Software Implementation of Duval Triangle Technique for DGA in Power Transformers

Fault diagnosis of power transformers have always drawn the attention among the users, without removing the transformers from the service. Thus it is necessary to detect the incipient fault of a power transformer at an early stage and diagnose properly on optimum way. Dissolved gas analyses (DGA) is widely used to detect incipient faults in oil filled power transformers. Throughout the world, different countries/utilities are using different techniques/tools to diagnose the faults; such as Key gas ratio, Roger’s gas ratio and Doernenburg gas ratio and Duval Triangle methods, etc. Also different international/national standards are adopted subjected to country’s tropical conditions; ie C.E.G.B. (Central Electricity Generating Board, UK), IEC and IEEE ratio codes and IS standards. Different transformer oil sampling standard practices/procedures are used to minimise the errors and contamination during the whole process of sampling, transportation, preservation and gas extractions at suitable conditions. In this paper, authors have found that Duval Triangle methods’ software implementation ( in MATLABs) for fault interpretations can provide total solution for any kind of fault exist in the power transformers. The whole Duval triangle interpretations are applied on merely three gases methane (CH4), ethane (C2H4) and acetylene (C2H2) after collecting through chromatography. Also for cross verification purposes Duval Triangle’s manual (graphical) interpretation is applied. The results show that Duval Triangle interpretation is a robust and optimum 530 Sukhbir Singh et al technique and does not require much expertise. Software implementation of Duval Triangle also cross verified with other high level languages to emphasise its supremacy.