Towards High-frequency High-efficiency Hybrid DC-DC Converters for Large-conversion-ratio Applications
| dc.contributor.advisor | Lee, Hoi | |
| dc.contributor.advisor | Liu, Jin | |
| dc.contributor.advisor | Chen, Feng | |
| dc.contributor.committeeMember | Balsara, Poras T. | |
| dc.contributor.committeeMember | Akin, Bilal | |
| dc.creator | Chen, Chen | |
| dc.date.accessioned | 2024-08-30T19:23:08Z | |
| dc.date.available | 2024-08-30T19:23:08Z | |
| dc.date.created | 2022-05 | |
| dc.date.issued | 2022-05 | |
| dc.date.submitted | May 2022 | |
| dc.date.updated | 2024-08-30T19:23:13Z | |
| dc.description.abstract | Growing demands for energy-efficient electronics and trend of miniaturization increase the needs of the high-conversion-ratio non-isolated DC-DC converters. They use single step to directly realize large voltage conversions, thereby greatly reducing the system distribution loss and improving the power density through high-frequency operation. The high-conversion-ratio singlestep DC-DC converters gain popularity among various applications such as automotive systems, data center & telecommunication applications, and consumer electronics. Since the conventional DC-DC converters have technical limitations to operate in large-voltageconversion conditions, four different types of hybrid DC-DC converters, which support all stepup, step-down, and step-up / -down voltage conversions for different applications, are developed in this research. These hybrid converters possess some of the following benefits: lower voltage stress of power switches, reduced inductor current and its ripple, enlarged switch on-time under high-conversion-ratio scenarios, doubled effective frequency, multiple DC outputs, flyingcapacitor self balancing, etc. Among them, this research first develops a three-switch ZVS hybrid step-up / -down power converter for automotive applications. It not only supports a wide input range of 9-V – 45-V and delivers a maximum 48-W output power, but also achieves peak power efficiencies of 98% and 96% in step-down and -up modes at 2-MHz frequency. The volume of external components in the converter is also reduced by at least five times compared with the prior art. Two different hybrid converters are also proposed for large input-to-output step-down applications. The first one is a dual-path hybrid Dickson (DPHD) converter with large outputcurrent capability. Through using a 7:1 prototype with 25-V silicon MOSFETs, high voltage conversions from 36 – 65-V VIN to 1 – 2-V VOUT with the maximum output current up to 32 A were validated. The DPHD converter achieves a high peak power efficiency of 92.7% under 48- V-to-2-V conversion and a power density of 481 W/in3 that is at least 2 times higher than other prior single-inductor hybrid converters. The second one is a class of Ladder-based capacitorassisted dual-inductor (CADI) hybrid converters suitable for high-frequency operations. The proposed topology was validated using a 3-to-1 Ladder-based CADI converter with fully on-chip power nMOS transistors. It supports voltage conversions from a wide input range of 36 – 55 V to an output of 1 – 2 V at high frequencies of 2.5 MHz – 5 MHz. Specifically, under 48-V-to-1-V direct conversion, the proposed converter is the first to achieve competitive high power efficiencies at a high frequency from 2.5 MHz to 5 MHz. Finally, a hybrid step-up converter with a scalable VOUT / VIN conversion ratio boosting (SCRB) scheme is developed for LED backlighting applications. It can produce large output-to-input voltage conversions while generating multiple DC output voltages. Through a four-stage prototype, the converter produces four different outputs, achieves the highest VOUT / VIN conversion ratio and switching frequency, and obtains high peak efficiencies under high-conversion-ratio and highfrequency conditions. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | https://utd-ir.tdl.org/handle/10735.1/9811 | |
| dc.identifier.uri | https://hdl.handle.net/10735.1/10117 | |
| dc.language.iso | en | |
| dc.subject | Engineering, Electronics and Electrical | |
| dc.title | Towards High-frequency High-efficiency Hybrid DC-DC Converters for Large-conversion-ratio Applications | |
| dc.type | Thesis | |
| dc.type.material | text | |
| local.embargo.lift | 2024-05-01 | |
| local.embargo.terms | 2024-05-01 | |
| thesis.degree.college | School of Engineering and Computer Science | |
| thesis.degree.department | Electrical Engineering | |
| thesis.degree.grantor | The University of Texas at Dallas | |
| thesis.degree.name | PHD |
Files
Original bundle
1 - 1 of 1