Hi,

We are doing power plant Automation project using ABB 800XA Automation Platform.

At present we are in pre-commissioning stage in control builder. during the online we opened the interaction window of tuning page. In tuning page i don't know how to setup the parameters and what are to be consider to make autotuning. Can anybody explain in detail to make it possible?

Thanks & Regards
S.krishna

 

I'm sorry but I'm going to be a little blunt here

Do NOT use the Autotune facility until you know a little more about what it will do and how it will affect your plant as misuse could cause SERIOUS damage.

OK, now that's out of the way .... In general, ABB Autotune uses two types of bump test - Step and Relay. To use autotune you configure the maximum size of the steps that the controller is allowed to make. The controller will then make set-point (relay) or output (step) changes and attempt to analyze the results. The ABB Autotune algorithm will have difficulty dealing with deadtime and you can only use Step tuning on pPI loops.

You should read the information in the Control Builder help files and the ABB Manuals - in particular the Extended Software manual - carefully. Depending on the type of PID control Module you are using Relay tuning may or may not work.

Finally, please do not think that the Autotune facility will always provide you with optimal (or even good) loop tuning.

Rob
www[.]lymac.co.nz

 

So, if I understood good, main difference between step and relay tests is that really works in a closed loop while step works in a open loop?

For example, if an actuator is a control valve and is used to control temperature, then step test would open or close this valve for a certain %, while relay test will change set point. That makes sense in case there is a closed loop.

Correct me if I'm wrong.

Thanks

 

Dear Rob,

Thank u for kind words to me