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Submodular Controllability Metrics in Complex Networks


F. Cortesi

Master Thesis, FS13 (10268)

The understanding and efficient operation and control of complex networks, such as power grids, transportation networks, and biological networks, is an important challenge in science and engineering. Controllability is often thought of as a binary concept; however, there are many quantitative measures which can be used to assess the degree to which a given system can be controlled. Such metrics could be utilized in actuator placement problems, for example, in the placement of power electronic actuators in a grid to improve transient stability properties. In this work several energy related measures associated with the controllability Gramian in linear dynamical systems are shown to have a strong structural property, called submodularity, which allows for an approximation guarantee by using a simple greedy heuristic for their maximisation. The results are illustrated for placement of HVDC lines in a model of the European power grid. Furthermore, empirical investigations into the effects of various network characteristics, such as edge density, degree heterogeneity and correlation on control energy and its distribution among the nodes are presented, which are then contrasted with recent results using the concept of minimum driver nodes.


Type of Publication:

(12)Diploma/Master Thesis

T.H. Summers

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% Autogenerated BibTeX entry
@PhdThesis { Xxx:2013:IFA_4578
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