Advanced high frequency soft-switching converters for automotive applications
Many soft-switching topologies are reviewed but none of them is well suited for the given automotive applications. Two soft-switching PWM converters are proposed in this work. For low power automotive POL applications, a new active-clamp buck converter is proposed. Comprehensive analysis of this converter is presented. A 2.2 MHz, 25 W active-clamp buck converter prototype with Si MOSFETs was designed and built. The experimental results verify the operation of the converter. For 12 V to 5 V conversion, the Si based prototype achieves a peak efficiency of 89.7%. To further improve the efficiency, GaN FETs are used and an optimized SR turn-off delay is employed. Then, a peak efficiency of 93.22% is achieved. The EMI test result shows significantly improved EMI performance of the proposed active-clamp buck converter. Last, large- and small-signal models of the proposed converter are derived and verified by simulation.
For automotive dual voltage system, a new bidirectional zero-voltage-transition (ZVT) converter with coupled-inductor is proposed in this work. With the coupled-inductor, the current to realize zero-voltage-switching (ZVS) of main switches is much reduced and the core loss is minimized. Detailed analysis and design considerations for the proposed converter are presented. A 1 MHz, 250 W prototype is designed and constructed. The experimental results verify the operation. Peak efficiencies of 93.98% and 92.99% are achieved in buck mode and boost mode, respectively. Significant efficiency improvement is achieved from the efficiency comparison between the hard-switching buck converter and the proposed ZVT converter with coupled-inductor.]]>autNan, ChenhaothsAyyanar, RajadgcBakkaloglu, BertandgcKarady, George G.dgcQin, JiangchaopblArizona State UniversityengPartial requirement for: Ph.D., Arizona State University, 2016Includes bibliographical references (pages 106-110)Field of study: Electrical engineeringby Chenhao Nanhttps://hdl.handle.net/2286/R.I.4123500Doctoral DissertationAcademic thesesxii, 128 pages : illustrations (some color)114859540691630347607155173systemIn CopyrightAll Rights Reserved2016TextElectrical EngineeringAutomotiveDC-DChigh frequencysoft-switchingDC-to-DC convertersSwitching power suppliesAutomobiles--Electronic equipment.