies that balance performance improvements with manageable complexity. Methodology: The project will begin with a detailed analysis of conventional DAB operation, identifying loss mechanisms and ZVS limitations under wide voltage and load conditions. The research will then focus on: • Topology morphing: Modifying the H-bridge and transformer windings to dynamically adapt to varying voltage ratios, enhancing both step-up and step-down performance. • Advanced modulation: Implementing and experimentally validating EPS, DPS, and TPS strategies, as well as developing novel hybrid modulations that reduce complexity while maintaining high efficiency. • Control strategy development: Designing algorithms for real-time mode switching and dynamic load management, ensuring stable and efficient operation across all scenarios. • Experimental validation: Prototyping the proposed converter and benchmarking its performance against conventional designs in terms of efficiency, ZVS range, voltage gain, and loss reduction. Outcomes of this project will directly benefit EV fast charging, renewable energy integration, and next generation microgrid architectures by delivering a converter that: Achieves high efficiency over a broad voltage and load range, Provides robust bidirectional power transfer with minimal losses, Offers scalable and reconfigurable solutions for diverse applications and Simplifies control and implementation without compromising performance. By pushing the boundaries of DAB converter technology through innovative modulation and topology reconfiguration, this project aims to set new standards in power electronics for sustainable energy systems.