Conditioning Monitoring of Transformer by Dissolved Gas Analysis by Matlab with Case Studies

Abstract

Reliable operation of transformers largely depends o n a lifetime of insulating system. Due to the complexity of the power transformer design, operational and maintenance policies, it is impossible to accurately predict the expected life of a transformer. Consequently, power system operators have to depend on various condition monitoring and condition assessment techniques available to determine plant condition and remnant life. This paper deals with dissolved Gas Analysis (DGA) which is a widely used technique to estimate the condition of oil-immersed transformers. The measurement of the level and the change of combustible gases in the insulating oil is a trustworthy diagnostic tool which can be used as indicator of undesirable events occurring inside the transformer, such as hot spots, electrical arcing or partial discharge. The objective of my study is mainly to analyze available data from DGA, and investigate data that may be useful in quantitative modeling of the transformer's reliability. The experimental results showed that the application of faults occurring in transformer oils increased the concentration of combustible gases such as hydrogen, methane, ethane, ethylene and acetylene, etc. Dissolved gas analysis were done using Key gases, Roger's ratio The calculation includes condition ratings, weighting factors, and assigned scores for specific condition parameters by using  mat lab programming.