Ageing, Space Charge and Lifetime of Polymeric Insulating Materials

In the present paper, an attempt has been made to explore trap parameters as an ageing marker to assess polymeric insulating material status. The approach has been established on the principle that ageing is the result of changes of materials, including both chemical and physical changes. In terms of energy band theory, these changes will alter energy structures, resulting in extra energy levels in the forbidden gap, i.e. traps. By measuring charge dynamics in the aged material, it is possible to extract charge trap parameters. Using these changes in trap parameter, the status of the material can be revealed. To simplify the approach, two-level energy traps have been introduced in the present paper.