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 type and Nomex paper type.
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 production of distribution transformers, and in complete substation systems, dry-type transformers account for 80-90%.
The "2013-2017 China Dry-Type Transformer Industry Market Demand Forecast and Investment Strategy Planning Analysis Report" shows that my country has become the world's largest producer and seller of dry-type transformers. Currently, various high and low voltage electrical products from abroad occupy important parts of the domestic market, but dry-type transformers have been almost entirely eliminated from import since the late 20th century. Foreign dry-type transformers are rarely seen in key projects and major engineering projects in China. 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.
In my country, in 1966, Shenyang Transformer Factory successfully developed the ZSG-1800/10 directional air-cooled H-class dry-type transformer, and Shanghai Transformer Factory successfully developed the SG3-800/10/1.2/0.4 three-coil self-cooled H-class dry-type transformer. In the late 1970s, Shanghai Transformer Factory independently designed and developed the SCL-630 epoxy resin cast transformer.
In the past 20 years, with the development of the world economy, dry-type transformers have achieved rapid development worldwide, especially in distribution transformers, where the proportion of dry-type transformers is getting larger and larger. According to statistics, in developed countries such as Europe and the United States, it has accounted for 40 to 50% of distribution transformers. In my country, it accounts for about 50%. In terms of output, since the Second Urban Power Grid Renovation Conference in 1989, my country's dry-type transformer production has seen significant growth, increasing at a rate of approximately 20% annually since the 1990s. Total output in 1999 approached 10,000 MVA (significantly exceeding the 4,500 MVA predicted 10 years prior), reached 20,000 MVA in 2002, and peaked at 32,000 MVA in 2004. Such growth rates are unprecedented globally.
As the above data shows, my country has become one of the world's largest producers and sellers of dry-type transformers, leading the world in factory scale, product capacity, and voltage rating.
