Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (2)

Search Parameters:
Keywords = quasi-resonant flyback (QRF)

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
16 pages, 4206 KB  
Article
Modeling a Dual-Mode Controller Design for a Quasi-Resonant Flyback Converter
by Ching-Chun Chuang, Chih-Chiang Hua, Chong-Yu Huang and Li-Kai Jhou
Appl. Sci. 2019, 9(9), 1860; https://doi.org/10.3390/app9091860 - 6 May 2019
Cited by 4 | Viewed by 4931
Abstract
The proposed system can overcome the disadvantage of a high peak current in quasi-resonant fly-back (QRF) converters when operated under heavy load conditions. The operating mode and control scheme of a QRF converter with dual-mode control were established and analyzed. The dual-mode control [...] Read more.
The proposed system can overcome the disadvantage of a high peak current in quasi-resonant fly-back (QRF) converters when operated under heavy load conditions. The operating mode and control scheme of a QRF converter with dual-mode control were established and analyzed. The dual-mode control scheme not only enabled a valley-switching detection technique that satisfied the zero-voltage switching condition but also provided a constant frequency mechanism to reduce the conduction loss in QRF converters when operated in a continuous conduction mode and under heavy load conditions. The small-signal equivalent circuit model of QRF converter circuits was constructed using an average approximation method. The technological advancement of a QRF converter with a dual-mode controller was presented in this study. The circuit simulation result of the proposed QRF converter with a mix control scheme proved that the derived circuit component parameters meet the requirements of the converter. Full article
(This article belongs to the Special Issue Selected Papers from IMETI 2018)
Show Figures

Figure 1

23 pages, 21772 KB  
Article
Novel Frequency Swapping Technique for Conducted Electromagnetic Interference Suppression in Power Converter Applications
by Ming-Tse Kuo and Ming-Chang Tsou
Energies 2017, 10(1), 24; https://doi.org/10.3390/en10010024 - 27 Dec 2016
Cited by 8 | Viewed by 9036
Abstract
Quasi-resonant flyback (QRF) converters have been widely applied as the main circuit topology in power converters because of their low cost and high efficiency. Conventional QRF converters tend to generate higher average conducted electromagnetic interference (EMI) in the low-frequency domain due to the [...] Read more.
Quasi-resonant flyback (QRF) converters have been widely applied as the main circuit topology in power converters because of their low cost and high efficiency. Conventional QRF converters tend to generate higher average conducted electromagnetic interference (EMI) in the low-frequency domain due to the switching noise generated by power switches, resulting in the fact they can exceed the EMI standards of the European Standard 55022 Class-B emission requirements. The presented paper develops a novel frequency swapping control method that spreads spectral energy to reduce the amplitude of sub-harmonics, thereby lowering average conducted EMI in the low-frequency domain. The proposed method is implemented in a control chip, which requires no extra circuit components and adds zero cost. The proposed control method is verified using a 24 W QRF converter. Experimental results reveals that conducted EMI has been reduced by approximately 13.24 dBμV at 498 kHz compared with a control method without the novel frequency swapping technique. Thus, the proposed method can effectively improve the flyback system to easily meet the CISPR 22/EN55022 standards. Full article
(This article belongs to the Special Issue Power Electronics Optimal Design and Control)
Show Figures

Figure 1

Back to TopTop