一种基于初始闭环系统的性能评估方法

A New Approach to Performance Assessment Based on Initial-closed-system

基于初始闭环系统的输出方差和最小方差指标,提出了一种新的性能评估方法.在过程时滞变化的情况下,基于最小方差指标的评估可能会得到错误的结论,而新的方法可以避免这一缺点.扩展的性能指标以控制器投运后的初始状态作为零基准,能够更准确地反映操作工系统性能的变化,能够很好地替代最小方差指标.利用交互矩阵可将扩展指标推广到多变量系统的评估中,本文将这一算法应用于精馏塔过程的评估.精馏塔过程的仿真示例验证了方法的有效性,表明过程时滞变化时用扩展指标来进行评估更能反映系统性能的变化.

This article proposes a new approach to perfor- mance assessment based on initial-closed-system and minimum variance index. When the time delay of a process becomes shorter, assessment based on minimum variance index may draw a wrong conclusion, while the new approach can avoid this dis- advantage. A generalized index that chooses the initial perfor- mance of closed-system as zero-point can give operators more exact result about how the performance of system changes and can substitute for the minimum variance index effectively. By the interactor matrix, the generalized index can be extended for multivariable systems. This article applies the approach to performance assessment of a distillation columns process. Sim- ulation result of distillation columns process shows the validity of this method, indicating that the generalized index should be used for assessment when the time delay of the process becomes shorter.