• 한국전산유체공학회지
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• 제16권3호
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• pp.82-87
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• 2011

The battery pack, a main component of NEV(Neighborhood Electric Vehicle), needs cooling system when it is charging or discharging to prevent the degradation of the battery charging efficiency. The purpose of this study is to analyse the effects of cooling methods, changing positions of inlet and outlet and changing area ratios of inlet and outlet. It has been observed that in the point of uniform cooling, suction from the exit side is more efficient than blowing from the inlet. And there is a suitable inlet/outlet area ratio in maximizing the mass flow rate. A commercial code, STAR-CCM+(ver. 4.02), was used for the numerical study.

• 멤브레인
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• 제24권5호
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• pp.386-392
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• 2014

두 종류의 막(다공성 막, 양이온교환막)을 사용하여 아연-브롬 레독스-흐름 전지(ZBRFB, Zn-Br redox-flow battery)의 성능을 평가하였다. ZBRFB의 성능평가는 $20mA/cm^2$의 전류밀도에서 진행하였다. 다공성 막인 SF-600을 사용한 ZBRFB의 기전력(SOC 100%에서의 OVC)은 1.87 V, 양이온교환막인 Nafion117 막을 사용한 ZBRFB의 기전력은 1.93 V를 나타냈다. 각 막을 사용한 ZBRFB의 성능은 7회 충 방전 실험을 진행하여 평가하였다. SF600 막을 사용한 ZBRFB의 평균 전류효율은 89.76%, 평균 전압효율은 83.46%, 평균 에너지효율은 74.88%를 나타냈으며, Nafion117 막을 사용한 ZBRFB의 평균 전류효율은 97.7%, 평균 전압효율은 76.33%, 평균 에너지효율은 74.56%를 나타냈다.

• 한국수소및신에너지학회논문집
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• 제24권4호
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• pp.347-352
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• 2013

Four types of electrolyte were tested for the application as an electrolyte in the Zn-Br redox flow battery. Electrolyte was consist of $ZnBr_2$ (electrolyte number 1), $ZnBr_2+KCl$ (electrolyte number 2), $ZnBr_2+KCl+NH_4Br$ (electrolyte number 3) and $ZnBr_2+KCl+EMPBr(C_7H_{16}BF_4N)$ (electrolyte number 4). The each electrolyte property was measured by CV (cyclic voltammetry) method. The different between the potential of anodic and cathodic maximum current density in a CV experiment (${\Delta}E_P$) was 0.89V, 0.89V, 1.06V and 0.61V for the electrolyte number 1, 2, 3 and 4, respectively. The electrolyte involved KCl increased conductivity which was appeared by anodic and cathodic maximum current density in a CV experiment. It was estimated that the electrolyte of number 3 ($ZnBr_2+KCl+NH_4Br$) and number 4 ($ZnBr_2+KCl+EMPBr$) could be suitable as an electrolyte in the Zn-Br redox flow battery with non-appeared bubble, non-Br formation and high anodic-cathodic maximum current density.

• 멤브레인
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• 제31권4호
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• pp.262-267
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• 2021

메타바나듐산 암모늄으로 제조한 전해액과 양이온교환막인 Nafion117을 활용하는 바나듐 레독스 흐름 전지(vanadium redox flow battery, VRFB)의 전기화학적 성능을 평가하였다. VRFB의 전기화학적 성능은 전류밀도 60 mA/cm²에서 측정하였다. 메타바나듐산 암모늄으로 제조된 전해액을 사용한 VRFB의 평균 전류효율은 94.9%, 평균 전압효율은 82.2%, 평균 에너지효율은 78.0%를 보였다. 그리고 메타바나듐산 암모늄으로 제조된 전해액을 사용한 VRFB의 각 효율은 바나딜 설페이트(VOSO₄)로 제조된 전해액을 사용한 VRFB의 각 효율과 비교하여 거의 동등한 값을 갖는다는 것을 확인하였다.

