Study On The Application Of GPC Implicit PID Algorithm In Heating Station

Multi-variables,strong coupling,large time-delay and nonlinear are characteristics of city heating process control, and the mathematic model are ascertained difficultly. Based on in-depth analysis on pros and cons of generalized predictive control (GPC) algorithm, This paper apply the GPC implicit PID control algorithm in substation heating process control.Generalized predictive control (GPC) has been widely applied to temperature control, it takes minimize parameter model as the predicting model and introduces the ideas of multistep forecasting. The algorithm conducts optimized calculation by the way of rolling optimization in the entire control process, and corrects the deviation and uncertainty of predictive output by online calibration in optimization, So generalized predictive control has become one of the most representative algorithm of predictive control. However, GPC basic algorithm requires to solve Diophantine equations and on-line Inverse operations for the quadratic optimal control due to its own special features when the algorithm conducts optimized calculation according to the recursive principle of least square, this increases greatly the online computation burden and cuts down the real time ability of control system. So, this paper proposes the generalized predictive control implicit algorithm, which avoids the limitation of generalized predictive control basic algorithm, it estimates controller parameters directly, doesn't solve Diophantine equations and Inverse operations during on-line identified process, In the practical applications of industrial control systems, this decreases the computation cost and improves the real time ability for control, and is well adapted for on-line implementation and application in the engineering for complicated heating system. Although the optimal controlling strategy for GPC implicit algorithm can obtain better robustness and final stability, but due to the GPC implicit algorithm adopts the least square method to identify the system parameters, which are effected to a large extent by the initial value the identification assigned—it has the disadvantage of deviating from the set valve in initial operation stage. In view of these factors, the article introduces a conventional PID control algorithm on a basis of the GPC implicit control, to solve the problem of the system output can not very well track the system input.The simulation experiments prove the GPC Implicit PID control algorithm are applied to overcome control features of a system with multi-variables,strong coupling,large time-delay and nonlinear, the entire control process can gain better controlling effect.