Currently,the critical challenge in solar photovoltaic(PV)systems is to make them energy efficient.One of the key factors that can reduce the PV system power output is partial shading conditions(PSCs).The reduction in...Currently,the critical challenge in solar photovoltaic(PV)systems is to make them energy efficient.One of the key factors that can reduce the PV system power output is partial shading conditions(PSCs).The reduction in power output not only depends on a shaded region but also depends on the pattern of shading and physical position of shaded modules in the array.Due to PSCs,mismatch losses are induced between the shaded modules which can cause several peaks in the output power-voltage(P-V)characteristics.The series-parallel(SP),total-cross-tied(TCT),bridge-link(BL),honey-comb(HC),and triple-tied(TT)configurations are considered as conventional configurations,which are severely affected by PSCs and generate more mismatch power losses along with a greater number of local peaks.To reduce the effect of PSCs,hybrid PV array configurations,such as series-parallel:total-cross-tied(SP-TCT),bridge-link:total-cross-tied(BL-TCT),honey-comb:total-cross-tied(HC-TCT)and bridge-link:honey-comb(BL-HC)are proposed.This paper briefly discusses the modeling,simulation and performance evaluation of hybrid and conventional 7×7 PV array configurations during different PSCs in a Matlab/Simulink environment.The performance of hybrid and conventional PV configurations are evaluated and compared in terms of global maximum power(GMP),voltage and currents at GMP,open and short circuit voltage and currents,mismatch power loss(MPL),fill factor,efficiency,and a number of local maximum power peaks(LMPPs).展开更多
An efficient path planning algorithm based on topologic method is presented in this paper.The colli- sion free path planning for three-joint robotic arm consists of three parts:partition of C-space,construc- tion of C...An efficient path planning algorithm based on topologic method is presented in this paper.The colli- sion free path planning for three-joint robotic arm consists of three parts:partition of C-space,construc- tion of CN and search for a path in CN.We mainly solved the problems of partitioning the C-space and judging the connectivity between connected blocks,etc.For the motion planning of a robotic arm with a gripper,we developed the concepts of global planning and local planning,and discussed the basic fac- tors for constructing the planning system.In the paper,some evaluation and analysis of the complexity and reliability of the algorithm are given,together with some ideas to improve the efficiency and increase the reliability.At last,some experimental results are presented to show the efficiency and accuracy of the nigorithm.展开更多
With the Double Star Program TC1 in the equatorial orbit and Cluster tetrahedron in the high latitude polar orbit, a conjunct observation of FTEs on the dayside magnetopause (MP) on April 6, 2004 is presented in this ...With the Double Star Program TC1 in the equatorial orbit and Cluster tetrahedron in the high latitude polar orbit, a conjunct observation of FTEs on the dayside magnetopause (MP) on April 6, 2004 is presented in this study. The FTEs observed by TC1 at low latitudes are characterized to be generated in the subsolar region and the obtained flux tube axes orientate along the predicted low latitude component magnetic reconnection X-line, indicating that these FTEs were more likely to be generated through multiple X-line reconnection or single X-line bursty reconnec-tion. During the same period, Cluster also encountered a series of magnetosheath FTEs with their axes pointing roughly along the interplanetary magnetic field. At last, the global FTE configuration is obtained from observations in different loca-tions, which is in good agreement with the "elbow shape" model.展开更多
In this work the authors consider the problem of optimally distributing 8 points inside a unit square so that the smallest area of the(38)triangles formed by them is maximal.Symbolic computations are employed to reduc...In this work the authors consider the problem of optimally distributing 8 points inside a unit square so that the smallest area of the(38)triangles formed by them is maximal.Symbolic computations are employed to reduce the problem into a nonlinear programming problem and find its optimal solution.All computations are done using Maple.展开更多
负荷高密度地区现有的输电通道有限且系统内灵活性电源的占比较低,应对源端可再生能源及荷端负荷需求随机性波动的调节能力不足。储能系统(energy storage system,ESS)作为一种高效的灵活性资源,具有响应的快速性和功率双向转化的优点,...负荷高密度地区现有的输电通道有限且系统内灵活性电源的占比较低,应对源端可再生能源及荷端负荷需求随机性波动的调节能力不足。储能系统(energy storage system,ESS)作为一种高效的灵活性资源,具有响应的快速性和功率双向转化的优点,可以为电力系统提供灵活性支撑,基于双层规划模型建立了提升负荷高密度地区整体和局部灵活性的储能优化配置方法,上层模型对储能配置方案做出战略决策,下层模型基于场景分析法,对典型日场景进行运行模拟,使用条件风险价值(conditional value at risk,CVaR)量化灵活性不足风险成本,模型充分地考虑了电力供需平衡、新能源消纳以及网架结构的支撑作用,通过添加关联约束将双层模型转化为单层模型。最后通过MATLAB平台调用商用软件包GUROBI完成混合整数规划优化,求解得到最优配置方案。在某实际系统负荷高密度地区中验证了配置方法的有效性。展开更多
基金supported by the Science and Engineering Research Board(SERB),Department of Science and Technology,Government of India,under the Grant number:ECR/2017/000316.
