OPEN PARA LA SEGURIDAD Y EL RENDIMIENTO
Mejore la seguridad y el rendimiento de su planta gracias a la gestión de alarmas, la supervisión de rendimiento y de activos, la visualización web de datos, la optimización, el control avanzado y la sintonía con la nueva herramienta TaiJi.
Repiensen sus métodos de trabajo y obtengan resultados inmediatos gracias a nuestros servicios, nuestra capacitación y nuestra pericia en asesoría. Manejen el cambio inteligentemente con nuestras soluciones probadas.
March 2004
In this issue
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About us |
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Classes and seminars |
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Trick for this month |
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To contact us |
See our previous issues :
http://www.topcontrol.com/techinfo/news.php
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Our next Webinar March 25 2004, 10 :30 (E.T., GMT-5) :
Advanced Tools to Optimize your process:
- Cross Correlation, Auto Correlation
- Power Spectral Density, Statistical Analysis
http://www.topcontrol.com/training/tlistcourses.php?idcours=33
Price : 295$ per connection (no limit on number of attendees in the room)
Credit card or PO.
Many papers are now available on our web site. See :
http://www.topcontrol.com/techinfo/papers.htm
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Next classes:
Atlanta Ga., April 20-22
Seminar on Modern Control Methods.
See at http://www.topcontrol.com/training/tlistcourses.php?idcours=6
Boston Mass, May 3-5.
Class on Detailed loop analysis with Expertune.
See at http://www.topcontrol.com/training/tlistcourses.php?idcours=10
Boston Mass, May 6-7.
Seminar on performance assessment techniques #SE-120-2E
See at http://www.topcontrol.com/training/tlistcourses.php?idcours=29
Michel Ruel will be part of a course
«Process Integration - turning data into knowledge for decision making.»
http://www.paptac.ca/english/layout/index.htm by PAPTAC in May 10-14 2004.
Also in June, Webinars, classes in Houston, Milwaukee and St-John NB.
See our new calendar for 2004 Classes & Seminars
See at http://www.topcontrol.com/training/tcalendar.php
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Tuning and Performance…
Using
new Performance monitoring software (for example PlantTriage by
ExperTune), it is now easy and quick to tune loops since PlantTriage
will capture data (when a SP change or a CO change occurs) to ensure a
model is available all the time and also to obtain tuning parameters.
When we decide to tune the loop, there is no need to bump the process,
the model and tuning parameters are already available.
How to select a tuning criteron? What is performance for this loop?
- SP change or Load change?
- When a loop is tuned to handle load changes, the tuning parameters are choosen to ensure an aggressive response. On a SP change, the response could be oscillatory
- Using a filter on SP will ensure the SP response will be similar to a load change
- Sluggish tuning parameters :
- Very robust (if the process varies, the loop remains stable)
- Not really good to reject a disturbance
- Large errors on load changes
- Long response time to recover from a load change
- On a SP change, no overshoot, no cycling but very slow
Two examples are used to illustrate these results:.
(For more details, see table of results) :
Flow loop (Gp=1, td=2s, Tau=3s)
Results : If tuned sluggishly (Lambda std) robustness is 4 times better
than the one tuned aggressively; at the opposite, the load rejection is 4 times worse.
Temperature loop (Gp=1, td=10s, Tau=3s, Tau=100s)
Results : If tuned sluggishly (Lambda std) robustness is 25 times better than the one tuned aggressively;
at the opposite, the load rejection is 80 times worse. A SP filter will improve the response on SP changes.
In both cases, moderate tuning parameters (ExperTune default values) are a good compromise between stability and performance;
also no cycling is present and the response time is close to what was obtained using aggressive tuning.
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Comments, suggestions and requests are welcomed. Please e-mail us at:info@topcontrol.com
You are welcomed to visit our web site :http://www.topcontrol.com
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49 Bel-Air Street, Lévis, QC
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4734 Sonseeahray Drive
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