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Electrical Engineering Student Places Third in IEEE Poster Contest
September 26, 2011 — Jim Follum of Sundance, Wyo., placed third in
the undergraduate poster contest at the Institute of Electrical and
Electronics Engineers (IEEE) Power & Energy Society general meeting
earlier this year. The poster was based on work that he did under the
guidance of Dr. Ning Zhou while at the Department of Energy's Pacific
Northwest National Laboratory (PNNL) over the summer of 2010. Dr. Zhou
received his Ph.D. from UW. Dr. John Pierre, professor in the UW
Department of Electrical and Computer Engineering was also a co-author
on the project. Jim is pursuing his Ph.D. in electrical engineering
with an emphasis on power systems and signal processing at UW.
The major goal of the group's research was to develop methods for monitoring the stability of the power system. To accomplish this task, models are often developed using measurements from the power system. The group was especially concerned with the model's modes, which are a mathematical way to describe the interactions between generators that can cause stability problems. Unfortunately, one of the most widely used methods to obtain models of the power system, Prony analysis, doesn't provide any indication of how reliable these mode estimates are.
In response to this challenge, Jim's research sought to estimate the reliability of the mode estimates by relating mode estimate error to residuals. Residuals are the difference between the measurements used to build the model and the output of the model. In general, models with small residual values are better models.
The results of the research showed that mode estimates are linearly related to residual values. This relationship is useful because it allowed researchers to judge the reliability of the mode estimates based on the residual values, which are always available after modeling with Prony analysis. Preliminary efforts to approximate the error in mode estimates were also based on this linear relationship. This project served as a basis for future work that will continue to take advantage of the relationship between mode estimate error and residual values.
"This experience helped solidify my decision to remain at UW after graduating in May and pursue a master's in electrical engineering", says Jim. "I intend to build a career in the area of power system research following my studies at UW."