• 전력전자학회논문지
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• 제24권3호
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• pp.139-146
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• 2019

As the number of electric vehicles (EVs) in Jejudo Island increases, the secondary use of EV batteries is becoming increasingly mandatory not only in reducing greenhouse gas emissions but also in promoting resource conservation. For the secondary use of EV batteries, their capacity and performance at the end of automotive service should be evaluated properly. In this study, the battery state information from the on-board diagnostics or OBD2 port was acquired in real time while driving three distinct routes in Jejudo Island, and then the battery operating characteristics were assessed with the driving routes. The route with higher altitude led to higher current output, i.e., higher C-rate, which would reportedly deteriorate state of health (SOH) faster. In addition, the SOH obtained from the battery management system (BMS) of a 2017 Kia Soul EV with a mileage of 55,000 km was 100.2%, which was unexpectedly high. This finding was confirmed by the SOH estimation based on the ratio of the current integral to the change in state of charge. The SOH larger than 100% can be attributed to the rated capacity that was lower than the nominal capacity in EV application. Therefore, considering the driving environment and understanding the SOH estimation process will be beneficial and necessary in evaluating the capacity and performance of retired batteries for post-vehicle applications.

• International Journal of Automotive Technology
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• 제8권6호
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• pp.781-790
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• 2007

Hybrid electric vehicles(HEV) combined with more than one power sources have great potential to improve fuel economy and reduce pollutant emissions. The Integrated Starter Generator(ISG) HEV researched in this paper is a two energy sources vehicle, with a conventional internal combustion engine(ICE) and an energy storage system(batteries). In order to investigate the potential of diesel engine hybrid electric vehicles in fuel economy improvement and emissions reduction, a Dynamic Programming(DP) based supervisory controller is developed to allocate the power requirement between ICE and batteries with the objective of minimizing a weighted cost function over given drive cycles. A fuel-economy-only case and a fuel & emissions case can be achieved by changing specific weighting factors. The simulation results of the fuel-economy-only case show that there is a 45.1% fuel saving potential for this ISG HEV compared to a conventional transit bus. The test results present a 39.6% improvement in fuel economy which validates the simulation results. Compared to the fuel-economy-only case, the fuel & emissions case further reduces the pollutant emissions at a cost of 3.2% and 4.5% of fuel consumption with respect to the simulation and test result respectively.

• KEPCO Journal on Electric Power and Energy
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• 제1권1호
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• pp.33-38
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• 2015

시간대별 효율적인 전력 운영과 전력품질 향상을 위해 ESS (Energy Storage System)의 보급이 세계적으로 활발하게 이루어지고 있다. 이러한 ESS용 전원소자로 리튬이차전지의 채용이 급격히 늘어남에 따라, 리튬이차전지의 수명 및 출력 열화 거동을 측정 및 예측하는 기술이 시급히 요구되고 있다. 특히, ESS 운영에 있어 핵심 특성인 리튬이차 전지 출력은 측정이 어려울 뿐만 아니라, 정확한 측정을 위해서는 많은 시간이 소요되는 문제점이 있다. 따라서, 본 연구에서는 ESS용 리튬이차전지 단전지를 전산 모델링 한 후, 펄스 측정법을 적용하여 충전상태에 따른 방전 및 충전시의 직류저항(DC-IR)과 출력을 예측한다. 또한, 두 가지 펄스 측정법인 HPPC (Hybrid Pulse Power Characteristics)와 J-Pulse (JEVS D 713, Japan Electric Vehicle Association Standards)의 결과를 비교 분석한다.

