共查询到20条相似文献，搜索用时 46 毫秒
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赵慧 《广东轻工职业技术学院学报》2009,8(2):16-19
本文针对太阳能电动车的能源供给部件太阳能电池的工作特性,采用buck型DC—DC变换器和滑模控制技术来实现对太阳能电池输出最大功率点的跟踪,实验结果证明了滑模控制技术能够快速的跟踪太阳能电池输出最大功率点。 相似文献
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从太阳能电池数学模型出发,利用MATLAB/Simulink工具箱建立了太阳能电池的仿真模型,对影响太阳能电池输出性能因素(工作温度、光照强度)进行了仿真分析.仿真结果表明:太阳能电池输出特性呈非线性,相同光照强度下,环境温度升高,太阳能开路电压降低,输出最大功率值减小,其性能在逐渐减弱.相同环境温度下,光照强度提高,开路电压升高,输出最大功率值增加,太阳能电池输出性能提高. 相似文献
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《北京工业职业技术学院学报》2020,(3)
光伏系统的输出因受外界影响,无法长时间稳定供电,因此必须借助光伏充电控制器解决这一问题。为了保证在不同条件下输出功率最大,研究追踪最大功率点(MPPT)的光伏充电控制器,结合光伏电池的输出特性和充放电特性,设计完成基于MPPT的光伏充电控制器。经试验测试,该控制器能保证输出电压幅值稳定,追踪效率在0.95以上,充分提高了太阳能的利用率。 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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《实验室研究与探索》2016,(11):119-122
针对心电图机DC/DC电源进行了设计。以TPS5450 DC/DC转换芯片和MC9S08QG8单片机为核心的多路DC电源,包括DC/DC转换电路,充电电路,升压电路,单片机电路等,通过该电路来输出多路电压,利用软件编程实现对输出的多路电压值实时检测,并交由上位机处理,从而保证系统的可靠性和稳定性。实验结果表明,该DC/DC开关电源设计符合心电图机电源的要求,运行安全稳定可靠。 相似文献
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李中望 《西安文理学院学报》2015,(2):33-36
所讨论的太阳能充电控制电路选择Cuk电路实现升降压变化,完成恒压充电,通过控制功率开关管的导通与关断来实现电压的变换,调节占空比来调节输出电压.运用MATLAB软件对充电控制电路进行仿真,以为电路结构设计与参数设置提供重要依据. 相似文献
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目前,世界正在面临寻找替代能源以减少对常规能源的依赖,太阳能便是一个很好的解决方案。但是太阳能辐射强度和环境温度对太阳能电池技术参数和输出特性有很大影响,这里采用了太阳能电池的实用化的工程数学模型,在Matlab/Simulink的仿真系统中,建立了太阳能电池阵列的仿真模型,便于运用到太阳能的开发研究工作中。 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 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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Anton Franks 《English in Education》1999,33(2):39-49
This paper looks at the way drama works to bring a model of an arts curriculum into reality. He also shows how drama is valuable when discussed as a separate, autonomous subject in the school curriculum as opposed to one subsumed within English. He argues for a view of the arts and gives an example of a sequence of work in an English GCSE class based around Arthur Miller's play View from the Bridge. From this he draws out several strands about the relationship of the drama curriculum to the individual students and teachers, the school, and to culture. He also emphasises the primacy of performance in drama education. 相似文献