• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.2
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• pp.114-126
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• 2013

In this paper, we present a set of methodologies to model the electromagnetic susceptibility (EMS) testing of I/O buffers for mobile system memory based on the bulk current injection (BCI) method. An efficient equivalent circuit model is developed for the current injection probe, line impedance stabilization network (LISN), printed circuit board (PCB), and package. The simulation results show good correlation with the measurements and thus, the work presented here will enable electromagnetic susceptibility analysis at the integrated circuit (IC) design stage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1114-1119
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• 2000

In this paper, a current comparative frequency automatic tuning circuit for the CMOS bandpass filter are designed with the new architecture. And also, when the designed circuit is compared the typical tuning circuit, it has very simple architecture that is composed of the current comparator and charge pump and operated in 2V power supply. The proposed tuning circuit automatically compensate the difference between the operating current of the integrator and the reference current which is specified. Using CMOS 0.25um parameter, a CMOS bandpass active filter with center frequency(fo=100MHz) is designed, and according to the transister size the variation of the center frequency is simulated. As the HSPICE simulation results, the tuning operating of the proposed current comparative frequency automatic tuning circuit is verified.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1709-1710
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• 2006

풍력발전은 친환경적인 에너지를 사용함에도 불구하고 그 에너지의 불안정성 때문에 실용화가 어렵다. 이를 극복하기 위해 효과적인 에너지 보상시스템이 필요하다. 본 논문에서는 유도기를 모티브로 해서 플라이휠을 등가 모델링 한다. 그 후 PSIM을 이용하여 풍력발전기의 지락사고를 설정하고, 플라이휠의 보상 유무에 따른 부하의 과도현상을 살펴 보고자한다. 시뮬레이션 결과로부터 안정된 전력보상시스템의 구현할 수 있었지만, 한편으로는 고조파의 영향이 관찰되었다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.119-121
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• 2003

전력계통에 대해 적용되고 있는 수많은 안정화 방안으로 발전기 탈락, 부하차단, 계통분리 등의 방법 중에서, 우리나라 계통에서의 과도안정도 문제에 대한 안정화 대책으로는 주로 발전기 탈락이 많이 적용되어 왔다. 본 논문은 이러한 발전기 탈락량에 관한 주제를 다루고 있다. 이러한 발전기 탈락을 적용하기 위해서 과도안정도 취약지점에 대해 KPX 보고서를 참조하여 상정사고 지점을 선정하고, 해당지역 계통에 대해 등면적법을 적용, 적정 발전기 탈락량을 계산하였다. 이러한 사전 연산형(offline) 형 발전기 탈락 외에도 온라인 상에서의 발전기 탈락량 계산방법과 그 문제점에 대해서도 고려하였다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.438-440
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• 2003

This paper resents an application of an Artificial Neural Network(ANN) technique to forecast the short-term system marginal price(SMP). The forecasting of SMP is a very important factor in an electricity market for the optimal biddings of market participants as well as for the market stabilization of regulatory bodies. The proposed neural network scheme is composed of three layers. In this process, input data are set up to reflect market conditions. And the $\lambda$ that is the coefficient of activation function is modified in order to give a proper signal to each neuron and improve the adaptability for a neural network. The reposed techniques are trained validated and tested with the historical real-world data from korea Power Exchange(KPX).

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.261-262
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• 2014

본 논문은 풍력 발전 출력 안정화 성능을 평가하기 위해서는 다양한 부하변동과 계통 사고에 대한 검증이 필수적이나, 실제로 다양한 조건에서 실증하기는 현실적으로 불가능하여, 본 논문에서는 축소형 시뮬레이터를 통하여 제안된 알고리즘 검증하고자 한다. 특히 전체구성의 적용을 위해 3상 농형 유도전동기를 통한 발전기의 출력을 유도하였으며 이를 위한 인버터를 사용하여 시뮬레이터를 구성하였고 지형별 특성에 맞는 데이터를 기반으로 풍력데이터를 입력하여 출력조건을 형성하였다. 또한 조상기와 덤프로드를 통해 부하의 출력변동분에 대한 계측과 분석에 초점을 맞추어 특성 계측이 가능하도록 구성할 수 있다.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.212-215
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• 1995

In this paper, The characteristic of Harmonic spectrum is studied for generally used three-phase diode rectifier. and filter design criteria is showen in the sense of THD, DPF, and PF. As the becoming of Automative and informative era, the demand of critical and stable control becomes more and more important. But much EMI emissions are generated for more critical and stable control in power electronic system these EMI emissions can be measured using LISN(Line Impedance Stabilization Network). So we are to investigate the behavior of Conducted EMI emission in Diode Rectifiers using LISN in frequency domain.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.1039-1042
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• 2008

Wireless sensor networks enable pervasive, ubiquitous, and seamless communication with the physical world. In this paper, we are concerned for clustering sensors into groups, so that sensors communicate information only to cluster heads and then the cluster heads communicate the aggregated information to the sink node, that the network can save energy. In this paper, we propose the algorithm for electing the cluster head and fuzzy registration of cluster head in a dynamic cluster wireless sensor networks. For making decision for clustering we will use fuzzy logic system. In simulation, we could achieve power regulation of total consumption and also the stabilization of the networks energy efficiency.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.4
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• pp.369-372
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• 2017

This paper presents a control scheme for three-level NPC inverters using small DC-link capacitors. To reduce the inverter system volume, the film capacitor with small capacitance is a promising candidate for the DC-link. When small capacitors are applied in a three level inverter, however, the AC ripple component increases in the DC-link NPV (neutral point voltage). In addition, the three-phase input grid currents are distorted when the DC-link capacitors are fed by diode rectifier. In this paper, the additional circuit is applied to compensate for small capacitor systems defect, and the offset voltage injection method is presented for the stabilization in NPV. These two proposed processes evidently ensure the quality improvement of the input grid currents and output load currents. The feasibility of the proposed method is verified by experimental results.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.2
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• pp.227-233
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• 2006

A free-piston hydrogen fueled engine is considered as one of the next power systems which is able to obtain high efficiency and low emission, simultaneously. In this study, in order to ensure the possibility as the next generation power system, the combustion characteristics and the performance of the free-piston hydrogen fueled engine are analyzed by using the linear RICEM for the change of injection pressure and equivalence ratio. As the results, in-cylinder maximum pressure is shown at injection pressure $P_{inj}$=6bar. Backfire phenomenon is not observed under experimental condition and knock occurs over ${\Phi}=0.8$. The thermal efficiency is the highest at injection pressure, $P_{inj}$=6bar and equivalence ratio, ${\Phi}=0.7$, respectively.