Abstract
This paper present to study and analysis condition assessment of power transformer OLTC by Duval Triangle method via IT support. The historical test results of the dissolved gas analysis in the OLTC of power transformers rated 115/22 kV 50 MVA is analyzed as an example. To record the data conveniently and systematically as well as to encounter less time-consuming for the condition evaluation, IT support is required in this work. The recorded data with the quantity of combustible gases produced in the insulating oil of OLTC is analyzed by dissolved gas analysis, which is Duval triangle then applied to specify any faults occurring in the OLTC. Three combustible gases are plotted as a coordinated point into the triangle that is separated into several zones of specific faults. Finally, the known condition can be used to plan appropriate maintenance effectively in the utility. This results in higher system reliability and longer useful lifetime of the OLTC.
Keywords : Condition evaluation, power transformer, On Load Tap Changer
