“Simple frequency-dependent tools for analysis of inherent control limitations”
Authors: Sigurd Skogestad, Morten Hovd and Petter Lundström,Affiliation: NTNU
Reference: 1991, Vol 12, No 4, pp. 159-177.
Keywords: Dynamic resilience, relative gain array, disturbance rejection, process control
Abstract: By a plant´s inherent control limitations we mean the characteristics of the plant which will cause poor control performance irrespective of what controller is used. Another frequently used term is ´dynamic resilience´ which is the best closed-loop performance achievable using any controller. Since a plant´s dynamic resilience cannot be altered by change of the control algorithm, but only by design modifications, it follows that the term controllability provides a link between process design and process control. In this paper we focus on two aspects of controllability. The plants´ sensitivity to disturbances and the limitations imposed by interactions when using decentralized control. We use simple tools such as the RGA, the PRGA (Performance RGA) and the closely related Closed Loop Disturbance Gain (CLDG). For example, if kth column of the CLDG is large, then this indicates that disturbance k will be difficult to reject. This may pinpoint the need for modifying the process. The PRGA provides a measure of interaction which also includes one-way coupling. In the paper we apply these measures to distillation column control and fluid catalytic cracker (FCC) control.
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DOI: 10.4173/mic.1991.4.1DOI forward links to this article:
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BibTeX:
@article{MIC-1991-4-1,
title={{Simple frequency-dependent tools for analysis of inherent control limitations}},
author={Skogestad, Sigurd and Hovd, Morten and Lundström, Petter},
journal={Modeling, Identification and Control},
volume={12},
number={4},
pages={159--177},
year={1991},
doi={10.4173/mic.1991.4.1},
publisher={Norwegian Society of Automatic Control}
};