• 전력전자학회논문지
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• 제26권3호
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• pp.167-175
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• 2021

Reusing electric vehicle batteries after they have been retired from mobile applications is considered a feasible solution to reduce the demand for new material and electric vehicle costs. However, the evaluation of the value and the performance of second-life batteries remain a problem that should be solved for the successful application of such batteries. The present work aims to estimate the remaining useful life of Li-ion batteries through the neuro-fuzzy system with the equivalent circuit parameters obtained by Electrochemical Impedance Spectroscopy (EIS). To obtain the impedance spectra of the Li-ion battery over the life, a 18650 cylindrical cell has been aged by 1035 charge/discharge cycles. Moreover, the capacity and the parameters of the equivalent circuit of a Li-ion battery have been recorded. Then, the data are used to establish a neuro-fuzzy system to estimate the remaining useful life of the battery. The experimental results show that the developed algorithm can estimate the remaining capacity of the battery with an RMSE error of 0.841%.

• 전력전자학회논문지
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• 제25권4호
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• pp.251-260
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• 2020

A growing interest has emerged in recycling used automobile batteries into energy storage systems (ESSs) to prevent their harmful effects to the environment from improper disposal and to recycle such resources. To transform used batteries into ESSs, composing battery modules with similar performance by grading them is crucial. Imbalance among battery modules degrades the performance of an entire system. Thus, the selection of modules with similar performance and remaining life is the first prerequisite in the reuse of used batteries. In this study, we develop an instrument to measure the impedance spectrum of a battery module to predict the useful remaining life of the used battery. The developed hardware and software are used to apply the AC perturbation to the used battery module and measure its impedance spectrum. The developed instrument can measure the impedance spectrum of the battery module from 0.1 Hz to 1 kHz and calculate the equivalent circuit parameters through curve fitting. The performance of the developed instrument is verified by comparing the measured impedance spectra with those obtained by a commercial equipment.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.422-426
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• 2018

The lithium-ion battery pack of an electric vehicle (EV) deserves to be considered for an alternative use within smart-grid infrastructure. Despite the long automotive service life, EV batteries retain over 70~80% of their initial capacity. These battery packs must be managed for their reliability and safety. Therefore, a battery management system (BMS) should use specific algorithms to measure and estimate the status of the battery. Most importantly, the BMS of a grid-connected energy storage system (ESS) must ensure that the lithium-ion battery does not catch fire or explode due to an internal short from uncontrolled dendrite growth. In other words, the BMS of a lithium-ion battery pack should be capable of detecting the battery's status based on the electrochemical reaction continuously until the end of the battery's lifespan. In this paper, we propose a new protection algorithm for a dendritic lithium battery. The proposed algorithm has applied a parameter from battery pack aging results and has control power managing.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 추계학술대회
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• pp.216-217
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• 2019

The battery powered electric vehicle (EV) is one of most promising technologies in 21^st century. Though the lithium batteries are playing an important role in the EVs, they are only applicable until their capacities reach 80%, the end of its useful first life. Yet, these batteries can live a second life such as Energy Storage Systems (ESS). In order to utilize the Residual Useful Life (RUL) of the batteries the State of Health (SOH) of them needs to be estimated by a nondestructive test such as Electrochemical Impedance Spectroscopy (EIS) technique. Though many kinds of different EIS instruments are commercially available, most of them can only test a battery module less than 10V and the price of the instrument is very high. In this paper a low-cost EIS instrument suitable for measuring the impedance spectrum of the high voltage battery module is proposed and its validity is verified through the experiments. In order to prove the accuracy of the developed EIS instrument its measured impedance spectrum is compared with the results obtained by a commercial instrument. The Chi Square value calculated between two impedance spectrum measured by both developed and commercial instruments are less than 2%, which prove the strong correlation between two results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.345-346
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• 2016

The grid-connected energy storage systems, which could increase the reliability, efficiency, and cleanliness of the grid is presently restricted by the high cost of batteries. This problems could be solved by batteries retired from automotive services. These batteries can provide a low-cost system for energy storage and other applications such as residential applications and renewable energy integration. This paper gives an overview of technical requirements for the re-use of the electric vehicle batteries in energy storage systems.Firstly, the motivation of research is introduced. Secondly, the technologies needed for the re-use of the battery are introduced such asidentification of the battery characteristics, grading of the aged batteries, identification of the state-of-charge and state-of-health of the battery and suitable power electronic converter topologies. In addition the control strategy to maximize the battery lifespan and bypass the faulty batteries is presented and one-stop solution to implement the above mentioned technologies are also given.

