Transformers Magazine, Vol. 8 No. 1, 2021.
Original scientific paper
Absorption index of insulation at end of service life – Part I
Vitaly Gurin
; Kharkov Polytechnic Institute
Abstract
Absorption Index (AI) remains valid for old-aged unsealed transformers as a simple and effective method of non-destructive control insulation.
The reasons for AI decrease within transformer operation are insulation moistening and contamination. Seven gradation levels of the insulation condition and algorithm of the operating
procedures are proposed depending on the value of the measured AI and its variation in time. Along with AI, it is recommended to measure the polarisation index (PI) and the PI-2 (R600/R15 ratio).
Keywords
absorption index, cellulose insulation, insulation resistance, moisture, polarization index
Hrčak ID:
249901
URI
Publication date:
8.1.2021.
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