ISU Electrical and Computer Engineering Archives

Identification of cascaded generator over-excitation tripping events

Li, Juan (2007) Identification of cascaded generator over-excitation tripping events. Masters thesis, Iowa State University.

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Abstract

Undesirable tripping of generators contributed to the 1996 and 2003 blackouts in the U.S. Tripping of these generators initiated by over-excitation protection can lead to a shortage of reactive power supply. An effective way to prevent cascaded events is to identify the anticipated operations of generator protective devices such as over-current relays. For a given contingency, the post-disturbance field currents can be obtained from the results of steady-state contingency evaluation in the on-line security assessment process. However, their accuracy is inadequate compared with the post-contingency field current obtained from off-line time-domain dynamic simulations. In this thesis, a Fuzzy Inference System (FIS) is proposed to correct discrepancies between post-contingency field currents obtained from steady state contingency evaluation and the corresponding values obtained from time-domain dynamic simulations. Post-contingency field currents obtained from steady-state security assessment can be corrected on-line using an FIS constructed off line. A 200-bus system model is used to validate the performance of the developed FIS.

EPrint Type:Thesis (Masters)
Uncontrolled Keywords:Cascaded events, Dynamic simulation, Fuzzy Inference System, Over-current relay, Over-excitation protection, Steady state security assessment
Subjects:Electrical Engineering > ELECTRIC POWER & ENERGY SYSTEMS > Power System Dynamics, Control, Decision and Risk Analysis
ID Code:376
Identification Number:Identification Number UNSPECIFIED
Deposited By:Miss Juan Li
Deposited On:22 November 2007

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