Fault Diagnosis of Power Transformers Using Duval Triangle

Timely incipient fault identification in power transformers plays a very important role in improving transformer maintenance. Dissolved gas analysis (DGA) interpretation is a successful technique to detect incipient faults in power transformers. In this paper, dissolved gas analysis interpretation using Duval triangle technique is used to identify the type of faults in ten oil-immersed power transformers. The evaluation is based on the DGA data obtained from oil samples of the transformers and MATLAB program of Duval triangle developed. The results show that thermal faults were predominant in all the transformers.