Date of Award


Document Type

Open Access Master's Report

Degree Name

Master of Science in Electrical Engineering (MS)

Administrative Home Department

Department of Electrical and Computer Engineering

Advisor 1

Bruce Mork

Committee Member 1

Jeffrey Burl

Committee Member 2

John Lukowski


Transformers are the tie-points of electrical power systems. Their protection from power system faults and other innate issues is of prime importance. A few of the issues that are studied in this report are magnetic inrush currents, geomagnetically induced currents in power transformers and Over-excitation.

This project develops a novel way of initializing and visualizing the flux linkage in the transformer core for studies on energization inrush currents. In addition, a quasi-DC source for GIC has been developed in order to study the GIC effects on power transformers and a sensitivity analysis has been carried out to understand effects of GIC amplitudes and frequencies on the transformer core. Lastly, a study has been carried out in order to understand Over-excitation effects on transformers. The cases have been simulated in ATP (Alternative Transients Program) using the hybrid transformer model available in the program.

The simulation results suggest the models developed are capable of providing an in depth analysis of GIC, inrush currents and over-excitation. Future recommendations include studies on relationship of var absorption and GIC amplitude as well as developing a model for studying controlled switching with residual flux linkage monitoring for minimizing inrush currents.