The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the i...The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the impact of urban block landscape environment on thermal comfort in China,collected by CNKI(China National Knowledge Infrastructure)from 2002 to 2022,are used as the research object.Through bibliometric statistical analysis,LLR algorithm,and cluster analysis,the current research status of the impact of urban block landscape environment on thermal comfort in China is analyzed and processed,and its external characteristics are identified.Using the information visualization software CiteSpace,the research topics in the field of the impact of urban block landscape environment on thermal comfort are presented in the form of knowledge graphs.Through co-occurrence analysis of keywords and trend of word frequency changes,the development trends of research hotspots and cutting-edge fields of the impact of urban block landscape environment on thermal comfort are determined,hoping to provide reference for future research in this field.展开更多
智能软开关(Soft Open Points,SOP)的普及使得多台区联合运行成为趋势。针对大规模户用光伏接入低压配电网带来的电压越限、网损和三相不平衡问题,提出一种基于SOP的柔性互联两阶段优化控制架构。日前阶段,考虑长时间尺度光伏及负荷功率...智能软开关(Soft Open Points,SOP)的普及使得多台区联合运行成为趋势。针对大规模户用光伏接入低压配电网带来的电压越限、网损和三相不平衡问题,提出一种基于SOP的柔性互联两阶段优化控制架构。日前阶段,考虑长时间尺度光伏及负荷功率,建立以台区Ⅰ、Ⅱ总网损最小、三相不平衡度最小为目标函数的三相四线柔性互联低压配电网优化模型,求取SOP三相功率出力,采用模型凸化的方式降低求解难度。日内阶段,针对光伏及负荷5分钟短时功率扰动带来的电压波动越限问题,基于日前SOP优化结果,利用SOP两侧换流器电压-无功下垂控制方法抑制电压越限问题。仿真结果表明,所提两阶段优化控制策略能够有效抑制高比例光伏并网带来的供电质量问题。此外,为了保障优化结果对比分析的客观性,选取与本文优化参数相近、光伏接入情况与网络模型相同的文献案例进行对比分析。分析结果表明,通过功率在空间上的转移,实现不同交流台区间的功率互济,解决了多个台区存在的电压质量和网损问题,并且控制变量数目更少,综合优化结果更好。展开更多
With the continuous development of promoting high-quality and balanced basic education and the continuous advancement of research on spatial layout of school,it aims to ensure that the public enjoys educational resour...With the continuous development of promoting high-quality and balanced basic education and the continuous advancement of research on spatial layout of school,it aims to ensure that the public enjoys educational resources fairly.Based on 63 items of POI data of primary and secondary schools in Shijingshan District,Beijing,this study analyzes the spatial layout,degree supply,and coverage of primary and secondary schools in Shijingshan District using three spatial analysis methods:ArcGIS average nearest neighbor,kernel density analysis,and standard deviation ellipse.The results show that the spatial layout of primary and secondary schools in Shijingshan District,Beijing is characterized by overall clustering:the central region is high-density distribution,while the eastern and western parts are scattered.Moreover,this spatial structure continues to develop along the northwest-southeast direction.Although the high-density population areas in the nine streets correspond to the high-density distribution of schools,the service scope of primary and secondary schools does not cover all residential areas,and the distribution of residential areas within the coverage range is uneven.At the same time,the actual degree supply in Shijingshan District is insufficient.展开更多
针对大规模光伏并网引起的低压配电网电压越限、三相不平衡和高网损问题,考虑到智能软开关(soft open points,SOP)和储能设备对潮流的灵活控制作用,提出一种含3端口SOP与储能设备的三相四线制低压配电运行优化方法。首先,讨论了现有智...针对大规模光伏并网引起的低压配电网电压越限、三相不平衡和高网损问题,考虑到智能软开关(soft open points,SOP)和储能设备对潮流的灵活控制作用,提出一种含3端口SOP与储能设备的三相四线制低压配电运行优化方法。首先,讨论了现有智能软开关与储能设备对于三相四线制低压配电网的适用性,分析了含3端口SOP和储能设备的三相四线潮流计算模型。其次,针对SOP各端口换流器可能出现容量不足的问题,引入储能设备进行辅助调节;建立了以网络损耗、电压三相不平衡度作为目标函数,以SOP三相有功功率和无功功率、储能无功功率作为控制变量的协同优化模型。在模型求解方面,采用模型凸化的方式降低求解难度。算例验证结果表明,所提优化方案能够在大规模光伏单相并网条件下,改善电网运行环境。展开更多
基金the National Natural Science Foundation of China(51708004)Beijing Youth Teaching Master Team Construction Project(108051360023XN261)Yuyou Talent Training Program of North China University of Technology(215051360020XN160/009).
