Borsi - University of Hannover, Germany Institute of Electric Power Systems, Division of High Voltage Engineering Schering-Institute Callinstrasse ۲۵A D-۳۰۱۶۷ Hannover, Germany
Gockenbach - University of Hannover, Germany Institute of Electric Power Systems, Division of High Voltage Engineering Schering-Institute Callinstrasse ۲۵A D-۳۰۱۶۷ Hannover, Germany
Wasserberg - University of Hannover, Germany Institute of Electric Power Systems, Division of High Voltage Engineering Schering-Institute Callinstrasse ۲۵A D-۳۰۱۶۷ Hannover, Germany

Water and Oxygen are the most important enemies of the insulation of oil filed transformers leading to an accelerated aging of the insulation. Thus drying procedures and reducing the influence of oxygen are required to extend lifetime and operation reliability. In this contribution an innovative procedure for the dehydration of mineral insulating oils and insulating paper in transformers is presented, working online during transformer operation. This procedure not only performs a complete desiccation, it also purifies the liquid without influencing the dissolved gas analysis (DGA) or any other physical property. Furthermore a Zeolite filled air filtering is introduced which not only prevents water molecules from penetrating the transformer but also oxygen. Herewith presented investigations on the operation parameters like temperature and flow rate have shown, that the procedure is beneficial for insulating liquids as well as for solid insulations immersed therein.

Life Extension, Transformer Insulation, Transformer Drying