• Journal of Power Electronics
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• 제5권2호
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• pp.99-103
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• 2005

In this paper, a novel circuit topology of a three-winding coupling inductor-assisting a high-frequency PWM boost chopper type DC-DC power converter with a high boost voltage conversion ratio and low switch voltage stress is proposed for the new energy interfaced DC power conditioner in solar photovoltaic and fuel cell generation systems. The operating principle in a steady state is described by using its equivalent circuits under the practical condition of energy processing of a lossless capacitive snubber. The newly-proposed power MOSFET boost chopper type DC-DC power converter with the three-winding coupled inductor type transformer and a single lossless capacitor snubber is built and tested for an output power of 500W. Utilizing the lower voltage and internal resistance power MOSFET switch in the proposed PWM boost chopper type DC-DC power converter can reduce the conduction losses of the active power switch compared to the conventional model. Therefore, the total actual power conversion efficiency under a condition of the nominal rated output power is estimated to be 81.1 ％, which is 3.7％ higher than the conventional PWM boost chopper DC power conversion circuit topology.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.599-600
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• 2008

This paper presents a high performance DC-DC boost converter by current-mode control method. As load current change, the converter change PWM/PFM operation automatically. current-mode DC-DC boost converter is implemented in a standard $0.35{\mu}m$ CMOS process. The peak efficiency was 94 % with a switching frequency of 1.2MHz.

• 한국위성정보통신학회논문지
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• 제12권2호
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• pp.28-32
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• 2017

본 연구에서는 컨버터를 일정한 주파수로 제어할 수 있는 쿼지 공진형 컨버터를 제안하였다. 제안된 컨버터의 스위치는 쿼지 공진형 컨버터와 유사하게 고주파에서 고효율로 동작할 수 있도록 소프트 스위칭 특성을 갖는다. 또한, 쿼지 공진형 컨버터는 출력전압의 제어를 위해 컨버터의 스위칭 주파수를 변동시키는 데 비하여 제안된 컨버터는 일정한 주파수로 PWM 제어가 가능하다. 따라서 필터설계 및 EMI 필터설계의 최적화가 가능하다. 본 연구에서는 컨버터의 스위치 모드를 해석하여 컨버터의 동작원리를 기술하고, 컨버터의 스위치가 소프트 스위칭 조건을 만족하여 고주파에서도 동작할 수 있음을 보였다. 또한, DC-DC 컨버터에 대하여 100 kHz의 스위칭 주파수로 동작시켜 컨버터가 일정한 주파수로 PWM 제어되는 특성을 비롯한 컨버터의 특성을 시뮬레이션과 실험으로 증명하였다.

• 전기전자학회논문지
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• 제10권2호통권19호
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• pp.149-155
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• 2006

In this study, the design of low voltage DC-DC converter with low triggering ESD (Electro-Static Discharge) protection circuit was investigated. The purpose of this paper is design optimization for low voltage(2.5V to 5.5V input range) DC-DC converter using CMOS switch. In CMOS switch environment, a dominant loss component is not switching loss but conduction loss at 1.2MHz switching frequency. In this study a constant frequency PWM converter with synchronous rectifier is used. And zener Triggered SCR device to protect the ESD phenomenon was designed. This structure reduces the trigger voltage by making the zener junction between the lateral PNP and base of lateral NPN in SCR structure. The triggering voltage was simulated to 8V.

• 전기학회논문지
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• 제56권2호
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• pp.301-310
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• 2007

Bidirectional DC-DC converters allow transfer of power between two dc sources, in either direction. Due to their ability to reverse the direction of flow of power, Dey are being increasingly used in many applications such as battery charge/dischargers, do uninterruptible power supplies, electrical vehicle motor drives, aerospace power systems, telecom power supplies, etc. This Paper Proposes a new bidirectional Sepic/Zeta converter. It has low switching loss and low conduction loss due to auxiliary communicated circuit and synchronous rectifier operation, respectively Because of positive and buck/boost-like DC voltage transfer function(M=D/1-D), the proposed converter is very desirable for use in distributed power system. The proposed converter also has both transformer-less version and transformer one.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.85-90
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• 2022

In this paper, a DC converter to improve the performance of Power LED system is discussed. The mathematical model of PWM converter power stage using 3-Terminal PWM cell is introduced for power LED system. A controller for DC converter system is used as a self-tunning regulator with a recursive least-squares algorithm. Minimum variance control method is used as a control law. Experiment results verified that proposed control system could improve the performance of Power LED system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1339-1341
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• 2000

This paper presents a new PWM DC/DC converter with multi-output using single secondary winding, which has two output characteristics of the isolation and non-isolation simultaneously. The proposed converter topology is consisted of the only one switch and single secondary winding. The proposed converter, therefore, has advantages not only low cost but also high power density. Operating principal of the proposed converter topology with conventional ZVT (Zero-Voltage-Transition) is illustrated in detail and the validity of the converter is verified with several interesting simulation results.

• Journal of Power Electronics
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• 제8권4호
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• pp.363-370
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• 2008

In this paper, three kinds of PWM strategies for a three-phase current-fed dc/dc converter are proposed and compared in terms of losses and voltage transfer ratio. Each PWM strategy is described graphically and their switching losses are analyzed. With the proposed PWM C strategy, one turn-off switching of each bridge switch is eliminated to reduce switching losses under the same switching frequency. In addition, RMS current through the bridge switches is lowered by using parallel connection between two bridge switches and thus, conduction losses of the switches are reduced. Further, copper losses of the transformer are decreased due to the reduced RMS current of each transformer's winding. Therefore, total losses are minimized and the efficiency of the converter is improved by using the proposed PWM C strategy. Digital signal processor (DSP: TI320LF2407) and a field-programmable gate array (FPGA: EPM7128) board are used to generate PWM patterns for three-phase bridge and clamp MOSFETs. A 500W prototype converter is built and its experimental results verify the validity of the proposed PWM strategies.

• 항공우주기술
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• 제5권2호
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• pp.166-173
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• 2006

현대의 전자 장치는 안정적인 전력 공급을 위해 DC-DC Converter 등의 스위칭 전원을 사용하고 있다. 직류전원을 필요로 하는 통신장치는 안정적 동작과 높은 효율을 유지하기 위해 DC-DC Converter 등의 스위칭 전원의 사용이 불가피하며, 이는 에너지 절약이라는 시대적 요구에 부응하여 급속히 그 응용이 확산되고 있다. 이와같은 DC-DC Converter를 설계할 때는 각각의 동작 특징을 정확히 검토할 필요가 있다. 이를 위해 DC-DC Converter의 종류별 특성과 적용 분야 및 용도 분석을 통해 활용 분야를 파악하고, DC-DC Converter의 기본적 형태인 Buck type Converter를 선정하여 회로 설계 및 시뮬 레이션을 통해 이론적인 해석치과 설계치를 비교하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1015-1019
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• 2001

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.