Tune Your PID Loops Please!

“Who looks after PID tuning at your site?” This is a question I often ask many professionals. The answers vary from a definitive deparment to “don’t know” or “maintenance department”, “instrumentation department” etc. The replies almost always suggest to me that there is not enough focus or attention paid to this important but generally forgotton layer of automation.

PID (Proportional-Integral-Derivative) controllers still form the backbone of automatic control systems in refineries, (petro) chemical installations, power plants and numerous other processes. The success of PID schemes lies in the simplicity of the implementation, reliability of the hardware and the stabilising effect on processes. It is however necessary to enter values for the “P”, “I” and “D”, referred to as tuning parameters, to make this PID controller function in a stable and efficient manner.

Significant benefits can be achieved by optimising the performance of PID loops, especially interacting loops. This presentation explores optimisation possibilities for process industries with some case studies on PID tuning and introduces a new paradign on how to undertake a PID tuning project at your facility.