Oil-gas separation mechanism of polymer membranes applied to online transformer dissolved gases monitoring

Gas chromatography has been used to detect gases associated with transformer partial discharge, overheating, arcing and other problems. Now, gas chromatography diagnostics of power transformers has been recognized as the most efficient physical chemical online diagnostic method for determination of potential thermal or electrical faults in transformer. Gas dissolved in transformers oil is extracted automatically by certain polymer membranes. Some polymer membranes have already been applied to online transformer dissolved gas monitoring, such as polytetrafluoroethylene (PTFE), polyimide, and so on. The oil-gas separation mechanism of polymer membranes has been discussed in the paper. Also, factors that influence oil-gas separation are analyzed.