Segmentation of large AC systems through DC links introduces a new concept that utilizes the advantages of direct current transmission to improve network reliability and increase power transfer capacity. Technical lit...Segmentation of large AC systems through DC links introduces a new concept that utilizes the advantages of direct current transmission to improve network reliability and increase power transfer capacity. Technical literature argues that the segmentation of the AC network and the introduction of DC links at these systems connection points bring benefits to system operation, once contingencies generated on one side of the DC connection point would not be reflected on the other side of DC connection, thereby reducing the likelihood of cascading shutdowns and blackouts due to load restraint on transmission lines and transformers. Amidst this scenario, this paper presents a study of the main topics regarding the use of this new network segmentation philosophy, bringing a practical point of view for the use of this concept at the electrical power system planning. The effect of DC segmentation before a contingency that would initiate major outages in an adapted electrical system model IEEE-14 bus is studied and simulations have been performed with test HVAC systems and segmented by HVDC link. The results have been compared, principally in relation to the voltage bus, reactive power generation, system losses and power flow at the lines, and demonstrated that this new concept improved the grid reliability.展开更多
目前,将分割网络与SLAM(Simultaneous Localization and Mapping)结合已成为解决视觉SLAM不能应用于动态环境的主流方案之一,但是SLAM系统受到分割网络处理速度的限制,无法保证实时运行.为此,文中提出基于延迟语义的RGB-D SLAM算法.首先...目前,将分割网络与SLAM(Simultaneous Localization and Mapping)结合已成为解决视觉SLAM不能应用于动态环境的主流方案之一,但是SLAM系统受到分割网络处理速度的限制,无法保证实时运行.为此,文中提出基于延迟语义的RGB-D SLAM算法.首先,并行运行跟踪线程与分割线程,为了得到最新的延迟语义信息,采取跨帧分割的策略处理图像,跟踪线程根据延迟语义信息实时生成当前帧的语义信息.然后,结合成功跟踪计数(STC)与极线约束,筛选当前帧动态点的集合,并确定环境中先验动态物体的真实运动状态.若确定该物体在移动,继续将物体区域细分为矩形网格,以网格为最小单位剔除动态特征点.最后,利用静态特征点追踪相机位姿并构建环境地图.在TUM RGB-D动态场景数据集及真实场景上的实验表明文中算法在大部分数据集上表现较优,由此验证算法的有效性.展开更多
文摘Segmentation of large AC systems through DC links introduces a new concept that utilizes the advantages of direct current transmission to improve network reliability and increase power transfer capacity. Technical literature argues that the segmentation of the AC network and the introduction of DC links at these systems connection points bring benefits to system operation, once contingencies generated on one side of the DC connection point would not be reflected on the other side of DC connection, thereby reducing the likelihood of cascading shutdowns and blackouts due to load restraint on transmission lines and transformers. Amidst this scenario, this paper presents a study of the main topics regarding the use of this new network segmentation philosophy, bringing a practical point of view for the use of this concept at the electrical power system planning. The effect of DC segmentation before a contingency that would initiate major outages in an adapted electrical system model IEEE-14 bus is studied and simulations have been performed with test HVAC systems and segmented by HVDC link. The results have been compared, principally in relation to the voltage bus, reactive power generation, system losses and power flow at the lines, and demonstrated that this new concept improved the grid reliability.