Xichang Satellite Launch Center (XSLC), also known as "Xichang Satellite City", was founded in 1970 and put into operation in 1982. Since the launch of China's first communication satellite in January 1984, it has successfully put tianlian-04 satellite into the scheduled orbit with long march-3c carrier rocket on November 22, 2016. The launching activities of Xichang Satellite Launch Center have exceeded 100 times. Xichang Satellite Launch Center (XSLC), also known as "Xichang Satellite City", was founded in 1970 and put into operation in 1982. Since the launch of China's first communication satellite in January 1984, it has successfully put tianlian-04 satellite into the scheduled orbit with long march-3c carrier rocket on November 22, 2016. The launching activities of Xichang Satellite Launch Center have exceeded 100 times. SG (b) series non encapsulated dry-type transformer product description: the low-voltage winding is made of high-quality copper foil and high-temperature insulating material, which is solidified into a solid whole by VPI vacuum pressure impregnation, with strong impact resistance; The high-voltage winding is made of pressed cake or continuous structure, and the interlayer insulation is made of C-grade insulating Nomex Paper, which is impregnated by VPI vacuum pressure and solidified at high temperature, with strong short-circuit resistance; The iron core is made of high-quality and high magnetic conductivity silicon steel with multi-stage stepping process and low no-load loss; After the service life, copper and silicon steel can be recycled, and the insulation material is completely degraded, which is an environment-friendly product; It is the first one in China to pass the fire resistance, environment and climate test of European standard HD464; DuPont relatran ® Core technology, volume reduction of 10%, material saving of 10%, insulation grade up to C level（ Reliable; reliable; Transformers, reliatran ® It means: reliable transformer) can realize full intelligent data acquisition and analysis, intelligent "brain", active operation and maintenance; Scope of application: for shopping malls, residential areas, schools, hospitals and other places with high population density and strict safety requirements.