Power System Oscillations Detection Estimation & Control

The topic of this thesis is the electro-mechanical oscillations which to some ex-tent always are present in a power system. The demand of electric power is ever increasing. At the same time, the tolerance of disruptions in the power sup-ply is decreasing. The deregulated market together with distributed generation have then pushed the system to operate during circumstances for which it was not designed. To this we can then add that getting concessions for new lines becomes more and more difficult in densly populated areas. All these factors makes the electric power system operate with smaller safety margins. Decreas-ing these margins limits with sustained availability is achieved by the application of advanced monitoring and control methods. This thesis deals with this in several time-scales. When a large oscillation occurs it is important to detect it as fast as possible as the remedial action de-pends on if the current operating is due to a fault or an oscillation. In the thesis, a new method to distinguish these incidents from each other is presented