• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.12
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• pp.491-497
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• 1985

An applicaton of the linear optimal control theory to the problem or load follow control in pressurized water reactors (PWR) is investigated. In order to perform the steady-state and load follow operation in PWR, a nonlinear model for the reactor and steam generator is derived and linearized at 50% rated power. Simulation tests are performed for 10% demanded load. Comparing the dynamic response of the newly developed optimal load follow controller with those of the integral error feedback controller proposed by Yang, the rise time of dynamic response of the former is about 15 seconds faster than those of the latter, thus the results indicate that the fast response of the optimal load follow controller is verified. The results of this work are directly applicable to the design of the load follow control systems for commercially operated PWRs.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.198-200
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• 1987

This paper presents the choice of appropriate sets of input variables for large-scale linear multivariable systems. It is shown that the selection of a good set of input variables for control may become important when both strong and weak input variables are available. The transmission of information from the inputs to the outputs is investigated and appropriate scaling procedures to derive a scaled input matrix are proposed. Singular value decomposition methods facilitate the quantification of the systems excitation stemming from the various input variables, and thus the selection of an appropriately strong and orthogonal set of input variables. The need for and the implementation and benefits of reducing the number of input variables are illustrated by a large-scale steam generator model of a real process.

• Proceedings of the KIEE Conference
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• summer
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• pp.947-949
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• 2004

철심형 영구 자석 선형 전기기기에서 디텐트력은 구조상 피할 수 없는 기기 특성이다. 본 연구에서와 같이 정격 외부 입력이 작은 경우, 디텐트력은 기기의 성능에 크게 영향을 미칠 수 있으며, 이를 저감할 수 있는 설계법이 필수적이다. 본 논문에서는 1kw급 왕복 구동 평판형 선형 영구자석 발전기의 치의 구조에 따른 역기전력과 디텐트력의 관계를 해석 하였다. 치의 구조에 따른 디텐트력의 변화를 해석적 방법을 통해 예측하고, 이를 기기 설계에 적용, 유한요소법을 이용해 실제 모델을 해석하였다. 치 구조의 변화는 디텐트력 외에 역기전력에도 영향을 주게 되는데 기기의 목표 성능을 만족할 수 있도록 설계안의 적절한 선택이 필요하다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.1
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• pp.12-18
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• 2003

Recently the research for utilization of waste heat produced from electric power plants, casting factories, heat treating factories or commercial building are being afforded by the need for energy saving. The objective of this study is to develop a thermoelectric generation system which converts unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper presents a thermoelectric technology on a optimum system design method and efficiency and cost effective thermoelectric element on order to extract the maximum power output from energy conversion of waste energy. It is shown that the longitudinal stresses of module contacted with two point constrained AI tubes could be released more than those with a one-point constrained.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1554-1555
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• 2006

We have studied the backward wave oscillator, a power pulsed generator oscillator at 20 GHz has higher frequency then current one. An absolute instability linear analysis was used for the purpose of designing the slow wave structure. A large diameter of the slow wave structure was adopted to prevent the breakdown brought about by the increase of power density.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.297-299
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• 2000

본 논문은 휴대용 기기 충전을 위한 영구 자석형 선형 발전기의 특성 해석을 담고 있다. 발생된 전력의 크기와 용량, 충방전 시간 측정을 포함하고 있으며, 전압 평활화에 따른 결과 역시 고려하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.5
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• pp.431-437
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• 2012

PV simulators are essential equipment for testing power conditioning systems (PCS) which are one of an important part in PV generator systems, for testing before shipment. High dynamic PV simulator is required since MPPT(Maximum Power Point Tracking) test procedure has been established by EN50530 regulation recently. Most high quality PV simulator prevailed in the market is linear type which however has low efficiency. This paper proposes design guide lines for the power stage and LCL type filter cooperating with a switching mode PV simulator that shows high efficiency and very low power consumption. Proposed theory is verified by experiment.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.184-186
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• 2008

리니어 발전기는 리니어 엔진의 시동에 필요한 연소조건을 만들기 위하여 전동기로 동작하다가 연소가 안정화되면 발전기로 동작을 하여 PCS(Power Conditioning System)를 통해서 전력을 계통으로 보내주게 된다. 리니어 엔진의 초기 시동을 하기 위하여 발전기는 운동주파수와 운동방향, 그리고 힘의 크기를 제어해야 하며, 발전 시에는 엔진의 동작에 맞도록 전력을 제어해야 한다. 이를 효율적으로 제어하기 위하여 MSC(Machine Side Converter)에서 상전류를 독립적으로 조절할 수 있는 H-bridge로 각 상을 구성하였다. LSI(Line Side Inverter)는 DC-Link 전압을 제어하여, MSC의 동력/발전 동작에 따라서 전력을 계통에서 받아오거나 전력을 계통으로 보내는 동작을 한다. 본 연구에서는 리니어 발전기 모델링를 통해서 PCS 제어 알고리즘을 확인하고 전체 시스템과 연동을 한 실제 운전특성에 대하여 살펴보았다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.524-525
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• 2014

In this paper, we propose algorithm plan variable for detection of DC arc. Changes of surrounding frequencies of harmonic wave is proposed to detect DC arc. To prove validity of these variables, we analyzed frequency based on the measured data and waveform of load current by performing the experiment which generates DC arc by using DC arc generator regulated in UL1699 was carried out.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.7
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• pp.1007-1013
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• 2012

Modeling of photovoltaic power systems is significant to analytically predict its dynamics in practical applications. This paper presents a novel modeling algorithm of such system by using probability and statistic theories. We first establish a linear model basically composed of Fourier parameter sets for mapping the input/output variable of photovoltaic systems. The proposed model includes solar irradiation and ambient temperature of photovoltaic modules as an input vector and the inverter power output is estimated sequentially. We deal with these measurements as random variables and derive a parameter learning algorithm of the model in terms of statistics. Our learning algorithm requires computation of an expectation and joint expectation against solar irradiation and ambient temperature, which are analytically solved from the integral calculus. For testing the proposed modeling algorithm, we utilize realistic measurement data sets obtained from the Seokwang Solar power plant in Youngcheon, Korea. We demonstrate reliability and superiority of the proposed photovoltaic system model by observing error signals between a practical system output and its estimation.