The 220kV oil-immersed power transformer produced by our company is developed on the basis of advanced technology at home and abroad, aiming at the characteristics of urban and rural power grids in China. Its products meet the national manufacturing standard GB/T1094 and the recommended standard of IEC60076 International Electrotechnical Commission. This series of products has the characteristics of low loss, low noise and no hanging core, and its safety, reliability and economy can be guaranteed. The transformer core adopts a five-step lapping process, the lamination is a 45 ° inclined seam holeless binding structure, and the burr at the shear edge of the silicon steel sheet is less than 0.02mm. The advanced core turnover table and strict stacking fully ensure the grain orientation of cold-rolled silicon steel sheets, effectively reducing the no-load loss of the transformer. The winding is made of combined conductors and transposed conductors, which improves the filling coefficient of the transformer iron window, reduces the eddy current loss and circulating current loss of the conductors, and improves the short-circuit resistance of the transformer. All windings are equipped with auxiliary bracing on the inside and locking bracing on the outside. The unique climbing pad is used at the transposition, which greatly enhances the mechanical strength and short-circuit resistance of the winding. All windings are equipped with auxiliary bracing on the inside and locking bracing on the outside. The unique climbing pad is used at the transposition, which greatly enhances the mechanical strength and short-circuit resistance of the winding. The transformer body adopts the new technology of eight-sides positioning, which makes the body and oil tank become a solid body. The tank structure is bell type or barrel type. All sealing surfaces are processed into sealing structures with grooves. The tank edge is sealed with double oil channels to ensure that the transformer oil tank does not leak. The performance of the transformer conforms to European energy efficiency standards and Chinese energy efficiency standards.