• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.256-257
• /
• 2011

The development for Eco-friendly cars has been expanded as the concern about environmental pollution and a rise in gas prices. The Electric Vehicle(EV) and Plug in Hybrid Electric Vehicle(PHEV) are generally connected on distribution power systems to charge the traction batteries. The growing number of EV/PHEVs could have a effect on distribution power systems and result in overload of power utilities and power quality problems. In order to reduce the adverse effect on distribution power systems, the influence of electric vehicle loads should be evaluated. In this paper, the influence of electric vehicle loads is evaluated by using OpenDSS(Open Source Distribution System Simulator) according to the penetration rate of electric vehicle.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회B
• /
• pp.2001-2006
• /
• 2008

The most concerning issue of these days is the energy crisis by increasing threat of dependency on foreign oil and its volatility itself. In the situations, the PHEV is drawing attention for the next generation's car which could give a chance to decrease the dependency on foreign oil. As well as, the Korean electric power infrastructure is a strategic national asset that is under utilized most of the time. With the proper changes in the operational paradigm, it could generate and deliver necessary energy to charge the PHEVs which could penetrate the market within few years. In doing so, it would reduce greenhouse gas emissions, improve the economics of the electricity industry, and reduce the energy dependency. This paper investigate the technical potential and impacts of using the existing idle capacity of the electric infrastructure in conjunction with the emerging PHEVs technology to meet the majority of daily energy needs of the Korean LDV fleet.

• 대한기계학회논문집B
• /
• 제33권4호
• /
• pp.278-287
• /
• 2009

Plug-in hybrid electric vehicle (PHEV) with capability of being recharged from the power-grid will reduce oil consumption. Also, the PHEV will affect the utility operations by adding additional electricity demand for charging. In this research, the power-grid impact by demand of PHEV charging is presented and the optimal charging control strategy for utility operators is proposed with simulated data. The penetration of PHEV is assumed to be 50% in the circumstances of Korean passenger car market and Korean power-grid market limitedly. To obtain smooth load shape and utilize the surplus electricity in power-grid at midnight and dawn, the peak of charging demand should be controlled to be located before 4:00 a.m., and the time slot which can supply the electricity power to PHEV should be allowed between 1:00 a.m.$\sim$7:00 a.m.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 1999년도 가을 학술발표논문집 Vol.26 No.2 (3)
• /
• pp.783-785
• /
• 1999

Distributed Object Systems are very complex. So, it is difficult to see overall relationship among objects participated in the system. Moreover the performance tuning or maintenance are also important issues of it. So, it needs a way to view the system with low-cost and an efficient method. One of solutions is a visualization tool or system. In this paper, we proposed a tracing facility for Java-based distributed object system, especially RM(Remote Method Invocation). Our up-coming visualization system will use two phase hybrid post-mortem/on-the-fly technique. To support it, the fundamental tracing part must have some flexible and dynamic mechanism. The main idea of our tracing technique is the Plug-in Sensor Model(PSM). The relationship between tracing (monitoring) part and visualization part is closely related. So, we considered the appropriate factors for visualization. We developed 'Traced RMI(TRMI)'. For more precise visualization of a working system, the casuality of events has to be preserved. TRMI can support global event ordering.

• Advances in materials Research
• /
• 제4권2호
• /
• pp.63-76
• /
• 2015

The energy crisis involving depletion of fossil fuel resource is not the sole driving force for developing renewable energy technologies. Another driving force is the ever increasing concerns on the air quality of our planet, associated with the continuous and dramatic increase of the concentration of greenhouse gas (mainly carbon dioxide) emissions. The internal combustion engine is a major source of distributed $CO_2$ emissions caused by combustion of gasoline derived largely from fossil fuel. Another major source of $CO_2$ is the combustion of fossil fuels to produce electricity. New technologies for generating electricity from sources that do not emit $CO_2$, such as water, solar, wind, and nuclear, together with the advent of plug-in hybrid electric vehicles (PHEV) and even all-electric vehicles (EVs), offer the potential of alleviating our present problem. Therefore, the relevant technologies in $LiFePO_4$ as cathode material for Li-ion batteries suitable to the friendly environment are reviewed aim to provide the vital information about the growing field for energies to minimize the potential environmental risks.

