MSc Thesis: Evaluation of Power Loss from Corona Discharge on an ACSR ZEBRA 220 kV Conductor
REYKJAVIK, May 27 - MSc in Electric Power Engineering candidate, Trung Anh Tran , successfully defended his master's thesis where he researched the topic of Evaluation of Power Loss from Corona Discharge on an ACSR ZEBRA 220 kV Conductor. Trung's work was supervised by Dr. Ragnar Kristjánsson from Reykjavik University and Laurentiu Anton from Reykjavik University.
Trung began by explaining that when designing high voltage transmission lines, power losses are minimized in the design, including corona losses . To date, there are no definitive texts that explain how corona loss is calculated in practice. He investigated two empirically derived formulas, Peek and Peterson, used to calculate corona loss, observe their working boundary conditions, and how power loss relates to parameters such as spacing between conductors, frequency, operating voltage, etc.
Trung implemented several methods to digitize the q factor in the Peterson formula, as well as overcome the challenges of digitizing this factor from an image. His results also show the Peek formula covering the upper part and Peterson formula covering the lower part of the loss curve.
Trung also points out the mismatch between the two formulas because the Peek empirical formula was obtained from practical experiments while Peterson was in part empirical formula obtained by the geometric layout of the conductor. Furthermore, Trung showed the root causes of why they do not match. He showed the discrepancy of Peek in calculating the disruptive gradient, g0, which causes the mismatch with the Peterson formula, and also the reliable results for Peterson formula, which is only correct for the voltage ratios e / e0 in the vicinity of 1.3.
The process to derive both formulas was done in Matlab and with a Zebra cable data as a sample conductor to evaluate corona losses.
Congratulations Trung for an excellent thesis defense!