基于S函数的调节阀粘滞特性检测方法

Stiction detection method of control valve based on S function

调节阀粘滞特性引起的振荡是工业控制回路性能恶化的最常见来源。目前虽然已有许多检测调节阀粘滞特性的方法,但这些方法的复杂性或存在的缺陷限制着其在实际工况中的具体应用。本文提出了一种检测过程控制回路中调节阀粘滞故障的新方法。该方法将控制器输出(OP)和过程变量(PV)的变化(ΔPV)在相平面图中所构成变化趋势与标准S函数进行对比,根据实际函数趋势与标准S函数间的差异计算相关系数,通过相关系数的数值具体得出调节阀中是否存在粘滞特性。仿真实例和实际工业数据分析实验验证了提出方法的有效性。

Oscillations caused by the viscous characteristics of pneumatic control valves are the most common source of deterioration in the performance of industrial control loops.Although there are many methods to detect the viscosity characteristics of control valves,the complexity or defects of these methods limit their specific application in practical working conditions.This paper proposes a new method for detecting the viscous fault of the regulating valve in the process control loop.The proposed method compares the change trend of controller output(OP)and process variable(PV)(ΔPV)in the phase plane diagram with the standard S function,calculates the correlation coefficient according to the difference between the actual function trend and the standard S function,and can specifically determine whether there is viscosity characteristics in the control valve through the value of the correlation coefficient.The proposed method is analyzed and experimented by simulation examples and actual industrial data,and its effectiveness is verified.