Urban rail traffic station contains multiple weak current equipment systems, such as communication, signal, integrated supervision, environmental monitoring, office automation, access control, automatic fare collection, automatic fire alarm, shield gate, emergency lighting, integrated automation of transformer substation, etc. These systems shoulder the responsibility of environmental monitoring of passenger transport, information transfer, passenger guidance, and others, which are the critical first-order load, High-reliable power supply system is required to guarantee the quality and continuity of power supply.