Title page for etd-0704114-124835


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URN etd-0704114-124835
Author Chung-Che Huang
Author's Email Address No Public.
Statistics This thesis had been viewed 5568 times. Download 46 times.
Department Electrical Engineering
Year 2013
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Variable Dead Time Control Strategies for Light-Load Efficiency Improvement of Phase-Shift Full-Bridge Converters
Date of Defense 2014-07-28
Page Count 117
Keyword
  • Light-Load Efficiency
  • Variable Dead Time Control
  • Zero-Voltage Switching (ZVS)
  • Phase-Shift Full-Bridge Converter (PSFBC)
  • Abstract Generally, the Phase-Shift Full-Bridge Converter (PSFBC) could achieve Zero-Voltage Switching (ZVS) for power switches by controlling the phase shift of switch signals. However, constrained by the resonant inductor and the resonant current, the traditional PSFBC can’t achieve ZVS for light loads due to small resonant current.It results in low efficiency for light loads. Therefore, how to improve and enhance the light-load efficiency of PSFBC is emerging and needs to be realized. In the past, adding the passive components such as capacitors and inductors into the PSFBC was a common technique to enhance the light-load efficiency of PSFBC since they could achieve ZVS under light load. Moreover, increasing inductance value, which enhanced the energy capacity, was also the way used to accelerate the process to achieve ZVS. Though these methods are certain to increase the efficiency, they still have the problems of extra cost and volume in the circuit. This thesis aims to improve the light-load efficiency of PSFBC by dead time adjustment. By the proposed variable dead-time control strategies, the light-load efficiency of PSFBC can be improved without adding extra electronic components. A PSFBC with specification of the input voltage 320V, output voltage 48V, and rate power 480W is designed and implemented in this thesis. Experiments adjust the dead time for one of the switches of lagging leg of PSFBC and compare the efficiency differences of the conventional dead-time control strategy to the proposed dead-time control strategies. Experimental results show that using two same switches for lagging leg of PSFBC, the maximum efficiency improvement for light loads between the proposed dead-time control strategies and the conventional one is 2.16% (output currents between 0.2A to 1.7A). Besides, comparing with the traditional PSFBC without dead-time adjustment, maximum efficiency improvement, 5.14%, can be achieved for light loads by the proposed dead-time control strategies.
    Advisory Committee
  • Chung-Ming Young - chair
  • Yi-Hua Liu - co-chair
  • Yong-Nong Chang - co-chair
  • Jen-Hao Teng - advisor
  • Files
  • etd-0704114-124835.pdf
  • Indicate in-campus at 5 year and off-campus access at 5 year.
    Date of Submission 2014-08-15

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