Combined transformer (american tank-type transformer) is a kind of transformer including the transformer body, high voltage load switch and fuse in a transformer oil tank, with smaller size of component and compact structure by immersed in oil. On the other side of the shared wall, all components required by high and low voltage system are equipped to form a transformer station with small size and convenient transportation and easy operation.

    Combined transformer station(European tank-type transformer) is a kind of transformer station including transformer, high voltage cabinet and low voltage cabinet in one enclosing. The transformer, high voltage cabinet and low voltage cabinet are either independent or combined together by cable. It is larger than American tank-type transformer in size. It has a more beautiful appearance and is usually placed in the field in Europe as a beautiful landscape to the world.

    Shared tank type transformer station is a kind of transformer station combining general oil-immersed transformer with the integrated high and low voltage cabinet by cable or copper bar after placing the transformer and the cabinet on the same foundation structure.