ZBW series combined substation, commonly known as European box transformer, is a combination of high-voltage electrical equipment, transformers, low-voltage electrical equipment into a compact complete set of power distribution devices, used in urban high-rise buildings, urban and rural buildings, residential areas, high-tech development zones, small and medium-sized factories, mines and oilfields, and temporary construction of electricity and other places, for receiving and distributing electrical energy in the distribution system. ZBW series combined substations have the characteristics of strong set, small size, compact structure, safe and reliable operation, convenient maintenance, and movable. Compared with conventional earth-built substations, the combined substations of the same capacity usually cover only 1/10 to 1/5 of the conventional substations, greatly reducing the design workload and construction amount, and reducing the construction cost. In the distribution series, it can be used for ring network distribution system, dual power supply or radiation end point distribution system. It is a new type of complete set of equipment for the construction and re-selection of urban and rural substations. ZBW series combined substations meet the standards of SD320-1992 “Technical Conditions for Box-type Substations” and GB/T17467-1997 “High Voltage/Low Voltage Prefabricated Substations”.