• Nuclear Engineering and Technology
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• v.36 no.5
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• pp.430-449
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• 2004

A quantitative model for a control system that integrates human operators, systems, and their interactions is developed based on discrete functions. After identifying the major entities and the key factors that are important to each entity in the control system, a quantitative analysis to estimate the recovery failure probability from an abnormal state is performed. A numerical analysis based on assumed values of related variables shows that this model produces reasonable results. The concept of 'relative sensitivity' is introduced to identify the major factors affecting the reliability of the control system. The analysis shows that the hardware factor and the design factor of the instrumentation system have the highest relative sensitivities in this model. T도 probability of human operators performing incorrect actions, along with factors related to human operators, are also found to have high relative sensitivities. This model is applied to an analysis of the TMI-2 nuclear power plant accident and systematically explains how the accident took place.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.85-87
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• 2000

In real-time power system control, it is essential to measure the power system variables which are voltage. current, real and reactive power, power factor, system frequency and etc. this variables can be estimated or calculated by the synchronized phasor informations of voltage and current. Therefore, the synchronized phasor measurement of voltage and current is very important to real-time power system control. So, we develop SPMD(Synchronized Phasor Measurement Device) for synchronized phasor measurement of voltage and current. In this paper, we present the design and implementation of SPMD for real-time phasor measurement and prove its performance by the test results.

• Archives of design research
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• v.12 no.3
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• pp.29-40
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• 1999

Walter Gropius, famous architect of Bauhaus, once treated of pure mind which was revealed in the system of object and its phenomena through sense of sight while examining material being and illusive being. And Thomas Aquinas said that man can have a creative power only with modest mental state void of prejudice saying that he expected God to come to him after his soul went out of him. The same thing was said by so many great philosophers and thinkers other than him. I think his saying, "God comes after Soul's escape from the body for a new creation", has a real truth for all times and places and beauty itself beyond expression. Why\ulcorner The reason why the saying is so true is because it has a Yin and Yang Idea, that is, the Soul means a dark spirit correspondent to Yin between both oriental ideas and God does a bright spirit correspondent to Yang between them. By reason of this idea, I would like to assert that we should take it granted that we stand in need of the same bright Yang's spirit as God has for the new creation, and let the Yang's bright spirit come to our minds. We can call it divine 'Providence', or call it God's guidance, which we cannot help accepting as a man's fatality. As God was pleased after he made man and all the creatures by dint of his design, so man was pleased after he made everything he needed by the same design that he accepted from God. In spite of pleasure of different dimensions from what God and Man has each other, their way of empathies were all the same. In this paper I compared a worldly lower conception by which man designed his products for his sensuous satisfaction with a higher conception by which God designed his creatures for his mental satisfaction. I intended to infer what destined relation there must be between both God's and man's creations, trying to remind designers that they have to confess to have not so divine a providence as God has for creation because I think the real truth is that they had regarded their works of product design as a routine occurrence for their physical convenience in the industrial plans.ial plans.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.487-490
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• 2002

Wind farm paralleled with electric power network can supply the power into a power network not only the normal conditions, but also the fault conditions of distribution network. If the fault happened in the power line with wind farm, the fault current level measured in a relaying point might be lower than that of distribution network without wind turbine generator. Consequently, it is difficult to detect the fault happened in the distribution network connected with wind generator. This paper describes the influence of wind turbine generator on the protective relaying system for detecting the fault occurred in a power line network. Simulation results shows that the fault current depends on the fault impedance, location, and the capacity of wind farm and distribution network load.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.83-85
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• 1999

Recently, a rapid increase of electricity demands have made Transmission & Substation device large-sized. complicated and diverse. Moreover, a rising level of customer's requirement and high growth of industry increase the reliability of electricity service. Therefore on the basis of the case study on the occurrence of fault, the prevention of defects for each device and the analyzing of the outbreak and prevention of systematic breakdown in Sin-Incheon Power Transmission Branch Office, this paper presents some important matters and suggests the method of improvement in design, construction, maintenance, and repairing the Transmission & Substation device.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.4
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• pp.249-256
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• 2009

As a wireless handset deals with multiple application standards concurrently, RF transmitters and power amplifiers are required to be more power efficient and reconfigurable. In this paper, we review the recent advances in the design of the power amplifiers and transmitters. Then, the systematic design approaches to improve the performance with the digital baseband signal processing are introduced for the next generation mobile handset.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.741-743
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• 2004

In this paper, we describe a Control Element Drive Mechanism(CEDM) operation test using a Power Controller. By testing, we can catch the mechanical and electrical characteristics of CEDM and obtain the information about the improvement of CEDM and the design of CEDM power cabinet. The power controller for CEDM introduced in this paper can input firing angles directly into gate drive circuits of thyristors so that this method can be used to derive the maximum and minimum values of firing angles within available limits for a 3-phase half-wave rectifier. Angle inputs help us understand each coil's response characteristics. Since this power controller generates a serial sequence for CEDM insertion and withdrawal operations, we may judge whether CEDM works correctly as expected or not in each phase of a step movement.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.160-161
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• 2011

우리나라는 냉방부하로 인해 여름철에 연중 전력소모량이 크게 증가한다. 이로 인해 전력설비의 여유도가 낮아져 전력계통의 취약성이 높아진다. 전기사업자는 송 변전설비 신설 및 보강, 발전설비 조기 준공을 통해 최대전력 발생에 대비한 준비를 한다. 전력거래소는 여름철을 기준으로 신규로 운영되는 송 변전설비 및 발전설비를 고려하여 최적의 전력계통 운영방안을 수립한다. 이때 수립된 전력계통 구성은 겨울철 운영방안 수립 전까지 우리나라 전력계통의 기본 틀이 된다. 본 논문은 2011년도 여름철 최대전력 발생에 대비하여 수립한 전력계통의 최적 운영방안을 제시한다. 주로 전년도와 비교하여 올해의 계통변화 내용 및 상정고장 발생에 대비한 전압안정도 및 과부하 해소대책을 다루고 있다.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.74-76
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• 2008

The power expansion planning is large and capital intensive capacity planning. In the past the expansion planning was established with the proper supply reliability in order to minimize social cost. However, the planning not used cost minimizing objective function in the power markets with many market participants. This paper proposed the power expansion planning process in the power markets. This system is composed of Regulator and GENCO's model. Regulator model used multi-criteria decision making rule. GENCO model is very complex problem. Thus, this system transacted the part by several scenario assuming GENCO model.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.163-165
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• 2008

휴전검토는 계통의 안정적인 운영과 신뢰도에 직접적으로 영향을 줄 수 있어 매우 중요한 업무라할 수 있다. 본 논문에서는 이러한 휴전검토 업무를 체계적이고 효율적으로 수행할 수 있는 휴전검토 종합시스템의 역할을 간단히 소개하고, 구성요소 중 하나인 휴전 일정 관리 및 검토 프로그램 설계에 대해 설명하고자 한다.