Comparative study of dielectric spectroscopy measurements and anayses of oil and paper samples from a transformer undergoing repair
Konferensbidrag (offentliggjort, men ej förlagsutgivet), 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.

Författare

Jörgen Blennow

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

K Walczak

Andreas Dernfalk

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Belen Garcia

Aleksander Bartnicki

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

Stanislaw Gubanski

Chalmers, Material- och tillverkningsteknik, Högspänningsteknik

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

Ämneskategorier

Materialteknik

Elektroteknik och elektronik