Study Of Coordinate Control And Improvement Of Dcs Of ＃4 Unit In Dagang Power Plant

The control system of the fourth unit in Tian Jin Dagang power plant is a coordinated control system which is based upon the principle of turbine following boiler. It is composed of the actual load demand after AGC speed limiting, turbine main control station, boiler main control station, boiler combustion commands and superheated steam pressure signal. During the process of improvements of DCS, the main reason that influences the CCS load response rate is analyzed, local modification of the coordinated control system(CCS)is committed, the control loop is optimized and the combustion parameters of the boiler are adjusted to ensure the long-term and stably running of CCS as well as its sub-control systems, to achieve undisturbed switch between manual and automation when reaching certain load after interconnection, to realize the fast response of the output in power generators when AGC instructions change dramatically and to basically solve the problems of poor adjusting performance, long load response time and not being able to satisfy the request of fast adjustment in modern grid when using the turbine-follow-boiler control method. Meanwhile, analysis and solutions are proposed concerning the existing problems in the hardware of INFI90 in this paper.