In wide area backup protection of electric power systems, the prerequisite of protection device's accurate, fast and reliable performance is its corresponding fault type and fault location can be discriminated qui...In wide area backup protection of electric power systems, the prerequisite of protection device's accurate, fast and reliable performance is its corresponding fault type and fault location can be discriminated quickly and defined exactly. In our study, global information will be introduced into the backup protection system. By analyzing and computing real-time PMU measurements, basing on cluster analysis theory, we are using mainly hierarchical cluster analysis to search after the statistical laws of electrical quantities' marked changes. Then we carry out fast and exact detection of fault components and fault sections, and finally accomplish fault isolation. The facts show that the fault detection of fault component (fault section) can be performed successfully by hierarchical cluster analysis and calculation. The results of hierarchical cluster analysis are accurate and reliable, and the dendrograms of hierarchical cluster analysis are in intuition.展开更多
During the last decade, large rockfalls occurred on the steep limestone slopes along the Adriatic Coast of Croatia, causing injury to people and serious damage to buildings and traffic facilities. The rockfalls along ...During the last decade, large rockfalls occurred on the steep limestone slopes along the Adriatic Coast of Croatia, causing injury to people and serious damage to buildings and traffic facilities. The rockfalls along the limestone slopes were caused by unfavorable characteristics of the rock mass, weathering in combination with heavy rainfall and artificial influences during highway construction. Rockfall protection projects were conducted to protect human lives and facilities from future rockfalls. The rockfall protection program started with rockfall hazard analyses to identify the potential of rockfalls to occur and the potential consequences. At the locations of hazards where related risks were determined, detailed field investigations were conducted. Based on the indentified characteristics of potentially unstable rock masses, analyses of movement and resulting pathways were conducted. The trajectories, impact energy and the height of bouncing are dependent on slope geometry, slope surface roughness and rockfall block characteristics. Two protection measure approaches were adopted： prevention of rockfalls by removing potentially unstable rock mass or installation of rock mass support systems and suspending running rockfall masses with rockfall protection barriers. In this paper, rockfall hazard determination, rockfall analyses and rockfall protection designs for rockfall protection systems at selected locations on the limestone slopes along the Adriatic coast of Croatia are presented.展开更多
文摘In wide area backup protection of electric power systems, the prerequisite of protection device's accurate, fast and reliable performance is its corresponding fault type and fault location can be discriminated quickly and defined exactly. In our study, global information will be introduced into the backup protection system. By analyzing and computing real-time PMU measurements, basing on cluster analysis theory, we are using mainly hierarchical cluster analysis to search after the statistical laws of electrical quantities' marked changes. Then we carry out fast and exact detection of fault components and fault sections, and finally accomplish fault isolation. The facts show that the fault detection of fault component (fault section) can be performed successfully by hierarchical cluster analysis and calculation. The results of hierarchical cluster analysis are accurate and reliable, and the dendrograms of hierarchical cluster analysis are in intuition.
文摘During the last decade, large rockfalls occurred on the steep limestone slopes along the Adriatic Coast of Croatia, causing injury to people and serious damage to buildings and traffic facilities. The rockfalls along the limestone slopes were caused by unfavorable characteristics of the rock mass, weathering in combination with heavy rainfall and artificial influences during highway construction. Rockfall protection projects were conducted to protect human lives and facilities from future rockfalls. The rockfall protection program started with rockfall hazard analyses to identify the potential of rockfalls to occur and the potential consequences. At the locations of hazards where related risks were determined, detailed field investigations were conducted. Based on the indentified characteristics of potentially unstable rock masses, analyses of movement and resulting pathways were conducted. The trajectories, impact energy and the height of bouncing are dependent on slope geometry, slope surface roughness and rockfall block characteristics. Two protection measure approaches were adopted： prevention of rockfalls by removing potentially unstable rock mass or installation of rock mass support systems and suspending running rockfall masses with rockfall protection barriers. In this paper, rockfall hazard determination, rockfall analyses and rockfall protection designs for rockfall protection systems at selected locations on the limestone slopes along the Adriatic coast of Croatia are presented.
