Simulation And Oscillation Diagnosis Of Control Systems With Valve Characteristics

In the modern industrial control site,the valve is the most widely used industrial equipment.However,it is well known that the control valve is a wear-resistant mechanical device relative to time.In the early stages of the control valve operation,the equipment may run well,but with the long-term opening,closing,rotation,or lubrication maintenance is not in place,will inevitably make the physical friction between the mechanical increase,resulting in valve viscous or within the system limit cycle,Resulting in the shock within the system eventually make the system performance degradation.But,the deterioration of the performance of the control system may not only be caused by the valve,oscillatory external interference,control system design,aggressive controller tuning may affect the final system performance too.Therefore,it is necessary to carry out modeling and simulation analysis of the system including the control valve to determine the source of the oscillatory,so as to more effectively improve the stability of the system and reduce the losses in industrial production to a minimum.It is based on the nonlinear characteristics of the static friction of the valve,and the inherent nonlinearity of the system may generate the self-oscillation,and the process of the modeling valve and the judgment of the oscillation source are deeply studied.The contents of the paper are mainly as follows:1.Modeling the control valve.In view of the static friction model and the binary valve model,the shortcomings are pointed out and the improvement is improved.2.Based on the method of descriptive function analysis,the oscillation source of the control system including the valve is quantitatively analyzed,and the qualitative analysis of the system is given.