Research On Coordinated Control System Of Supercritical Unit

Supercritical unit is becoming the main thermal power generation unit in China because of its higher thermal efficiency and better economy.As the control center of generating unit,Coordination Control System(CCS)plays an important role in the automation system of power grid.The coordinated control system of supercritical unit is different from the traditional drum boiler.The coordinated control system of supercritical unit is a typical multivariable controlled object,which has the characteristics of nonlinearity,strong coupling,time-varying parameters,large delay and so on.Therefore,it is necessary to set up the model,decoupling control,and then optimize the control algorithm to make the system more stable operation.Feed water control is the key in the CCS of supercritical units,mean while the coal-water ratio control is the core of the feed water control.This paper first introduces the supercritical unit feed water control characteristics,and combined with a power plant,introduces and analyzes the various stages of the boiler(Startup and Wet stage,Dry stage)control strategy of feed water control system.It focuses on the study of the feed water control in Dry stage,analyzes influence factors of coal water ratio plan,and verifies the effectiveness of the feed water system in the process of variable load.Finally,through the analysis of the adjustment process of the RB test of the feed draft fan(Induced fan),the effectiveness of the feed water control is verified.