为解决带T型支路的混合输电线路故障测距问题,结合故障行波在带T型支路输电线路中的传播特性,提出一种基于组合行波测距原理的T型输电线路故障测距方法。首先通过双端测距原理判断故障所在区间,然后利用单端测距原理得到故障距离。与传...为解决带T型支路的混合输电线路故障测距问题,结合故障行波在带T型支路输电线路中的传播特性,提出一种基于组合行波测距原理的T型输电线路故障测距方法。首先通过双端测距原理判断故障所在区间,然后利用单端测距原理得到故障距离。与传统T型支路故障测距方法主要适用于单一架空线路相比,该方法适用于带有T型支路的混合输电线路,可进一步提高测距精度。电力系统计算机辅助设计软件(Power Systems Computer Aided Design,PSCAD)仿真验证了该方法的有效性和实用性,满足对故障测距精度的要求,能够简单有效、准确可靠的得出测距结果。展开更多
The influence of melt convection on dendrite growth during the upward-directional solidification of Pb-33%Sn binary alloys was investigated.The melt convection was modulated by traveling magnetic field.When the direct...The influence of melt convection on dendrite growth during the upward-directional solidification of Pb-33%Sn binary alloys was investigated.The melt convection was modulated by traveling magnetic field.When the direction of traveling magnetic field was changed from upward to downward,the primary dendrite spacing gradually increased,and the distribution peak of the primary dendrite spacing shifted to the field of narrower spacing.These result from the different intensities of melt convection,which are controlled by the traveling magnetic field.The effects of the traveling magnetic field on melt convection are similar to those of adjustment in the gravity level,thus,the primary dendrite spacing varies.When the intensity of the traveling magnetic field was 1 mT,and the drawing speed was 50 μm/s,the gravity acceleration reached 0.22g for the downward-traveling magnetic field and 3.07g for the upward-traveling magnetic field.展开更多
文摘为解决带T型支路的混合输电线路故障测距问题,结合故障行波在带T型支路输电线路中的传播特性,提出一种基于组合行波测距原理的T型输电线路故障测距方法。首先通过双端测距原理判断故障所在区间,然后利用单端测距原理得到故障距离。与传统T型支路故障测距方法主要适用于单一架空线路相比,该方法适用于带有T型支路的混合输电线路,可进一步提高测距精度。电力系统计算机辅助设计软件(Power Systems Computer Aided Design,PSCAD)仿真验证了该方法的有效性和实用性,满足对故障测距精度的要求,能够简单有效、准确可靠的得出测距结果。
基金Project(50827102)supported by the National Natural Science Foundation of ChinaProject(2010CB631202)supported by the National Basic Research Program of ChinaProject(28-TP-2009)supported by Research Fund of State Key Laboratory of Solidification Processing(NWPU),China
文摘The influence of melt convection on dendrite growth during the upward-directional solidification of Pb-33%Sn binary alloys was investigated.The melt convection was modulated by traveling magnetic field.When the direction of traveling magnetic field was changed from upward to downward,the primary dendrite spacing gradually increased,and the distribution peak of the primary dendrite spacing shifted to the field of narrower spacing.These result from the different intensities of melt convection,which are controlled by the traveling magnetic field.The effects of the traveling magnetic field on melt convection are similar to those of adjustment in the gravity level,thus,the primary dendrite spacing varies.When the intensity of the traveling magnetic field was 1 mT,and the drawing speed was 50 μm/s,the gravity acceleration reached 0.22g for the downward-traveling magnetic field and 3.07g for the upward-traveling magnetic field.
