|Ph.D Student||Spitsa Vitaly|
|Subject||Robust Approach to Power System Voltage Stability|
|Department||Department of Electrical Engineering||Supervisors||Professor Emeritus Ezra Zeheb|
|Professor Emeritus Abraham Alexandrovitz|
|Full Thesis text|
In the present work voltage stability of a power system is studied. The main factors affecting this type of stability are described. Among them load characteristics play a key role. Traditional power system analysis does not account for large uncertainties which are inevitably present in these characteristics due to a constantly changing power demand. In the research work it is shown how by adopting robust control theory one may find a complete set of uncertain load parameters for which voltage stability is preserved. The proposed techniques are based on a particular testing function, a root clustering analysis and on a zero set concept. Voltage stability can be improved by a proper reactive power support. In the second part of the work, this problem is solved using a static synchronous compensator (STATCOM). Its best location in the power system is determined using a modal analysis. Then a robust state-feedback controller for STATCOM is designed. The design method combines ideas from a theory of linear matrix inequalities and zero set calculations. Finally, design centering was performed to obtain controller gains providing maximally possible safety margins.