• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2601-2603
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• 1999

This paper describes on the development of Controller for the Utility Car combined photovoltaic. The Utility Car is generally composed of Controller, separately excited DC motor. battery and potbox. According to using battery, Utility Car have the problem of small operation time. So operating time is expanded by using parallel operating sollar cell and battery.

• 전력전자학회논문지
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• 제25권2호
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• pp.103-110
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• 2020

In this study, the design and operating strategy of DC home grid with PV, battery, and ultracapacitor have been discussed, The proposed sizing method can find the optimum size of the battery and PV which can reduce yearly utility energy consumption, whereas the control scheme can maintain the DC-bus voltage level of the DC home grid under different operating conditions, where day or night time operation, load and PV power levels, and the maximum current and state-of-charge of batter are considered. In addition, a supervisory power management strategy has been suggested, and its validity has been verified by HILS (hardware in-the-loop simulation) results.

• 정보처리학회논문지A
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• 제18A권3호
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• pp.93-98
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• 2011

최근 배터리로 동작하는 임베디드 시스템의 사용이 급격히 증가하고 있지만, 현재 배터리 기술의 발전 속도는 임베디드 시스템의 전력 사용량의 증가를 따라가지 못하여, 장시간 사용을 위해서는 배터리의 크기가 커져야 하는 단점이 있다. 내장형 시스템에서 소모하는 전력량은 시스템을 구성하는 하드웨어와 시스템을 구동하는 소프트웨어에 의해 결정된다. 그러나 하드웨어적으로 저전력을 지원하더라도 운영체제 등 소프트웨어 수준에서 이를 활용하지 못하면 절전 효과를 극대화할 수 없다. 따라서 본 논문에서는 모바일 임베디드 시스템 환경에서 멀티미디어 애플리케이션 구동시 BET(Break Even Time)기반 태스크 분할을 이용하여 소비 전력을 감소시키는 스케줄링 기법을 제안한다.

• 전기학회논문지
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• 제60권1호
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• pp.142-149
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• 2011

This paper presents a new state of charge(SOC) estimation of large capacity of Li-ion battery (LIB) based on the multiple model adaptive estimation(MMAE) method. We first introduce an equivalent circuit model of LIB. The relationship between the terminal voltage and the open circuit voltage(OCV) is nonlinear and may vary depending on the changes of temperature and C-rate. In this paper, such behaviors are described as a set of multiple linear time invariant impedance models. Each model is identified at a temperature and a C-rate. These model set must be obtained a priori for a given LIB. It is shown that most of impedances can be modeled by first-order and second-order transfer functions. For the real time estimation, we transform the continuous time models into difference equations. Subsequently, we construct the model banks in the manner that each bank consists of four adjacent models. When an operating point of cell temperature and current is given, the corresponding model bank is directly determined so that it is included in the interval generated by four operating points of the model bank. The MMAE of SOC at an arbitrary operating point (T $^{\circ}C$, $I_{bat}$[A]) is performed by calculating a linear combination of voltage drops, which are obtained by four models of the selected model bank. The demonstration of the proposed method is shown through simulations using DUALFOIL.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권4호
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• pp.445-453
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• 2015

A fully integrated cost-effective and low-power single chip Lithium-Ion (Li-Ion) battery protection IC (BPIC) for portable devices is presented. The control unit of the battery protection system and the MOSFET switches are integrated in a single package to protect the battery from over-charge, over-discharge, and over-current. The proposed BPIC enters into low-power standby mode when the battery becomes over-discharged. A new auto release function (ARF) is adopted to release the BPIC from standby mode and safely return it to normal operation mode. A new delay shorten mode (DSM) is also proposed to reduce the test time without increasing pin counts. The BPIC implemented in a $0.18-{\mu}m$ CMOS process occupies an area of $750{\mu}m{\times}610{\mu}m$. With DSM enabled, the measured test time is dramatically reduced from 56.82 s to 0.15 s. The BPIC chip consumes $3{\mu}A$ under normal operating conditions and $0.45{\mu}A$ under standby mode.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.694-702
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• 2014

One of the most important devices in an underwater vessel is a propulsion system. It should be a quiet and efficient system for stealthy operations in the large mission area. Hence lead-acid battery system has been used to supply the energy to electric motor. Recent technological developments and improvements, such as polymer electrolyte membrane(PEM) fuel cell and lithium polymer battery and have created the potential to improve overall power and propulsion performance. An underwater vessel always starts their mission with a limited energy and is not easy to refuel. Therefore design of energy elements, such as fuel cell and battery, and their load distribution are important to increase the maximum operating time of underwater vessel. In this paper, the lead-acid battery/PEM fuel cell and lithium polymer battery/PEM fuel cell were suggested as propulsion system and their performances were analyzed by modeling and simulation using Matlab/Simulink. Each model concentrated on representing the characteristics of energy element depending on demand current. As a result the effect of load distribution between battery and fuel cell was evaluated and the operation time of each propulsion system was able to be estimated exactly.

