Since the German company AEG developed the first 400kVA/20kV epoxy-cast dry-type transformer in 1964, dry-type transformers have entered a period of rapid development. Simultaneously, the United States discovered Nomex insulating paper, which can be used as insulation material for H-class dry-type transformers. Thus, there are currently two main types of dry-type transformers: epoxy-cast and Nomex-paper-cast.
Currently, in developed countries such as the United States, Germany, and Japan, the production of dry-type transformers accounts for more than 20% of the total production of distribution transformers, and in complete substation systems, dry-type transformers account for 80-90%.
According to the "2013-2017 China Dry-Type Transformer Industry Market Demand Forecast and Investment Strategy Planning Analysis Report," my country has become the world's largest producer and seller of dry-type transformers. While various high- and low-voltage electrical products from abroad occupy important positions in the domestic market, dry-type transformers have been almost entirely eliminated from import since the late 20th century. Foreign dry-type transformers are rarely seen in key domestic projects and major engineering projects. Under the current organizational structure of my country's power transmission network, the proportion of 10kV dry-type transformers is increasing year by year.
Currently, the pace of urban and rural power grid construction is accelerating, and my country's power generation and consumption are increasing daily. Generally speaking, for every 1kW increase in power generation, an additional 11kVA of total transformer capacity is required; among these, Satons distribution transformers account for approximately 1/3 to 1/2 of the total transformer capacity. It is estimated that dry-type distribution transformers account for approximately 1/5 to 1/4 of all distribution transformers. Driven by investment in power grid construction, the transformer industry is experiencing high growth, with production expected to maintain a growth rate of around 20% after 2010. Based on historical experience and changes in transformer voltage level structure, the proportion of distribution transformers is around 40%. Calculated based on this 40% proportion, my country's newly added dry-type transformer production will reach approximately 200 million kVA.