Temperature correction to dielectric modulus and activation energy prediction of oil-immersed cellulose insulation

The dielectric modulus Μ∗(ω) is used for studying the frequency domain response and activation energy (Ea) of transformer immersed cellulose insulation. Existing literatures show that the temperature is a crucial factor affecting the Μ∗(ω) and aging rate of transformer oil-paper insulation, while the Ea 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 Μ∗(ω) and Ea is of great significance. This paper attempts to report an approach for understanding the temperature impact on both Μ∗(ω) and Ea. The obtained knowledge can be used to establish two available models for temperature correction on Μ∗(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 Μ∗(ω) and Ea technique.