PID: 6 common configuration errors; how are you fixing loop tuning problems?

PID loop tuning problems can hobble a process unit or a whole plant. So how do operators get regulatory loops into stable operation? An amazing percentage of regulatory loops are problematic. Sad statistics about control loop health say that....
By Control Engineering Staff November 5, 2008

A new whitepaper from ExperTune discusses common PID problems, with suggestions for solutions. Given the number of regulatory loops that are problematic, this resource could prove very useful, and best of all, it’s free.

The new whitepaper, ” The Six Most Common PID Configuration Errors: How to Find and Fix Them , ” can be downloaded at no charge, a good price, given the sad statistical shape many control loops are in (see below).

PID Loop Analyzer for PLC Systems is among

PID control loops are one of the most common methods used in process industries. Around the world, millions of PID loops strive to keep processes safe, stable, and profitable. But many of these control loops are not properly configured, and either limp along with frequent operator intervention or simply run in manual. ( Read an earlier article about reasons why control loops often are not properly configured .)

“I have worked on thousands of control loops over the past 20 years,” says George Buckbee, ExperTune president. “Most DCS systems require you to configure over 50 parameters for each PID loop. It is very easy to make costly mistakes in the configuration, unless you know how to avoid these errors.”

According to ExperTune, as many as 75% of control loops actually increase variability because they simply do not do their jobs. Setpoints are not followed, valves swing around creating oscillations, and many loops are disabled by the operator and placed in manual mode. Studies of control loops in process industries give some insight into the root cause of these issues. For example:

  • 30% of DCS control loops are improperly configured;

  • 85% of control loops have sub-optimal tuning; and

  • 15% of control valves are improperly sized.

The whitepaper identifies the most common errors, and gives solutions for correcting or avoiding them.

Find and fix the six most common PID loop tuning errors, with help from Expertune.
Find and fix the six most common PID loop tuning errors, with help from Expertune, in this white paper.

—Edited by Peter Welander, process industries editor, PWelander@cfemedia.com ,
Process & Advanced Control Monthly
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