Energy Efficient And Power Dense Dc Dc Converters In Data Center And Electric Vehicle Applications Using Wide Bandgap Devices

The ever increasing demands in the energy conversion market propel power converters towards high efficiency and high power density. With fast development of data processing capability in the data center, the server will include more processors, memories, chipsets and hard drives than ever, which requires more efficient and compact power converters. Meanwhile, the energy-efficient and power-dense converters for the electric vehicle also result in longer driving range as well as more passengers and cargo capacities. DC-DC converters are indispensable power stages for both applications. In order to address the efficiency and density requirements of the DC-DC converters in these applications, several related research topics are discussed in this dissertation. For the DC-DC converter in the data center application, a LLC resonant converter based on the newly emerged GaN devices is developed to improve the efficiency over the traditional Si-based converter. The relationship between the critical device parameters and converter loss is established. A new perspective of extra winding loss due to the asymmetrical primary and secondary side current in LLC resonant converter is proposed. The extra winding loss is related to the critical device parameters as well. The GaN device benefits on device loss and transformer winding loss is analyzed. An improved LLC resonant converter design method considering the device loss and transformer winding loss is proposed. For the DC-DC converter in the electric vehicle application, an integrated DC-DC converter that combines the on-board charger DC-DC converter and drivetrain DC-DC converter is developed . The integrated DC-DC converter is considered to operate in different modes. The existing dual active bridge (DAB) DC-DC converter originally designed for the charger is proposed to operate in the drivetrain mode to improve the efficiency at the light load and high voltage step-up ratio conditions of the traditional drivetrain DC-DC converter. Design method and loss model are proposed for the integrated converter in the drivetrain mode. A scaled-down integrated DC-DC converter prototype is developed to verify the design and loss model.

Nowadays, power electronics is an enabling technology in the energy development scenario. Furthermore, power electronics is strictly linked with several fields of technological growth, such as consumer electronics, IT and communications, electrical networks, utilities, industrial drives and robotics, and transportation and automotive sectors. Moreover, the widespread use of power electronics enables cost savings and minimization of losses in several technology applications required for sustainable economic growth. The topologies of DC–DC power converters and switching converters are under continuous development and deserve special attention to highlight the advantages and disadvantages for use increasingly oriented towards green and sustainable development. DC–DC converter topologies are developed in consideration of higher efficiency, reliable control switching strategies, and fault-tolerant configurations. Several types of switching converter topologies are involved in isolated DC–DC converter and nonisolated DC–DC converter solutions operating in hard-switching and soft-switching conditions. Switching converters have applications in a broad range of areas in both low and high power densities. The articles presented in the Special Issue titled "Advanced DC-DC Power Converters and Switching Converters" consolidate the work on the investigation of the switching converter topology considering the technological advances offered by innovative wide-bandgap devices and performance optimization methods in control strategies used.

This book covers advancements of power electronic converters and their control techniques for grid integration of large-scale renewable energy sources and electrical vehicles. Major emphasis is on transformer-less direct grid integration, bidirectional power transfer, compensation of grid power quality issues, DC system protection and grounding, interaction in mixed AC/DC systems, AC and DC system stability, design of high-frequency high power density systems with advanced soft magnetic materials, modeling and simulation of mixed AC/DC systems, switching strategies for enhanced efficiency, and protection and reliability for sustainable grid integration. This book is an invaluable resource for professionals active in the field of renewable energy and power conversion. Md. Rabiul Islam received his PhD from the University of Technology Sydney (UTS), Australia. He was appointed as a Lecturer at Rajshahi University of Engineering & Technology (RUET) in 2005 and promoted to full-term Professor in 2017. In early 2018, he joined the School of Electrical, Computer, and Telecommunications Engineering, University of Wollongong, Australia. He is a Senior Member of IEEE. His research interests include the fields of power electronic converters, renewable energy technologies, power quality, electrical machines, electric vehicles, and smart grids. He has authored or coauthored more than 200 publications including 50 IEEE Transactions/IEEE Journal papers. He has been serving as an editor for IEEE Transactions on Energy Conversion and IEEE Power Engineering Letters, and associate editor for IEEE Access. Md. Rakibuzzaman Shah is a Senior Lecturer with the School of Engineering, Information Technology and Physical Science at Federation University Australia. He has worked and consulted with distribution network operators and transmission system operators on individual projects and has done collaborative work on a large number of projects (EPSRC project on multi-terminal HVDC, Scottish and Southern Energy multi-infeed HVDC) - primarily on the dynamic impact of integrating new technologies and power electronics into large systems. He is an active member of the IEEE and CIGRE. He has more than 70 international publications and has spoken at the leading power system conferences around the world. His research interests include future power grids (i.e., renewable energy integration, wide-area control), asynchronous grid connection through VSC-HVDC, application of data mining in power system, distribution system energy management, and low carbon energy systems. Mohd. Hasan Ali is currently an Associate Professor with the Electrical and Computer Engineering Department at the University of Memphis, USA, where he leads the Electric Power and Energy Systems (EPES) Laboratory. His research interests include advanced power systems, smart-grid and microgrid systems, renewable energy systems, and cybersecurity issues in modern power grids. Dr. Ali has more than 190 publications, including 2 books, 4 book chapters, 2 patents, 60 top ranked journal papers, 96 peer-reviewed international conference papers, and 20 national conference papers. He serves as the editor of the IEEE Transactions on Sustainable Energy and IET-Generation, Transmission and Distribution (GTD) journal. Dr. Ali is a Senior Member of the IEEE Power and Energy Society (PES). He is also the Chair of the PES of the IEEE Memphis Section.

