Dissolved gas analysis of alternative dielectric fluids under thermal and electrical stress

Dissolved gas in oil analysis (DGA) has been used for many years successfully for diagnosis and condition monitoring of mineral oil filled transformers. In future the diagnostic methods have to be transferred to new fluids. This contribution presents results of the gassing behavior of different insulating liquids from experiments, which represent electrical and thermal faults. Also the suitability of existing mineral oil interpretation methods for DGA is considered. The main investigated fluid is Envirotemp^® FR3™. Where possible the amount and relation of the gases are compared to mineral oil and other synthetic esters gassing behaviour.