文摘The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the impact of urban block landscape environment on thermal comfort in China,collected by CNKI(China National Knowledge Infrastructure)from 2002 to 2022,are used as the research object.Through bibliometric statistical analysis,LLR algorithm,and cluster analysis,the current research status of the impact of urban block landscape environment on thermal comfort in China is analyzed and processed,and its external characteristics are identified.Using the information visualization software CiteSpace,the research topics in the field of the impact of urban block landscape environment on thermal comfort are presented in the form of knowledge graphs.Through co-occurrence analysis of keywords and trend of word frequency changes,the development trends of research hotspots and cutting-edge fields of the impact of urban block landscape environment on thermal comfort are determined,hoping to provide reference for future research in this field.
文摘智能软开关(Soft Open Points,SOP)的普及使得多台区联合运行成为趋势。针对大规模户用光伏接入低压配电网带来的电压越限、网损和三相不平衡问题,提出一种基于SOP的柔性互联两阶段优化控制架构。日前阶段,考虑长时间尺度光伏及负荷功率,建立以台区Ⅰ、Ⅱ总网损最小、三相不平衡度最小为目标函数的三相四线柔性互联低压配电网优化模型,求取SOP三相功率出力,采用模型凸化的方式降低求解难度。日内阶段,针对光伏及负荷5分钟短时功率扰动带来的电压波动越限问题,基于日前SOP优化结果,利用SOP两侧换流器电压-无功下垂控制方法抑制电压越限问题。仿真结果表明,所提两阶段优化控制策略能够有效抑制高比例光伏并网带来的供电质量问题。此外,为了保障优化结果对比分析的客观性,选取与本文优化参数相近、光伏接入情况与网络模型相同的文献案例进行对比分析。分析结果表明,通过功率在空间上的转移,实现不同交流台区间的功率互济,解决了多个台区存在的电压质量和网损问题,并且控制变量数目更少,综合优化结果更好。
文摘With the continuous development of promoting high-quality and balanced basic education and the continuous advancement of research on spatial layout of school,it aims to ensure that the public enjoys educational resources fairly.Based on 63 items of POI data of primary and secondary schools in Shijingshan District,Beijing,this study analyzes the spatial layout,degree supply,and coverage of primary and secondary schools in Shijingshan District using three spatial analysis methods:ArcGIS average nearest neighbor,kernel density analysis,and standard deviation ellipse.The results show that the spatial layout of primary and secondary schools in Shijingshan District,Beijing is characterized by overall clustering:the central region is high-density distribution,while the eastern and western parts are scattered.Moreover,this spatial structure continues to develop along the northwest-southeast direction.Although the high-density population areas in the nine streets correspond to the high-density distribution of schools,the service scope of primary and secondary schools does not cover all residential areas,and the distribution of residential areas within the coverage range is uneven.At the same time,the actual degree supply in Shijingshan District is insufficient.
文摘针对大规模光伏并网引起的低压配电网电压越限、三相不平衡和高网损问题,考虑到智能软开关(soft open points,SOP)和储能设备对潮流的灵活控制作用,提出一种含3端口SOP与储能设备的三相四线制低压配电运行优化方法。首先,讨论了现有智能软开关与储能设备对于三相四线制低压配电网的适用性,分析了含3端口SOP和储能设备的三相四线潮流计算模型。其次,针对SOP各端口换流器可能出现容量不足的问题,引入储能设备进行辅助调节;建立了以网络损耗、电压三相不平衡度作为目标函数,以SOP三相有功功率和无功功率、储能无功功率作为控制变量的协同优化模型。在模型求解方面,采用模型凸化的方式降低求解难度。算例验证结果表明,所提优化方案能够在大规模光伏单相并网条件下,改善电网运行环境。
