Condition assessment techniques for large power transformers

An important task for electric utilities is to maintain the reliability of their power systems whilst minimising the necessity for capital expenditure on asset replacement. To achieve this, the best possible knowledge of the plant condition and likely future problems is required. Effective assessment techniques are required, and this is especially so for power transformers since these are very often the single most expensive items of plant. Here, the authors describe condition assessment techniques for such power transformers. The detail how condition assessment encompasses a wide range of activities and many complementary techniques are required, and how condition assessment tests should be easy to perform and should provide useful information from one test to be cost effective. Ideally, diagnoses should not depend on the analysis of trends