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The Analysis Of Vegetation-Related Failures And Cascading Outages On Transmission Lines From The Viewpoint Of Blackouts

Posted on:2008-08-31Degree:MasterType:Thesis
Country:ChinaCandidate:W ChenFull Text:PDF
GTID:2132360245491905Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
With the increasingly expanding of interconnected power system scale, the latency security threats to the whole power systems increase rapidly. Some serious faults in local power system may affect neighboring regions, and induce malignant cascading, eventually may cause large-scale blackouts.From the detailed analysis of typical blackouts world-wide in recent years, we can find out that most blackouts were initiated by incidental faults, and expanded by cascading events. Among the cascading events, vegetation-related failures happen with relatively large probabilities, and have key influences, but are often being neglected. The reasons of vegetation-related failures are the consequences of inadequate management of transmission right-of-way. On the other hand, cascading processes are the typical processes of blackouts, thus searching cascading paths is the key for studying blackouts.Researches in following two aspects are done:1. From the viewpoints of blackouts, vegetation-related failures have being considered. A tree-growth model to predict the height of trees has been built, which has considered the influences of the trees'biography characteristics and climates. Based on this new model, a flexible method to manage vegetations under transmission lines is presented.2. Based on the probabilistic insecurity index of power systems, a direct cascading paths priority sequencing search method for cascading outages is proposed. According to system operation conditions, components'parameters, and the stochastic characteristics of faults, the probabilistic insecurity index of transmission lines can be calculated. By arranging the components in a descendent order of the indexes, an initial fault component set can be formed, and then cascading paths can be searched. The presented method considers various main stochastic factors that influence cascading faults, which makes the searched system cascading modes more reasonable.
Keywords/Search Tags:Large-scale blackouts, vegetation-related failures, transmission right-of-way, cascading outages, probabilistic insecurity index, dynamic security region
PDF Full Text Request
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