采用基于闭环辨识IMC-PID实现串级汽温的鲁棒控制

摘要

An IMC-based-PID Controller design method for cascade control of superheated steam temperature through frequency identification is proposed in this paper.In this design method,the process model of superheated steam temperature is identified first.In the identification procedure,the set-point change tests are adopted to calculate the models based on the inputs and outputs of the inner and outer control loops.The process frequency-response matrix is estimated,and then a transform function matrix is obtained by the least squares method.The parameters of the IMC-based PID controller of the SST (steam temperature cascade control loop) are determined by using the internal model control (IMC) and improved SIMC method based on the identified model.It is shown that this strategy achieves better control performance and minimizes the effects of the external or the internal disturbances.%提出了一个基于频域辨识方法设计串级汽温内模-PID控制器.首先进行汽温过程对象的模型辨识,在辨识部分,通过进行常规的设定值扰动试验,获得串级系统各回路输入输出的扰动试验数据,估算出内回路及外回路的频率响应矩阵,然后通过最小二乘法计算出内回路及外回路模型变换函数的参数矩阵.基于内模控制(IMC)的汽温串级PID控制回路的参数整定,是基于辨识出的模型采用IMC方法计算出来的.现场应用情况表明,采用基于频域辨识方法设计串级汽温内模-PID控制器的控制方案,使汽温串级控制性能大大提高,能有效地减少各种内外干扰对系统的影响.