• 전자공학회논문지SC
• /
• 제39권5호
• /
• pp.43-50
• /
• 2002

다이오드 정류회로의 전류 파형을 향상시키기 위해서 배전압 다이오드 정류회로에 대한 새로운 동작원리를 제안하였다. 기존의 배전압 정류회로는 대용량 캐패시터를 이용하여 출력전압을 높였으나 제안한 회로는 소용량의 캐패시터와 리액터를 이용하기 때문에 출력전압은 높아지지 않지만 입력전류의 파형을 개선할 수 있다. 그리고 역률과 효율이 각각 97[%], 98[%]을 얻을 수 있다. 제안한 정류기는 고조파 규제값과 스위치가 서로 영향을 미치지 않고 다이오드와 인덕터 그리고 콘덴서로 구성된 비선형 임피턴스 회로이다. 또한 일반적인 펄스 폭 변조 인버터와 하프 펄스 폭 변조 인버터를 비교하여 설명하였으며 제안된 하프 펄스 폭 변조 인버터에 의해서 낮은 스위칭 손실과 오버슈팅을 제어할 수 있다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 F
• /
• pp.2020-2022
• /
• 1997

An active clamp forward converter is proper for minimization and basically makes high efficiency of the system because of soft switching type. Especially, when applied to forward converter, it widens the control range of duty ratio and is suitable for high input voltage. In other hand, the current doubler has high utility efficiency of transformer and reduces output current ripple because it always transfers the power through the transformer and has two inductor with opposite slope. So, this paper explained the conduction mode of an active clamp forward converter with the current doubler rectifier.

• 한국전자파학회논문지
• /
• 제20권8호
• /
• pp.714-720
• /
• 2009

본 논문에서는 초광대역 특성을 가지는 평면형 대역 가변 체배기의 설계 과정을 소개하고 있다. 제안된 체배기에서는 초광대역 마이크로스트립-CPS 전이 구조(발룬)를 입력단의 정합 회로로, 초광대역 마이크로스트립-CPW 전이 구조를 출력단의 정합 회로로 사용하였다. 입력단에 사용된 발룬 구조로 인해 다이오드에 바이어스를 가할 수 있는데, 구현된 체배기의 대역 가변은 다이오드에 인가되는 전압을 가변함으로써 얻을 수 있다. 바이어스 전압이 -0.6 V일 때 체배기의 동작 주파수는 $10{\sim}20$ GHz, 인가 전압이 $-0.2{\sim}-0.4$ V일 때 동작 주파수는 $10{\sim}30$ GHz, 인가 전압이 0 V일 때 동작 주파수는 $20{\sim}30$ GHz로 변함을 확인하였다. 또한, 구현된 체배기의 변환 손실은 최대 15 dB 이고, 입력 주파수의 억압 특성은 평균 30 dB 이상이 되는 우수한 특성을 확인하였다.

• Journal of Power Electronics
• /
• 제13권1호
• /
• pp.20-30
• /
• 2013

This paper presents a soft switching DC/DC converter for high voltage application. The interleaved pulse-width modulation (PWM) scheme is used to reduce the ripple current at the output capacitor and the size of output inductors. Two converter cells are connected in series at the high voltage side to reduce the voltage stresses of the active switches. Thus, the voltage stress of each switch is clamped at one half of the input voltage. On the other hand, the output sides of two converter cells are connected in parallel to achieve the load current sharing and reduce the current stress of output inductors. In each converter cell, a half-bridge converter with the asymmetrical PWM scheme is adopted to control power switches and to regulate the output voltage at a desired voltage level. Based on the resonant behavior by the output capacitance of power switches and the transformer leakage inductance, active switches can be turned on at zero voltage switching (ZVS) during the transition interval. Thus, the switching losses of power MOSFETs are reduced. The current doubler rectifier is used at the secondary side to partially cancel ripple current. Therefore, the root-mean-square (rms) current at output capacitor is reduced. The proposed converter can be applied for high input voltage applications such as a three-phase 380V utility system. Finally, experiments based on a laboratory prototype with 960W (24V/40A) rated power are provided to demonstrate the performance of proposed converter.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
• /
• pp.364-368
• /
• 1999

