Design And Implementation Of Substation Central Signal System Based On S7-200

As the developing of the computer control technology,computer monitoring technolgy are more perfect than before, PLC is using widerly in industry because of its Vulnerability and Reliability. Security of supply has been always a key factor in the development of the electric industry.In order to keep an eye on all kinds of unnormal working states, the central signal system in substation is set and it is truely necessaryIn the paper, with the analysis on the working principle of substation central signal system functioning mainly through signal relay and literal light—emitting screen,this paper indicates all the defects of conventional substation alarm mode as well as the necessity of modification on such system to improve its automatic and intelligent level.The means of using S7-200 series programmable logic controller. It deals with the working principle and trapezium chart of the wrong sound signal and advanced sound signal system by the use of PLC.Including the design of both the wrong signal and advanced signal,and the wrong signal compose of wrong sound and flashing signal.. The advanced signal can tell us all the abnormal working states of electric device and lines,and help us to prevent the abnormal be much worse.At last the I/O assignment and trapezium chart be finished.