• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.3-4
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• 2006

본 논문에서는 계통의 불확실성을 고려한 확률론적인 방법으로 전력계통의 신뢰도를 평가한다. 발전기 3 state modeling 및 부하의 정규분포 곡선으로 확률론 신뢰도 평가 모델을 가정하였다. 그리하여 Adequacy 및 계통의 전압 및 송전선제약 조건 외에도, 소신호 안정도 항목을 추가하여 보다 동적인 측면에서의 신뢰도 평가가 이루어지도록 하였다. 이러한 평가 방법의 결과에 의하여 각 평가 항목간의 비율을 비교하였으며, 이를 통한 PSS의 설치 위치 선정의 근거를 마련하였다. 모의 방법은 Monte Carlo Simulation방법을 사용하였으며, WSCC 3기 9모선과 New England 10기 39모선을 모의계통으로 하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.182-188
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• 2006

An artificial neural network model for the microwave characteristics of an InGaAs/InP hemt for 70 nm gate length has been developed. The small-signal microwave parameters have been evaluated to determine the transconductance and drain-conductance. We have further investigated the frequency characteristics of the device. The neural network training have been done using the three layer architecture using Levenberg-Marqaurdt Backpropagation algorithm. The results have been compared with the experimental data, which shows a close agreement and the validity of our proposed model.

• Journal of Power Electronics
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• v.2 no.3
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• pp.212-219
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• 2002

A novel mode of parallel operation of a modular 3-phase AC-DC flyback converter for power factor correction along with tight regulation was recently analyzed and presented. The advantage of the proposed converter does not require expensive high voltage and high current devices that are normally needed in popular boost type 3-phase converter. In this paper tile detailed small signal analysis of the modular 3-phase AC-DC flyback converter is provided for control purpose and also experimental results are included to confirm the validity of the analysis.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.324-328
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• 2001

This paper presents parallel operation and control loop design of ZVT(Zero Voltage Transition) Full Bridge DC/DC Converter. At parallel operation of ZVT Full Bridge Converter, dynamic current shared inductor devides the same current of unit converter and ZVT circuit and aids to high efficiency in the system. Base on the modeling of ZVT. Full Bridge Converter, the control loop is designed using a simple two-pole, one-zero compensation circuit. To show the validity of the design procedures, the small signal analysis of the closed loop system and open loop system is carried out and the superiority of the dynamic characteristics is verified through the experiment with a 2kW, 50kHz prototype converter.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.334-335
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• 2018

본 논문에서는 스위칭 소자의 저항을 고려한 벅 컨버터의 소신호 모델링을 통해 회로를 등가화하고, 등가 모델의 동특성을 분석하였다. 또한 분석한 결과를 토대로 3P2Z(3Pole 2Zero) 제어기를 기반으로 한 전압 보상 제어기를 구현하였다. MATLAB을 이용하여 등가 모델을 바탕으로 설계한 제어기의 안정도를 판별 및 분석하였고, 최종적으로 PSIM을 사용한 시뮬레이션을 통해 분석한 결과가 타당함을 검증하였다.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.222-223
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• 2019

3-Level 부스터 컨버터는 기존의 부스터 컨버터에 비해 인덕터의 크기를 줄이고, 더 낮은 전류리플을 취할 수 있다는 장점이 있다. 그러나 스위치의 동작은 Duty가 0.5 이상과 이하일때에 따라 달라진다. 이에 본 토폴로지의 제어기를 설계하기 위해서는 Duty가 0.5 이상일때와 이하일때의 두가지 경우의 상태로 토폴로지를 분석한 뒤 소신호 모델링을 할 필요가 있다. 따라서 본 논문에서는 경우에 따라 두가지의 상태 평균화 방정식을 세우고, 이를 비교한뒤 소신호 모델링을 통해 제어기를 설계한다. 또한 상단과 하단 커패시터에서 생기는 전압 불균형을 개선하기 위해 Duty를 보상하여 전압 불평형을 개선하는 제어 방법을 제안한다. 제안된 컨트롤러는 PSIM 시뮬레이션을 통해 검증된다.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.119-121
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• 2003

In small signal stability analysis of power systems, eigenvalue analysis is the most useful method and the detailed modeling of generator gives an important effect to the eigenvalues. Generator full model is used for precise dynamic analysis of generators and controllers while two-axis model is used for multimachine systems because of the reduced order of the state matrix. Also, the eigenvalue sensitivity coefficients are used for optimization of controller parameters to improve system stability. This paper compare the first order eigenvalue sensitivity coefficients of controllers in case of generator full model with those of two-axis model. As a result of an example the estimated eigenvalues using sensitivity coefficients in case of generator full model is very close to those of state matrix within 1% error ratios.

• Journal of Power Electronics
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• v.16 no.1
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• pp.102-110
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• 2016

Contactless power transfer technology is gaining increasing attention in city transportation applications because of its high mobility and flexibility in charging and its commensurate power level with conductive power transfer method. In this study, an inductively coupled contactless charging system for a 48 V light electric vehicle is proposed. Although this study does not focus on system efficiency, the generic problems in an inductively coupled contactless power transfer system without ferromagnetic structure are discussed. An active load matching method is also proposed to control the power transfer on the receiving side through a load matching converter. Small signal modeling and linear control technology are applied to the load matching converter for port voltage regulation, which effectively controls the power flow into the load. A prototype is built, and experiments are conducted to reveal the intrinsic characteristics of a series-series resonant inductive power charger in terms of frequency, air gap length, power flow control, coil misalignment, and efficiency issues.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.218-222
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• 2002

Two existing continuous-time models for the current-mode control have presented noticeable differences in their small-signal predictions. As an attempt to clarify the origin of these disparities, this paper presents an alternative way of deriving a continuous-time model for the current-model control. The results of this paper would provide insights to comprehend the dissimilarity in the modeling method and final results of the earlier models of current-mode control.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.530-531
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• 2012

본 논문에서는 태양광 발전시스템에서 사용되는 벅 컨버터의 새로운 모델을 제시하고, 선형화하여 모델링하였다. 이 모델을 통하여 전류와 전압 제어기를 설계하고, 그 특성을 MATLAB과 PSIM으로 모의실험하여 검증하였다.