• 전력전자학회논문지
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• 제4권2호
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• pp.111-121
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• 1999

대용량 IGBT를 위한 새로운 능동 게이트 구동회로를 제안한다. IGBT의 우수한 스위칭 성능을 성취하기 위해 필요한 여러 구동 조건들을 최적으로 조합시킨 게이트 구동 회로이다. 스위칭 노이즈와 스트레스를 감소시키기 위해 필요한 느린 구동 조건과 스위칭 속도를 증가시키고 손실을 저감시키기 위해 요구되는 고속 구동 조건들을 동시에 만족시키고 있다. 또한 작은 전류의 턴-온시 발생되는 진동현상을 효과적으로 감쇠시킬 수 있는 특성을 지니고 있다.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.632-642
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• 2017

This paper presents an improved approach towards reducing the switching loss of insulated gate bipolar transistors (IGBTs) for a medium-capacity-class power conditioning system (PCS). In order to improve the switching performance, the switching operation is analyzed, and based on this analysis, an improved switching method that reduces the switching time and switching loss is proposed. Compared to a conventional gate drive scheme, the switching loss, switching time, and delay are improved in the proposed gate driving method. The performance of the proposed gate driving method is verified through several experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.713-717
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• 2001

This paper focuses on a network model for GCTs which can be used to investigate high power circuits with or without using RC-snubbers. The series connection of GCTs is commonly applied in the high power inverter field. Here expensive and space-consuming snubbers are applied, to overcome the problem of an asymmetric distribution of the blocking voltage among the single GCTs. As an alternative to large snubbers, a new active gate drive concept is proposed and investigated by simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1966-1968
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• 1998

This paper describes a gate drive circuit for series connected IGBTs in high voltage applications. The proposed control criterion of the gate circuit is to actively limit the voltages during switching transients, while minimizing switching transient and losses. In order to achieve the control criterion, an analog closed loop control scheme is adopted. The performance of gate drive circuit is examined experimentally by the series connection of three IGBTs with conventional snubber circuits. The experimental results show the voltage balancing by an active control under wide variation in loads and imbalance conditions.

• 한국정보전자통신기술학회논문지
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• 제11권6호
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• pp.732-741
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• 2018

여러 배터리 셀을 직렬로 연결해서 사용하는 BMS에서 사용 가능 용량을 최대화시키기 위하여 각 셀의 전압을 같도록 맞춰주는 셀 밸런싱 기술이 필요하다. 다중 권선 변압기를 사용하는 능동 셀 밸런싱 회로에서 셀 간 직접적 (direct cell-to-cell)으로 에너지를 전달하는 밸런싱 회로는 PMOS 스위치와 NMOS 스위치를 구동하기 위한 게이트 구동 칩은 PMOS 스위치와 NMOS 스위치 개수 만큼 TLP2748 포토커플러(photocoupler)와 TLP2745 포토커플러가 필요하므로 원가가 증가하고 집적도가 떨어진다. 그래서 본 논문에서는 포토커플러를 사용하여 PMOS와 NMOS 스위칭소자를 구동하는 대신 70V BCD 공정기반의 PMOS 게이트 구동회로와 NMOS 게이트 구동회로, 스위칭 시간이 개선된 PMOS 게이트 구동회로와 NMOS 게이트 구동회로를 제안하였다. 스위칭 시간이 개선된 PMOS 게이트 구동 스위치의 ${\Delta}t$는 8.9ns이고, NMOS 게이트 구동 스위치의 ${\Delta}t$는 9.9ns로 양호한 결과를 얻었다.

• Journal of Electrical Engineering and information Science
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• 제3권3호
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• pp.366-372
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• 1998

A high efficiency interleaved active clamp forward converter with self driven synchronous rectifiers for a modular power processor is presented. To simplify the gate drive circuits, N-P MOSFETs coupled active clamp method is used. An efficiency about 90% for the load range of 50-100% is achieved. The details of design for the power stage and current mode control circuit are provided, and also some experimental results are given.

• Journal of Power Electronics
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• 제12권5호
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• pp.723-730
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• 2012

This paper presents a new ZVS single phase bridgeless (Power Factor Correction) PFC, using an active clamp to achieve zero-voltage-switching for all main switches and diodes. Since the presented PFC uses a bridgeless rectifier, most of the time, only two semiconductor components are in the main current path, instead of three in conventional single-switch configurations. This property significantly reduces the conduction losses,. Moreover, zero voltage switching removes switching loss of all main switches and diodes. Also, auxiliary switch turns on zero current condition. The presented converter needs just a simple non-isolated gate drive circuitry to drive all switches. The eight stages of each switching period and the design considerations and a control strategy are explained. Finally, the converter operation is verified by simulation and experimental results.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1466-1469
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• 2008

We have fabricated 2.5 inch QQCIF AM-OLED panel driven by ZnO-TFT on a plastic substrate for the first time. The number of photo mask for the whole panel process was 5 and the TFT structure was top gate with active protection layer as a first gate insulator. Optimizing the process for the substrate buffer layer, active layer, ZnO protection layer, and gate insulator was key factor to achieve the TFT performance enough to drive OLED. The ZnO TFT has mobility of $5.4\;cm^2/V.s$, turn on voltage of -6.8 V, sub-threshold swing of 0.39 V/decade, and on/off ratio of $1.7{\times}10^9$. Although whole process temperature is below $150^{\circ}C$ to be suitable for the plastic substrate, performance of ZnO TFT was comparable to that fabricated at higher temperature on the glass.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.23-28
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• 2008

In this paper, transient characteristics of the Punch Through Insulated Gate Bipolar Transistor (PT-IGBT) have been studied. On the contrary to Non-Punch Through Insulated Gate Bipolar Transistor(NPT-IGBT), it has a buffer layer and reduces switching power loss. It has a simple drive circuit controlled by the gate voltage of the MOSFET and low on-state resistance of the bipolar junction transistor. The transient characteristics of the PT-IGBT have been analyzed analytically. Excess minority carrier and charge distribution in active base region, the rate of anode voltage with time are expressed analytically by adding the influence of buffer layer. The experimental data is obtained from manufacturer. The theoretical predictions of the analysis have been compared with the experimental data obtained from the measurement of a device(600 V, 15 A) and show good agreement.

• Journal of Power Electronics
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• 제16권1호
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• pp.190-204
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• 2016

An active front end (AFE) is required for a three-phase induction motor (IM) fed by a voltage source inverter (VSI), because of the increasing need to derive quality current from the utility end without sacrificing the power factor (PF). This study investigates a proportional-plus-integral (PI) controller based AFE topology that uses a super-lift converter (SLC). The significance of the proposed SLC, which converts rectified AC supply to geometrically proceed ripple-free DC supply, is explained. Variations in several power quality parameters in the intended IM drive for 0% and 100% loading conditions are demonstrated. A simulation is conducted by using MATLAB/Simulink software, and a prototype is built with a field programmable gate array (FPGA) Spartan-6 processor. Simulation results are correlated with the experimental results obtained from a 0.5 HP IM drive prototype with speed feedback and a voltage/frequency (V/f) control strategy. The proposed AFE topology using SLC is suitable for three-phase IM drives, considering the supply end PF, the DC-link voltage and current, the total harmonic distortion (THD) in supply current, and the speed response of IM.