• Journal of the Korean Electrochemical Society
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• v.27 no.2
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• pp.55-72
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• 2024

Secondary batteries are used as an essential renewable energy source in our lives, such as electric vehicles and energy storage systems (ESS), as an alternative to fossil fuels due to global warming. However, cases of battery fires and explosions have been reported due to thermal runaway in secondary batteries due to various causes such as overdischarge, high-speed charging and discharging, and external short circuit, and great efforts are being made to find solutions suitable for each cause. In particular, as cases presumed to be caused by the overcharging process have been reported, this review will examine the chemical reactions of secondary batteries that can occur during the overcharging process and discuss risk investigation methods to check and prevent them.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6053-6059
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• 2013

Heat pumps have attracted considerable attention as a green energy system because they use renewable energy, such as geothermal, solar energy and waste heat, and can have a low electricity consumption rate compared to other conventional electric heating system. Many studies of high efficient heat pump system design was performed previously,but it is not easy to find any an analytical model that consists of components (e.g. compressor, heat exchangers, and expansion valve), not only having an interrelation and interconnection each other but also being flexible to any change in geometry and operating parameters. In this study, a computational model was developed for a heat pump with warm air as a heat source using the one-dimensional modeling software, AMESim. In combination with an independently-developed analytical model for a scroll compressor, the heat pump model can simulate the physical characteristics and actual behavior of the heat pump precisely. In addition, the reliability of the model was improved by verifying the simulation results using experimental data. The simulation data fell into the 10% error range compared with the experimental data. The heat pump model can be used for system optimization studies of product development and applied to other applications in a range of industrial field.

• Journal of IKEEE
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• v.19 no.3
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• pp.295-303
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• 2015

Considering to Energy Storage System (ESS) is a global trend In order to reduce global warming and carbon emissions. South Korea has announced various policies to vitalize the development and uptake of renewable energy. South Korea is planning the cumulative capacity of ESS of two million kW in 2020. According to the government support and development of technology companies, the battery of ESS prices are expected to fall gradually. In this paper, we develop a planning model that take into account the supply expansion of technology of ESS and prices. Based on planning model, we analyze the cost of ESS linked with wind power and the revenue for trading electricity and renewable energy certifications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3327-3333
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• 2011

The interest on the recovery of thermal energy using the industrial waste has been rising to solve the problems of continuous increase of waste generation and the depletion of the fossil fuel recently. To recovery from the waste among the new recyclable energies has been proved as the most favorable when the potential value of energy source is compared. The RDF made from the industrial waste has been approved as the most economical method. This research has analyzed the heavy metal components containing in the industrial waste. The concentration of Cl and S in the industrial waste generated in C-industrial complex are slightly high than that of the B- and A-industrial complex. The main components generated from A-industrial complex, B-industrial complex, and C-industrial complex are alumina-silicates, calcium alumina silicates, and the mixture of lime and calcium alumina silicate. These results could be used to reveal the origin of inorganic components in industrial waste and utilized as a basic data to improve the performance of the RDF as fuel.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.243-248
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• 2022

As the scope of use of portable and wearable electronic devices is expanding, the limitations of heavy and bulky solid-state batteries are being revealed. Given that, it is urgent to develop a small energy harvesting device that can partially share the role of a battery and the utilization of energy sources that are thrown away in daily life is becoming more important. Contact electrification, which generates electricity based on the coupling of the triboelectric effect and electrical induction when the two material surfaces are in contact and separated, can effectively harvest the physical and mechanical energy sources existing in the surrounding environment without going through a complicated intermediate process. Recently, the interest in the harvest and utilization of wind energy is growing since the wind is an infinitely ecofriendly energy source among the various environmental energy sources that exist in human surroundings. In this study, the optimization of the energy harvesting device for the effective harvest of wind energy based on the contact electrification was analyzed and then, the utilization strategy to maximize the utilization of the generated electricity was investigated. Natural wind based Fluttering TENG (NF-TENG) using fluttering film was developed, and design optimization was conducted. Moreover, the safe high voltage generation system was developed and a plan for application in the field requiring high voltage was proposed by highlighting the unique characteristics of TENG that generates low current and high voltage. In this respect, the result of this study demonstrates that a portable energy harvesting device based on the contact electrification shows great potential as a strategy to harvest wind energy thrown away in daily life and use it widely in fields requiring high voltage.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.353-360
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• 2016

