Title :
Effect of DC Bias Current on Group-Type Transformer and Its Restraining Measures
Author :
Jiang, Wei ; Yang, Lin ; Liu, Xi ; Wu, Guangning
Author_Institution :
Sichuan Electr. Power Res. Inst., Chengdu, China
Abstract :
Group-type transformer has poor ability withstand DC bias, which causes transformer local overheating, increases vibration, noise and other adverse reactions. The internal characteristics of group-type transformer DC bias are analyzed in this paper. Pointed out what it is increased with the increase of DC that harmonic of excitation current and frequency. With different DC bias current, the variation of magnetic flux density and magnetic flux of group-type transformer core is presented. Three main restraining measures of neutral current flowing to the transformer are introduced, which are respectively series capacitance, connecting dynamic compensation device and series resistance. The series resistance method is practical, economical, and easy to promote the application in the AC system near the DC grounding electrode.
Keywords :
earth electrodes; magnetic flux; power transformers; transformer cores; AC system; DC bias current effect; DC grounding electrode; dynamic compensation device; excitation current harmonic; group-type transformer core; magnetic flux density variation; series capacitance; series resistance method; transformer local overheating; Circuit faults; Current measurement; Magnetic flux density; Transformer cores; Transmission line measurements;
Conference_Titel :
Power and Energy Engineering Conference (APPEEC), 2011 Asia-Pacific
Conference_Location :
Wuhan
Print_ISBN :
978-1-4244-6253-7
DOI :
10.1109/APPEEC.2011.5749137
