الفهرس | Only 14 pages are availabe for public view |
Abstract The work described in the thesis is concerned lIith an experimental study of the effect of organic additives when present in transformer oil and liquid paraffin on the gassing characteristics of these liquids. The change in gas volume under constant pressure and electric stress was recorded at different intervals. The three organic additives examined are benzophenone, diphenyl, and anthraquinone. These organic additives are known to affect the breakdown and conduction current values of insulating oils. H2’ 02 , N2 and air wore used as gas phases for each liquid sample. Experiments were carried out under 50 c/s elternating voltage and each test sample was tried at three electric stresses and a new lic.l.uid sample 1J’las used in each test run. The effect of chang~ng the temperature of the liquid sample on its gassing characteristics was also examined for both transformer oil and liquid paraffin w~th and without dissolved additives. All additives examined when present in the test liquid produced a decrease in the gas evolution and an increase in the gas absurption. However, these beneficial effects depended on the concentration of the additive in the liquid. Results shC7”ed that each additive had an optimum concentration which gave maj~. mum beneficial effect, i. e~ ~ maximum gas absorption and min::”J1-t”,;J gas evolution. The optimum concentration of the additive V~8 found to be i.ndependent of the applied electric stress (for th::•, range of stresses tried), gas phase, and temperature of the 1:’.\1 uid. The results are discussed in the light of existing theo!.’,; ,J” on conduction, gassing, and breakdown of liquid dielectrics. |