The 27.5kV box house (partition house, AT house, opening and closing house) is an important facility and equipment of traction power supply system; it integrates high-voltage electrical equipment, comprehensive automation system, AC/DC power supply system, auxiliary monitoring system, etc. in a closed metal box through system integration and primary and secondary fusion technology; it adopts factory design and pre-assembled production, featuring compact structure, small footprint, excellent performance, reliable operation and low cost; it is widely used in 27.5kV new construction and reconstruction projects. The 27.5kV box house product series include partition house, AT house, opening and closing house and switching station, etc.; high voltage equipment types are divided into air insulated type (AIS) and gas insulated type (GIS); applicable scenarios include high speed railway, passenger special railway, heavy load and general speed railway.