Incatools blog

Benefits in feedforward in PID controllers

Posted by Pramit Patodi on Jul 14, 2020 12:02:08 PM

At most plants, the biggest challenge in tuning PID controllers is to reject process disturbances. However, in many PID controller’s information regarding process disturbances is missing in the PID algorithms which drastically affects PID performance. Do you need to understand how to add that information in PID controllers? Check out this blog, about the benefits in feedforward in PID controllers.

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Topics: PID tuning, PID tuning parameters, PID tuning methods

PID tuning example: Controller with a nonlinear response on the valve

Posted by Leandro Diaz on Jun 8, 2020 4:00:29 PM

When we work with PID controllers, we always assume that the control valve flow characteristic is linear. PID controllers cannot handle nonlinear responses properly. However, most of the time valves are nonlinear and we have to deal with them when tuning a loop. Process units that change their operating window regularly, have the tendency to affect the performance of the PID controllers. This probably has happened to you before and i know it's really frustrating! But I'll show you a PID tuning example where it's possible to tune a PID controller and have a good performance on a large operating window of a process unit. And that is what I will explain in this blog.

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Topics: PID tuning, PID tuning parameters, PID tuning methods

Optimal PID tuning for Cascade loops

Posted by Gustavo Müller on Jun 8, 2020 3:53:24 PM
PID tuning normally requires the DCS engineer to have a good knowledge of the process and the control strategy, and specially time. While other also important activities are waiting the conventional bump-test-tuning procedure gets more complicated when tuning master-cascade strategy loops, when two, or often more, variables need to be tested and each of the loops individually tuned. To make the challenge even greater, these loops are normally configured for important and slow response variables, such as temperatures in distillation columns, or reactors.
 
In these cases, what would be only a simple PID parameter modification, turns out to take days after having affected the product quality and/or the throughput.
 
The best way out in this scenario is to do it right and at the first try. How? That is what I’ll explain in this blog.
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Topics: PID tuning, PID tuning parameters, PID tuning methods

Furnace and Boiler excess air control

Posted by Hitendra Chauhan on May 27, 2020 9:18:03 AM

From furnace or boiler efficiency point of view, excess air control is very important to be set up correctly. When there is too much air in the combustion process, additional fuel is being burned to raise the temperature of this excess air to the combustion temperature. Excess air absorbs the heat that goes up the stack, rather than in the process. To control the excess air to its minimum level, it's required to control it tightly in a “safe way”. If there is not enough air being introduced into the combustion process, all fuel will not be burned and, consequently, it will be lost up the stack in the form of combustibles. Not only does this result in an obvious waste of valuable energy, safety and pollution hazards are created. 

Discover in this blog how to reduce specific energy consumption of furnace or boilers by implementing the correct control strategies. 

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Topics: PID tuning, PID tuning parameters, PID tuning methods

5 common PID tuning mistakes you can easily avoid

Posted by Hitendra Chauhan on May 26, 2020 3:18:42 PM

When the grass root plant starts production, 70% to 80% of the PID loops are in default mode. There is nothing wrong with default settings. However, when time passes and alarms occur, the production manager will complain about spending too much time on controlling the plant. You need to check all the PID loops to make sure the plant will run smoothly. In this blog, you will read 5 of the most common mistakes made by DCS engineers in PID tuning. And more importantly, how you can avoid those mistakes.

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Topics: PID tuning, PID tuning parameters, PID tuning methods

PID Tuning Example: How to do PID tuning for interacting loops?

Posted by Didac Recio on May 25, 2020 4:40:08 PM

Tuning of PID controllers has shown to improve plant performance and increase stability and safety. Very often, single control loops are tuned with the focus only on that specific loop, without regard for process interaction with other control loops. Depending on the nature of the process, this interaction can lead to a destabilizing effect where the control loops fight each other instead of working together in harmony. Discover in this PID tuning example how to analyze and tune interacting loops in this blog.

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Topics: PID tuning, PID tuning parameters, PID tuning methods

How to do PID tuning on a furnace?

Posted by Hitendra Chauhan on May 25, 2020 2:56:52 PM

In most of the chemical and metallurgical industries a furnace or heater is the most common and important thermal equipment used. Some control schemes have been recognized for automatic control of furnace outlet temperature, cascade control of temperature with fuel, control of fuel to air mixture ratio, and excess oxygen control content in flue gas. The design of a control scheme is very important, and it may vary as per the process and plant requirement. The final control performs well only if the underlying PID loops are designed and tuned correctly. Without robust and safe PID tuning parameters, tight and safe control of the furnace outlet temperature is not possible. Picking the correct temperature control scheme design and tuning the PID loops in it properly are equally important. In this blog you'll learn about PID tuning of a furnace.

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Topics: PID tuning, PID tuning parameters, PID tuning methods