针对长距离输电行波波头精确标定困难、行波波速难以准确选取等问题,提出了一种基于虚拟故障波形匹配的行波网络定位方法。首先分析行波在输电网络中的传播特性,对传播过程各环节建立等效模型。利用改进的深度优先搜索(depth first sear...针对长距离输电行波波头精确标定困难、行波波速难以准确选取等问题,提出了一种基于虚拟故障波形匹配的行波网络定位方法。首先分析行波在输电网络中的传播特性,对传播过程各环节建立等效模型。利用改进的深度优先搜索(depth first search,DFS)算法,实现任意故障位置到测量点行波传播路径搜索。进而根据路径信息构建行波传播模型。结合动态虚拟故障思路,利用行波传播模型模拟各测量点虚拟故障行波波形。最后提出虚拟故障与真实故障行波波形自适应匹配方法,构造行波波形匹配率来衡量虚拟故障与真实故障位置的差异性。通过PSCAD仿真平台验证,该方法无需标定初始波头到达时间,降低了波速误差,实现了故障精确定位。展开更多
In automatic visual inspection, the object image subspace should be segmented and matched quickly so that the affine relationship can be built between the template image and the sample image. When the interference is ...In automatic visual inspection, the object image subspace should be segmented and matched quickly so that the affine relationship can be built between the template image and the sample image. When the interference is strong and the illumination is uneven, for example in an industrial application, this can make it difficult to obtain an objects subspace quickly and accurately in real-time. In this paper, a novel strategy is proposed to adopt discrete radial search paths instead of searching all points in an image. Therefore, the searching time can be substantially reduced. In order to reduce the influence coming from the industrial environment, the paper proposes another method that is local energy level set segmentation, which can locate the object subspace more efficiently and accurately. The detection of ＂crown caps＂ is presented as an example in this paper. Detection effects and computing time are compared between several detection methods, and the mechanisms of inspection have also been analyzed.展开更多
This article extend the John E. Hopcroft and Richart M. Karp Algorithm (HK Algorithm) for maximum matchings in bipartite graphs to the non-bipartite case by providing a new approach to deal with the blossom in alterna...This article extend the John E. Hopcroft and Richart M. Karp Algorithm (HK Algorithm) for maximum matchings in bipartite graphs to the non-bipartite case by providing a new approach to deal with the blossom in alternating paths in the process of searching for augmenting paths, which different from well-known “shrinking” way of Edmonds and makes the algorithm for maximum matchings in general graphs more simple.展开更多
文摘针对长距离输电行波波头精确标定困难、行波波速难以准确选取等问题,提出了一种基于虚拟故障波形匹配的行波网络定位方法。首先分析行波在输电网络中的传播特性,对传播过程各环节建立等效模型。利用改进的深度优先搜索(depth first search,DFS)算法,实现任意故障位置到测量点行波传播路径搜索。进而根据路径信息构建行波传播模型。结合动态虚拟故障思路,利用行波传播模型模拟各测量点虚拟故障行波波形。最后提出虚拟故障与真实故障行波波形自适应匹配方法,构造行波波形匹配率来衡量虚拟故障与真实故障位置的差异性。通过PSCAD仿真平台验证,该方法无需标定初始波头到达时间,降低了波速误差,实现了故障精确定位。
文摘In automatic visual inspection, the object image subspace should be segmented and matched quickly so that the affine relationship can be built between the template image and the sample image. When the interference is strong and the illumination is uneven, for example in an industrial application, this can make it difficult to obtain an objects subspace quickly and accurately in real-time. In this paper, a novel strategy is proposed to adopt discrete radial search paths instead of searching all points in an image. Therefore, the searching time can be substantially reduced. In order to reduce the influence coming from the industrial environment, the paper proposes another method that is local energy level set segmentation, which can locate the object subspace more efficiently and accurately. The detection of ＂crown caps＂ is presented as an example in this paper. Detection effects and computing time are compared between several detection methods, and the mechanisms of inspection have also been analyzed.
文摘This article extend the John E. Hopcroft and Richart M. Karp Algorithm (HK Algorithm) for maximum matchings in bipartite graphs to the non-bipartite case by providing a new approach to deal with the blossom in alternating paths in the process of searching for augmenting paths, which different from well-known “shrinking” way of Edmonds and makes the algorithm for maximum matchings in general graphs more simple.
