Risk and Vulnerability Analysis of Large Scale Technical Infrastructures - Electrical Distribution Systems

Abstract

The thesis treats the subject of risk and vulnerability analysis of large-scale

technical infrastructures. In particular the focus is on the development of

methods for vulnerability analysis of electrical distribution systems. The

methods and the concepts behind them should nevertheless also be seen as

applicable to other technical infrastructures.

Robust and reliable technical infrastructures are a prerequisite for modern

society. If they fail to deliver their services, severe consequences arise. Two

major crises in Sweden regarding the supply of electricity have clearly showed

the magnitude of the consequences on society and its dependency on a

reliable electricity supply and the emergency response necessary to return to

normal. Furthermore, most technical infrastructures depend on a reliable

power supply for their proper functioning. The power supply in turn relies on

some of these for its proper operation and control. There is a need for

methods aimed at assessing the vulnerability of the interconnected

infrastructures the society depends upon.

In the thesis two approaches, or methods, of assessing the vulnerability of

technical infrastructures are presented: global vulnerability analysis and

critical components. The applicability of the methods was tested by empirical

studies of three electrical distribution systems in Sweden. The result from the

global vulnerability analysis clearly shows that distribution systems are highly

vulnerable to some type of perturbations. The results from the analysis of

critical components show that the methods can be used for finding and

ranking components that are critical for the system and that they render a

very feasible way to test the system for N-k contingencies.

The design approach of the methods was to use a network model and a

corresponding physical model of the electrical distribution system. The

network model contains the topological information. The physical model

describes the behavior of the network. Performance measures have been

developed to describe the consequences of perturbation to the network. The

studies indicate that these measures are relevant for describing vulnerability of

an electrical distribution system and in finding its critical components. The

design approach of the methods constitutes an important step towards

vulnerability analysis of interdependent infrastructures.

The results from applying the methods can be useful for emergency

mitigation and preparedness planning. The results can further be visualized in

the form of geographical vulnerability maps. These maps can facilitate the

discussions between persons working in different fields.

• author: Johansson, Jonas
• supervisor: Gustaf Olsson; Olof Samuelsson
• organization: Industrial Electrical Engineering and Automation
• publishing date: 2007
• type: Thesis
• publication status: published
• subject: Other Electrical Engineering, Electronic Engineering, Information Engineering
• pages: 101 pages
• ISBN: 9789188934451
• language: English
• LU publication?: yes
• id: 9405d77e-abb8-4ac3-ae62-17b61b559529 (old id 587943)
• alternative location: http://www.iea.lth.se/publications/Theses/LTH-IEA-1053_rev2.pdf
• date added to LUP: 2016-04-04 10:11:09
• date last changed: 2018-11-21 20:57:18