Looking at the development history of transformer energy-saving technology, transformers have undergone several replacement processes, including S6, S7, S9, and S11 series. Currently, S9 energy-saving products have become the market mainstream, while the market size of S11 energy-saving products is growing. During the promotion of S11, the sales price of S11 is on average 14.2% higher than that of S9, so price remains the main factor affecting the popularization and promotion of S11 transformers. Currently, although the new S9 products have occupied a large share of the market, with economic development, the demand for S11 products from users (especially rural power grids and users with lower transformer load rates) is gradually increasing. The S11 type laminated core transformer is designed and developed based on the mature technology of the new S9, and its performance indicators have been significantly improved while maintaining product reliability. Compared with traditional laminated transformers, S11 wound core distribution transformers have the characteristics of saving raw materials, energy saving, improved power supply quality, low noise, and high degree of mechanization.
Oil-immersed transformers use an oil-paper insulation structure. Its core processes are the drying treatment of the insulation materials and the vacuum dehydration of the transformer. Vapor phase drying: In the mid-1980s, Chinese transformer manufacturers were the first to import vapor phase drying equipment from Switzerland. In recent years, a new product, the built-in kerosene evaporator, has been developed. Compared with the traditional external evaporator, both have their advantages and disadvantages. Transformer oil treatment: Entering the 1980s, with the introduction of advanced oil filtration equipment from Europe and America, China's oil purification technology has made significant progress. Most enterprises have adopted the advanced vacuum spray oil purification method, which has remarkable effects on impurity removal and dehydration.