YB-12/0.4 type high/low voltage intelligent prefabricated substation (referred to as box transformer) is developed by our company, consisting of high voltage unit, power transformer, low voltage unit, FA device, UPS and other power supply modules, intelligent terminal, automation unit, communication unit and acquisition unit. The high voltage side can meet the requirements of the power department for distribution network automation, and the low voltage side can meet the requirements of intelligent property management in residential areas. The "four remote" (telemetry, remote signaling, remote adjustment, remote control) system management of the box transformer can be carried out using the upper computer set at the central station or property management office. As a complete standardized module power distribution device, the box transformer is used to receive and distribute electrical energy. It has the characteristics of simple structure, small footprint, safety and reliability, maintenance free, safety and environmental protection.