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刘文武 《洛阳师范学院学报》2014,(5):44-48
为了缩短铅酸蓄电池的充电时间和延长其使用寿命,设计了一种太阳能LED路灯自动控制系统.通过实时采集蓄电池和太阳能电池板的电压来调整PWM波形的占空比,从而实现快速脉冲充电.恒压限流快速脉冲充电方法能有效消除蓄电池极化现象,提高充电效率.此系统能准确控制蓄电池充放电过程,可广泛用于农村道路亮化工程,具有可靠性高、性价比高、节能环保、CO2零排放等优点. 相似文献
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根据光伏阵列的输出特性与蓄电池充电特性,设计了一套具有最大功率点跟踪的光伏充电系统。该系统以dsPIC30F5011单片机为控制器,采用Cuk电路为充电主回路,根据蓄电池端电压对蓄电池采用四阶段充电控制策略。在欠电压充电阶段,采用基于PI调节的涓流对蓄电池充电;在快速充电的阶段,使用基于电导增量法的最大功率跟踪算法对蓄电池充电;在过冲与浮充阶段,使用基于PI调节的带有温度补偿的恒压充电。试验结果表明,最大功率点跟踪能快速跟踪外界环境的变化,并稳定工作在最大功率点,提高光伏电池的使用效率;过冲和浮充电压精度高,能延长蓄电池使用寿命。 相似文献
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基于DS2438的多功能智能蓄电池充电器的设计 总被引：1，自引：0，他引：1
陈辉煌 《江西电力职业技术学院学报》2011,24(3):52-55
介绍了一种基于DS2438智能充电器的设计方案,该智能充电器能对各类蓄电池进行充电,并对充电电池具有自动检测能力.监测芯片将电池的电压、电流、温度等参数通过单总线的方式送到单片机,由单片机AT89S52进行控制,保证蓄电池不过充,以合理的充电方式进行充电,使其蓄电池延长使用寿命. 相似文献
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针对铅酸蓄电池充电过程对其使用寿命的影响,研制了基于MC68HC08的智能型充电器,设计了硬件电路和智能控制软件,提出了恒流、恒压和浮充三阶段的充电方式,实现了智能化控制。 相似文献
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SS9型电力机车蓄电池充放电流表是与蓄电池并接在一起的,不管蓄电池是否在充电,充放电流表均显示放电状态,蓄电池是否出现亏电也无法确定,为了解决这一设计上的缺陷,使蓄电池充放电流表能正确地显示充放电状态,势必要对其线路进行改造。 相似文献
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《绵阳师范学院学报》2017,(2):21-25
铅酸蓄电池作为动力电池仍然在电动汽车中被广泛使用,然而蓄电池的充电技术是制约电动汽车快速普及的一个重要原因.本文阐述了电动汽车铅酸蓄电池的充放电特性,分析了铅酸蓄电池的可接受充电电流.通过对蓄电池常规充电方法比较的基础上,采用了分阶段脉冲快速充电方法,给出了新能源电动汽车铅酸蓄电池脉冲充电系统总体设计方案.通过常规分阶段充电机与脉冲充电样机的对比测试,验证了分阶段脉冲快速充电的可行性. 相似文献
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均衡充电是串联蓄电池充电过程的重要组成部分,讨论了影响阀控铅酸蓄电池性能的均衡充电问题。指出了被动均衡充电,即传统过充电方式的弊端:速度太慢,尤其当单元电池串联块数超过12块更是如此。主动均衡充电优势明显,可加快充电进程,支持故障单元电池或单体电池更换。指出了主动均衡充电能达到10m V/单元电池数量级,可延长蓄电池组使用寿命。适当设计的主动均衡充电可使串联蓄电池组寿命与单元电池寿命一致。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献