Shielding angle is one of the main factors influencing lightning performance of transmission lines,which always stays in the focus of the design and the evaluation of lightning protection.A formula for the improved sh...Shielding angle is one of the main factors influencing lightning performance of transmission lines,which always stays in the focus of the design and the evaluation of lightning protection.A formula for the improved shielding angle is proposed for evaluating the lightning performance in different terrains.The digital elevation model(DEM) is used to obtain the micro-topography data,such as the slope gradient,slope aspect,etc.The following results are obtained by analyzing the influence of topography factors on the improved shielding angle:(1) improved shielding angle non-linearly increases with the increase of the slope gradient and the slope aspect,(2) improved shielding angle is more sensitive to the slope gradient than to the slope aspect,(3) the improved shielding angle in the mountain terrains is much greater than the designed shielding angle.This may be the reason why the designed shielding angle is limited into the rational range,while the shielding faults occur frequently.展开更多
With the rapid development of electronics and the growing demand for highervehicle performance, intelligent shift technology is becoming increasingly important, and itpromises to be a developing trend in vehicle autom...With the rapid development of electronics and the growing demand for highervehicle performance, intelligent shift technology is becoming increasingly important, and itpromises to be a developing trend in vehicle automatic transmissions, A new simulation model ispresented, which includes engine, powertrain, tire and vehicle dynamics models. Based on the model,simulation experiments are conducted to investigate the slope shift strategy. The data andconclusions obtained from the simulations are valuable contributions to the development of anintelligent slope shift strategy.展开更多
基金Project supported by National Natural Science Foundation of China （51277064）.
文摘Shielding angle is one of the main factors influencing lightning performance of transmission lines,which always stays in the focus of the design and the evaluation of lightning protection.A formula for the improved shielding angle is proposed for evaluating the lightning performance in different terrains.The digital elevation model(DEM) is used to obtain the micro-topography data,such as the slope gradient,slope aspect,etc.The following results are obtained by analyzing the influence of topography factors on the improved shielding angle:(1) improved shielding angle non-linearly increases with the increase of the slope gradient and the slope aspect,(2) improved shielding angle is more sensitive to the slope gradient than to the slope aspect,(3) the improved shielding angle in the mountain terrains is much greater than the designed shielding angle.This may be the reason why the designed shielding angle is limited into the rational range,while the shielding faults occur frequently.
基金This project is supported by Important Scientech Problem Tackling Subject Foundation under the State 9th 5-Year Plan, China(No.96-A05-04-01).
文摘With the rapid development of electronics and the growing demand for highervehicle performance, intelligent shift technology is becoming increasingly important, and itpromises to be a developing trend in vehicle automatic transmissions, A new simulation model ispresented, which includes engine, powertrain, tire and vehicle dynamics models. Based on the model,simulation experiments are conducted to investigate the slope shift strategy. The data andconclusions obtained from the simulations are valuable contributions to the development of anintelligent slope shift strategy.
文摘本文以崇文至紫荆500k V线路工程为例,探讨超高压输电线路工程三维全景可视化技术路径,包括:采用卫星影像数据和高精度数字高程数据合成输电线路工程地形地貌模型;运用无人机倾斜摄影技术进行敏感区域重要建筑地物实景建模;基于BIM技术对铁塔、输电线等进行建模;最后采用Super Map 3D Designer三维地理设计引擎进行倾斜摄影、激光点云图以及BIM模型等数据融合处理,实现省市远景视角、镇村中景视角及铁塔近景视角的三维全景展示。研究结果表明基于GIS、倾斜摄影、BIM建模以及三维引擎技术融合的三维建模技术能够全方位展示超高压输电线路地形地貌,真实反映交叉和跨越情况,为超高压输电线路工程的精细化管理提供了支撑。
