The 220kV oil immersed power transformer produced by our company is self-developed based on the digestion and absorption of advanced technology at home and abroad, and is tailored to the characteristics of China's urban and rural power grids. Its product performance indicators are superior to GB/T6451 "Technical Parameters and Requirements for Three-phase Oil Immersed Power Transformers", and fully comply with JB/T3837-1996 "Method for Compiling Transformer Product Models" and GB1094.1-1996; GB1094.2-1996; GB1094.3-2003; GB1094.4-2005; GB1094.5-2003 "Power Transformers" manufacturing standard and IEC 60076 recommended standard. This series of products has outstanding characteristics of low loss, low noise, and no need for hanging cores. Its safety, economy, and other aspects have extraordinary innovation, making it a first-class technology product in China.

This product mainly has the following characteristics:

Significant energy-saving effect

tank

　　The structural type of the fuel tank is a bell type. The box wall is welded with folded plate reinforced iron or plate reinforced iron, which improves the mechanical strength of the oil tank (can withstand a vacuum degree of 133Pa and a positive pressure of 0.1MPa); Special processing is carried out on the sealing parts of the oil tank, and the overall "shot blasting" treatment is carried out on the box body to completely eliminate the oxide skin on the surface of the box body and the sharp burrs and welding slag generated during processing. High performance dual component paint is used to improve the adhesion of the paint film, making the appearance quality both beautiful and long-lasting. Radiators and components are installed and tested under simulated on-site operating conditions, effectively ensuring the elimination of leakage points. All flange surfaces are precision machined and have slotted and limit structures. At the same time, high-quality nitrile rubber gaskets that are oil resistant, weather resistant, and ozone resistant are used to prevent leakage from the transformer. In addition, when dealing with the bolted connection between the upper and lower oil tanks, a welded seam sealing box edge structure can also be used according to customer needs.

　　In short, our company relies on technological progress, a sound quality assurance system, and a strong sense of responsibility and innovative spirit from all employees, as well as effective work, to ensure that our products always maintain low emissions, low noise, low losses, and high reliability.

　　All of the company's in-service oil immersed power transformer products have not experienced any damage accidents or oil leakage. The transformer body assembly is completed in a fully enclosed constant temperature and constant pressure purification room, meeting the cleaning requirements and body temperature requirements for manufacturing 220kV products, ensuring the cleanliness and dryness of the body. At the same time, imported kerosene vapor phase drying equipment is used to improve the cleanliness effect of the product. The lower supporting plate and upper pressing plate of the transformer body are all made of electrical laminated cardboard with high mechanical strength and good electrical performance. The supporting bars and pads used in the transformer have undergone two densification treatments and rounding processes, reducing partial discharge. The steel clamp and steel pressure nail have sufficient strength, and a pressure nail bowl made of paper pulp insulation is selected, and the positions of the support blocks, braces, and pressure nails are supported to make the winding force relatively balanced as much as possible, improving the overall stability of the device body. The body adopts a whole set of constant pressure drying process to shorten the assembly time of the body after winding stabilization treatment. Adjust the centers of each winding to be as consistent as possible, fully ensuring that the reactance height of each coil is equal, making each winding uniformly stressed, thereby improving the short-circuit resistance of each winding. In addition, the lower clamp and the lower fuel tank, as well as the upper beam and upper fuel tank, are all positioned with steel and locked through anti pressure nails. Therefore, the device body can withstand the impact tests under various transportation conditions and the axial electric force during operation in the fuel tank without displacement.

　　In addition, oil guided structures are installed inside the high, low, and voltage regulating windings, thereby reducing the temperature rise at the hottest point of the winding and extending its service life.

　　The independent voltage regulating winding (for on load voltage regulating transformers) makes the ampere turns of each winding more balanced, improves stability, prevents instability and deformation, effectively reduces the axial electric force caused by external short circuits of the transformer, and improves the dynamic stability of the transformer in the event of external faults and short circuits.

　　Partial photo of pressing plate and nail

　　The iron core lamination adopts a 5-stage step overlap structure, with a lamination size of 45. Fully inclined non perforated binding structure. The silicon steel sheet is cut by a cutting line introduced by German company Georg, and the burrs at the cutting edge are less than 0.02mm. In addition, advanced iron core stacking and flipping platform, strict stacking and non pre stacking iron choke process fully ensure the grain orientation characteristics of cold rolled silicon steel sheets, effectively reducing the no-load loss of the transformer. The clamp structure adopts a plate type clamp, and a magnetic shield is installed on the clamp to reduce stray losses. The iron core clamping adopts a unique American imported Shino tape clamping and binding process, fully ensuring the clamping degree of the iron core. At the same time, years of mature technology have made the iron core, pull plate, support beam, and foot pads a solid whole, ensuring that the iron core is in the optimal stress state, which not only reduces no-load loss but also greatly reduces noise.

　　The high, low, and voltage regulating windings are wound on high-strength insulation drums. The low-voltage winding is wound with transposed wires or semi hard copper wires; The high and voltage regulating windings adopt composite wires and are insulated with high-strength Denison paper imported from the United States, which improves the filling coefficient of the transformer iron window, reduces eddy current and circulating current losses of the wires, and improves the transformer's short-circuit resistance. All windings have auxiliary support bars (reinforced support bars) on the inner side and locking support bars on the outer side. The amplitude fastening of the windings adopts a "zero" margin design, and wire tensioning devices are used during winding. Unique climbing pads are used at the transposition, greatly enhancing the mechanical strength and short-circuit resistance of the windings.

　　The no-load loss has decreased by an average of 35% compared to the national standard GB/T6451-1999, and the load loss has decreased by 10-20% compared to the national standard.

　　The high and voltage regulating tap leads are fixed with brackets and led to the switch, while the low voltage lead copper bars are fixed to the iron core clamp and the upper plane of the lower oil tank, improving the stability of the leads. Additionally, there are coil outlet binding technical requirements and process guarantees, fully meeting the requirements of low partial discharge.

tank

Local area on the high-pressure side of the fuel tank