國立虎尾科技大學 |

High-Performance Power Converters Leveraging Capacitor-based Energy Transfer.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	High-Performance Power Converters Leveraging Capacitor-based Energy Transfer./
Author:	Lei, Yutian.
Description:	1 online resource (157 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 79-09(E), Section: B.
Contained By:	Dissertation Abstracts International79-09B(E).
Subject:	Electrical engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9780355890082

High-Performance Power Converters Leveraging Capacitor-based Energy Transfer.
Lei, Yutian.

High-Performance Power Converters Leveraging Capacitor-based Energy Transfer. - 1 online resource (157 pages)

Source: Dissertation Abstracts International, Volume: 79-09(E), Section: B.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2017.

Includes bibliographical references

The increasing demand for high performance power conversion systems continuously pushes for improvement in efficiency and power density. This dissertation focuses on a topological effort to efficiently utilize the active and passive devices. In particular, a hybrid approach is adopted, where both capacitors and inductors are used in the voltage conversion and power transfer process.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9780355890082Subjects--Topical Terms:

596380
Electrical engineering.
Index Terms--Genre/Form:

554714
Electronic books.

High-Performance Power Converters Leveraging Capacitor-based Energy Transfer.
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100 1 $a Lei, Yutian. $3 1193346
245 1 0 $a High-Performance Power Converters Leveraging Capacitor-based Energy Transfer.
264 0 $c 2017
300 $a 1 online resource (157 pages)
336 $a text $b txt $2 rdacontent
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500 $a Source: Dissertation Abstracts International, Volume: 79-09(E), Section: B.
500 $a Adviser: Robert C. N. Pilawa-Podgurski.
502 $a Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2017.
504 $a Includes bibliographical references
520 $a The increasing demand for high performance power conversion systems continuously pushes for improvement in efficiency and power density. This dissertation focuses on a topological effort to efficiently utilize the active and passive devices. In particular, a hybrid approach is adopted, where both capacitors and inductors are used in the voltage conversion and power transfer process.
520 $a Conventional capacitor-based converters, called switched-capacitor (SC) converters, suffer from poor efficiency due to the inevitable charge redistribution process. With a strategic placement of one or more inductors, the charge redistribution loss can be eliminated by inductively charging/discharging the capacitors, a process called soft-charging operation. As a result, the capacitor size can be greatly reduced without reducing the efficiency. A general analytical framework is presented, which determines whether an arbitrary SC topology is able to achieve full soft-charging operation with a single inductor. For topologies that cannot, a split-phase control technique is introduced, which amends existing two-phase controls to completely eliminate the charge redistribution loss. In addition, alternative placements of inductors are explored to extend the family of hybrid converters.
520 $a The hybrid converters can have two modes of operation, the fixed-ratio mode and pulse width modulated (PWM) mode. The fixed-conversion-ratio hybrid converters operate in a similar manner to that of a conventional SC converter, with the addition of a soft-charging inductor. The switching frequency of such converters can be adjusted to operate in either zero current switching (ZCS) mode or continuous conduction mode (CCM), which allows for the trade-off of switching loss and conduction loss. It is shown that the capacitor and inductor values can be selected to achieve a minimal passive component volume, which can be significantly smaller than that of a conventional SC converter or a magnetic-based converter. On the other hand, PWM-based hybrid converters generate a PWM rectangular wave as the terminal voltage to the inductor, similar to the operation of a buck converter. In contrast to conventional SC converters, such hybrid converters can achieve lossless and continuous regulation of the output voltage. Compared to buck converters, the required inductor is greatly reduced, as well as the switch stress. A 80--170 V input, 12--24 V output prototype PWM Dickson converter is implemented using GaN switches. The measured peak efficiency is 97%, and high efficiency can be maintained over the entire input and output operating range. In addition, the similarity between multilevel converters (for example, flying capacitor multilevel (FCML) converters) and the PWM-based hybrid SC converters is discussed. Both types of converters can be seen as a hybrid converter which uses both capacitors and inductors for energy transfer. A general framework to compare these converters, along with conventional buck converters, is proposed. In this framework, the power losses (including conduction loss and switching loss) are kept constant, while the total passive component volume is used as the figure of merit.
520 $a Based on the principle of maximizing energy utilization of passive components, a 7-level FCML converter and an active energy buffer are designed and implemented for single phase dc-ac applications. In addition, the stand-alone system includes a start-up circuitry, EMC filter and auxiliary power supply. The enclosed box achieves a combined power density of 216 W/in3 and an efficiency of 97.4%, and compares favorably against the state-of-the-art designs under the same specification.
520 $a To further improve the efficiency and power density, soft-switching techniques are investigated and applied on the hybrid converters. A zero voltage switching (ZVS) technique is introduced for both the fixed-ratio mode and the PWM mode operated hybrid converters. The previous hardware prototypes are modified for ZVS operation, and prove the feasibility of simultaneous soft-charging and soft-switching operation.
520 $a Last but not the least, some of the practical issues associated with the hybrid converter are discussed, such as practical capacitor selection, capacitor voltage balancing and other circuit implementation challenges. Future work based on these topics is given.
520 $a In summary, these hybrid converters are suited for applications where extreme efficiency and power density are critical. Through efficient utilization of active and passive devices, the hybrid topologies can offer a greater optimization opportunity and ability to take advantage of technology improvement than is possible with conventional designs.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Electrical engineering. $3 596380
650 4 $a Energy. $3 784773
655 7 $a Electronic books. $2 local $3 554714
690 $a 0544
690 $a 0791
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a University of Illinois at Urbana-Champaign. $b Electrical & Computer Eng. $3 1184123
773 0 $t Dissertation Abstracts International $g 79-09B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10832077 $z click for full text (PQDT)