Causes And Control Measures On Copper Corrosion In Transformer Oil

Electricity, as the center of the energy strategy development, is essential to ensure the power system safe, stable, efficient and economic operation. Safe and reliable operation of the transformer has close relationship with quality of transformer oil. Copper corrosion led to a transformer fault accident, which caused huge economic losses to the society. Study of copper corrosion in transformer oil causes and control measures to reduce power grid accidents and to improve reliability of transformer operation, has very important scientific significance and practical value.The effect of temperature, sulfur content and the initial moisture content to copper corrosion in transformer oil was studied. By measuring the trace water, interfacial tension, dielectric loss, acid value, CO2/CO and copper content, the influence of various factors was evaluated. The results show that the temperature of oil sample is higher,, the copper is more susceptible to corrosion, and the corrosion rate is faster; The higher of active sulfur content, the faster corrosion of copper components; The greater of the initial moisture content, oil oxidation reaction is more severe, leading to more severe corrosion of copper components. At the same time, the measures to control the three factors were proposed.Cu+ affect the performance of transformer oil under different temperature was studied, coming to a conclusion that the interfacial tension, dielectric loss, acid value, CO2/CO and Cu content of oil has a close relationship with the aging condition of temperature and sample. Under different temperature, Cu+ influence on the performance of transformer oil size sequence is 140℃ >120℃ >100℃.This paper studied the inhibition effect and mechanism of Irgamet39 to copper corrosion. By comparing the new transformer oil and copper content exceeded oil add Irgamet 39 before and after the acid value, dielectric loss, interfacial tension, CO2/CO and copper content, the discovery of new oil was the copper content almost not change compared with the initial value, and in the oil with exceeded copper,the copper content decreased from the initial value 2.02 x 10"6 to 0.89 x 10-6. Meanwhile, the other parameters have also been improved to some extent, which described the inhibiting effect Irgamet39 to copper corrosion was well.The mechanism of Irgamet 39 against copper corrosions was studied by density functional theory (DFT), come to a conclusion that the lowest unoccupied orbital energy and the difference between the highest occupied orbital energy is 3.6986eV, and the small value indicates that the molecule is unstable with high reactivity. Combined frontier orbital distribution and nucleophilic and offensive power fukui function data, we can see Irgamet39 molecule adsorbed on a copper conductor duing to the benzene ring,-C-N and -N= N.