Comparative study of dielectric spectroscopy measurements and anayses of oil and paper samples from a transformer undergoing repair
Conference contribution, 2005

New methods, based on characterisation of dielectric response measurements, for assessing moisture content of pressboard and paper are gaining ground. However, there is a need for calibrating results with results from other techniques. This communication presents results from a study of a 19.5/6.8/6.8 kV - 40 MVA power transformer, which was opened on-site during maintenance work, thus allowing for collecting paper samples. Dielectric spectroscopy measurements were conducted before and after its opening. Results were compared with measurements on oil and paper samples. These showed that the moisture levels in the interior of the solid insulation were unchanged. Further, it was found that FDS measurements gave more accurate estimates of moisture levels than estimates based on oil analyses and equilibrium curves.

Author

Jörgen Blennow

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

K Walczak

Andreas Dernfalk

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Belen Garcia

Aleksander Bartnicki

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Stanislaw Gubanski

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

In Proc. of 19th Nordic Insulation Symposium, Trondheim, Norway, June 13-15

Subject Categories

Materials Engineering

Electrical Engineering, Electronic Engineering, Information Engineering

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Created

10/7/2017