A universal tuning method of large dead-time system
Chang-liang Liu1, Zeng-hui Ma1, Ping-an Kai2
COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(5) 19-23
1State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources (NorthChina Electric Power University), Beijing, 100052, China
2Energy Research Institute, National Development and Reform Commission, Beijing, 100010, China
The current approach of the PID controller design and tuning for the large dead-time system are almost based on the first-order time delay model, such as all PID algorithms and Ziegler function in MATLAB. And these algorithms generally only apply to the following system 0.1<=t /T <= 2 . Therefore, the application effect of these algorithms in large dead-time system are not ideal. Based on the second-order system, this paper proposed a universal tuning method of PID controller for large dead-time process. By the introduction of the controller pre-coefficient Kf , this method makes the large dead-time system PID controller design and tuning simplistic. The fitting formula of controller pre-coefficient Kf was given in this paper. The method is simple, versatile, suitable for the object of (t /T )→ +∞ and second-order, higher-order system, overcomes the limitations of traditional PID control algorithm in large dead-time system applications. The simulation results show that the method is correct, effective and has practical value.