• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1440-1443
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• 2004

In this paper, to assess and enhance the reliability of Korea High Speed Train, auxiliary power is selected and reliability analysis is carried out. The auxiliary power system is classified into subsystems and functional analysis is conducted. Reliability block diagrams are drawn. and reliability parametric analysis is performed. Analysis results show that the reliability of auxiliary power system depends on critical items. To grow the system reliability, activities have been concentrated on improvement of critical items and the results were successful.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1501-1505
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• 1999

Highly Integrated Total Energy System for system operational planning and analysis is a totally integrated computerized system for various parts of power system operation planning and power system analysis. It is developed by KEPCO for about 8 years, named HITES. Nowadays restructuring, deregulation, privatization and competition of electricity market is introduced in the world. This paper describes HITES application for two typical models of a competitive electricity market.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.151-162
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• 2022

This study was conducted to develop a rail-type boom sprayer, performing safe spraying with improved ergonomic postures during pesticide spraying of agro-photovoltaic power system. The sprayer was designed to reduce labor cost and to be safe from pesticide exposure, and was analyzed through a comparison with a conventional spray method. The rail-type boom sprayer, consisted of a self-propelled spray and hose winder, hose, and boom sprayer parts, was designed to automatically pull and spray in the vertical and horizontal directions. The performance of the sprayer for an agro-photovoltaic power system was appropriate. From the analysis of postures with the Ovako Working posture Analysis System (OWAS), Rapid Entire Body Assessment (REBA), and Rapid Upper Limb Assessment (RULA) methods, the musculoskeletal risk factors to the body using the rail-type boom sprayer were less than those with the conventional power sprayer. In addition, the possibility of pesticide poisoning was reduced compared to the conventional power sprayer. The working capacity with the rail-type boom sprayer was more than five times greater, compared with the conventional power sprayer. After performing pesticide spraying with the rail-type boom sprayer, the labor cost was reduced to 42,750 won·yr^-1, which was 90% (402,750 won·yr^-1) less than the cost with the use of a conventional power sprayer (445,500 won·yr^-1).

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.101-108
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• 2012

The purpose of this study is to establish a design method of tower service lift for offshore wind power system, as well as to conduct structure analysis of the service lift system. The service lift system will be built in the internal area of tower of the offshore wind power system. Design and structure analysis for the tower service lift system are conducted to clarify the stability and reliability of the system. Main objective of the design is to secure sufficient capability of transportation of workers and equipment with satisfactory performance within the designed tolerance limit. Total deformation and equivalent stress of the lift system by external load are examined using the results of structure analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1703-1707
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• 2008

Low frequency oscillation of inter-area system is important problem in power system areas because the operation conditions of power system depend on it. Generally, the analysis of the problem is used by small signal stability. Especially, the analysis results are affected by decision of load models. In this paper, the effect of the analysis results was studied according to load component characteristics. ZIP model, popular in large-scaled power system analysis, was used as the load model. Many cases were studied according to the combination of ZIP model in inter-area system.

• Journal of Power System Engineering
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• v.19 no.5
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• pp.67-72
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• 2015

The reliable operation of onsite emergency diesel generator(EDG) should be ensured by a conditioning monitoring system designed to maintain, monitor and forecast the reliability level of diesel generator. The purpose of this paper is to develop condition diagnosis algorithm(logic) and analysis program of engine for the accurate diagnosis in actual condition of emergency diesel generator engine. As a result of this study, we confirmed that developed engine condition diagnosis algorithm and analysis program could be efficiently applied for actual EDG engine in nuclear power plant.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.45-52
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• 2007

Electric power is an important element in any modern economy. The availability of a reliable power supply at a reasonable cost is important for the economic growth and development of a country. Electric power utilities throughout the world therefore strive to meet customer demands economically with high quality and reliability. As the power industry moves towards open competition, therefore, there has been a call for a methodology by which to evaluate power system reliability through the use of customer interruption characteristics. This paper presents the results of an investigation and analysis of interruption characteristics of an industrial customer in Korea. This study used a direct visit survey to determine the investigation and analysis of electric service quality and the characteristics of industrial customers in Korea. A customer survey conducted throughout Korea via personal interviews of 660 sample customers is presented here. Variation according to characteristics of interruption such as duration, time of day, frequency and day of interruption was also investigated

• Journal of Power Electronics
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• v.10 no.4
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• pp.335-341
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• 2010

In this paper, an interleaved soft switching boost converter for a Photovoltaic Power Conditioning System (PV-PCS) with high efficiency is proposed. In order to raise the efficiency of the proposed converter, a 2-phase interleaved boost converter integrated with soft switching cells is used. All of the switching devices in the proposed converter achieve zero current switching (ZCS) or zero voltage switching (ZVS). Thus, the proposed circuit has a high efficiency characteristic due to low switching losses. To analyze the power losses of the proposed converter, two experimental sets have been built. One consists of normal devices (MOSFETs, Fast Recovery (FR) diodes) and the other consists of advanced power devices (CoolMOSs, SiC-Schottky Barrier Diodes (SBDs)). To verify the validity of the proposed topology, theoretical analysis and experimental results are presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.45-53
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• 1998

This paper describes the development of educational and training package with Integrated graphic environment for power system analysis '||'&'||' operation. This package runs on a personal computer with interactive scheme and includes a graphic editor for modeling of power system, a database system, the various graphic illustration '||'&'||' animation modules to represent the simulation results, and the application module of the power system analysis '||'&'||' operation. The proposed package is tested on a sample system, the package will be useful for the education and training of power system analysis and operation.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.271-281
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• 2013

In order to improve the performance of analysis, it is important to consider the nonlinearity in power system. The Carleman embedding technique (linearization procedure) provides an effective approach in reduction of nonlinear systems. In the approach, a group of differential equations in which the state variables are formed by the original state variables and the vector monomials one can build with products of positive integer powers of them, is constructed. In traditional Carleman linearization technique, the tensor matrix is truncated to form a square matrix, and then regular linear system theory is used to solve the truncated system directly. However, it is found that part of nonlinear information is neglected when truncating the Carleman model. This paper proposes a new approach to solve the problem, by combining the Poincar$\acute{e}$ transformation with the Carleman linearization. Case studies are presented to verify the proposed method. Modal analysis shows that, with traditional Carleman linearization, the calculated contribution factors are not symmetrical, while such problems are avoided in the improved approach.