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Effect of lightning impulse prestress on AC partial discharge characteristics in cast resin transformer
Author(s) -
Maruyama Hirofumi,
Matsuo Kensuke,
Kozako Masahiro,
Hikita Masayuki,
Iida Kazuo,
Umemura Tokihiro,
Nakamura Yusuke,
Nakamae Tetsuo,
Maeda Teruhiko,
Higashiyama Masakazu
Publication year - 2019
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.23177
Subject(s) - partial discharge , materials science , composite material , impulse (physics) , void (composites) , transformer , impulse generator , voltage , electrical engineering , engineering , physics , quantum mechanics
It is crucial for cast resin transformer to detect void and delamination existing in the cast resin because these defects reduce insulation performance of cast resin equipment. Furthermore, defects are likely to be mixed in cast resin because of several surface boundaries between resin and conductor. It is considered that detecting partial discharge (PD) is effective to diagnose equipment of power equipment. However, it is reported that withstand lightning impulse voltage test may give influence on AC partial discharge test, especially partial discharge inception voltage. This paper deals with accumulated charge in a void under AC voltage to investigate the effect of the impulse voltage prestress on subsequent AC PD characteristics in cast resin transformer. AC PD characteristics were compared before and after impulse application. In addition, recovery of PD characteristics was measured to investigate charge decay. As a result, the mechanism of prestress effect is revealed and surface charge density is estimated quantitatively in cast resin transformer.