This paper suggests switching regulator technique to overcome the drawback of conventional variable linear power supply. Switching regulator technique can eliminate the extremely lossy operation and reduce the size and weight of variable linear power supply and provide nearly constant output power over the majority of output voltage range. The topology of variable switched mode power supply is employed active clamp forward converter with a current doubler rectifier and by using control of variable-frequency together with control of fixed-frequency, output voltage can be controled. Equivalent circuits pertinent to each operational mode of converter are derived, and an experimental 20V, 50A converter was designed and built. The converter operates from an output voltage of zero to 25 V, under 100 kHz switching frequency.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 B
• /
• pp.980-982
• /
• 2002

In this paper, we report the experimental results of the Forward-flyback DC-DC converter with current doubler and synchronous rectifier. The experimental converter, that has a output voltage 1.8V, output current 25A, maximum power of 45W, switching frequency of 290kHz and input voltage range of 36-75V, has been successfully implemented. As a result, in the entire voltage range the measured full load efficiency was above 82%, and the output voltage was regulated at 1.8V within ${\pm}$3% tolerance.

• Journal of Power Electronics
• /
• 제19권5호
• /
• pp.1099-1107
• /
• 2019

A soft switching converter with wide voltage range operation is investigated in this paper. A series resonant converter is implemented to achieve a high circuit efficiency with soft switching characteristics on power switches and rectifier diodes. To improve the weakness of the narrow voltage range in LLC converters, an alternating current (ac) power switch is used on the primary side to select a half-bridge or full-bridge resonant circuit to implement 4:1 voltage range operation. On the secondary-side, another ac power switch is adopted to select a full-wave rectifier or voltage-doubler rectifier to achiever an additional 2:1 output voltage range. Therefore, the proposed resonant converter has the capacity for 8:1 (320V~40V) wide output voltage operation. A single-stage hybrid resonant converter is employed in the study circuit instead of a two-stage dc converter to achiever wide voltage range operation. As a result, the study converter has better converter efficiency. The theoretical analysis and circuit characteristics are verified by experiments with a prototype circuit.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
• /
• pp.1006-1007
• /
• 2006

An active-clamp current-fed push-pull converter for the step-up application is proposed. The proposed converter is composed of active-clamp circuits and a voltage doubler rectifier. Thus, the voltage stress of the main switches is reduced and the output diodes are clamped to output voltage. Moreover, the output diodes can achieve zero current switching (ZCS) by the series resonance between resonant capacitors and leakage inductances. The prototype is designed for 350V/1.5kW with input voltage range $30{\sim}60V$. The theoretical analysis and experimental results are presented.

• Journal of Power Electronics
• /
• 제12권1호
• /
• pp.113-119
• /
• 2012

This paper describes the design and control of a phase shift full bridge converter with a current doubler, which can be used for the on-board charger for the lead-acid battery of electric forklifts. Unlike the common resistance load, the battery has a large capacitance element and it absorbs the entire converter output ripple current, thereby shortening the battery life and degrading the system efficiency. In this paper a phase shift full bridge converter with a current doubler has been adopted to decrease the output ripple current and the transformer rating of the charger. The charge controller is designed by using the small signal model of the converter, taking into consideration the internal impedance of the battery. The stability and performance of the battery charger is then verified by constant current (CC) and constant voltage (CV) charge experiments using a lead-acid battery bank for an electric forklift.

• 전력전자학회논문지
• /
• 제11권1호
• /
• pp.14-21
• /
• 2006

본 논문에서는 출력 전압의 리플을 이용하여 지상 레그(lagging leg)의 스위치들의 영전류 스위칭(ZCS)을 수행하는 두 개의 트랜스포머를 가지는 위상천이 풀-브릿지 컨버터를 제안하다. 제안된 컨버터는 진상 레그(leading leg)의 스위치들은 영전압 스위칭(ZVS)을 수행하고, 지상 레그의 스위치들은 출력 전압-더블러(Voltage-Doubler)의 전압 리플차를 이용해 출력 다이오드의 전류 전환(commutation)이 빠르게 이루어지도록 하여서 중부하에는 영전류 스위칭을, 경부하에서는 영전압 스위칭을 가능하게 한다. 또한 출력측의 전압 리플차를 이용하기 때문의 기존의 1차측 부스트 캐패시터를 이용하는 컨버터에 비해 턴비를 이용하여 보다 빠른 전류 전환을 수행할 수 있는 장점을 가진다. 따라서 별도의 추가적인 소자없이 모든 스위치의 소프트스위칭이 가능하도록 하고, 지상 레그의 영전류 스위칭을 통해서 환류구간의 순환전류도 없애줌으로써 높은 효율을 얻을 수 있다. 모드 해석과 실험을 통하여 제안 컨버터의 성능을 검증한다.