Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

On identification and control tuning of cylinder dryers

Slätteke, Ola LU ; Forsman, Krister ; Hägglund, Tore LU and Wittenmark, Björn LU (2002) Control Systems 2002 p.298-302
Abstract
The steam pressure control loops in the drying section of a paper machine play an important role for the quality of the moisture content control. The steam pressure loops are essential for the effective use of advanced control schemes for the moisture control. From mathematical model building and experiments on industrial paper machines it is found that the dynamics from the steam valves to the steam pressure can be described by a simple process model, the so called IPZ model. This model has an integrator, one pole, and one zero. The process is characterised by three parameters that vary significantly with the operating conditions. A typical step response of the open loop process has a fast and a slow transient. The steam pressure in the... (More)
The steam pressure control loops in the drying section of a paper machine play an important role for the quality of the moisture content control. The steam pressure loops are essential for the effective use of advanced control schemes for the moisture control. From mathematical model building and experiments on industrial paper machines it is found that the dynamics from the steam valves to the steam pressure can be described by a simple process model, the so called IPZ model. This model has an integrator, one pole, and one zero. The process is characterised by three parameters that vary significantly with the operating conditions. A typical step response of the open loop process has a fast and a slow transient. The steam pressure in the cylinders is in general controlled by PI-controllers. Some previous work on this subject has been done by Nelson and Gardner.The paper discusses the specifications for control of the IPZ process. Different controller structures are discussed and general tuning rules for the IPZ process are derived. It is shown that the tuning should be based on a compromise between reference signal tracking and disturbance attenuation. The disturbance attenuation is essential to avoid coupling between the different steam groups.An important property of the tuning rules is that it is possible to determine the controller parameters based on quite simple experiments on the process. The new tuning rules are compared with the common practice of making lambda-tuning based on the fast dynamic of the process.The main results of the paper are a controller structure for steam pressure control and a set of tuning rules for the controller. The tuning rules have been tested on paper machines in the industry. (Less)
Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
drying paper
host publication
Proceedings : control systems 2002, june 3-5 2002, Stockholm, Sweden : The world pulp and paper week 2002 (SPCI-meddelande ; 76)
pages
298 - 302
publisher
Stockholm
conference name
Control Systems 2002
conference location
Stockholm, Sweden
conference dates
0001-01-02
ISSN
0280-6800
language
English
LU publication?
yes
id
adbb0974-ecb9-427f-9fec-2597ac62dce0 (old id 537780)
date added to LUP
2016-04-01 17:04:04
date last changed
2018-11-21 20:46:24
@inproceedings{adbb0974-ecb9-427f-9fec-2597ac62dce0,
  abstract     = {{The steam pressure control loops in the drying section of a paper machine play an important role for the quality of the moisture content control. The steam pressure loops are essential for the effective use of advanced control schemes for the moisture control. From mathematical model building and experiments on industrial paper machines it is found that the dynamics from the steam valves to the steam pressure can be described by a simple process model, the so called IPZ model. This model has an integrator, one pole, and one zero. The process is characterised by three parameters that vary significantly with the operating conditions. A typical step response of the open loop process has a fast and a slow transient. The steam pressure in the cylinders is in general controlled by PI-controllers. Some previous work on this subject has been done by Nelson and Gardner.The paper discusses the specifications for control of the IPZ process. Different controller structures are discussed and general tuning rules for the IPZ process are derived. It is shown that the tuning should be based on a compromise between reference signal tracking and disturbance attenuation. The disturbance attenuation is essential to avoid coupling between the different steam groups.An important property of the tuning rules is that it is possible to determine the controller parameters based on quite simple experiments on the process. The new tuning rules are compared with the common practice of making lambda-tuning based on the fast dynamic of the process.The main results of the paper are a controller structure for steam pressure control and a set of tuning rules for the controller. The tuning rules have been tested on paper machines in the industry.}},
  author       = {{Slätteke, Ola and Forsman, Krister and Hägglund, Tore and Wittenmark, Björn}},
  booktitle    = {{Proceedings : control systems 2002, june 3-5 2002, Stockholm, Sweden : The world pulp and paper week 2002 (SPCI-meddelande ; 76)}},
  issn         = {{0280-6800}},
  keywords     = {{drying paper}},
  language     = {{eng}},
  pages        = {{298--302}},
  publisher    = {{Stockholm}},
  title        = {{On identification and control tuning of cylinder dryers}},
  url          = {{https://lup.lub.lu.se/search/files/4864382/8866561.pdf}},
  year         = {{2002}},
}