Abstract: Water quality is related to the national economy and a major event,water turbidity after filtering in the water supply system is one of the key indicators of water quality.Against to large inertia,large delay,model parameters time varying and much disturbance of water turbidity control in city supply system,a new control algorithm is proposed to obtain better control results.The specific idea of the algorithm is the double controller:the track controller and the disturbance controller in view of different task.The former adopts a nonlinear compensation PI controller to track the set point,the latter uses a traditional PI controller to restrain the disturbance from the process.The gain K of the nonlinear compensation part is very important to the track controller and adopts expert rules according to the system response.The simulation comparison of the new algorithm and the traditional PID feedback control algorithm,Smith predictive control and dual PI control algorithm has been done in this paper.Finally the new control algorithm is applied to a pilot base.The results of simulation and experiment show that the new control algorithm can overcome disturbance in time,is not sensitive to changes of model parameters and has a strong robustness and a good tracking ability to ensure the stability of water quality.

Key words: city water supply, turbidity, dualcontroller, nonlinear compensation PI controller

摘要： 针对城市供水过程中,待滤水浊度控制过程的大惯性、大滞后、模型参数时变和干扰多等特点,采用一种新型的控制算法来实现对该过程的控制,其具体思想是:分别从对设定值的跟踪性要求和对扰动的抑制性要求出发,采用双控制器分别实现各自的控制,且两个独立的控制器分别采用常规PI和带非线性补偿的PI算法。并将该种新型控制算法和传统PID反馈控制算法、Smith预估控制算法和双PI控制算法进行了仿真比较。最后,还将该种算法实际应用到某水厂的中试实验基地。仿真和实验结果表明:所采用算法能够及时克服扰动,并对模型参数变化不敏感,具有很强的鲁棒性,对设定值具有良好的跟踪能力,确保了供水质量的稳定性。

关键词: 城市供水, 浊度, 双控制器, 非线性补偿PI控制器