• 한국가스학회지
• /
• 제15권5호
• /
• pp.50-56
• /
• 2011

엔진의 제동시의 유효일을 이용하여 고압의 압축 공기를 저장하고 운전 시에는 저장된 압축 공기를 동력원으로 사용하는 신개념의 Air hybrid 엔진의 구현 가능성 검토를 위한 실험적인 연구를 진행하였다. Air hybrid 엔진 시스템의 구현을 위하여 연구용 단기통엔진을 개조하였고, 배기 밸브 중의 하나에 독립 가변 밸브리프트 시스템을 장착하여 압축 행정 동안에 고압의 공기를 저장할 수 있도록 하였다. 또한, 엔진의 구동을 위하여 점화플러그 위치에 공기 분사 모듈을 장착하여 팽창행정 중에 고압의 공기를 분사할 수 있도록 하였다. 압축 공기 저장 모드에서는 800rpm 아이들 조건에서 800 사이클 동안 30리터의 공기 저장 탱크를 최대 13 bar 까지 충전할 수 있었고, 충전된 고압의 공기를 이용하여 800rpm 아이들 조건에서 0.41 bar의 평균도시유효압력의 일을 얻을 수 있었는데 이것은 정상적인 아이들 조건보다 1.1 bar의 유효일이 증가한 것이다.

• 상하수도학회지
• /
• 제27권1호
• /
• pp.21-29
• /
• 2013

Present study was conducted to evaluate the performance of Anaerobic Hybrid Reactor (AHR) combined with two types of anaerobic attached growth reactors at mesophilic temperature ($37^{\circ}C$). The reactor was operated at the influent substrate condition of 19,400 mg/L soluble chemical oxygen demand (sCOD). The organic loading rate (OLR) and flow rate were varied in the range of $9.5{\sim}22.5kg/m^3$. day and 10.6 ~ 26.0 L/day respectively since start-up was done. The COD removal efficiency of 93 % was measured at the OLR of $14kg/m^3$. day in AHR. However a reduction in removal efficiency to as low as 85 % could have been related to a combined effect of high concentration suspended solids (SS) concentration over 3,800 mg/L. On the other hand the total COD removal efficiencies were measured to be 96.3 % and 96.2 % for AHR+APF and AHR+ADF respectively. The pH of the POME was adjusted to neutral range by using sodium bicarbonate at the initial stages of the reactor feed, later stages pH adjustment was not required as the pH was maintained in the desired neutral range due to self-buffering capacity of the reactor. The reactor proved to be economically acceptable and operationally stable. The biogas was measured to have $CH_4$ and $CO_2$ with a ratio of 35:65, and methane gas production rate was estimated to be $0.17{\sim}10.269L\;CH_4/g\;COD_{removed}$.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.947_948
• /
• 2009

In an attempt to minimize the air pollution caused by CO2, $NO_X$x, and $SO_X$ and the fuel cost, the auto industries and researchers recently are looking into replacing the diesel and gasoline cars with hybrid electric vehicles, plug-in electric vehicles, or battery powered electrical vehicles. This paper reports the technical status of the primary components such as batteries, motors, power control units and auxiliary parts to be used for electric vehicles.

• Journal of Power Electronics
• /
• 제13권4호
• /
• pp.528-535
• /
• 2013

Most eco-friendly cars can adopt the concept of an integrated battery charger (IBC), which uses currently available motor drive systems. The IBC has a lot of strong points such as low cost and minimum space for the high voltage battery charger. On the other hand, it also has some defects caused by its structure. In this paper, the shortcomings of the conventional IBC for PHEVs with interior permanent magnet motors are discussed, and two advanced IBCs with improved performance are presented. Compared with the conventional IBC, the two advanced IBCs have plenty of strengths such as low common noise, high efficiency, simple sensing methods, etc. Then, the digital control algorithm is modified and a power loss calculation is carried out with simulation software. Finally, experimental results are provided to show the performance of the IBC systems.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2012년도 추계학술대회 논문집
• /
• pp.83-84
• /
• 2012

본 논문에서는 전기자동차 (Electric Vehicles, EVs) 및 플러그인 하이브리드 자동차 (Plug-in Hybrid Electric Vehicles, PHEVs)용 통합형 배터리 충전기의 토폴로지 구성에 따른 동작 및 성능 특성을 비교한다. 기존에 제안된 통합형 배터리 충전기를 토대로 개별 모듈에 적용 가능한 토폴로지를 검토한다. 또한, 검토한 모듈의 통합을 위한 양방향 구현 시 동작 및 성능을 비교한다. 이를 통해 선정된 토폴로지들이 가질 수 있는 조합들을 구성하고, 상호간의 영향을 분석한다. 분석한 결과를 기반으로 각각의 조합의 성능 및 특성의 시뮬레이션을 통한 비교추이를 제시한다.