This paper covers such important problems as earth connection,ups,super shielded transformer,earth free of power system and computer room, and methods to deal with them are also put forward.

• 介绍DCS和PLC供电系统设计和实践中关于接地、不间断电源、超隔离变压器、电源浮空和机房等几个主要问题及处理方法。