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Title: Time Domain Analysis of the Impact of Geomagnetically Induced Current on Power System
Committee:
Dr. Sakis Meliopoulos, ECE, Chair , Advisor
Dr. Santiago Grijalva, ECE
Dr. Daniel Molzahn, ECE
Dr. Lukas Graber, ECE
Dr. Sung Ha Kang, Math
Abstract:
Geomagnetic disturbances (GMD) occur when solar activity increases and solar wind interacts with the earth’s magnetic field. This interaction affects power systems in the form of geomagnetically induced current (GIC), which refers to a quasi-DC current flowing through transmission lines and transformer windings. The DC component and harmonics generated by GIC threaten the normal operation of the power grid. Past solar events have resulted in overheating and structure damages in transformers, mis-operation in protective relays, and even blackout of the grid. To understand the GIC impact, a time domain simulation based analysis is presented in this dissertation. This analysis starts with developing the device models in time domain considering the effect of GIC, such as transformers saturation and harmonics flowing through transmission lines. A set of physically based models are developed in this dissertation including a low-frequency broadband model and transformer models with detailed magnetic circuits. The analysis results demonstrate the advantage of the time domain based GIC analysis, which captures all the relevant transients, while conventional GIC analysis ignores detailed transients occurring during GMD activities, including the rise of GIC at the beginning of GMD, the variation of the flux in different transformer configurations, the increase of instrumentation channel errors and the risk of misoperation in protective relays, etc.
