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51.
《IEEJ Transactions on Electrical and Electronic Engineering》2017,12(4):615-622
Series‐connected lithium batteries can be charged in the pack‐charging mode, which is most widely used in the lithium battery application field. But the pack‐charging mode will lead to cell imbalance because of the difference in the electrochemical characteristics of the cells of series‐connected batteries. On the other hand, the cell‐charging mode can avoid the imbalance problem by charging each cell independently, but it will reduce the charging efficiency and increase the cost. In this paper, a novel balancing strategy is proposed with a mixed pack‐charging and cell‐charging mode to implement the balancing algorithm. The proposed strategy aims to solve the problem of charge/discharge imbalance with the simplest balancing algorithm with high balancing performance. There is no complex balancing behaviors during the charging process – as is the case with many other existing schemes – so the control algorithm can be greatly simplified. Because each cell can be fully charged and discharged with the proposed algorithm, it helps to make full use of the energy and capacity of each cell. The system stability and reliability of the proposed system, as well as its good performance, are verified through experiments. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
52.
The partial pressures of equilibrium gaseous species in pack-cementation diffusion processes using pure condensed Al(l), Cr(s), and Si(s) metals activated by various halide salts under Ar or reducing environments which contain different amounts of hydrogen have been calculated. The analyses indicate that the presence of hydrogen gas in the system does not significantly alter the equilibrium partial pressures of gaseous species for a pack containing Al at unit activity. In general, the partial pressures of CrCl2 and SiCl2 are higher in a chloride-activated pack than in a fluoride-activated pack. Therefore, the codeposition of Cr or Si with Al is possible when a chloride salt is used as the activator with a masteralloy of composition dilute in Al. The addition of hydrogen to the gas phase decreases the partial pressure of Cl2 and thereby the partial pressures of CrCl2 and SiCl2. However, the presence of hydrogen and the formation of hydrogen halides and metal hydrides could increase the kinetics of the transporting processes, particularly for the coatings of Cr and Si. The study also indicates that the vapor pressures for the volatile chlorides of Fe are significantly higher than those for Ni or Co, so that displacement reactions leading to the loss of Fe from the substrate are expected for coating processes involving high halide activities. 相似文献
53.
在粉末渗剂和45钢试样上施加4 A电流的直流电场,于800℃进行直流电场增强渗硼。以X射线衍射、光学显微观察和显微硬度测试等手段,分析位于电场不同位置试样渗硼层的相结构、显微组织、厚度与及显微硬度分布。结果表明:电场渗硼的渗层组织形态基本与常规渗硼的一致,以锯齿状楔入基体,但其相结构、显微硬度分布、厚度等与试样位置有关;朝正极面的渗层一般由Fe B和Fe2B两相组成,渗层较厚且较硬;朝负极面的渗层主要由Fe2B组成,随渗硼时间延长Fe B先增加,后减少至消失;渗硼时间等于及超过2 h,渗层下出现明显的过渡区;渗层厚度与保温时间关系曲线呈抛物线特征。从直流电场对渗剂化学反应、含硼活性基团在气氛中的扩散及硼在试样内扩散的影响等方面进行了分析。 相似文献
54.
介绍了铁路救援设备液压性能测试装置工作原理、结构组成和技术特点,通过铁路液压救援设使用备维护现状的分析,提出提高液压救援设备管理维护质量的建议。 相似文献
55.
56.
采用料浆烧结法在TZM钼合金表面制备Mo层,再通过包埋渗法制得双层结构的MoSi2厚涂层。利用内热法在大气环境下测试了钼合金Si-Mo涂层在1 600 ℃下的高温抗氧化性能。结果表明,涂层由多孔MoSi2外层和致密MoSi2内层组成,Mo粉细化对涂层组织致密化和高温抗氧化性能提升有益,平均粒度9.8 μm和2.2 μm的Mo粉制备的涂层在1 600 ℃下的高温抗氧化寿命分别为5.1 h和14.8 h,高温氧化后涂层结构转变为SiO2氧化层-多孔MoSi2层-致密层-Mo5Si3层。随着氧化持续进行,SiO2层和Mo5Si3层不断增厚,而MoSi2层持续减薄并转化为Mo5Si3,硅元素的持续贫化导致涂层最终失效。 相似文献
57.
S. S. Satheesh Kumar S. Sathiyanarayanan A. Sambasiva Rao T. Raghu 《Transactions of the Indian Institute of Metals》2009,62(2):129-133
Low density, excellent corrosion resistance, moderate strengths at high temperatures make titanium based alloys candidate
materials for advanced aerospace structures. Advanced joining techniques are emulating for fabrication of complex aerospace
structures. Roll bonding is one such solid state joining technique where bonding between two rough and clean surfaces is obtained
under high temperature and pressure. The work horse dual phase titanium alloy Ti-6Al-4V finds extensive structural application
in aerospace and space industries. In the present study, two Ti-6Al-4V sheets are stacked together and encapsulated in a mild
steel can followed by evacuation and hot crimping. The pack is extensively deformed to ∼84% reduction in thickness employing
conventional hot rolling mill. Partially roll bonded 0.74mm thick sheets were obtained and microstructural evolution was studied
using light microscopy and scanning electron microscopy. The incompletely bonded interface was analyzed through elemental
mappings by Electron Probe Micro Analyzer and compared with completely bonded region. The partially bonded region revealed
the presence of aluminium oxide at the interface which possibly could have hindered complete bonding at that region. The room
temperature tensile properties of as- roll bonded Ti-6Al-4V nearly approaches the base material properties. 相似文献
58.
大孔径、高孔密防砂射孔技术主要适用于砾石充填防砂的油井,它有利于降低充填防砂井的充填压力,提高油井产能。2002年在草13区块实施大孔径、高孔密防砂射孔作业9井次,降低施工压力8-14MPa,日产油量增加6.8t。固井质量分析表明,大孔径、高孔密防砂射孔对套管和水泥环末造成损害,是一种具有广阔应用前景的先进射孔工艺。 相似文献
59.
HISTORICALLY superalloys have been used in gasturbine applications with a protective coating to combatoxidation problems in aero engines and hot corrosionproblems in industrial and marine engines.Theprotective coatings used are predominantly of thediffusion type produced by variety of techniques suchas pack cementation,chemical vapor deposition,slurryfusion and hot dipping[1,2].The purpose of this typeof coatings is to increase the amount of Al at thesurface of a component,so that a protec… 相似文献
60.
K.-R. Eschke 《Packaging Technology and Science》1995,8(3):139-147
German legislation on the avoidance of packaging waste has provoked German industry to reduce packaging in a number of ways. One of these is reducing the sensitivity of engineered products to transport conditions. The principle of designing such products for the minimisation of their packaging requirements should be supplemented to existing design principles and should be included within the conventional design process. Thereby, future savings of materials, energy and recycling would be ensured and the competitiveness of industry would be increased as a result of cost reductions. 相似文献