• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.201-208
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• 2006

An alternative to the nuclear and fossil fuel power is renewable energy technologies (hydro, wind, solar and ocean), and the research about the highest efficiency machinery have been processed. The high-power LED is the representative one among those. In this paper, a high efficiency lighting system using a battery charged with solar or wind power is proposed for a high power LED. And a new efficient converter called 'Back-boost' is proposed. The validity of the lighting system scheme is verified by experimental results based on a laboratory prototype.

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.242-243
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.168-168
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• 2002

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.703-707
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• 2001

The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight increase the over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection. First, the problem of adding inductance of existing High-Speed and new Typower fuses in DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2089-2091
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• 2000

Pulsed power systems consist of a capacitor bank, an isolated high-voltage charging power-supply, high-current bus-work for charging and discharging and a control system. In such pulsed power systems, the operating-lifetime of the capacitors is closely dependent on the voltage reversal. Hence, most capacitor-discharging systems includes crowbar circuits. The crowbar circuit prevents the capacitor recharging with reverse voltage. Usually it consists of crowbar resistors and high pulse-current diode-stacks connected in series. The requirements for the diode-stacks are fast-recovery time and high-voltage and large-current ratings, which results in the high cost of the pulsed-power system. This paper presents a protection scheme of a charging and discharging system of a 500kJ capacitor bank using a low-cost crowbar circuit and safety-fuses.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.111-120
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• 2019

The output power of a crystalline silicon (c-Si) photovoltaic (PV) module is not directly the sum of the powers of its unit cells. There are several losses and gain mechanisms that reduce the total output power when solar cells are encapsulated into solar modules. Theses factors are getting high attention as the high cell efficiency achievement become more complex and expensive. More research works are involved to minimize the "cell-to-module" (CTM) loss. Our paper is aimed to focus on electrical losses due to interconnection and mismatch loss at PV modules. Research study shows that among all reasons of PV module failure 40.7% fails at interconnection. The mismatch loss in modern PV modules is very low (nearly 0.1%) but still lacks in the approach that determines all the contributing factors in mismatch loss. This review paper is related to study of interconnection loss technologies and key factors contributing to mismatch loss during module fabrication. Also, the improved interconnection technologies, understanding the approaches to mitigate the mismatch loss factors are precisely described here. This research study will give the approach of mitigating the loss and enable improvement in reliability of PV modules.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.184-191
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• 2015

As the power electronics system increases the frequency, the power loss and thermal management are paid more attention. This research presents a real time model of dissipation power with junction temperature response for 120kw IGBT inverter which is applied to the thermal management of high power IGBT inverter. Since the computational time is critical for real time simulation, look-up tables of IGBT module characteristic curve are implemented. The power loss from IGBT provides a clue to calculate the temperature of each module of IGBT. In this study, temperature of each layer in IGBT is predicted by lumped capacitance analysis of layers with convective heat transfer. The power loss and temperature of layers in IGBT is then communicated due to mutual dependence. In the dynamic model, PWM pulses are employed to calculation real time IGBT and diode power loss. Under Matlab/Simulink$^{(R)}$ environment, the dynamic model is validated with experiment. Results showed that the dynamic response of power loss is closely coupled with effective thermal management. The convective heat transfer is enough to achieve proper thermal management under guideline temperature.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.51-52
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• 2013

본 논문에서는 박막형 태양전지 및 LCD 제조공정에서 증착 공정 후 챔버 내부에 쌓이는 Si(실리콘)을 화학적으로 세정하기 위한 F(불소) RADICAL을 공급하는 원격 고밀도 플라즈마를 발생시키기 위한 고출력 Generator에 대해 소개하고자 한다. 개발되어진 Generator는 입력 직류전원을 공유하여 7kW급 단일 Power Amp Module의 상호결합 및 전력분담에 대한 편차 극복을 위한 기술과 고조파 저감비가 우수한 대전력 필터를 구현하였고, 크기 및 부피의 축소를 위하여 필터의 Q Factor의 극대화 기술이 적용되어졌다. 개발된 400kHz 30kW Generator는 NF3 60리터의 대용량 Remote Plasma Source의 리액터를 구동시킬 수 있으며, 38kW급 DC Link, 7kW급 Power Amp module, LC 필터, Controller로 구성되어 진다. 개발된 장치는 실제 플라즈마 공정에서 시험 평가한 결과를 통해 검증할 수 있었다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.287-288
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• 2010

The Induction Heating equipment is widely used for steel plate heating in the surface treatment process of steel industries. In the case of thin steel plate, for high efficiency We need the high frequency induction heating equipment more than 100kHz. But it is difficult to realize the high frequency and high power at the same time. That's why most high frequency equipment more than 100kHz has been imported from advanced Manufacturer. This paper will describe the development of 100kHz/5MVA inverter module for 100kHz/20MVA induction heating. We used the LCL resonance topology and ZVS/ZCS switching technology. And we also developed the low loss gate drive board and plate busbar inverter stack. We proved the performance by various experiment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.168-173
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• 2008

In this paper, we have designed transmit/receive Module for X band which can be applied to active phase array radar system. AESA(active electrically beam steered array) is able to transmit high power as like TWTA with composition of TH Module and steer a main beam faster than mechanically steering system. The proposed structure of T/R Module for X band is brick type for physical structure, common leg structure electrically and small size design as MCM(multi chip module). The results show that the characteristic of proposed T/R module can fully cover the specification of required military radar application.