文摘Currently,the critical challenge in solar photovoltaic(PV)systems is to make them energy efficient.One of the key factors that can reduce the PV system power output is partial shading conditions(PSCs).The reduction in power output not only depends on a shaded region but also depends on the pattern of shading and physical position of shaded modules in the array.Due to PSCs,mismatch losses are induced between the shaded modules which can cause several peaks in the output power-voltage(P-V)characteristics.The series-parallel(SP),total-cross-tied(TCT),bridge-link(BL),honey-comb(HC),and triple-tied(TT)configurations are considered as conventional configurations,which are severely affected by PSCs and generate more mismatch power losses along with a greater number of local peaks.To reduce the effect of PSCs,hybrid PV array configurations,such as series-parallel:total-cross-tied(SP-TCT),bridge-link:total-cross-tied(BL-TCT),honey-comb:total-cross-tied(HC-TCT)and bridge-link:honey-comb(BL-HC)are proposed.This paper briefly discusses the modeling,simulation and performance evaluation of hybrid and conventional 7×7 PV array configurations during different PSCs in a Matlab/Simulink environment.The performance of hybrid and conventional PV configurations are evaluated and compared in terms of global maximum power(GMP),voltage and currents at GMP,open and short circuit voltage and currents,mismatch power loss(MPL),fill factor,efficiency,and a number of local maximum power peaks(LMPPs).
文摘An efficient path planning algorithm based on topologic method is presented in this paper.The colli- sion free path planning for three-joint robotic arm consists of three parts:partition of C-space,construc- tion of CN and search for a path in CN.We mainly solved the problems of partitioning the C-space and judging the connectivity between connected blocks,etc.For the motion planning of a robotic arm with a gripper,we developed the concepts of global planning and local planning,and discussed the basic fac- tors for constructing the planning system.In the paper,some evaluation and analysis of the complexity and reliability of the algorithm are given,together with some ideas to improve the efficiency and increase the reliability.At last,some experimental results are presented to show the efficiency and accuracy of the nigorithm.
基金the NSFC (Grant No. 40731056)the Chinese Key Research Project (Grant No. 2006CB806300)
文摘With the Double Star Program TC1 in the equatorial orbit and Cluster tetrahedron in the high latitude polar orbit, a conjunct observation of FTEs on the dayside magnetopause (MP) on April 6, 2004 is presented in this study. The FTEs observed by TC1 at low latitudes are characterized to be generated in the subsolar region and the obtained flux tube axes orientate along the predicted low latitude component magnetic reconnection X-line, indicating that these FTEs were more likely to be generated through multiple X-line reconnection or single X-line bursty reconnec-tion. During the same period, Cluster also encountered a series of magnetosheath FTEs with their axes pointing roughly along the interplanetary magnetic field. At last, the global FTE configuration is obtained from observations in different loca-tions, which is in good agreement with the "elbow shape" model.
基金the National Natural Science Foundation of China under Grant Nos.12171159 and 12071282“Digital Silk Road”Shanghai International Joint Lab of Trustworthy Intelligent Software under Grant No.22510750100。
文摘In this work the authors consider the problem of optimally distributing 8 points inside a unit square so that the smallest area of the(38)triangles formed by them is maximal.Symbolic computations are employed to reduce the problem into a nonlinear programming problem and find its optimal solution.All computations are done using Maple.
文摘负荷高密度地区现有的输电通道有限且系统内灵活性电源的占比较低,应对源端可再生能源及荷端负荷需求随机性波动的调节能力不足。储能系统(energy storage system,ESS)作为一种高效的灵活性资源,具有响应的快速性和功率双向转化的优点,可以为电力系统提供灵活性支撑,基于双层规划模型建立了提升负荷高密度地区整体和局部灵活性的储能优化配置方法,上层模型对储能配置方案做出战略决策,下层模型基于场景分析法,对典型日场景进行运行模拟,使用条件风险价值(conditional value at risk,CVaR)量化灵活性不足风险成本,模型充分地考虑了电力供需平衡、新能源消纳以及网架结构的支撑作用,通过添加关联约束将双层模型转化为单层模型。最后通过MATLAB平台调用商用软件包GUROBI完成混合整数规划优化,求解得到最优配置方案。在某实际系统负荷高密度地区中验证了配置方法的有效性。
