• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.541-548
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• 2012

On this paper, we proposed a design rule of charger monitoring system which allow us to watch the charging status and verify it for building the electric chargers infrastructure by spread of electric vehicle. Gathering the charging status of battery by proposed system makes us to enhance the charging algorithm, to interface with BMS(Battery Management System) of electric vehicle, to control the charging process with users. Because the technology of rapid charging is dependant upon various factors such as a performance and stability of battery. We proposed the monitoring system of rapid charger based on CAN protocol that can watch a working status of rapid charger including the charging status of battery with real time and can reduce the charging time of battery with optimized status. We also implement it and evaluate its performance.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.505-512
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• 2019

According to the "hydrogen economy roadmap" announced recently by the government, fuel cell electric vehicle diffusion and hydrogen refueling station construction are actively being carried out to prepare for the hydrogen economy era. The station will be expanded by introducing various charging station models such as hydrogen complex charging station, package, and mobile. Accordingly, the study on the safety demonstration of the charging station and related regulations should be compromised. The purpose of this study is to collect monitoring data during charging according to the distinct four seasons in Korea, and to use it as safety demonstration data by analyzing the charging status, charging rate and charging time during charging.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.434-441
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• 2003

This paper presents a generator for stand-alone vibration monitoring system of bridge structure based on ambient vibration of bridge. In this paper, a novel electric power generator which has minimum effect of armature reaction is proposed. The related mechanical and electrical design equations are obtained and a pilot generator has been implemented. In addition, the charging system for extremely low generator current is discussed, and some improvements are identified for the system. This investigation reveals that diode characteristics of rectifier is dominant factor in the charging process. Finally, both the simulation, which uses real measurement data of the Namhae bridge as input of the pilot generator, and indoor test are carried out. The results showed the applicability and effectiveness of the stand-alone vibration powered generator.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.8
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• pp.40-48
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• 2015

In this paper, battery charging and discharging circuit with a single voltage power supply is proposed. The proposed circuit has the separated current path and charging-monitoring sequence control scheme. In the charging sequence, the proposed 2-level comparator combined with control signal of the micro-processor can control the constant charging current to protect the over current of the battery. Furthermore, the proposed circuit uses a periodic main power switch control to detect the discharging characteristics to estimate the approximated battery life-time. In the experiments, the proposed emergency power supply for emergency call system has 89% efficiency with 98% power factor. And the proposed sequence control scheme is well operated in the designed emergency power system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.31-37
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• 2012

In this paper, we present a smart grid monitoring system connected with electric vehicle charging system using anti-islanding method. Electric vehicles can be charged through remote control of smart grid monitoring system and the charging process may be more stable and more efficient by wireless communication between the Local Area Module and End Modules. It is illustrated by some experiments that electric vehicle charging process may not be interrupted without any serious fault even though the islanding phenomena occurred in the grid if the presented monitoring system was applied to the smart grid system.

• Corrosion Science and Technology
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• v.16 no.4
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• pp.201-208
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• 2017

A finite element analysis is proposed to study the effect of specimen dimensions on lateral diffusion of hydrogen during hydrogen permeation flux measurements. The error of measurement on thick specimens because of 1D diffusion approximation may be as much as 70%. A critical condition for accurate measurements is to designate the area of hydrogen monitoring/exit surface smaller than the area of hydrogen charging/entry surface. For thin to medium thickness specimens (ratio of thickness to specimen radius of 5:10 and below), the charging surface should be maximized and the monitoring surface should be minimized. In case of relatively thick specimens (ratio of thickness to specimen radius above of 5:10), use of a hydrogen-diffusion barrier on the specimen boundaries is recommended. It would completely eliminate lateral losses of hydrogen, but cannot eliminate the deviation towards 2D diffusion near the side edges. In such a case, the charging surface should be maximized and the monitoring surface should be as closer in dimension as the charging surface. A regression analysis was carried out and an analytical relationship between the maximum measurement error and the specimen dimensions is proposed.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.75-79
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• 2008

To control the lead storage batteries it is necessary to consider the characteristics of each battery connected in series. In this study, the charging and discharging characteristics of sealed lead storage batteries 12V/1.2A was investigated one by one through experiments. The results of the experiment shows that one should consider the state of each battery to prevent overcharge or deep discharge. Also, we designed an equipment to measure battery voltages simultaneously using micro-controller. This equipment will be useful for monitoring batteries at PV generation system.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.205-214
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• 2013

In this paper, we analyzed the various EV charging-infra information(charging status, charging pattern, charging rate, charging fee, etc.) through the charging infra simulator which would be of help to effectively construct the EV charging infrastructure. The proposed simulator virtually made the EV motoring pattern referred to TMS(Traffic Monitoring System) & Ministry of Land, Transport and Maritime Affairs, and analyzed the charging-infra information(amount of charging, accumulated charging fee, etc.) based on vehicle types, charging type, time and days using EV charging-fee list noticed by KEPCO. Through this simulator, we deducted some considerable contents to build the EV charging infrastructure similarly with real environment.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.2
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• pp.247-253
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• 2015

The components of an aero-engine gas path cannot be monitored in a timely way due to a lack of real-time monitoring technologies. As an attempt to address this problem, we have conducted research on a condition monitoring technology based on the charging characteristics of particles in an aero-engine gas path, and emphatically analyze the formation of particles in an aero-engine gas path, the charging mechanism of carbon particles and the factors that influence the charge quantity and polarity. The verification experiments are performed on the simulated experiment platform and a turbo-shaft engine test bench. The results show the carbon particles' carry charge, and an obvious change in the total electrostatic charge level in the aero-engine gas path due to the increased carbon particles produced by burning or abnormal metal particles; the charge number is related to the size of particles, and the bigger carbon particles carry a negative charge and metal particles carry a positive charge; the change in engine power can lead to an obvious change in the level of electrostatic charge in the gas path, and the change in electrostatic charge results from the extra carbon particles formed in the rich-oil burning process. The research provides a reference for establishing the baseline of electrostatic charge while the engine runs on different power. The study also demonstrates the validity of the electrostatic monitoring technology and establishes a base for developing the application of electrostatic monitoring technology in aero-engines.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.85-92
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• 2003

This paper presents an electric power generating system for stand-alone health monitoring sensor unit of bridge structure based on ambient vibration of bridge. In this paper, a novel electric power generator which has minimum effect of armature reaction is proposed. The related mechanical and electrical design equations are obtained, and a pilot generator has been implemented. In addition, the charging system for extremely low generator current is discussed, and some improvements are identified for the system. This investigation reveals that diode characteristics of rectifier is dominant factor in the charging process. Finally, both the simulation, which uses real measurement data of the Namhae bridge as input of the pilot generator, and indoor test are carried out. The results showed the applicability and effectiveness of the stand-alone vibration powered generator.