• Journal of Power Electronics
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• 제12권3호
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• pp.439-447
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• 2012

In this paper, an input-series auxiliary power supply scheme is proposed, which is suitable for high input voltage and multiple-output applications. The power supply scheme is based on a two-transistor forward topology, all of the series modules have a common duty ratio, all the switches are turned on and off simultaneously, and the whole circuit has a single power transformer. It does not require an additional controller but still achieves efficient input voltage sharing (IVS) for each series module through its inherent transformer-integration strategy. The IVS process of this power supply scheme is analyzed in detail and the design considerations for the related parameters are given. Finally, a 100W multiple-output auxiliary power supply prototype is built, and the experimental results verify the feasibility of the proposed scheme and the validity of the theoretical analysis.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.207-210
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• 2002

This paper describes a design of multiple-mode single-output DC/DC converter which can be used in both up and down conversion. Proposed up/down converter does not produce a negative voltage which is generated in conventional buck-boost type converter. Three types of operation mode(up/down/bypass) are controlled by the input voltage sense and command signals of target output voltage. PFM(pulse frequency modulation) control is adopted and modified for fast tracking and for precise output voltage level with an aid of output voltage sense. Designed DC/DC converter has the performance of less than 5 % ripple and higher than 80 % efficiency. Chip area is 3.50 mm ${\times}$ 2.05 mm with standard 0.35 $\mu\textrm{m}$ CMOS technology.

• 전력전자학회논문지
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• 제27권2호
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• pp.106-117
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• 2022

Multiple output converters can be utilized when various output voltages are required in applications. Recently, one of the multiple output converters called fly-buck has been proposed, and has attracted attention due to the advantage that multiple output can be easily obtained with a simple structure. When constant on-time (COT) control is applied, the output ripple voltage must be treated carefully for control stability and voltage regulation characteristics in consideration of the inherent energy transfer characteristics of the fly-buck converter. This study analyzes the operation principle of the fly-buck converter with a ripple generation network and presents the design guideline for the improved output voltage regulation. Validity of the analysis and design guideline is verified using a 5 W prototype of the COT controlled fly-buck converter with a ripple generation network for telecommunication auxiliary power supply.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.125-126
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• 2010

In this paper, a novel multiple output converter using quasi load is proposed. Conventional multiple output converters using multi-winding transformer has poor output voltage regulations. To solve this problem, there are many proposals like post regulation method, weighted control method, and etc. However, the post regulation method regulates output voltage tightly but its conduction loss and cost are increased. And the weighted control can achieve high efficiency and low cost but its regulation is not enough. To solve these problems, this paper proposes a novel multiple output converter using quasi load. The proposed method uses a quasi load which acts like an active dummy load for tight regulation but there is rarely increase of loss and cost. The proposed method is verified by hardware test by two output(24V and 15V) flyback type converter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.291-294
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• 1990

Fuel cell system needs DC-AC conversion inverter system because its output is DC. And the inverter system can be operated not only in stand-alone load but also in interactive mode in interactive mode, it is necessary to control active-reactive power of inverter and to synchronize inverter output voltage to power line voltage. In this paper, a 12 phase multiple VSI type GTO inverter system for fuel cell is described. Synchronization between power line voltage phase and inverter output voltage phase, and reduction of harmonics in the output voltage phase are the purpose of this inverter system. This control algorithm for the system is realized by the software method utilizing 8031AH 8bit Microprocessor.

• 전력전자학회논문지
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• 제6권4호
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• pp.307-316
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• 2001

본 논문에서는 직류 특성과 절전 모드에서 비절전 모드 변환과 같은 부하 변동 시의 동특성을 동시에 개선할 수 있는 가중치 전압 제어를 적용한 PC 전원용 다중출력 포워드 컨버터를 설계하였다. 기생성분을 포함한 전력회로를 모델링하고 소신호 해석하였으며, 가중치 결정 방법과 전압 보상회로 설계 방법을 제시하였다. SABER 시뮬레이션과 실험을 통해 제안한 방법이 PC 전원의 직류 특성과 동특성을 향상시킴을 입증하였다.

• 한국전자통신학회논문지
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• 제19권5호
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• pp.853-860
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• 2024

본 연구에서는 최근, 산업 전자 기기에서 요구되는 다중 출력 전압을 가지는 PWM 제어 기반 단일 입력/단일 출력 강압형 DC-DC 컨버터 설계 방법을 연구하였다. 강압형 DC-DC 컨버터의 기본 이론을 기반으로 강압형 컨버터의 설계 방법을 결정하였고 다중 레벨의 출력 전압을 선택적으로 얻을 수 있는 단일 입력, 단일 출력 강압형 컨버터에 대한 PWM 제어 기반의 전압 제어 알고리즘을 개발하였다. 설계 방법론의 유효성을 검증하기 위해 하나의 시작품을 설계, 시험 제작하였다. 다음, 시작품을 기반으로 하는 시험 환경 하에서, 고정 입력 전압과 가변 입력 전압에 대해 목표 전압들이 선택적으로 결정될 때 다중 출력 전압들이 목표 전압들을 오차율 7%이내에서 추종하는 것을 확인함으로써 PWM 제어 기반의 전압 제어 방법의 유효성을 검증할 수 있었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.179-180
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• 2011

This paper focuses on the Current-Voltage concurrent control method devoted to the multiple LED (light-emitting diode) string driver. Isolated DC to DC converter with cascaded chopping switch is proposed for smart lighting system such as light with sensor or back light unit of display, which need to control the current of parallel connected multiple LED stings and regulate DC voltage for micro controller for brightness control. The proposed circuit regulates the current of parallel connected multiple LED strings and additional DC voltage output simultaneously. To verify the performance, experimental results are presented based on the prototype board. 5V, 1A voltage mode electric load and two LED strings with different forward voltages are used for output loads. 23W output power is achieved and measured efficiency is in the range of 85%-87%

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.501-504
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• 2000

In this paper the PC power supply is studied from the point of system stability. The power stage model of a multiple output forward converter with weighted voltage mode control is derived including all the major parasitic components and the small signal model is also derived. Determination of the weighting factors and a design procedure for the loop compensation are presented. Finally the model is verified through the simulation of three output forward converter with SABER.

• Journal of Power Electronics
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• 제19권5호
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• pp.1122-1132
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• 2019

In this paper, aiming at high-voltage applications, transformer windings schemes of multiple-output two-transistor flyback converters are investigated, which are mainly based on the stray capacitances effect. First, based on a transformer model including equivalent stray capacitors, the operational principle of the converter is presented, and the main influence of its stay capacitors is determined. Second, the windings structures of the transformer are analyzed and designed based on the stray capacitances effect. Third, the windings arrangements of the transformer are analyzed and designed through a coupling analysis of the secondary windings and a stray capacitance analysis between the primary and secondary windings. Finally, the analysis and design conclusions are verified by experimental results obtained from a 60W laboratory prototype of a multiple-output two-transistor flyback converter.