• 센서학회지
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• 제32권6호
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• pp.462-469
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• 2023

Electric vehicles (EVs) have recently been in the spotlight and have been rapidly developed to reduce the carbon emission with respect to the transport sector. Most EVs currently employ lithium-ion batteries (LIBs) as power sources because they have a higher energy density and a lower self-discharge than other batteries. However, the LIBs cannot respond to high power demands when the state of health (SOH) falls below 80%. Therefore, the SOH of the LIBs must be accurately measured or estimated. To date, many methods have been studied and proposed for measuring or estimating the SOH. In this paper, representative methods among them are reclassified and introduced.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.123-129
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• 2011

Due to restriction of vehicle emissions and high demand for fossil fuels nowadays, car manufacturers around the world are looking into alternative ways in introducing new car model that would vastly captured the market. Thus, Electric Vehicle (EV) has been further developed to take the advantage of the current global issues on price of fossil fuels and impact on the environment. Since car battery plays the crucial role on the overall performance of EV, many researchers have been working on improving the component. This paper focused on the reliability of EV battery which involves recognizing failure types, testing method and life prediction method. By focusing on these elements, the reliability feature being identified and as a result the batteries life will be prolonged.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1175-1176
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• 2011

Electric Vehicle Supply Equipment(EVSE) is a system or an equipment to supply electric power for charging the traction batteries on the electric vehicle. EVSEs are classified with a conductive charging system and an inductive charging system by the power transfer method. Inductive charging systems are necessary to use high frequency converters to increase the output power and to reduce the size of the charging systems. In this paper, a 20kHz inverter for inductive charging system has been designed and PSCAD/EMTDC have been used to simulate the output characteristics of the 20kHz inverter.

• 에너지공학
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• 제21권1호
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• pp.86-108
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• 2012

자동차산업이 해결해야 과제로서 $CO_2$배출에 의한 지구온난화, 배기가스배출에 의한 도시부 대기오염 그리고 석유자원고갈 등에 대한 대처 등이 있다. 이들의 현실적인 해법으로 시장에서 높은 평가를 받고 있는 것이 배터리전기자동차이다. 배터리전기자동차의 핵심 기술은 모터, 배터리, 전력제어, 전기적 제동 기술 등이다. 본 연구에서는 전기자동차에 대한 각국 정부의 주요 정책현황, 메이저 자동차 메이커의 판매전략, 핵심 요소기술의 개발동향 및 기술분석, 그리고 이들 기술들에 대한 세계특허출원동향을 조사분석하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.318-319
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• 2011

Many countries are concentrating on the development of electric vehicle technology with increasing concerns about the global environment. Along with these concerns, plug-in hybrid electric vehicles(PHEVs) are being developed as environment-friendly cars which reduce greenhouse gas emissions and also eliminate the problem of range anxiety associated to all-electric vehicles, because the combustion engine works as a backup when the batteries are depleted. In this paper, electric equipments of the PHEV which meet the target specifications were developed, and their performance was proven through confirmatory testing on the PHEV at Korea Automotive Technology Institute(KATECH).

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.183-186
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• 2011

본 논문에서는 전기동력 추진기관을 사용하는 비행체의 추진시스템에 대하여 분석하고, 무게분석을 통하여 PAV의 전기동력시스템을 살펴보았다. 현재 1,000 kg의 PAV를 개발할 경우 PEMFC와 리튬전지를 조합한 추진기관이 내연기관을 대체할 수 있을 것으로 예상된다. 내연기관을 대체하기 위해서는 연료전지 출력밀도 2.5 kW/kg, 배터리 에너지밀도 0.75 kWh/kg 이상의 성능이 요구된다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.333-334
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• 2016

This paper proposes a new cascoded configuration for hybrid energy storage system (HESS) which consists of batteries and supercapacitor (SC) for Electric Vehicle applications. In this configuration,a resonant LLC converter is interfacedin series with a battery module and it converts a part of the energy from the batteries and transfer it to the dc-link bus. The LLC converter is controlled by a phase-shift angle between the primary and secondary switches to maintain a constant dc-link voltage and obtain soft-switching conditions for all the primary switches. By placing the SC moduleina cascoded concept, the rated voltage of SC can be reduced significantly compared with the conventional topologies. It helps save the cost and reduce the number of SC cells. The proposed configuration can operate with four different modes: feeding load, acceleration, regenerative braking andSC charging. A scaled-down prototype converter (2 kW, 600V output) is designed and tested to verify the advantages of the proposed topology. The maximum efficiency obtained with the proposed topology is 99%.