High Speed Cascode Flyback Converter Using Multilayered Coreless Printed Circuit Board (PCB) Step-Down Power Transformer

Hari Babu Kotte,Radhika Ambatipudi,Kent Bertilsson 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

In this paper, design and analysis of the high speed isolated cascode flyback converter using multilayered coreless PCB step down power transformer is presented. The converter is tested for the input voltage variation of 60-120V with a nominal DC input voltage of 90V. The designed converter was simulated and tested successfully up to the output power level of 30W within the switching frequency range of 2.6-3.7㎒. The cascode flyback converter is compared with the single switch flyback converter in terms of operating frequency, gate drive power consumption, conduction losses and stresses on MOSFETs. The maximum energy efficiency of the cascode converter is approximately 81% with a significant improvement of about 3-4% compared to single switch flyback converter. The gate drive power consumption which is more dominant compared to conduction losses of the cascode converter using GaN MOSFET is found to be negligible compared to single switch flyback converter.

PV 시스템의 차동 전력 조절기 모듈용 양방향 플라이백 컨버터 설계 방법

박승빈,김민아,정회정,김태원,김예린,정지훈 전력전자학회 2019 전력전자학회 논문지 Vol.24 No.5

A bidirectional flyback converter is a suitable topology for use in a PV-to-bus differential power processing (DPP) module for PV applications due to its electrical isolation capability, bidirectional power transfer, high step-up ratio, and simple circuit structure. However, the bidirectional flyback converter design should consider the effect of the output-side power switch utilized for bidirectional operation compared with that of the conventional flyback converter. This study presents the structure and design methodology of the bidirectional flyback converter for a PV DPP module. Magnetizing inductance is designed by calculating the power loss of converter components within the rated load range under the discontinuous conduction mode, which is unaffected by the reverse recovery characteristics of the anti-parallel diode of the output-side power switch. The validity of the proposed design methodology is verified using a 25 W bidirectional flyback converter prototype. The operational principles and the performance of the DPP operation are verified using practical DPP modules consisting of bidirectional flyback converters implemented according to the proposed design methodology.

A ZCT Double-Ended Flyback Converter with Low EMI

Mohammad Rouhollah Yazdani,Saeid Rahmani,Mehdi Mohammadi 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.3

In this paper, a zero current transition (ZCT) double-ended flyback converter is proposed. All of the switching elements act under soft switching conditions and the voltage stress of the main switches is limited to the input voltage due to the innate behavior of the double-ended flyback converter. Providing soft switching conditions and clamping the voltage stress improves the efficiency and electromagnetic compatibility (EMC). The Proposed converter is analyzed in detail and its operating modes are discussed in detail. Experimental results are presented to verify the theoretical predictions. Moreover, the conducted electromagnetic emissions of the proposed ZCT double-ended flyback converter are measured to show another merit of the proposed converter in addition to providing soft switching conditions. The measured electromagnetic interference (EMI) of the proposed converter demonstrates that its EMI is lower than the conventional double-ended flyback converter. Furthermore, two simple and cost effective EMI reduction methods are applied to satisfy the EMC standard.

Improved Single-Stage AC-DC LED-Drive Flyback Converter using the Transformer-Coupled Lossless Snubber

Gang-Youl Jeong,Su-Han Kwon 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

This paper presents an improved single-stage ac-dc LED-drive flyback converter using the transformer-coupled lossless (TCL) snubber. The proposed converter is derived from the integration of a full-bridge diode rectifier and a conventional flyback converter with a simple TCL snubber. The TCL snubber circuit is composed of only two diodes, a capacitor, and a transformer-coupled auxiliary winding. The TCL snubber limits the surge voltage of the switch and regenerates the energy stored in the leakage inductance of the transformer. Also, the switch of the proposed converter is turned on at a minimum voltage using a formed resonant circuit. Thus, the proposed converter achieves high efficiency. The proposed converter utilizes only one general power factor correction (PFC) control IC as its controller and performs both PFC and output power regulation, simultaneously. Therefore, the proposed converter provides a simple structure and an economic implementation and achieves a high power factor without the need for any separate PFC circuit. In this paper, the operational principle of the proposed converter is explained in detail and the design guideline of the proposed converter is briefly shown. Experimental results for a 40-W prototype are shown to validate the performance of the proposed converter.

Improved Single-Stage AC-DC LED-Drive Flyback Converter using the Transformer-Coupled Lossless Snubber

Jeong, Gang-Youl,Kwon, Su-Han The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

This paper presents an improved single-stage ac-dc LED-drive flyback converter using the transformer-coupled lossless (TCL) snubber. The proposed converter is derived from the integration of a full-bridge diode rectifier and a conventional flyback converter with a simple TCL snubber. The TCL snubber circuit is composed of only two diodes, a capacitor, and a transformer-coupled auxiliary winding. The TCL snubber limits the surge voltage of the switch and regenerates the energy stored in the leakage inductance of the transformer. Also, the switch of the proposed converter is turned on at a minimum voltage using a formed resonant circuit. Thus, the proposed converter achieves high efficiency. The proposed converter utilizes only one general power factor correction (PFC) control IC as its controller and performs both PFC and output power regulation, simultaneously. Therefore, the proposed converter provides a simple structure and an economic implementation and achieves a high power factor without the need for any separate PFC circuit. In this paper, the operational principle of the proposed converter is explained in detail and the design guideline of the proposed converter is briefly shown. Experimental results for a 40-W prototype are shown to validate the performance of the proposed converter.

A 40-W Flyback Converter with Dual-Operation Modes for Improved Light Load Efficiency

강진규,박정표,공정철,유창식 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.4

A flyback converter operates with either pulse width modulation (PWM) or pulse frequency modulation (PFM) control scheme depending on the load current. At light load condition, PFM control is employed to reduce the switching frequency and thereby minimize the switching power loss. For heavier load, PWM control is used to regulate the output voltage of the flyback converter. The flyback controller has been implemented in a 0.35 μm BCDMOS process and applied to a 40-W flyback converter. The light-load power efficiency of the flyback converter is improved up to 5.7-% comparing with the one operating with a fixed switching frequency.

Sampled-Data Modeling and Dynamic Behavior Analysis of Peak Current-Mode Controlled Flyback Converter with Ramp Compensation

Zhou, Shuhan,Zhou, Guohua,Zeng, Shaohuan,Xu, Shungang,Cao, Taiqiang The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

The flyback converter, which can be regarded as a nonlinear time-varying system, has complex dynamics and nonlinear behaviors. These phenomena can affect the stability of the converter. To simplify the modeling process and retain the information of the output capacitor branch, a special sampled-data model of a peak current-mode (PCM) controlled flyback converter is established in this paper. Based on this, its dynamic behaviors are analyzed, which provides guidance for designing the circuit parameters of the converter. With the critical stability boundary equation derived by a Jacobian matrix, the stable operation range with a varied output capacitor, proportional coefficient of error the amplifier, input voltage, reference voltage and slope of the compensation ramp of a PCM controlled flyback converter are investigated in detail. Research results show that the duty ratio should be less than 0.5 for a PCM controlled flyback converter without ramp compensation to operate in a stable state. The stability regions in the parameter space between the output capacitor and the proportional coefficient of the error amplifier are enlarged by increasing the input voltage or by decreasing the reference voltage. Furthermore, the ramp compensation also can extend to the stable region. Finally, time-domain simulations and experimental results are presented to verify the theoretical analysis results.

Sampled-Data Modeling and Dynamic Behavior Analysis of Peak Current-Mode Controlled Flyback Converter with Ramp Compensation

Shuhan Zhou,Guohua Zhou,Shaohuan Zeng,Shungang Xu,Taiqiang Cao 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

The flyback converter, which can be regarded as a nonlinear time-varying system, has complex dynamics and nonlinearbehaviors. These phenomena can affect the stability of the converter. To simplify the modeling process and retain theinformation of the output capacitor branch, a special sampled-data model of a peak current-mode (PCM) controlled flybackconverter is established in this paper. Based on this, its dynamic behaviors are analyzed, which provides guidance for designingthe circuit parameters of the converter. With the critical stability boundary equation derived by a Jacobian matrix, the stableoperation range with a varied output capacitor, proportional coefficient of error the amplifier, input voltage, reference voltageand slope of the compensation ramp of a PCM controlled flyback converter are investigated in detail. Research results show thatthe duty ratio should be less than 0.5 for a PCM controlled flyback converter without ramp compensation to operate in a stablestate. The stability regions in the parameter space between the output capacitor and the proportional coefficient of the erroramplifier are enlarged by increasing the input voltage or by decreasing the reference voltage. Furthermore, the rampcompensation also can extend to the stable region. Finally, time-domain simulations and experimental results are presented toverify the theoretical analysis results.

A 40-W Flyback Converter with Dual-Operation Modes for Improved Light Load Efficiency

Kang, Jin-Gyu,Park, Jeongpyo,Gong, Jung-Chul,Yoo, Changsik The Institute of Electronics and Information Engin 2015 Journal of semiconductor technology and science Vol.15 No.4

A flyback converter operates with either pulse width modulation (PWM) or pulse frequency modulation (PFM) control scheme depending on the load current. At light load condition, PFM control is employed to reduce the switching frequency and thereby minimize the switching power loss. For heavier load, PWM control is used to regulate the output voltage of the flyback converter. The flyback controller has been implemented in a $0.35{\mu}m$ BCDMOS process and applied to a 40-W flyback converter. The light-load power efficiency of the flyback converter is improved up to 5.7-% comparing with the one operating with a fixed switching frequency.

A 40-W Flyback Converter with Dual-Operation Modes for Improved Light Load Efficiency

Jin-Gyu Kang,Jeongpyo Park,Jung-Chul Gong,Changsik Yoo 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.4

A flyback converter operates with either pulse width modulation (PWM) or pulse frequency modulation (PFM) control scheme depending on the load current. At light load condition, PFM control is employed to reduce the switching frequency and thereby minimize the switching power loss. For heavier load, PWM control is used to regulate the output voltage of the flyback converter. The flyback controller has been implemented in a 0.35 μm BCDMOS process and applied to a 40-W flyback converter. The light-load power efficiency of the flyback converter is improved up to 5.7-% comparing with the one operating with a fixed switching frequency.