MDPI - Publisher of Open Access Journals

21 pages, 7747 KiB

Open AccessArticle

Analysis and Optimization of a Regenerative Snubber for a GaN-Based USB-PD Flyback Converter

by Fabio Cacciotto, Alessandro Cannone, Emanuele Cassarà and Santi Agatino Rizzo

Electronics 2024, 13(6), 1045; https://doi.org/10.3390/electronics13061045 - 11 Mar 2024

Cited by 1 | Viewed by 2455

This paper presents a high-efficiency GaN-based 65 W Quasi-Resonant (QR) Flyback converter. The converter is characterized by a wide input voltage range and a variable output voltage, and it is designed as a Switch Mode Power Supply (SMPS) for high power density USP-Power Delivery (USB-PD) applications. To increase the efficiency and power density, a regenerative snubber clamp solution has been used to limit the excursion of the drain voltage during the power switch turn-off. The activity involved the modeling of the converter, the sizing of the regenerative snubber, and the design of the flyback transformer. Furthermore, a dedicated test application board was used to verify the effectiveness of the solution. The results were compared with those obtained using a flyback converter with an RCD snubber. Full article

(This article belongs to the Special Issue Section Collection Series: New Horizons and Recent Advances in Power Electronics)

► Show Figures

Figure 1

13 pages, 6174 KiB

Open AccessArticle

Development and Implementation of LED Street Lights with Bright and Extinguishable Controls and Power Converters

by Kai-Jun Pai, Liang-Hsun Wang and Ming-Hung Chen

Micromachines 2023, 14(7), 1453; https://doi.org/10.3390/mi14071453 - 20 Jul 2023

Cited by 2 | Viewed by 1688

Abstract

This study developed and implemented a driving power supply for light-emitting diode (LED) array streetlamps. The power stage was a quasi-resonant (QR)-flyback converter, its input power was the alternating-current power, and the LED array streetlamp was driven by the direct-current output power. The developed QR-flyback converter was operated in discontinuous conduction mode, and the pulse-width modulation (PWM) control chip was used to switch and conduct at the resonant valley of the drain-source voltage on the metal-oxide-semiconductor field-effect transistor (MOSFET) switch to reduce the switching loss. Moreover, the PWM control chip had a disable function, which was connected with a bright and extinguishable control circuit, and the high/low voltage level signal output by the Arduino development board can be used to control the output power of the QR-flyback converter, achieving bright and extinguishable controls for the LED array streetlamp. Full article

(This article belongs to the Special Issue Power Electronics and Power Conversion-Related Applications of Micro Energy Devices, 2nd Edition)

► Show Figures

Figure 1

21 pages, 11618 KiB

Open AccessArticle

A High-Efficiency QR Flyback DC–DC Converter with Reduced Switch Voltage Stress Realized by Applying a Self-Driven Active Snubber (SDAS)

by Jeong-Sang Yoo, Jong-Ok Baek and Tae-Young Ahn

Energies 2023, 16(3), 1068; https://doi.org/10.3390/en16031068 - 18 Jan 2023

Cited by 7 | Viewed by 4826

Abstract

In this paper, a QR flyback converter using a self-driven active snubber (SDAS) was proposed to solve the problem of voltage surge in the switch of QR flyback converters. In the proposed converter, the SDAS consisting of a clamping capacitor and an active switch can be configured in parallel with the main switch or transformer to reduce the voltage surge in the switch. To confirm the steady-state characteristics of the QR flyback converter to which the proposed SDAS is applied, equivalent circuits for each state were constructed, and the equations and characteristics for each state were determined. A 60 W class small AC–DC adapter was constructed to confirm the effectiveness of the proposed converter and the control circuit method, and the experimental results were analyzed. The size of the experimental AC–DC adapter was

74 \times 29 \times 23 mm

, and it had a high power density of

20 W / {in}^{3}

or more. The experimental circuit was limited to the high power conversion efficiency of up to 91.56%, and the maximum voltage surge in the switch was approximately 450 V. One of the reasons for such high efficiency is the SDAS circuit, which sufficiently reduces the voltage surge of the QR flyback switch, compared with the RCD clamp circuit, and does not consume power in principle. Full article

(This article belongs to the Topic Power Converters)

► Show Figures

Figure 1

17 pages, 4060 KiB

Open AccessArticle

A Dual-Mode Control Scheme to Improve Light Load Efficiency for Active-Clamp Flyback Converter

by Thanh Nhat Trung Tran, Hung-Chia Wang and Jian-Min Wang

Electronics 2022, 11(9), 1308; https://doi.org/10.3390/electronics11091308 - 20 Apr 2022

Cited by 4 | Viewed by 2910

Abstract

A novel dual-mode control scheme is proposed in this paper that permits the active-clamp flyback (ACF) converter to operate in both the quasi-resonant (QR) mode under light load and the active-clamp mode under medium or heavy load. The mode transition is performed based on the external dual-mode control circuit. In addition, the proposed converter incorporates a new QR mode valley switching (VS) control circuit that reduces switching loss in the main switch by achieving VS. Under medium to full load, the proposed converter becomes an ACF converter designed to achieve zero-voltage switching (ZVS), which reduces switching losses in both power switches. The proposed dual-mode control ACF converter has the following advantages: (1) compared with conventional ACF converters, the proposed ACF converters minimize switching losses by combining VS and ZVS; (2) under light load conditions, the frequency-limiting QR control mechanism is used to avoid disadvantageous switching losses caused by high switching frequencies. The 65 W ACF converter prototype with a DC 155 V input and a DC 19 V/3.42 A output under 65 kHz switching frequency was implemented. The experimental results demonstrate the feasibility of the proposed control scheme. The efficiency of the proposed converter reached 79% at a load of 3.5 W, which is 11% higher than the conventional ACF converter. Full article

(This article belongs to the Topic Application of Innovative Power Electronic Technologies)

► Show Figures

Figure 1

16 pages, 4206 KiB

Open AccessArticle

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 3 | Viewed by 4009

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 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 KiB

Open AccessArticle

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 7814

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 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

7 pages, 393 KiB

Open AccessArticle

Quasi-Resonant Flyback DC/DC Converter Using GaN Power Transistors

by S. L. Jeng, M. T. Peng, C. Y. Hsu, W. H. Chieng and Jet P.H. Shu

World Electr. Veh. J. 2012, 5(2), 567-573; https://doi.org/10.3390/wevj5020567 - 29 Jun 2012

Cited by 11 | Viewed by 1678

Abstract

Quasi-resonant flyback converter is realized with the aim to demonstrate the topology feasibility using the normally-on switching behaviour of the gallium nitride (GaN) power transistor. Reference converters utilize GaN and silicon-based MOSET as the switching devices to compare the electric characteristics, and power losses. Quasi-resonant technology offers reduced turn-on losses, resulting in increased efficiency and lower device temperature. The turn-on losses dominate the power losses as the switching frequency of the power supply increases. The combined advantages of gate charge and on-resistance for GaN in the 60 watt reference converter leads to improve the turn-off conduction loss. GaN based power converter provides up to 7.02% improved efficiency over silicon based MOSFETs. The converter performance improvement opens the possibility of fully exploiting the wide advantages of GaN transistors in power electronic application. Full article

Search Results (7)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (7)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI