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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

多種連鎖性失效的電網分析及有效率多重攻擊策略 / Various cascading failure models on power grids and efficient multi-target attack strategy

林丁順 Unknown Date (has links)
在真實網路中,一個節點或連結的損壞可能會造成網路大規模崩解,這現象亦出現在過去許多電力系統的大停電事件中。因此由網路的觀點對電力系統是否安全和穩定之研究一直是備受探討。在本論文中使用複雜網路方法對台灣電力網路進行脆弱性分析,並由攻擊者的角度使用多重攻擊策略探討網路脆弱性。 本論文中使用了拓樸性效率脆弱性(efficiency vulnerability)和四種連鎖性失效模型針對台灣電力網路進行分析,其中包含三種靜態負載的連鎖性失效模型(static load cascading failure model)和一種動態負載的連鎖性失效模型(dynamic load cascading failure model),藉由這些不同觀點檢視台灣電力網路的脆弱性。 以上模擬皆為攻擊單一連結,但若以攻擊者的觀點,其可以同時對多個連結進行破壞,因此最後部分為如何有效對網路造成傷害的多重攻擊策略,我們應用此攻擊策略於隨機網路(random network)以及無尺度網路(scale-free network)測試其有效性,最後將此攻擊策略應用於台灣電力網路,並從結果中透露出台灣電力網路相當脆弱。
2

基於圖形理論的電網脆弱性分析及抵禦連鎖性失效之安全策略 / Graph-based vulnerability analyses on power grid and associated protection strategies against cascading failures

易敬剛, Yi, Ching Kang Unknown Date (has links)
於歷史事件中我們知道電力網路中些許的傷害會導致大停電事件的發生,而電力網路的安全是學者們一直以來關心的議題,複雜網路發展至今,已有不少研究人員利用複雜網路的方法來分析電力網路,本論文即利用複雜網路的分析方法,分析台灣電力網路脆弱性,並提出一新穎的保護策略。 文章中引用三種分析方法分析台灣電力網路的脆弱性,第一為根據網路效率(efficiency of complex network),第二為根據靜態負載的連鎖性失效(static load cascading failure),第三為根據動態負載的連鎖性失效(dynamic load cascading failure),三種脆弱性分析的方法得到結果的交集處,在文中被認為是電力網路中最具風險的變電站。根據靜態負載的連鎖性失效的結果,我們在不改變網路結構和整體網路的負載量之下,提出一新穎的安全策略,試圖降低靜態負載時連鎖性失效帶來的傷害,並分析此安全策應用至ER隨機網路(ER random network)、BA無尺度網路(BA scale-free network)和台灣電力網路,且量化其結果。 三種脆弱分析的結果皆有共通的部份,表示台灣電力網路在拓樸分析下並不堅固,其結果顯示此安全策略是有效的。本篇論文分析的網路均是無權重也無方向性的網路,如此,未來在網路脆弱性與安全策略的研究還有進一步的研究空間。 / From blackout events in history, we know the damage of a few substations or transmission lines can lead to a big blackout, and the robustness of power grids are always a great concern. Recently the topological analyses of power grid network have developed rapidly and its achievements have become a center of attention. This thesis aims to investigate the vulnerability of Taiwan’s power grid through topological analyses and propose a novel protection strategy. This thesis introduces three methods to investigate the vulnerability of Taiwan’s power grid. The first method is based on efficiency of complex network. The second method is based on static load cascading failure. The third method is based on dynamic load cascading failure. The common results of the three results are considered the high risks in Taiwan’s power grid. According to the static load cascading failure, we propose a protection strategy against cascading failure without changing the structure of network and the whole load of the network, and then demonstrate the effectiveness of this strategy on an ER random network, a BA scale-free network and Taiwan’s power grid numerically. The three methods having the common results, one may say Taiwan’s power grid isn’t robust under the topological analyses, and our protection strategy may be useful for decreasing the damage after cascading failure.
3

透過網路效率探討電網連鎖性失效行為 / Exploring the cascading failure of power grids by network efficiency

黃帥舞, Huang, Shuai Wu Unknown Date (has links)
現實社會中,有時會發生大規模的停電事件,一經調查後才瞭解,只是因為一根電纜線、一根高壓電塔或是一個變電站故障導致,令人好奇電力系統的運作模式。因此藉由拓蹼網路的特性去研究電力系統的安全性及穩定性,一直受到人們的關注和討論。本篇論文利用動態負載去模擬現實中的電流,並藉由連鎖性失效的攻擊策略對於網路效率的影響,去判斷其網路的脆弱性分析。 本論文利用網路效率的(efficiency)影響來作為網路脆弱性(vulnerability)的分析,藉由在靜態負載中連鎖性失效的模型(static load cascading failure model)和動態負載中連鎖性失效的模型(dynamic load cascading failure model)來判斷及討論,其中動態負載為不同發電量及消耗量的狀況,藉此觀察台灣的電力網路系統在狀況下的結果。 此外以攻擊方來思考,單一攻擊、多重攻擊和策略性的多重攻擊的狀況底下,網路效率的變化,並將此運用在台灣電力網路系統上,發現台灣電力網路相當脆弱。 / In the real world, sometimes there will be black out (power shortage) happening in large scale areas. After investigating, we found out that it was cause by either a broken transmission line, a high-voltage tower or a substation. We are very interesting to know how the operation scheme of power system works. Therefore, we study the safety and the stability in power system by the characteristics of topology network. This subject is always concerned and discussed by the society. The thesis use dynamic load to simulate current in real world. We foc us effect on network efficiency by the strategy of cascading failure, analyze the vulnerability of network. The thesis use the variation of network efficiency as index to analyze network. According to determining and discussing by static load cascading failure model and dynamic load cascading failure model, dynamic load is the situation in different amount of generating and consumption of electrical energy. We used the data to observe the result of Taiwan power system under the situation. In addition to, changing of internet efficiency by single attack, multi-attack and strategic multi-attack in attacker method of thinking. We found that Taiwan power system is weak after we used the statistics on it.

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