• 한국산학기술학회논문지
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• 제18권10호
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• pp.669-674
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• 2017

화석 연료의 고갈 및 환경오염의 증가로 인하여 전기 에너지를 사용하는 전기 자동차가 차세대 교통수단으로 주목받고 있으며 전 세계적으로 인기를 끌고 있다. 전기 자동차의 보급률 및 관심이 높아짐에 따라 V2G (Vehicle to Grid) 및 IT 기술을 이용한 충전 인프라에 대한 연구가 활발히 진행되고 있다. 특히, 전기 자동차의 안정적인 충전 및 부하 관리를 위하여 그리드 네트워크와의 통신은 가장 중요한 요소이다. 그러나 기존의 중앙 집중형 인프라 구조의 경우 제어 메시지 요청이 증가할 경우 느린 응답속도로 인하여 충전 인프라가 효율적으로 작동하지 못하는 문제점들이 존재한다. 본 논문에서는 분산형 클라우드 컴퓨팅 기술을 무선 기지국에 적용하여 충전 인프라에 혼잡을 줄이고 지연시간을 줄이기 위해 MEC (Mobile Edge Computing)를 활용한 새로운 전기자동차 충전 인프라 구조를 제안한다. 성능 평가를 통해 본 논문에서 제안한 저 지연시간을 가지는 충전 인프라가 기존에 존재하는 충전 인프라보다 효율적으로 전력 피크 상황에 대처함을 확인하였다.

• 디지털융복합연구
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• 제11권7호
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• pp.141-148
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• 2013

스마트그리드는 정보통신기술을 이용하여 전력공급자와 소비자의 양방향통신을 가능하게 한다. 또한 동적인 전력 공급이 가능하기 때문에 전기 자동차 기술과 접목시킬 경우 전기 자동차 충전 인프라를 활성화시키고 전기 자동차의 배터리를 가정용 축전지로 활용하여 재판매할 수도 있다. 이러한 전기 자동차 충전 인프라는 가정, 아파트, 건물, 기타 충전소 등에 고정적으로 위치하여 있고 사용자만 유동적으로 서비스를 이용한다. 만약 유동적으로 서비스를 이용하는 사용자에 대해 인증이 이루어지지 않을 경우 전력 서비스의 불법적인 사용, 전력 정보 유출, 불법적인 전력 요금 변경 등의 피해가 발생할 수 있다. 본 논문에서는 스마트그리드 환경에서 안전하게 전기 자동차 관련 서비스를 이용하기 위해 스마트카드 및 동적 ID 기반 사용자 인증 스킴을 제안한다.

• 한국공간구조학회논문집
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• 제11권1호
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• pp.105-112
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• 2011

전기자동차의 상용화시대에 대비한 전기자동차 충전네트워크가 시급해지고 있다. 해외에서는 주차장에 PV시스템을 설치하여 얻어진 전력으로 전기자동차 충전을 할 수 있는 전기자동차 충전소가 설치되어지고 있다. 또한 우리나라에서도 충전인프라 구축방안 및 전기자동차 충전시설 지원기준 등을 설정하여 제시하고 있지만 해외처럼 PV시스템을 이용한 전기자동차 충전소의 사례가 국내에는 없으며, 일반전력을 이용한 전기자동차 충전소만 제시하고 있다. 따라서 본 논문에서는 국내의 전기자동차 충전네트워크 구축에 대비하여 국내 외 태양광 주차장과 해외 PV시스템 전기자동차 충전소의 사례를 조사하여 구조시스템, 구조 재료 등을 분석하여 비교 분석한 결과, 해외 PV시스템 전기자동차 충전소의 경우 캔틸레버 구조와 소규모 타입이 많이 설치되었다.

• 산업경영시스템학회지
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• 제43권3호
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• pp.53-60
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• 2020

Evaluating the operational efficiency of electric vehicle charging stations (EVCSs) is important to understand charging network evolution and the charging behavior of electric vehicle users. However, aggregation of efficiency performance metrics poses a significant challenge to practitioners and researchers. In general, the operational efficiency of EVCSs can be measured as a complicated function of various factors with multiple criteria. Such a complex aspect of managing EVCSs becomes one of the challenging issues to measure their operational efficiency. Considering the difficulty in the efficiency measurement, this paper suggests a way to measure the operational efficiency of EVCSs based on data envelopment analysis (DEA). The DEA model is formulated as constant returns of output-oriented model with five types of inputs, four of them are the numbers of floating population and nearby charging stations, distance of nearby charging stations and traffic volume as desirable inputs and the other is the traffic speed in congestion as undesirable one. Meanwhile, the output is given by the charging frequency of EVCSs in a day. Using real-world data obtained from reliable sources, we suggest operational efficiencies of EVCSs in Seoul and discuss implications on the development of electric vehicle charging network. The result of efficiency measurement shows that most of EVCSs in Seoul are inefficient, while some districts (Nowon-gu, Dongdaemun-gu, Dongjak-gu, Songpa-gu, Guro-gu) have relatively more efficient EVCSs than the others.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.349-352
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• 2008