• Design & Manufacturing
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• 제16권4호
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• pp.34-39
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• 2022

Sustained economic development around the world is accelerating resource depletion. Research and development of secondary batteries that can replace them is also being actively conducted. Secondary batteries are emerging as a key technology for carbon neutrality. The core of an electric vehicle is the battery (secondary battery). Therefore, in this study, the temperature change by the heat source of the hammer and the rotational speed (rpm) of the abrasive disc of the Classifier Separator Mill (CSM) was repeatedly calculated and analyzed using the heat flow simulation STAR-CCM+. As the rotational speed (rpm) of the abrasive disk increases, the convergence condition of the iteration increases. Under the condition that the inlet speed of the Classifier Separator Mill (CSM) and the heat source value of the disc hammer are the same, the disc rotation speed (rpm) and the hammer temperature are inversely proportional. As the rotational speed (rpm) of the disc increases, the hammer temperature decreases. However, since the wear rate of the secondary battery material increases due to the strong impact of the crushing rotational force, it is determined that an appropriate rpm setting is necessary. In CSM (Classifier Separator Mill), it is judged that the flow rate difference is not significantly different in the direction of the pressure outlet (Outlet 1) right above the classifier wheel with the fastest flow rate. Because the disc and hammer attachment technology is adhesive, the attachment point may deform when the temperature of the hammer rises. Therefore, it is considered necessary to develop high-performance adhesives and other adhesive technologies.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.431-434
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• 1999

This paper presents design of controllers for battery energy storage system. The proposed battery energy storage system can be controlled to operate in the power conditioning mode or the inverter mode. The operation of this mode further divided into three cases: (a) in the peak load period, the load power supplied from the utility is minimized as far as possible; (b) in the off-peak load period, the utility supplies power to the load and charges the battery bank with automatic charging control; (c) in the medium load period, to save battery energy the real power flow out of the battery energy storage system is minimized. Besides, in all cases, the proposed battery energy storage system also automatically compensates the harmonics, subharmonics and reactive power factor in the utility side are much improved. Simulation results are presented by the effectiveness of the proposed controllers for battery energy storge system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.115-116
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• 2013

Recently environmental problems such as greenhouse gas emissions has become a global problem. As a result, the current that can be easily used to Petroleum and coal reserves of fossil energy and environmental issues, coupled with the limitations of this finding for renewable energy to replace the movement is spreading around the world. Among them Energy Storage System with secondary battery technology has been increased interest in, Redox flow batteries, unlike the conventional theory, the life of the rechargeable battery almost no restrictions existing lithium-ion batteries 10 times more than the life of the road. In this paper, power plant or power system, installed in a building that can cope with the rapid increase in demand for power redox flow battery for 100kW PCS will be introduced.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.200-205
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• 2017

The three electrodes (carbon felt) were tested in all-vanadium redox flow battery (VRFB) to confirm the its usefulness. The electrode property was measured by the CV (cyclic voltammetry) method. The current ratio of maximum peak(IPA/IPC) in GF040BH5 and GF051BH3 had almost the same value compared to that in XF30A. The performances of VRFB using the each electrode were measured during 5 cycles of charge-discharge at the current density of $60mA/cm^2$. An average energy efficiency of the VRFB was 77.8%, 77.3%, and 79.2% for XF30A, GF040BH5 and GF051BH3, respectively. It was confirmed from the data that GF040BH5 and GF051BH3 is well suited for use in a VRFB as a electrode, like XF30A.

• 멤브레인
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• 제21권2호
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• pp.107-117
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• 2011

바나듐 레독스-흐름 전지 (V-RFB)는 대용량 전력저장 시스템의 하나로 연구가 많이 진행되고 있다. 특히 최근에 지구온난화의 해결을 위한 태양광, 풍력 발전 등 재생에너지에 의한 발전과 함께 이 전력 원들의 부하 평준화 및 전력 공급 원활화 등을 위한 전력 저장 시스템의 하나로 주목을 받고 있다. 본 총설에서는 V-RFB 에 대한 원리 및 구성, 최근 연구 동향, 경제성, 요소기술에 대해 설명하고자 한다.

• 전력전자학회논문지
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• 제19권2호
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• pp.106-115
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• 2014

This paper proposes ESS DC-DC Converter using Redox Flow Battery (RFB) for stand-alone microgrid. Price, safety, expandability and dynamics are crucial in ESS. Reports show that Zinc-bromine (ZnBr) RFB is the best choice in ESS. Simple electrical ZnBr RFB model is obtained from charging test. DC-DC converter Inductor current-DClink Voltage model is proposed for the DC microgrid. For the controller design in z-domain, the K-factor method is by considering nature of the digital controller. The control performance has been verified with simulation and hardware experiments. Lastly 10kW DC microgrid using RFB test result is shown.