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Contek Systems Ltd, Aberdeen, UK Control engineering consultant for the oil and gas industry. Process control, de-bottlenecking, compressors, slugging and control system PID tuning. |
| Recent press releases and other news are available here. |
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Contek Systems Ltd, 25 Wilson Road, Banchory, AB31 5UY +44 (0)1330 823643 |
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Try my well-known Process Identification and PID Tuning package
U-Tune.
Click here for details and screenshot. |
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See my FREE
tuning calculator.
Download here. |
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I have written several
tutorials on the practicalities of process control.
Click here for links to our tutorials. |
| Check back from time to time. New articles will be added as time permits. |
| Note: emails can be accessed offshore - telephones can't! |
| Home page |
| Process Control Information and Documents | |
| Documents and Tutorials from Contek Systems | |
| Observing and analysing process data | |
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There is frequently a tendency to ‘leap in’ and tune control loops regardless of the actual problem. It is very often the case that process instability has its root cause in operational or instrumentation issues rather than inadequate tuning. So the very first stage in approaching a tuning exercise is to observe the data. This article introduces the importance of collecting historical trends with sufficient resolution to enable fault-finding and process-learning. Detailed analysis at this stage may indicate that the problem is not a tuning issue at all. Read more Download as PDF. |
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| Split range controllers | |
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A very common control
scheme is split range control in which the output of a
controller is split to two or more control valves. This article
introduces the correct way to implement split range control.
Read more Download as PDF. |
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| High and low output select logic | |
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High and low output select
logic is used when two controllers are adjusting the same
control valve. If not implemented correctly, integral windup
will result in process instability.
Read more Download as PDF. |
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| Collecting data for controller tuning | |
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Depending on the control system, there are several options
available for recording process data for tuning purposes. It may
be possible to extract text files of trend displays from the
control system which can then be converted into whatever format
is required for the tuning software.
Read more Download as PDF. |
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| Error squared controllers | |
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I am
frequently asked to visit offshore production platforms to sort
out problems with the oil export or the produced water quality
where the ultimate issue is not poor control in the export or
water-handling systems but due to over-aggressive level control
at the reception end of the process.
Read more Download as PDF. |
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| Tuning anti-surge controllers | |
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This document discusses the tuning of
anti-surge controllers on centrifugal compressors, most of which are designed
around standard proportional-integral controller algorithms, possibly assisted
by various vendor-specific techniques to ensure that the recycle valve opens
when needed. Being a PI (or PID) controller, its tuning is actually no more
difficult than any other process controller.
Read more Download as PDF. |
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| U-Tune (micro-lite) User Guide | |
| The user guide is included in the U-Tune (micro-lite) installation software. The document includes details on general tuning techniques and controller algorithms. PDF | |
| My favourite process control books | |
| PID Controllers: Theory, Design and Tuning by Karl Astrom | |
| Multivariable Feedback Control: Analysis and Design by Sigurd Skogestad and Ian Postlethwaite | |
| Nonlinear Dynamics and Chaos by Steven H. Strogatz | |
| PID without the Math by David W St Clair | |
| Products for process control | |
| Dataq Instruments | |
| MATLAB | |
| General Algebraic Modelling System (GAMS) | |
| Contek's FREE tuning calculator and other products | |
Books on PID control
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Books on control engineering
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| Tutorials and other learning material | |
| Course Notes and Learning Resources - Process Control | |
| Control Tutorials for Matlab | |
| PID controller laboratory | |
| Industrial Systems and Control Ltd | |
| Directories related to control engineering and oil & gas | |
| Read-Out Ireland's Journal of Instrumentation and Control | |
| The Engineers' Club - Online Resources | |
| Useful internet discussion groups for control engineering topics | |
| control.com | |
| sci.engr.control | |
| Control Systems Engineering at Eng-Tips | |
| Reciprocal links | |
| If you would like to add your control engineering URL to this page and would be willing to put a reciprocal link on your own site, please send an email with details to: JohnGreene@contek-systems.co.uk | |