Application Of Active Disturbance Rejection Control To The Coordinated System Of Supercritical Power Unit

An ultra-supercritical（USC） unit is a multivariable strong coupling systemwith typical nonlinear, large delay and large inertia characteristics. It often makesthe coordinated control quality deteriorate under variable conditions withconventional PID control method, thus affecting the load response speed of the unit,at the same time, leading to fluctuations of main steam pressure and otherparameters. It is of great importance to apply advanced technology of activedisturbance rejection control(ADRC) to the coordinated control of anultra-supercritical unit and to carry out experimental study with the help of thepower station simulation system, in improving the coordination control quality.Firstly, the dynamic performance and the coordinated control characteristics ofan supercritical power unit are analyzed. Then the principle of ADRC is introducedand the nonlinear and linear ADRC algorithms and their discretization areexpounded separately. The parameter setting rules of ADRC are also discussed. Bytaking a1000MW ultra-supercritical unit as the investigated object, the coordinatedADRC scheme is designed. Two kinds of real-time ADRC algorithms areprogrammed in MATLAB platform. Finally, detailed load-changing controlsimulation tests are made in the full-scope simulator of the given1000MW powerunit, by two-way data communication with UDP/IP protocol between the controlprogram and simulator. It is shown that the control effect of the proposedADRC/LADRC coordinated control scheme is significantly superior to the originalPID controller both from load-following capability and the stability of main steampressure.