• 한국기계가공학회지
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• 제11권4호
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• pp.1-6
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• 2012

This paper addresses the issue of Renewable Energy for Electricity Storage device is one of the NAS (Sodium-Sulfur) battery will be about the module. For safety reasons, not the actual battery cells using a dummy cell in the module's operating temperature setting to examine the characteristics of the insulation vacuum of the wall temperature and external temperature changes measured over time. Upper and lower boundaries of the wall vacuum insulation characteristics cotton C intervals over time, average $5^{\circ}C$, but the temperature is rising, 4C section with little temperature change did not occur. On the other hand, about $3^{\circ}C$ in section 4D, and it was confirmed that the temperature rises. Wall vacuum insulation characteristics over time to look at the experiments and measurements are described.

• 조명전기설비학회논문지
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• 제28권8호
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• pp.106-112
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• 2014

This paper presents the analysis of connected operation of photo voltaic source and Li energy storage system. The micro-grid has been installed and operated for several years at the campus of USF and has been a role of test bed. Photo voltaic source has been strongly influenced by the location, weather and climate of a installed area and Li battery is connected directly to the photo voltaic source to compensate for the limitations. The Li battery is operated to supply power output to the grid by the charging or discharging mode based on the average power output of the PV source which is calculated from monitored data for several years. The load of the PV and Li battery system is operated as a severe loading condition and the operating characteristics of PV source and Li battery are analyzed in detail. In connected operations of PV and Li battery to power system, the PV and Li battery is operated to supply constant power during only day time or peak time to increase load shedding ratio and efficient usage of generation sources in power system.

• 전자공학회논문지SC
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• 제45권6호
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• pp.60-66
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• 2008

리튬 전지(Li/SOCl2)는 오랜기간 방치후 부하를 인가하였을 때 순간적으로 전압이 하강하여 정상적인 작동전압을 회복하는데 까지 일정 시간이 경과해야만 하는 단점이 있는데, 이를 리튬전지의 초기전압지연이라 한다. 리튬 전지에서 필연적으로 발생하는 초기전압지연으로 인해 장비를 즉시 사용할 수 없는 단점이 있으므로, 초기전압지연 시간을 단축하는 것은 Li/SOCl2 시스템에서 극복해야 할 근본적인 과제이다. 본 논문에서는 전해액에 첨가제를 투입하거나, 리튬 음극에 PVC를 도포하는 등의 직접적인 방법으로 리튬 표면에 염화리튬 성장을 억제하는 것이 아니라, 양극의 성형밀도를 조절하여 양극 내에서 이온의 이동을 원활하게 유도함으로써, 용액저항을 감소시켜. 초기전압지연을 개선한 연구결과를 수행하였고, 특히 용액의 저항이 증가하는 저온에서 리튬전지의 초기전압지연 감소방안을 실험적 연구를 통해 개선하였다.

• 산업경영시스템학회지
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• 제37권2호
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• pp.70-76
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• 2014

In industrial situation, electronic and electro-mechanical systems have been using different type of batteries in rapidly increasing numbers. These systems commonly require high reliability for long periods of time. Wider application of battery for low-power design as a prime power source requires us knowledge of failure mechanism and reliability of batteries in terms of load condition, environment condition and other explanatory variables. Battery life is an important factor that affects the reliability of such systems. There is need for us to understand the mechanism leading to the failure state of battery with performance characteristic and develop a method to predict the life of such battery. The purpose of this paper is to develope the methodology of monitoring the health of battery and determining the condition or fate of such systems through the performance reliability to predict the remaining useful life of primary battery with load condition, operating condition, environment change in light of battery life variation. In order to evaluate on-going performance of systems and subsystems adopting primary batteries as energy source, The primitive prototype for performance reliability analysis device was developed and related framework explained.