基于仿射非线性系统的超临界机组中间点温度控制的仿真研究

摘要

Due to the severe nonlinearity and complex mechanism of the temperature at intermediate point of the supercritical units,its accurate control is difficult to achieve.Thus,the method based on affine nonlinear system and feedback linearization was adopted to control the intermediate point temperature.By analyzing mechanism equations of the steam-separator and evaporation zone,the affine nonlinear system model for the intermediate point temperature was established.Moreover,taking a 600 MW supercritical unit the object, the system stability analysis and simulation test were carried out,to verify the anti-disturbance capability of the system under water disturbance and the control effect of the system with unit load ranging from 40%to 100%.Furthermore,comparison of the control effect between the affine nonlinear system and the con-ventional PID system was performed.The results show more effective performances.%由于超临界机组中间点温度具有高非线性、机理复杂等特点，难以对其进行控制。对此，采用仿射非线性系统和反馈线性化控制中间点温度，即通过分析汽水分离器和蒸发区的机理方程建立中间点温度仿射非线性系统模型，以超临界600 MW机组为研究对象，对所建模型进行稳定性分析和仿真试验，以验证在给水扰动下系统的抗扰动能力以及在40％~100％负荷范围内各负荷段的中间点温度控制效果，将基于仿射非线性系统的中间点温度控制系统与PID中间点温度控制系统进行对比，结果表明仿射非线性控制系统控制方法具有更优的控制效果。