The most concerning issue in these days is the energy crisis by increasing threat of global warming and depletion of natural resources. In the situations, the Plug-in Hybrid Electric Vehicle (PHEV) is drawing attention from many countries for the next generation's car which has higher fuel efficiency and lower environmental impact. This paper presents simulation results about the limit capacity of central power-grid which doesn't have enough surplus electric power for charging PHEVs. Therefore, this paper also presents a smart charging system that can charge the PHEVs with a function of distributing demands of charging. The smart charging system is an agent facility between the government and consumer, which can recommend the best time to charge the battery of PHEVs by the lowest energy cost. This function of choosing time-slots is the technical system for the government which wants to control the consumption rate of electric power for PHEVs. Finally, this paper presents the economic feasibility of PHEVs from the two kinds of price system, midnight electric price and home electric price.

• 전기학회논문지
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• 제62권8호
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• pp.1138-1143
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• 2013

In this paper, we propose a smartphone application based on a wireless fidelity(WiFi) in order to control the charging of electric vehicle(EV) and monitor the charging status together with the vehicle history information. The driver obtains much information on vehicle status through a smartphone application which communicates with the electric vehicle supply equipment(EVSE) management server while the EV also communicates with the EVSE for the authentification through controller area network(CAN). We also implement the simulator for the EV charging control system to verify the functions of the proposed application where the simulator consists of an EV model, an EVSE, and a smartphone. It is shown by the simulator that the proposed smartphone application allows the driver to control and to monitor the charging process of an EV conveniently and, moreover, it can provide the driver with vehicle information stored in the EVSE management server.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.341-342
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• 2015

Attention has been focused on how to charge an electric vehicle in accordance with the increase of interest in the electric vehicle in recent years. The charging of an electric vehicle with a solar power is way to increase the stability of the grid and to supplement the grid power demand. In this paper, the EMTP / ATPDraw presents a method of charging an electric vehicle in connection to the grid and the solar power system, and analyze the trends in supply power from the solar power system according to changes in temperature and irradiation.

• 한국방재안전학회논문집
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• 제14권2호
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• pp.35-42
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• 2021

본 논문은 전기자동차 충전시설 확충계획에 중요한 요소인 전기자동차 전력 수요량 예측정보를 생산하기 위하여 Exponential Smoothing를 이용하여 전력 수요량 예측 모형을 제안하였다. 모형의 입력자료 구축을 위하여 종속변수로 월별 시군구 전력수요량을 독립변수로 월별 시군구 충전소 보급대수, 월별 시군구 전기자동차 충전소 충전 횟수, 월별 전기자동차 등록대수 자료를 월 단위로 수집하고 수집된 7년간 자료 중 4년간 자료를 학습기간으로 3년간 자료를 검증 기간으로 적용하였다. 전기자동차 전력 수요량 예측 모형의 정확성을 검증하기위하여 통계적 방법인 Exponential Smoothing(ETS), ARIMA모형의 결과와 비교한 결과 ETS, ARIMA 각각의 오차율은 12%, 21%로 본 논문에서 제시한 ETS가 9% 더 정확하게 분석되었으며, 전기자동차 전력 수요량 예측 모형으로써 적합함을 확인하였다. 향후 이 모형을 이용한 전기자동차 충전소 설치 계획부터 운영관리 측면에서 활용될 것으로 기대한다.

• 산업경영시스템학회지
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• 제44권2호
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• pp.1-14
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• 2021

It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

• 한국기후변화학회지
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• 제8권3호
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• pp.265-273
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• 2017

Recently the Paris Climate Change Accord has been officially put into effect, making global efforts to implement Greenhouse Gas (GHG) reductions, and also International environmental regulations in the automotive sector will be further strengthened. The electric vehicle, which minimizes the particulate matter generated by existing internal combustion engine automobiles, is evaluated as a representative eco-friendly automobile. However, charging the battery of an electric vehicle is not fully environment-friendly if it is fueled by electricity that is being generated by fossil fuels as an energy source. The energy generated by the photovoltaic power generation system, which is an infinite clean energy, can be used to charge an electric vehicle's battery. Currently, shortage of charging facilities, time of charging, and high battery prices are the problem of activating the supply of electric vehicles. This study is to build a conjunction between the EVBSS (Electric Vehicle Battery Supply System) and ESS (Energy Storage System), which can quickly supply the photovoltaic charged battery to the required demand. If the charged battery in the Battery Swapping Station (BSS) is swapped swiftly, it will dramatically shorten the waiting time for charging the battery. As a result, if the battery is rented when it is needed, electric vehicles can be sold without the cost of a battery, which accounts for a large portion of the total cost, then the supply of electric vehicles are expected to expand. Furthermore, it will be an important alternative to maneuver climate change by minimizing GHG emissions from internal combustion engine vehicles.