• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.856-866
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• 2021

The increasing international awareness regarding air pollutant reduction has resulted in increasing demand for eco-friendly ships; hence, electric ships are being actively developed by various countries. Presently, studies on electric ships are mainly focused on electric propulsion systems and electric motors. However, from the ship perspective, there are no studies on conceptual designs for coastal car ferries powered by removable power supply systems. In the present study, the main research consideration is regarding the conceptual design of a fully electrified car ferry using a battery-based removable system as the main power source. By analyzing the dimensions of more than 100 domestic coastal car ferries, the main criteria satisfying the requirements for developing a suitable vessel were derived, and a study on intact/damage stability was conducted considering the application of a removable battery truck. Further analyses of the problems concerning the conceptual design were also performed to derive solutions.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.437-442
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• 2009

In the case of a Linear Induction Motor (LIM), numerical analysis method like Finite Element Method (FEM) has been mainly used to analyze the travelling magnetic field problem which includes the velocity-induced electromotive force. If the problem including the velocity-induced electromotive force is analyzed by FEM using the Galerkin method, the solution can be oscillated according to the Peclet Number, which is determined by conductivity, permeability, moving velocity and size of mesh. Consequently, the accuracy of the solution can be low and the vortexes of flux can be occurred at the secondary back-iron. These vortexes of the flux occurred at the secondary back-iron does not exist physically, but it can be occurred in the analysis. In this case, the vortexes of the flux can be generally removed by using Up-Wind method which is impossible to apply a conventional S/W tool (Maxwell 2D). Therefore, in this paper, authors examined the vortexes of the flux occurred at the secondary back-iron of the LIM according to variations of the Peclet Number, and analyzed whether these vortexes of the flux affect on the dynamic force characteristics of the LIM or not.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1103-1104
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• 2011

This paper presents 1kW BLDC motor drive system and magnetic coupler for water thrust in ROV. In order to get a high performance and reliability, some design flow is proposed in this paper. The proposed system is verified by the experimental tests.

• The Magazine for Energy Service Companies
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• s.11
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• pp.26-29
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• 2001

비티아이가 ''실적''보다는 ''실속'' 우선의 ESCO사업 추진에 힘입어 연일 성장일로를 달리고 있다. 1970년 시계 제조사업으로 출발한 이 회사가 에너지사업에 뛰어든 것은 지난 98년. 소재옥 본부장이 직접 개발한 모터절전기가 전동기의 정격용량과 회전수를 그대로 유지하면서 전기사용량은 $10\%$ 감소하고 모터의 수명은 연장해주는 효과를 발휘함에 따라 주목받기 시작했다. 모터절전기와 조명절전기를 중심으로 한 내실있는 ESCO사업이 요즘 더욱 그 진가를 발휘하는 듯하다.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.55-58
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• 1995

An optimum design method of electric machines using neural network is presented. In this method, two multi - layer perceptrons of analysis and design neural network are used in optimizing process. A preliminary model of linear induction motor for subway is designed by the electric and magnetic loading distribution method and then optimized by presented method.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1296-1302
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• 2008

This paper deals with modeling and dynamic characteristic analysis of a large-powered LNG electric ship propulsion system. Basically, we perform to verify the adequacy of system modeling on the sea going mode and LNG unloading mode based on load flow analysis. And then, we observe the dynamic characteristic of system to perform motor starting analysis and transient stability analysis. Particularly, this paper examine analysis results in comparison with the IEEE standard 141 and the class rule. Hence, this paper has evaluated stability of the electric ship propulsion system at static and dynamic conditions.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.18-23
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• 2005

Ships have been propelled and maneuvered by electrical drives since trle late seventies. Recently, rare earth PMs allow the design of brushless motors with very high efficiency over a wide speed range. This is the most important factor in ship propulsion technology. Several types PM motors have been developing for ship propulsion system. However these have disadvantage such as cogging torque. It causes an undesired effect that contributes to output ripple, vibration, and noise of machine. Therefore several techniques may be adopted in designing PM motor in order to reduce the cogging torque. This paper describes cogging torque receding methods such as adjusting arigap length, magnet arc, and magnet thickness. That are analysed by using the finite element method(FEM) and the maxwell stress tensor method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.914-921
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• 2022

The International Maritime Organization (IMO) has set a goal of reducing ship's carbon dioxide emissions by 70% and greenhouse gas emissions by 50% by 2050 compared to 2008. Shipowners and shipyards are promoting various R&D activities such as LNG propulsion, ammonia propulsion, electric propulsion, CO₂ capture, and shaft generators as a way to satisfy this problem. The dual shaft generator has the advantage that it can be directly applied to an existing ship through remodeling. In this paper, the total fuel reduction rate that can be obtained by applying the shaft generator to the existing ship was verified through simulation. For this purpose, the size of the medium-sized ship was defined, and the governor, diesel engine, propeller, torque switch, generator for shaft generator, propulsion motor for shaft generator, and ship model were modeled and simulated.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.868-876
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• 2014

Arleigh Burke(DDG-51) and Sejong warship are AEGIS destroyer of US Navy and Korea Navy. These are designed to make more than 30knots by applying a COGAG(COmbined Gas turbine And Gas turbine) system. However, the gas turbine(LM2500) in this system has a low SFC (Specific Fuel Consumption) when the warship operated low speed. So, many kinds of companies are researching the HED(Hybrid Electric Drive) system to improve this problem. The purpose of this paper is to analyze the HED system and simulate by Sejong warship data. Serveral methods were used for that purpose. More specifically, the equipment modeling are employed for regression analysis by LabVIEW. As a result, it was found that the warship installed HED system could cut their fuel bills by as much as about 80,000,000won per year.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.6
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• pp.483-490
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• 2007

The aim of the paper is to analysis on train propulsion system and to study for energy saving. For this study, we make the program that simulate actual operation of the train route. The train running simulation is performed from starting station to 4th station by using the route datas of Deajeon Metro Subway. The study for control method of electrical motor and energy recovery to save energy is selected. The train propulsion system is constituted as a M-G Set, which is realized via Space Vector Modulation(SVM) - Direct Torque Control(DTC), the energy consumption during train operation and energy recovery during breaking is simulated by Simplorer program, from this result, the energy consumption and recovery of train with SVM-DTC is studied.