Performance Of Wide Band Gap Switching Devices In Dc Dc Converters Of Electric Vehicles

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.

Wide-bandgap power semiconductors promise to reshape the power electronics landscape, opening completely new use cases and increasing efficiency and power density in existing ones. Most notably, gallium nitride (GaN) and silicon carbide (SiC) were successfully commercialized in the past decades, with theoretical benefits over silicon of multiple orders-of-magnitude. When combined with soft-switching techniques and topologies, these wide-bandgap materials have the potential to move power conversion to MHz operating frequencies, radically shrinking power converters and enabling new fabrication methods with the frequency-driven reduction of passive component requirements. Unfortunately, soft-switched converters built at MHz frequencies have consistently underperformed their modeled efficiency, as this work shows for three DC-RF inverters at high- and very-high-frequency. These inverters have measured semiconductor losses nearly an order-of-magnitude greater than expected from manufacturer-provided simulation models, a discrepancy that demands investigation. These losses are attributed to the process of resonantly charging and discharging the output capacitance (Coss) of the power semiconductors, a loss mechanism termed "soft-switching losses" or "Coss losses." Our measurements constitute the first recognition of this problem in GaN HEMTs, and these initial measurements are then extended to SiC and Si MOSFETs, finding dependencies and scaling laws for each device class. To complete the understanding of losses at high-frequencies, the well-understood phenomenon in GaN HEMTs of dynamic on-resistance is then revisited. Our work conclusively shows that dynamic on-resistance cannot be accurately characterized using the standardized double-pulse-test, and uses the underlying physics to determine the parameters that must be controlled for accurate reporting. Using this measurement framework, this work extends the dynamic on-resistance measurements to MHz frequencies for the first time, finding that the majority of the dynamic effects in soft-switched converters occur below 1 MHz for the tested device. With both off-state and on-state losses precisely understood at MHz frequencies, the promise of high-frequency power conversion can finally be realized. While adopted widely in cell phones, inductive wireless power transfer for higher-value applications (e.g. electric vehicles) is beset by both low performance and high cost due to the limitations of litz wire. At 6.78 MHz, the first international industrial, scientific, and medical (ISM) band above 200 kHz, litz wire can be completely eliminated, paving the way to low cost, small, light, and high-performance systems. A 1 kW DC-DC converter that transfers power across a 2 cm gap with 6.6 cm diameter coils at over 95% efficiency is demonstrated, a new benchmark in power density and efficiency for MHz-frequency wireless power transfer. This performance would, plainly, not have been possible without the identification and quantification of Coss losses. Our future power, transportation, and computing infrastructures are dependent on the implementation of wide-bandgap power semiconductors to reduce size, weight, and cost while increasing efficiency to address the climate challenge. This thesis is our small contribution to meaningfully improving these semiconductors and showing what's possible for the next generation of power conversion.

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 explains the basic and advanced technology behind the Power Electronics Converters for EV charging, and their significant developments, and introduces the Grid Impact issues that underpin the grid integration of electric vehicles. Advanced Concepts and Technologies for Electric Vehicles reviews state-of-the-art and new configurations and concepts of more electric vehicles and EV charging, mitigating the impact of EV charging on the power grid, and technical considerations of EV charging infrastructures. The book considers the environmental benefits and advantages of electric vehicles and their component devices. It includes case studies of different power electronic converters used for charging EVs. It offers a review of PFC-based AC chargers, WBG-based chargers, and Wireless chargers. The authors also explore multistage charging systems and their possible implementations. The book also examines the challenges and opportunities posed by the progressive integration of electric drive vehicles on the power grid and reported solutions for their mitigation. The book is intended for professionals, researchers, and engineers in the electric vehicle industry as well as advanced students in electrical engineering who benefit from this comprehensive coverage of electric vehicle technology. Readers can get an in-depth insight into the technology deployment in EV transportation and utilize that knowledge to develop novel ideas in the EV area.

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.

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 includes original, peer-reviewed research papers from the 5th International Conference on Energy Storage and Intelligent Vehicles (ICEIV 2022), held online, from December 3 to December 4, 2022. The topics covered include but are not limited to energy storage, power and energy systems, electrified/intelligent transportation, batteries and management, and power electronics. The papers share the latest findings in energy storage and intelligent vehicles, making the book a valuable asset for researchers, engineers, university students, etc.

Wide Bandgap Semiconductor Power Devices: Materials, Physics, Design and Applications provides readers with a single resource on why these devices are superior to existing silicon devices. The book lays the groundwork for an understanding of an array of applications and anticipated benefits in energy savings. Authored by the Founder of the Power Semiconductor Research Center at North Carolina State University (and creator of the IGBT device), Dr. B. Jayant Baliga is one of the highest regarded experts in the field. He thus leads this team who comprehensively review the materials, device physics, design considerations and relevant applications discussed. Comprehensively covers power electronic devices, including materials (both gallium nitride and silicon carbide), physics, design considerations, and the most promising applications Addresses the key challenges towards the realization of wide bandgap power electronic devices, including materials defects, performance and reliability Provides the benefits of wide bandgap semiconductors, including opportunities for cost reduction and social impact

This book is a printed edition of the Special Issue "Advanced Energy Storage Technologies and Their Applications (AESA)" that was published in Energies