• International Journal of Computer Science & Network Security
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• 제21권11호
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• pp.338-344
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• 2021

The recently continuous enhancement and development in the biomedical side for the betterment of human life. The Wireless Body Area Networks is a significant tool for the current researcher to design and transfer data with greater data rates among the sensors and sensor nodes for biomedical applications. The core area for research in WBANs is power efficiency, battery-driven devices for health and medical, the Charging limitation is a major and serious problem for the WBANs.this research work is proposed to find out the optimal solution for battery-friendly technology. In this research we have addressed the solution to increasing the battery lifetime with variable data transmission rates from medical equipment as Wireless Endoscopy Capsules, this device will analyze a patient's inner body gastrointestinal tract by capturing images and visualization at the workstation. The second major issue is that the Wireless Endoscopy Capsule based systems are currently not used for clinical applications due to their low data rate as well as low resolution and limited battery lifetime, in case of these devices are more enhanced in these cases it will be the best solution for the medical applications. The main objective of this research is to power optimization by reducing the power consumption of the battery in the Wireless Endoscopy Capsule to make it battery-friendly. To overcome the problem we have proposed the algorithm for "Battery Friendly Algorithm" and we have compared the different frame rates of buffer sizes for Transmissions. The proposed Battery Friendly Algorithm is to send the images on average frame rate instead of transmitting the images on maximum or minimum frame rates. The proposed algorithm extends the battery lifetime in comparison with the previous baseline proposed algorithm as well as increased the battery lifetime of the capsule.

• 유통과학연구
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• 제14권9호
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• pp.5-13
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• 2016

Purpose - This study proposes a framework for service innovation strategy to cope with the emergence of electric vehicles. Research design, data, and methodology - This study designs an electric-vehicle lease program and collects the resulting data to analyze. By analyzing the previous studies on the electric-vehicle market with cases, a theoretical framework based on existing theories is to be set. Results - This study proposes a strategy for the rapid diffusion of electric vehicles. First, a partitioned-pricing system is proposed to create an advantage for electric vehicles in terms of initial purchasing cost relative to traditional internal combustion vehicles. Second, focusing on reducing switching costs is important because electric vehicles have relatively low resale values due to the uncertainty of battery life. Third, a battery-leasing strategy is supposed to reduce the cost of switching from a traditional internal combustion vehicle to an electric vehicle. Conclusions - This paper can provide strategic guidance for decision makers in firms that have already entered the electric-vehicle leasing market by making a recommendation such as a service innovation strategy. The proposed strategy can be considered as an electric vehicle market in the future and can contribute to the wider diffusion of electric vehicles.

• 전기화학회지
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• 제22권3호
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• pp.122-127
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• 2019

유기이차전지가 가지고 있는 전극 내 낮은 접합력과 높은 계면저항의 단점을 해결하기 위하여 본 연구에서는 흑연 코팅 처리된 집전체를 사용하여 lithium terephthalate (LTA)전지의 전기화학적 특성 변화를 분석하였다. LTA 음극 활물질은 산의 이온 치환반응에 의하여 불순물 없이 합성되어 졌다. 막대 형태의 LTA 활물질로 제작된 전극과 흑연 코팅 처리된 집전체와의 접합특성은 SEM 단면과 EIS를 통하여 확인하였다. 흑연 코팅된 집전체를 사용한 LTA전지의 계면저항은 현저히 감소되었다. 순수한 금속 집전체 LTA 전지와 흑연 코팅 처리된 금속 기판 LTA 전지는 0.1C의 두 번째 사이클에서 107.6 mAh/g와 148.8 mAh/g의 방전 용량을 보인다. 흑연 코팅된 집전체를 사용한 LTA 전지는 순수한 LTA 전지에 비하여 우수한 수명 특성과 높은 방전 용량, 그리고 높은 고율 특성을 가진다.

• 산업진흥연구
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• 제7권3호
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• pp.71-75
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• 2022

본 연구는 산만 및 충동성향 6세 여아에 대한 아동중심놀이치료 이론을 기반으로 한 아동상담 사례이다. 아동의 산만 및 충동성향으로 인하여 어머니는 양육에 어려움을 겪고 있었다. 아동상담은 Full Battery 심리검사를 실시한 후, 2020년 11월 19일부터 2022년 6월 16일까지 주 1회 회기별 아동상담 40분 부모상담 10분씩 총 63사례회기 진행하였다. 아동은 상담과정에서 아동의 주도적인 놀이를 통해 애정욕구 및 공격적이고 충동적인 모습을 나타냈으며, 상담을 통해 안정감을 느끼며 산만 및 충동성향이 감소하는 행동을 보였다. 또한 아동은 부모에게 자신의 감정을 언어로써 구체적으로 표현하고, 초등학교 입학 후 학교적응이 원만한 모습을 보였다. 어머니는 아동양육이 전보다 훨씬 수월해졌다고 보고했으며, 한달에 한번 추후 상담을 하기로 결정하며 상담을 종료하였다. 본 연구는 유아기 아동상담의 시작으로 1년 8개월가량 진행된 사례연구로서, 그 결과로 아동이 초등학교에 입학하여 1, 2학년 시기 동안의 적응적 생활양식을 확인한 연구라는 점에서도 의의가 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1391-1393
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• 2002

There arc some problems on storage batteries which are called Secondary Battery, such as long charging time, limited cycle life, low coulomb efficiency and inaccurate residual power meter. To solve those problems, a complex system of capacitors and Super Capacitors of increased energy density. Though the capacitors alone arc not capable of delivering stable output, the accompanied circuits compensate the various characteristics all through the charge-and discharge-cycle. This paper deals with Energy Storage System with Super Capacitor for PV System Discussed in this paper are, explains the accompanied circuits of Super Capacitor which is compared with the Second Batteries.