Temperature correction to dielectric modulus and activation energy prediction of oil-immersed cellulose insulation
Jiefeng Liu, Xianhao Fan, Yiyi Zhang, Hanbo Zheng, Jian Jiao
Abstract
The dielectric modulus M*(ω) is used for studying the frequency domain response and activation energy (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> ) of transformer immersed cellulose insulation. Existing literatures show that the temperature is a crucial factor affecting the M*(ω) and aging rate of transformer oil-paper insulation, while the E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> can be regarded as an indicator to reflect the average aging rate of the transformer immersed cellulose insulation. Therefore, the discussion of the temperature-dependence on both M*(ω) and E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> is of great significance. This paper attempts to report an approach for understanding the temperature impact on both M*(ω) and E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> . The obtained knowledge can be used to establish two available models for temperature correction on M*(ω) and activation energy prediction of transform immersed cellulose insulation, respectively. These findings are expected to promote the reliability of the condition prediction result of transformer immersed cellulose insulation by using M*(ω) and E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</sub> technique.