Condition monitoring of power transformers in the Australian State of New South Wales using transfer function measurements

A Power transformer is a critical unit within a power network. A large transformer failure could cause long interruptions and costly repairs. Therefore, it is desirable to detect potential failures as early as possible. Model based diagnosis such as the transfer function method is becoming increasingly popular in transformer condition monitoring. The transfer function method is particularly useful in identifying faults such as winding deformation and displacement, inter-turn and inter-disc faults. In this paper, practical experiences in transfer function measurements on four identical 132/66/11 kV 30 MVA power transformers has been presented.