Power transformer insulation response and risk assessment

Transformer insulation plays an important role in its life expectancy. Abnormal ambient conditions (high temperature, humidity index) and extreme operational situations have significant effect on the insulation of a transformer. Periodic insulation assessment based on condition monitoring is essential to determine the life expectancy of a transformer, in particular for an aged transformer or the one with suspicious behavior. This will help in determining the aging rate of the insulation and provide an assessment of the overall integrity of the transformer. Thus early warning of any abnormality can limit the risk of catastrophic failure. This will also help reduce the aging rate and extend the life by suggesting new operational (loading) conditions. This can result in economical operation and cost effective maintenance strategies.