Phasor Measurement based Out-Of-Step Detection
Examensarbete för masterexamen
Berkestedt, Ann Helen
This thesis deals with Out-Of-Step conditions in a network, how to detect the events and how to make improvements on the protection devices that are being used today. Power systems and stability analysis are studied in general and Out-Of-Step conditions are reviewed in detail. Experiments with a one machine against an infinite bus are performed to connect theory with reality. The laboratory model is exposed to transient faults in the range 100 ms to 800 ms. A PMU is used to measure voltages and currents at the generator bus and at the infinite bus. The thesis includes the development of an algorithm that can detect power swings. The algorithm is programmed in MATLAB. This algorithm detects faults in the system and predicts loss of synchronism. The data collected with the PMU from the laboratory measurements are run in the program to be able to determine the capability of the algorithm. The thesis also includes design and assembly of two voltage transformers. The voltage transformers are needed to be able to connect the PMU to the laboratory model. The voltage transformers are rated 400:110 V, 45 VA.
Elkraftteknik , Electric power engineering