• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.485-486
• /
• 2010

FPS(Filament Power Supply), one of the KSTAR NBI (Neutral Beam Injections) is implemented by full-bridge DC/DC converter. NBI heating device for KSTAR(1.5MW) is developed for heating an ion source of plasma in KSTAR tokmak. The full-bridge DC/DC converter is applied to FPS for isolation with input and output. And FPS is operated with PWM control method which is the most usual method. In this paper, NBI FPS of 4.8kW is simulated by using the PSIM 6.0. And the full-bridge DC/DC converter using IGBTs is fabricated to demonstrate it. The processor DSP 28335 is implemented for digital control.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.4
• /
• pp.552-559
• /
• 2015

Hydrogen is commonly used in many industrial field. However, hydrogen should be filled in a high pressure container to use it. Therefore, many researches have been conducted about an electrolyzer. The operating principle of the electrolyzer is that the electrolyzer can separate water molecules into hydrogen and oxygen. To use the electrolyzer, a power conversion system is needed because the current of the electrolyzer increases exponentially depending on the voltage of the electrolyzer. Thus, this paper proposes the power conversion system for the electrolyzer using a full-bridge DC-DC converter topology.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.286-288
• /
• 2005

Conventional phase shift full bridge (PSFB) converter has serious voltage oscillation problem across the secondary rectifier diodes, which would require the dissipate snubber circuit, thus degrades the overall efficiency. To overcome this problem, a new voltage oscillation reduction technique (VORT) which effectively reduce the voltage oscillation of the secondary rectifier diodes for phase shift 1011 bridge converter is proposed. Therefore, no dissipate snubber for rectifier diodes is needed. In addition, since it has wide zero voltage switching (ZVS) range, high efficiency can be achieved. Operational principle, analysis of voltage oscillation, and design consideration are presented compare with that of the conventional PSFB converter. To confirm the validity of the proposed VORT, experimental results from a 420W, 385Vdc/210Vdc prototype are presented.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.436-438
• /
• 2005

This paper presents a Zero-Current Switching(ZCS) two-transformer phase-shift full-bridge(TTFB) converter using voltage ripple. The proposed converter provides Zero-Voltage Switching(2VS) of leading leg switches and ZCS of lagging leg switches using volt-age ripple. Especially, circulating current Is reduced by ZCS operation and there are no additional components required for the soft switching of power switches. Furthermore, in case of light load, ZVS operation of lagging leg can be achieved. The operations, analysis and design consideration of proposed converter are presented. To verify the validity of the proposed converter, experimental results for a flow (205V, 2A) prototype are presented.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1303-1305
• /
• 2000

A zero voltage and zero current switching(ZVZCS) fullbridge (FB) PWM converter with secondary auxiliary circuit is proposed. Based on the ZVZCS technique, the ZCS of the lagging-leg switch and ZVS of the leading-leg switch are implemented. And the each secondary side voltage overshoot is decreased by additional secondary auxiliary circuit in this paper. The illustration of its operation principle and the simulation result are presented here.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.11a
• /
• pp.251-255
• /
• 2005

This paper proposes a new soft switching technique for a phase-shift controlled bi-directional DC-DC converter. The described converter employs a low profile high frequency transformer and two active full-bridge converters for bidirectional power flow capability. A new soft switching technique is proposed, which guarantees soft switching over wide range (no load to full load) without any additional circuit components. In the proposed switching scheme, the switch pairs in the diagonal position of the converter each are turned on/off simultaneously by the switching signals with a variable duty ratio depending on the phase shift amount, and the converter is operated without freewheeling interval.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.135-137
• /
• 2007

A phase shifted full-bridge PWM converter (PSFBC) has been used as the most popular topology for many applications. But, for the reasons of the cost and performance, the control circuits for the PSFBC have generally been implemented using analog circuits. The studies on the digital control of the PSFBC were recently presented. However, they considered only the digital implementation of the analog controller. This paper presents the modeling and design of the digital controller for the PSFBC in the discrete time domain. The discretized PSFBC model is first derived considering the sampling effect. Based on this model, the digital controller is directly designed in discrete time domain. The simulation and experimental results are provided to verify the proposed modeling and controller design.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.90-91
• /
• 2017

본 논문은 전략광물 탐사를 위한 25kW급 양극성 펄스전원장치에 대하여 기술한다. 고효율 LCC 공진형 컨버터를 적용한 DC/DC 전력변환 회로부와 펄스를 발생시키기 위한 풀 브릿지 기반의 양방향 펄스 스위칭부로 구성된 500V, 12.5A 단위모듈을 설계하고, 4개의 모듈을 직병렬 구성하여 탐사 방식에 따라 요구되는 고전압 저전류(2kV, 12.5A) 혹은 저전압 대전류(500V, 50A) 동작이 가능한 전략광물 탐사용 펄스전원장치를 개발한다. 본 논문에서는 공진회로, 변압기 등 단위모듈의 상세설계에 대하여 기술하고, 시뮬레이션 및 실험 결과를 통해 이를 검증한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.3
• /
• pp.179-184
• /
• 2019

In many countries, such as developing countries where electricity is scarce, small wind turbines in the form of Off Grid are an effective solution to solve power supply problems. In some countries, the expansion of power systems and the decline of electricity-intensive areas have led to the use of small wind power in urban road lighting, mobile communications base stations, aquaculture and seawater desalination. With this change, the size of the small wind power industry is expected to have greater potential than large-scale wind power. In the case of small wind power generators, the generator is controlled at a variable speed, and the voltage and current generated by the generator have many harmonic components. To solve this problem, the AC to DC converter to be studied in this paper is a three-phase step-up type converter with a single switch. The inductor current is controlled in discontinuous mode, and has a characteristic of having a unit power factor by eliminating the harmonic of the input current. The proposed converter is composed of LCL filter and three phase rectification boost converter at the input stage and a single phase full bridge for grid connection. It is a control system with energy storage system(ESS) that the system stabilization can be pursued against the electric power.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.1
• /
• pp.30-40
• /
• 2002

This paper studies the electronic ballast development for 250w MH lamps. We have improved the input power factor using a PFC IC. To provide the rating voltage required In the lamps, we have used the buck type dc-dc converter By this method, the stress of switching devices in inverter can be reduced. The inverter is the Full-Bridge type. To eliminate the acoustic resonance phenomena of MH lamps, we have added the high frequency sinewave voltage to the low frequency square-wave voltage to the lamp. We hove developed the igniter circuit using the L, C devices. We could control dimming of the lamp by varying the output voltage of the buck converter. The time of illuminating lamps and luminous intensity could be adjusted by season and time band. The buck converter output voltage can be controlled and the no load and over current situation were Protected by the development of the microprocessor Program.