强制循环蒸发系统的非线性自适应解耦PID控制

本文结合现场的实际过程数据,首先应用能量平衡建立了强制循环蒸发过程的动态模型.针对该过程的多变量、非线性以及强耦合特性,在常规增量式PID控制器的基础上提出基于神经网络与多模型切换的非线性自适应解耦PID控制策略.该控制器是由线性自适应解耦PID控制器和基于神经网络的非线性自适应解耦PID控制器以及切换机构组成.其中线性自适应解耦PID控制器可以保证系统的稳定,而基于神经网络的非线性自适应解耦PID控制器则可以有效地提高系统的性能.上述过程的PID参数是通过广义预测的方法得到,最后通过仿真表明,上述控制方法不仅消除了回路间的耦合,在稳定生产的同时提高了蒸发的效率.

Nonlinear adaptive decoupling PID control for the forced-circulation evaporation system

Based on the principle of energy balance, the dynamic model of the forced-circulation evaporation system is developed by using real operation data. The process of the forced-circulation evaporation is characterized by multiple variables, non-linearity and strong coupling. A nonlinear adaptive decoupling PID control strategy combined with the conventional PID controllers is introduced based on neural network and multiple models. The adaptive decoupling PID controller is composed of a linear adaptive PID decoupling controller, a neural network nonlinear adaptive PID decoupling controller and a switch mechanism. The PID parameters of this controller are determined by the multivariable generalized predictive control law. The linear adaptive PID controller ensures the boundedness of the input and output signals in the closed-loop system; the nonlinear adaptive PID controller improves the performance of the system. Finally, experiment results show that this approach eliminates the coupling of each loop and improves the efficiency of evaporation.