• Journal of the Korean Solar Energy Society
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• v.36 no.5
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• pp.19-30
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• 2016

In this study, realize voltage regulation $220Vac{\pm}10%$ or less, frequency fluctuation $60Hz{\pm}1%$ or less over the independent operation and grid-connected operation technologies for power stabilization relates to the ESS designed and manufactured in conjunction with solar installations and solar to compensate the output reduction due to the polarization of the solar module through the polarization prevention technology for preventing the optical module efficiency is lowered, in conjunction with the BMS inverter efficiency was more than 92%, more than 90% of the charging efficiency to the target. This study was designed in conjunction with the ESS solar power plants, grid-connected operation and independent operation, Peak-Cut, it can stabilize the grid via the Peak-Shifting operation

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.2
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• pp.131-136
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• 2015

We develop the 60 W class hybrid solar LED street lamp controller. The controller is providing power via an inverter in the day with the least solar cell and battery and charging the battery for the ESS, acts as a power failure, the built-in battery. Rated output of the fabricated LED street lamp is 300 W or greater battery capacity 300 Wh, discharge time 10 hr, LED street lamp efficiency showed a very high level of light efficiency by about 127 lm/W. In addition, as a result of light distribution pattern according to the distance and the light intensity measurement will be able to ensure a very high quality, show the constant brightness in the distance from the road lights 6 m is about 35~40 lux in uniformity ratio. The proposed hybrid solar LED street lamp system showed a high energy capacity of approximately 1.5 to 152.7% power generation efficiency than typical conventional solar street lamp.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.11-11
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• 2010

Recently, annual usage of energy is dramatically increasing by industrialization is going faster and more electricity is needed due to various electronic devices. This paper present relationships between the Vmax, $V_T$, load and time constant of solar cell charge and discharge curve. Charging and discharging recording where the external resistance will become larger Vmax, $V_T$ is decrease and the time increases and decreases there is a possibility of knowing.

• 한국전기화학회:학술대회논문집
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• 1999.11a
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• pp.137-146
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• 1999

The rechargeable alkaline manganese dioxide(RAM)battery system has reached a performance level that enables the consumer to utilize RAM for practically all applications where currently single use cells(alkaline manganese, zinc-carbon)are being used. In addition, it can replace nickel-cadmium and nickel-metal hydride cells in low to medium power applications with much improved charge retention at higher operating temperatures and in intermittent use and works well with solar charging. A review is given on RAM cell performance as well as a comparison to competing rechargeable technologies. Potential new possibilities in the field of OEM(original equipment manufacturer) applications are discussed.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.472-473
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• 2012

그린 에너지에 대한 연구가 활성화 되면서 태양광전지의 효율에 관한 연구가 많이 이루어 지고 있다. 그중 제일 중요한 주제는 태양광 전지 관련 MPPT 제어이다. 태양전지에서 MPPT 제어는 효율을 높이기 위해 꼭 필요하지만, MPPT 제어는 대부분 대형 태양전지에서 적용되고 구현비용이 높아 소형 태양전지에 적용하기 어렵다. 그러므로 소형 태양전지를 대상으로 간략화된 MPPT 제어를 적용하고 시뮬레이션과 실제 배터리 충전 시스템을 구성하여 그 타당성을 알아보았다.

• Fashion & Textile Research Journal
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• v.13 no.5
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• pp.806-814
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• 2011

A solar jacket, which utilizes solar energy for generating electricity, is an example of clothing developed by the fusion of multiple technologies; such fusion of technologies can lead to further developments in the clothing industry and other industries in general. Many research institutes and garment manufacturing companies in Europe and America are developing solar garments; various solar-based products manufactured using solar cells, photovoltaic batteries, etc. are being sold at high prices. The purpose of this study was to investigate the development status of solar garments and their application for generating photovoltaic energy; the study also identified the type of design and upper body clothing preferred by Korean in their early 20s. The survey participants were 188 university students aged between 20 and 25. The design of the proposed six types of solar clothing was evaluated and rated; they were then ranked on the basis of the ratings. A survey on the management of solar garments was conducted, and ratings were assigned according to a 5-point Likert scale, with 5 indicating the strong affirmation. The survey results showed that among the six types of clothing, protective clothing (50%) and sportswear (22%) were more preferable than the others (working clothes (16%), casual clothes (3%), everyday wear(6%), and suits(1%)). Among the six proposed designs, the jumper design (22%) and jean jacket design (21%) were preferred over the others (casual jacket (19%), casual jacket I (15%), classic suit (14%), and climbing jacket (9%)). Factorial analysis of the management of solar garments revealed that the most important factors were the properties of the solar cell and time required for battery charging, and the second important factors were clothing weight and comfort.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1925_1926
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• 2009

This paper describes a novel power management circuitry for reducing the sleeping mode power dissipation. Based on the proposed power management circuitry, the sensor module can be activated by RF wake-up signal, perform designated process and deactivate itself. There is absolutely no power dissipation at the sleeping mode which takes almost time of the operation. The temperature sensor module using solar cell as energy source has been fabricated and tested. Experimental results show that the sensor module with 3300 ${\mu}$F for storage capacitor can transmits RF temperature data to a receiver at a distance of 20 m every 15 second in a normal indoor light condition and keep the capacitor voltage over 9 V. And the sensor module can operate 100 times with a single charging, that means it is possible for the sensor module to transmit every 5 minute for 8 hours without light or any other power input during the night time.

• Journal of Sensor Science and Technology
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• v.21 no.5
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• pp.379-384
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• 2012

This paper presents the power source of wireless sensor node (WSN) using supercapacitors and a solar cell. Supercapacitors have high lifetime cycling compared to that of batteries. Supercapacitors are connected in series to achieve higher voltage and a voltage balancing circuit is required to ensure that no individual cell goes overvoltage. We employ an active balancing circuit that draws minimal current by using transistors. A diode is connected in series with each supercapacitor. A new balancing circuit that equalize the cells-voltage reduces energy consumption of supercapacitors. Voltage of operating WSN is applied 2.2-3.3V by DC/DC converter and supercapacitor voltage 2.2-5.1V. Maximum operating time of wireless sensor node is about 16 hours in full charging.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.222-228
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• 2012

This paper presents a design and simulation of bi-directional DC/DC boost converter for a fuel cell system. In this paper, we analyze the equivalent model of both a boost converter and a buck converter. Also we propose the controller of bi-directional DC-DC converter, which has buck mode of charging a capacitor and boost mode of discharging a capacitor. In order to design a controller, we draw bode plots of the control-to-output transfer function using specific parameters and incorporate 3pole-2zero compensator in a closed loop. As a result, it has increased PM(Phase Margin) for better dynamic performance. The proposed bi-directional DC-DC converter's 3pole-2zero compensation method has been verified with computer simulation and simulation results obtained demonstrates the validity of the proposed control scheme.

• Journal of the Korean Solar Energy Society
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• v.32 no.spc3
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• pp.289-294
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• 2012

In recent years, understanding the dynamics of DC distribution system has become critically important due mainly to the increasing needs for the interconnection of DC distributed generators and the (DC-based) electric vehicle (EV) charging systems. In this paper, the characteristics of the DC grid system connected to the compact proton exchange membrane fuel cell (PEMFC) has been studied. In particular, the voltage and current transient phenomena were measured by varying the load of the DC grid system. Also, the voltage and current ripple were measured at the different load conditions. Our experimental results clearly manifested that the study contributes to the establishment of fundamental method to characterize the small DC grid system including distributed generation.