Simulation on Density Control of Cementing Slurry Based on Feed-forward Decoupling
Due to the problems of large inertia,long delay,and strong coupling in cementing slurry level control and density control system,it is quite difficult to achieve favorable control effect by traditional PID control method,Therefore,a level and density control strategy based on feed-forward decoupling is proposed.Firstly,based on the principles of flow conservation and mass conservation,the mathematical model of the cementing slurry mixing system was constructed by using the mechanism modeling method.Then the mathematical model is used to calculate the relative gain array of the cement slurry mixing system at the steady state operating point,and the optimal variable pairing and coupling degree of the level and density control process are obtained,as well as the feed-forward decoupling controller for the level density control of cement slurry is designed.Finally,the PID control and the PID feed-forward decoupling control method are simulated based on the Matlab/Simulink software.The results show that compared with the traditional PID method,the PID feed-forward decoupling method can effectively compensate for the coupling effect of level control and density control,the overshooting amount of the level control was reduced by 26.1%,the regulating time is reduced from 123.503 s to 32.090 s,and the regulating time of the density control was reduced from 62.620 s to 20.542 s.The feed-forward decoupling controller can better enhance the system stability and reduce response time to improve the system control performance,which is highly significant for improving the quality and efficiency of cementing operations.
万方数据
维普
