Owing to worse reliability of original safety power source control system of 2×600 units in first-phase project of Huaneng Caohu Power Plant

resulting from complexity in wire connection

secondary circuit

synchronism-inspecting circuit

and control logics

improvement has been carried out

the safety power source system being retrofitted from PLC control to DCS control

and the problems occurred in safety power source control system

such as interface between DCS and diesel-generator

switchover of load

criterion for power loss in safety section etc.

being perfected.After retrofitting

the safety power source control system boasts advantages of full hardware functions

rapid response speed

high reliability

and convenience in maintenance.