The oxidation resistance of transformer oil can directly affect the service life of oil products.
In order to evaluate the remaining service life of transformer oil in operation, oxidation stability tests of new transformer oil and running transformer oil samples were carried out at 100, 110 and 120 C, respectively, and their induction periods at different temperatures were detected. Then the remaining service life of transformer oil in operation was evaluated by induction periods. Estimate.
Measuring the interfacial tension between oil and water is also an indirect and effective method to check the soluble polar impurities in transformer oil caused by aging. It is a means to detect the early oxidation of transformer oil. Therefore, the samples of new transformer oil and running transformer oil are opened at 100 C, 110 C and 120 C, respectively. The interfacial tension of each aging oil sample is measured regularly by cup aging test, and the remaining service life of the oil product can be evaluated on the other hand.
The electrical strength of pure transformer oil is 200 250kV/cm, 4-7 times higher than that of air. Transformer oil can greatly reduce the volume of transformer. Transformer oil is widely used because of its abundant raw materials, low price, good mechanical strength and high electrical strength after being immersed in transformer oil. When transformer oil is broken down, insulation can be restored without leaving permanent discharge channel.
Transformer oil has high insulation strength and is mainly used as insulation medium in electrical equipment. It is also used as cooling medium because of its large specific heat capacity. It is used as arc quenching medium in circuit breakers, on-load tap changers and starter compensators and plays a role of cooling contacts.
In high-voltage cables, transformer oil fills and impregnates the cables to remove gases and improve electrical strength. In oil-immersed paper dielectric capacitors, transformer oil plays the role of filling, collapsing and insulation, so as to improve the capacitance and insulation strength.