A 2-DOF PID Controller Design And Application Research Based On Desired Dynamic Equation

In this paper, the control system design issue is studied. The controller structure is a two degree of freedom PID proposed by Wang Weijie et.al from Tsinghua University in 2008, which is designed base on the Desired Dynamic Equation. The essence of the algorithm is a equivalence deduction from the low-order non-linear TC controller to a kind of two degree of freedom PID control structure, whose parameters are tuned via the desired dynamic equation (DDE) method. Selection of initial values of the controller’s parameters in this method has been researched and the tuning procedure has been concluded. The tuning method is specifically described as follows:first of all, after we got the regulation time of the pure proportional control system using PID controller engineering tuning method, we should choose a reasonable desired dynamic and tune controller parameters according to the control system performance requirements. Finally, the dynamic simulations are done on various control plants. The results show that the tuning method is easy to use and can achieve good performance. Furthermore, the two degree of freedom PID controller can also be applied to practical plants. Therefore, we complete some test modeling studies of the typical control circuits (primary air control loop, furnace pressure control loop, secondary air control loop) on a 1000MW ultra-supercritical DCS simulation platform. Then we find the transfer function model with least square method. In order to facilitate controller design, if the fitted model order is high, the model should be approximate to a first order plus time delay (FOPTD) model. we take the high order model as the actual process, then we choose a desired dynamic adjustment time from open loop step response or closed loop engineering tuning so that we can design and tune the DDE-PID controller. Some simulation experiments about dynamic performance, anti-disturbance performance and robust performance. A comparative study of the control systems which is designed based on accurate mathematical model. Finally, summarize this paper, as well as the future research work of this paper is prospected.