Recently, solar photovoltaic(PV) power generation which generates electrical power from solar panels composed of multiple solar cells, showed the most prominent growth in the renewable energy sector worldwide. However, in spite of increased demand and need for a photovoltaic power generation, it is difficult to early detect defects of solar panels and equipments due to wide and irregular distribution of power generation. In this paper, we choose an optimal machine learning algorithm for estimating the generation amount of solar power by considering several panel information and climate information and develop a defect detection system by using the chosen algorithm generation. Also we apply the algorithm to a domestic solar photovoltaic power plant as a case study.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.881-884
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• 2009

태양열을 이용한 발전은 신재생에너지 사업으로 현재 각광을 받고 있는 분야 중의 하나이다. 본 논문에서는 3kv급 태양열 집전기를 유한요소법을 이용하여 돌풍이 불 때 풍하중에 의한 안전성을 평가하였다. 태양열 집전기는 옥외에 설치가 되므로 바람에 대한 영향을 가장 많이 받게 되는데 풍하중은 특히 강한 태풍이 불 때에 가장 높은 설계변수로 자중이나 프레임이 태양을 트레킹 할 때 생기는 동역학적인 변수보다도 크게 된다. 기존에 풍압력에 대한 산술식이 있지만 구조에 따라 적용하는 방법이 다르므로 돌풍이 불 때의 풍속을 적용, 유한요소법을 이용하여 우선 플레이트 프레임 표면에 발생하는 표면 압력을 계산하였다. 구한 표면 압력으로부터 플레이트 부분에 작용하는 하중으로 환산을 구조물에 대입하였고, 구조물이 크고 Mesh수에 문제로 인해 프레임을 두 부문으로 나누어서 포스트 부문과 플레이트 부분에 적용하여 해석하였다. 포스트의 경우에는 플레이트에서 받은 풍하중을 벡터로 나누어서 적용하였고 플레이트 부분에서 작용하는 자중을 고려하여 적용하였다. 플레이트의 경우 돌풍에 안정적이라 하더라도 변형량이 높을 경우를 적용하였다. 포스트 부분과 플레이트 연결부에서도 보강을 통하여 적정범위의 응력이 집전기에 문제가 발생할 수 있으므로 적정한 범위의 변형량을 유지하기 위해 설계변경 하여 안전한 구조물이 되도록 하였다.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.90-92
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• 2006

국가차원의 신 재생에너지 활성화 방안에 따라 지자체 등의 분산전원 시실계획이 점차 증가하고 있으나, 아직 우리나라에서는 분산전원의 배전계통 연계에 대한 체계적인 기술지침이 초기 단계에 있거나 제정 중에 있어서, 계통 연계와 관련하여 발전사업자와 전력회사간의 이해가 상충되는 등 문제점이 발생되고 있다. 또한, 대규모 분산전원 단지의 도입이 이루어지고 있으나, 이에 대한 기술적인 평가방안이나 해석 방법이 구체적으로 제시되어 있지 않아, 설치자(시도 및 지자체)와 운용자(한전의 배전지사/지점)들은 많은 혼돈과 어려움을 겪고 있는 실정이다. 따라서 본 논문에서는 태양광, 풍력 등의 분산전원이 배전계통에 도입되는 경우, 연계에 대한 기술적인적합여부를 종합적으로 평가 할 수 있도록 분산전원 연계판정 시뮬레이션 시스템을 연구하였다. 즉, 구체적으로는 전력용량, 전기방식, 역률, 뱅크 역 조류, 상시전압변동, 순시전압변동, 플리커, 단락용량, 연계가능용량 등이며, 이들 항목을 계통연계 가이드라인과 평가 알고리즘에 의하여 연계 적합 여부를 판단해 주는 시스템이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1099-1106
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• 2017

In this paper, a three phase inverter control methodology for photovoltaic generation system, which is a renewable energy source, was studied. The voltage source inverter type of the constant voltage supply type was selected as the three phase photovoltaic inverter, and SWPM method was selected as control technique. a small capacity three phase photovoltaic inverter system, which has a DSP with powerful high speed data processing ability as the main controller and a solar controller as current controller to supply a certain amount of current to charge the battery, was made and tested for SPWM function.

• KIPS Transactions on Computer and Communication Systems
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• v.1 no.3
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• pp.161-170
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• 2012

In recent years, many researchers and developers have been interested in renewable energy all over the world. Particularly, the development of wind power is being processed actively due to its high economic efficiency. A few years ago, Korean government has started the research for building a large-scale offshore wind farm in domestic west-southern area. Current domestic SCADA technology level for operating wind farm is very low compared with foreign SCADA technology level. In this paper, we found IT issues and solutions for developing SCADA system. Based on these solutions, we designed SCADA system for a large-scale offshore wind farm.