Automatic Field Monitoring of Dissolved Gases in Transformer Oil

Analysis of gases dissolved in oil is an advanced technique for incipient fault detection in oil filled transformers. Dissolved gas analysis (DGA), however, is rather expensive and time consuming, requiring skilled engineers and complicated equipment. To overcome these problems, we have developed apparatus for both analysis of dissolved gases and measurement of total combustible gases in which all procedures from the sampling of oil to the indication of analytical results are carried out automatically. Field tests were conducted at a primary substation for 8~18 months and it was ascertained that these apparatus can be used as transformer monitors.