Wide bandgap (WBG) semiconductor materials allow higher power and voltage, faster and more reliable power electronic devices. These characteristics lead to a massive improvement in power converters, especially for electric vehicles (EV) applications. As a result, new opportunities for high efficiency and power density is coming with the development of WBG power semiconductor. This paper introduces the application of WBG devices in power converters of EV. The EV development trend and the related circuit diagram of an EV system have been introduced. Serval typical power converters' topologies have been discussed. Meanwhile, WBG devices also bring challenges to a high voltage and frequency design. High current and voltage levels need a more powerful heating system. A higher switching speed requires lower loop parasitic inductance. This paper discusses how to apply WBG devices in the power converter design and address these challenges. Finally, The reliability test method of power converters has been discussed. The lifetime of all components in a power converter has been tested under different voltage and temperature levels. The failure reasons and influences parameters are analyzed.

Low losses fast switching wide band gap (WBG) semiconductors, such as Gallium Nitride (GaN) and Silicon Carbide (SiC), are becoming viable candidates for DC/DC converters switches in the powertrain of electric vehicle (EV). Thanks to the technology advancements, WBG power transistors are available now in the market with competing loss levels. In this research, the need for such devices to boost the system efficiency for extended vehicle mileage is justified. Case studies comparing the performance of the available options are presented, for the first time. The performance, motoring and regenerative braking, is studied at different junction temperatures. The results reported higher power density and increased car mileage using WBG semiconductors. These findings were consistent in automotive Nissan Leaf electric vehicle (NLEV) case and a Bombardier metro rail car, to provide the authentication of the developed plug-and-play model. Simulation and Experimental results were given to highlight the merits of the work.

PWM DC-DC power converter technology underpins many energy conversion systems including renewable energy circuits, active power factor correctors, battery chargers, portable devices and LED drivers. Following the success of Pulse-Width Modulated DC-DC Power Converters this second edition has been thoroughly revised and expanded to cover the latest challenges and advances in the field. Key features of 2nd edition: Four new chapters, detailing the latest advances in power conversion, focus on: small-signal model and dynamic characteristics of the buck converter in continuous conduction mode; voltage-mode control of buck converter; small-signal model and characteristics of the boost converter in the discontinuous conduction mode and electromagnetic compatibility EMC. Provides readers with a solid understanding of the principles of operation, synthesis, analysis and design of PWM power converters and semiconductor power devices, including wide band-gap power devices (SiC and GaN). Fully revised Solutions for all end-of-chapter problems available to instructors via the book companion website. Step-by-step derivation of closed-form design equations with illustrations. Fully revised figures based on real data. With improved end-of-chapter summaries of key concepts, review questions, problems and answers, biographies and case studies, this is an essential textbook for graduate and senior undergraduate students in electrical engineering. Its superior readability and clarity of explanations also makes it a key reference for practicing engineers and research scientists.

Photovoltaic (PV) energy generation is an excellent example of large-scale electric power generation through various parallel arrangements of small voltage-generating solar cells or modules. However, PV generation systems require power electronic converters system to satisfy the need for real-time applications or to balance the demand for power from electric. Therefore, a DC-DC power converter is a vital constituent in the intermediate conversion stage of PV power. This book presents a comprehensive review of various non-isolated DC-DC power converters. Non-isolated DC-DC converters for renewable energy system (RES) application presented in this book 1st edition through a detailed original investigation, obtained numerical/experimental results, and guided the scope to design new families of converters: DC-DC multistage power converter topologies, Multistage "X-Y converter family", Nx IMBC (Nx Interleaved Multilevel Boost Converter), Cockcroft Walton (CW) Voltage Multiplier-Based Multistage/Multilevel Power Converter (CW-VM-MPC) converter topologies, and Z-source and quasi Z-source. Above solutions are discussed to show how they can achieve the maximum voltage conversion gain ratio by adapting the passive/active component within the circuits. For assessment, we have recommended novel power converters through their functionality and designs, tested and verified by numerical software. Further, the hardware prototype implementation is carried out through a flexible digital processor. Both numerical and experimental results always shown as expected close agreement with primary theoretical hypotheses. This book offers guidelines and recommendation for future development with the DC-DC converters for RES applications based on cost-effective, and reliable solutions.

Nowadays, power electronics is an enabling technology in the energy development scenario. Furthermore, power electronics is strictly linked with several fields of technological growth, such as consumer electronics, IT and communications, electrical networks, utilities, industrial drives and robotics, and transportation and automotive sectors. Moreover, the widespread use of power electronics enables cost savings and minimization of losses in several technology applications required for sustainable economic growth. The topologies of DC-DC power converters and switching converters are under continuous development and deserve special attention to highlight the advantages and disadvantages for use increasingly oriented towards green and sustainable development. DC-DC converter topologies are developed in consideration of higher efficiency, reliable control switching strategies, and fault-tolerant configurations. Several types of switching converter topologies are involved in isolated DC-DC converter and nonisolated DC-DC converter solutions operating in hard-switching and soft-switching conditions. Switching converters have applications in a broad range of areas in both low and high power densities. The articles presented in the Special Issue titled "Advanced DC-DC Power Converters and Switching Converters" consolidate the work on the investigation of the switching converter topology considering the technological advances offered by innovative wide-bandgap devices and performance optimization methods in control strategies used.