Iron core material In the 1970s, Wuhan Iron and Steel Company introduced the Japanese high-magnetic grain-to-cold-rolled silicon steel sheet in the 1990s on the basis of introducing and digesting and absorbing Japanese cold-rolled silicon steel sheet manufacturing technology to produce cold-rolled silicon steel sheets. HI-B) manufacturing technology has produced a power transformer core material with better energy saving effect. However, due to the insufficiency of product quantity and production process, some cold-rolled silicon steel sheets are still imported from Japan, Russia and Western Europe.
In the development of amorphous alloy materials for distribution transformer cores, China had specialized work in the early 1990s by the former Ministry of Machinery, the former Ministry of Metallurgy, the former Ministry of Electric Power, the State Planning Commission, the State Economic and Trade Commission, and the former State Science and Technology Commission. In the group, the design and manufacturing process of amorphous alloy core material and amorphous alloy core transformer were deeply studied. The amorphous alloy core material developed basically met the requirements of the original planned index, and in 1994, the voltage was 10 kV and the capacity was tested. The distribution transformer of 160~500 kVA has been tested by power users and has basically reached the practical requirements. However, the manufacturing process of amorphous alloy materials still needs further improvement to meet the requirements of mass production.
In 1998, Shanghai Zhixin Company introduced the manufacturing technology of GE Company of the United States, and produced amorphous alloy core transformers from American amorphous alloy materials. At present, it can produce voltages of 10kV, capacity of 50~2500kVA, and no-load loss of between 34~700W. The amorphous alloy core transformer with load loss between 870 and 21500W has been applied to epoxy resin dry-type transformers, which further promotes the improvement of the manufacturing level of China's amorphous alloy core transformers. In China, some transformer manufacturers have applied products made of amorphous alloy materials to the grid.
Tooling equipment Before the 1980s, the technical level of special equipment for transformers in China was relatively low. Except for the production of professional equipment in the winding equipment, most of the others were relatively simple equipment made by the company, only a few. Several have simple iron core processing slitting lines. In the 1980s, the transformer industry began to introduce foreign advanced special key equipment, such as iron core slitting line and low frequency electric drying system. In the 1990s, due to the vigorous promotion of dry-type transformers, a number of epoxy casting equipment and foil winding machines were introduced. Several large-scale production plants also introduced insulation processing centers, which made China's transformer production tooling equipment level improve