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本文对2004年全国大学生数学建模竞赛B题进行了全面分析，按照电力市场规则和输电阻塞管理原则，建立了求下一时段各机组的出力分配预案模型、计算各机组当前出力下各线路上对应的有功潮流模型，同时公平地考虑了序内容量与序外容量部分的经济补偿——输电阻塞费用并建立了此费用的计算模型．针对这三个模型分别用数学软件Matlab6．5、Lingo8，0编写了计算程序． 相似文献
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潘国英 《福建教育学院学报》2005,6(4):98-103
本文根据2004年全国大学生数学建模竞赛的B题数据为基础,并依据我国目前电力系统的改革需要,发电侧电力市场必须采取交易与调度一体化的模式,以及电网公司在组织交易、调度和配送时,必须遵循电网“安全第一“的原则,制订一个电力市场交易规则,按照购电费用最小的经济目标来运作.当出现电力市场的输电阻塞时,还需实时调度承担AGC(自动发电控制)辅助服务的机组出力,以跟踪电网中实时变化的负荷,并给出因输电阻塞而不能执行初始交易结果而引起阻塞费用. 相似文献
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利用最优化原理设计一种简明、合理的阻塞费用计算规则，提出了电力市场中进行阻塞调度的一种方法．该方法以发电机出力调整的成本最小(即阻塞费用最小)为目标函数，考虑了电力市场中的约束条件，得到既保证电力系统经济性又满足电力系统安全性的最优调度计划方案．通过实例计算表明该方法正确、可行． 相似文献
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讨论了电力市场的输电阻塞管理同胚，根据电力市场交易规则、输电阻塞管理原则，建立了相应的数学优化模型，算出了各模型对应的配电方案。最后。利用计算机模拟求得在不致引起输电阻塞时最大的市场负荷需求为983．2MW，在不致引起拉闸限电时最大的市场负荷需求为1094．6MW，并对模型的具体算法进行了讨论。 相似文献
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易兆麟 《衡阳师范学院学报》2006,27(3):22-25
首先通过多元线性回归,找到了主要线路的有功潮流与各机组出力之间的线性函数关系,并对潮流与机组出力之间的线性关系,作了显著性检验;设计了一种简单、合理的阻塞费用计算规则,该规则兼顾了发电厂商与网方的利益,双方都能接受该计算规则。 相似文献
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《实验室研究与探索》2020,(2)
基于模型预测控制理论,提出一种多尺度功率协调调度优化模型。通过建立分布式电源、柔性负荷和储能装置预测模型来降低其出力不确定性对调度建模的影响;基于模型预测控制设计日前—日间—实时反馈优化调度模型,采用日前优化确定慢动作设备出力值;日间优化确定快速可调资源出力计划值;实时反馈优化以日间优化出力值为参考,进行闭环实时反馈滚动优化,提高了调度决策的准确性。在Matlab仿真平台搭建改进IEEE33节点仿真算例验证所提多尺度调度模型的可行性和有效性。 相似文献
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对2004年高教社杯全国大学生数学建模竞赛B题进行了深入研究,对我国电力系统改革中电力输电阻塞的问题进行深入的探讨分析,利用列解超线性方程组等方法建立数学模型,从而解决了我国电力市场输电阻塞管理中的有关问题。 相似文献
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通过对2004年全国大学生数学建模竞赛(B题)电力市场的输电阻塞管理问题中,电力市场清算价的分析,建立了4个数学模型,从多个角度探讨在数模竞赛中进行数学模型的建立和求解的方法. 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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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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《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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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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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