Analysis And Improvement Of 220KV Transformer Insulation

Transformer is one of the most important equipment in the power system, transformer fault is mostly due to insulation breakdown, reliable insulation structure design is not only to ensure the stable operation of transformer, but also related to the security and the efficient allocation of energy by electric power system. Transformer insulation design is important part of the large power transformer, especially the UHV power transformer. It has extremely important implications, not only the reliability of decisive significance for the transformer operation, but also the economics of transformerIn this paper, we studied the main insulation and graded insulation of transformer. Using Ansoft FEA software, analyzed the main insulation central electric field. Then we compared the position of the maximum electric field strength and insulation margin traditional analytical methods to identify weak point insulation.In this paper, we calculated the wave process, draw the gradient along the coil, analyze the appropriate insulation margin. This article also discussed the analysis method of composite electric in impulse voltages, drawn the electric field distribution, comparing with the maximum electric field strength in the middle of the model, we obtained the maximum field strength of the composite electric field under a surge voltage is higher than the maximum field intensity of the central model, We need to analyze for the power transformer insulation composite of the electric field, and need to check the safety margin insulation.In this paper, we found the insulation margin is too large. We proposed to improve the turn insulation from 1.95mm to 0.95mm. Then we analyze the new insulation weak positions of the structure, improved weak points of structures, enhanced the reliability. The final conclusion:the new insulation structure is feasible.