Thesis
Loss of field protection and its impact on power system stability
Washington State University
Master of Science (MS), Washington State University
2009
Handle:
https://hdl.handle.net/2376/101880
Abstract
The aim of this thesis is to study the impact of Loss of Field (LOF) protection at generators on the grid stability of the interconnected power system. Specifically, we will show the relationship between the operational speeds of the partial loss of field protection at critical plants on voltage stability of the neighboring power grid near the plants. Model based simulations will be studied in order to duplicate the actual TVA events using a detailed eastern system data. A back-up protection scheme which is based on terminal measurements is proposed for such a generator using synchrophasors which would trip the generator under LOF conditions by observing the line measurements at the plant. The real and reactive power-flows on some transmission lines near the plant are monitored to design the proposed back-up protection for the plant. The LOF is typically characterized by high MW flow out of the generator with large Q flow into the generator. An inverse timecharacteristic logic on the reverse Q flow into the plant (above a preset threshold) under high MW flow out of the plant is suggested. Reset logic is needed in order to prevent false tripping under stable system swings. Accordingly, tripping can be made slower under partial LOF conditions by encoding an inverse time characteristic on the trigger logic. This back-up protection scheme's settings will be based on P-Q and Q-V curve studies. Last, a LOF protection scheme which is based on internal measurements will be introduced. We will use the Q-V curve and two-axis model calculation in MATLAB to find the Efd threshold which will likely lead the system to voltage collapse.
Metrics
22 File views/ downloads
8 Record Views
Details
- Title
- Loss of field protection and its impact on power system stability
- Creators
- Ran Xu
- Contributors
- Mani Vaithianathan Venkatasubramanian (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525060001842
- Language
- English
- Resource Type
- Thesis