A Review of Diagnostic Tests and Condition Monitoring Techniques for Improving the Reliability of Power Transformers

Power transformer is a critical component for generation, transmission and distribution utility. It is expensive equipment and plays vital role in interconnecting renewable energy with main grid. The distribution transformers are installed at different locations in a power system and are critical assets in the electricity supply system as they feed power supply to the end users. In this era of deregulation, priority is given by utilities for uninterrupted and quality power supply to their consumers. However, distribution transformers are normally neglected components; less maintenance and less care have been taken in comparison with power transformers. Transformer failure causes extensive loss to the power utility, major industrial consumer and society. Proper operation and maintenance procedure may avoid failures and maintain the continuous power supply for end user. Due to these reasons conditioning monitoring of transformer become popular. Condition monitoring of transformer results in increase life span, reducing the risk of expensive equipments failure and increase high level reliability. An overview of various traditional and some new conditioning monitoring techniques are covered in this paper. The methods discussed in this paper are useful for both the power transformers and distribution transformers.