Industrial regulating valve non-linear operating characteristic diagnosis method

Abstract

The invention discloses an industrial regulating valve non-linear operating characteristic diagnosis method. The method comprises the following steps that in a control circuit corresponding to a to-be-diagnosed industrial regulating valve, a group of stationary process data is collected and recorded as x(t), and the oscillating period T0 of the stationary process data is determined; a mid-value line constant in a half oscillating period is calculated aiming at the stationary process data and recorded as HOPML; the maximum value and the minimum value in each oscillating period in the stationary process data are respectively recorded as emax and emin; aiming at all oscillating periods in the stationary process data, mean values of the maximum values and the minimum values are calculated and respectively recorded as emax1 and emin2, and a non-linear index number INL is calculated; if the INL is in a decision limiting interval omega, the operating characteristic of the to-be-diagnosed industrial regulating valve is linear, and otherwise, the operating characteristic of the to-be-diagnosed industrial regulating valve is non-linear. The industrial regulating valve non-linear operating characteristic diagnosis method is suitable for being used in regulating valves with non-linear operating characteristics, and quantitative evaluation of process non-linear characteristics can be achieved.

Description

technical field [0001] The invention relates to the field of fault diagnosis in industrial control systems, in particular to a method for diagnosing the nonlinear working characteristics of an industrial control valve. Background technique [0002] Modern industrial process equipment has the characteristics of large scale, high complexity, many variables, and operates under closed-loop control. For complex chemical production processes, there are often thousands of loops, and these loops affect each other, and the nonlinearity is strong. , however, the oscillation phenomenon of the control loop greatly affects the economic benefit and stability of the operation of industrial process equipment due to the ubiquity of controller over-tuning. [0003] Preliminary and accurate oscillation detection and fault diagnosis of industrial process equipment can reduce downtime, increase the safety of industrial process equipment operation, and reduce manufacturing costs. In actual produc...

AI Technical Summary

Problems solved by technology

These detection methods have two limitations in practical application. First, these detection and diagnosis algorithms can only distinguish the viscosity of the control valve, controller over-setting and external periodic oscillation disturbance, and the nonlinear operating characteristics of the control valve are combined. Second, the diagnostic algorithm using identification technology requires two sets of data output from the process and the controller, resulting in a significant increase in computational complexity, and the accuracy of calculation depends on the selection of many parameters. For dynamic characteristics For complex, diverse and unknown systems, there are relatively great difficulties in practical application

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