DOCTOR

This dissertation comprises the results I have obtained during my doc-toral studies at the Power Systems Laboratory of the Swiss Federal Institute of Technology (ETH) Zurich from June 2004 until November 2007. It has been an intensive but very interesting time for me. But without the support of many people around me I would not have man-aged to accomplish this dissertation. First of all, I want to gratefully thank Prof. Göran Andersson for provid-ing me the opportunity to join his group as an assistant and researcher and for his permanent technical as well as social support. I enjoyed the freedom to adjust my research according to my interests and the ability to get helpful advice whenever needed. Special thanks goes to Prof. Antonio Conejo and Prof. Manfred Morari for the acceptance of the co-examination of this thesis. Prof. Conejo was closely involved into the development of the Multi-Area Control method on which I based part of my studies. Prof. Morari was already the supervisor of my Master thesis and it is a pleasure for me that he also agreed to be co-examiner of my PhD thesis. I also very much appreciated the support and input I received from the industrial partners Mats Larsson, Alexandre Oudalov and Petr Korba from ABB and Walter Sattinger from swissgrid. The meetings were al-ways very constructive and encouraging. In addition, I would like to thank Mr. Sattinger and swissgrid for providing actual data of the UCTE system giving me the possibility to carry out studies in a re-alistic test system. A great and enriching experience during my PhD studies was my stay at TU Delft, the Netherlands, in September/October 2006 where I ben-iii iv Preface efited from intense and productive discussions with various people of the Delft Center for Systems and Control