Thermal effects on acoustic emission based PD in transformer oil: A study

Transformers operate at different service conditions in the field resulting in operating temperatures of oil and winding, much above ambient temperature. Acoustic emissions due to partial discharge activity in transformer insulation system, including transformer oil, have been investigated by a few researchers at temperatures ranging from 25°C to 40°C. It is more realistic to consider the study at service temperature which could be around 50°C to 70°C; depending on the service conditions and type of insulation employed. The paper deals with acoustic partial discharge behaviour in transformer oil at temperatures ranging from 30°C to 75°C along with some of the properties of transformer oil.