[?]: Working with Siemens s7 300 PID Self Tuner FB51

[Georgio]

Hi all! (Sorry for my English )


I have a question about using of Siemens s7 300 PID Self Tuner (FB51).
I have connected this self tuner with PID regulator FB41.
I have created simple program with visualisation to try all posibilities about Self Tuner. But I found out that Self Tuner probably doesnt work I want to.

I have created several transfer function (in WINMOD - this program can simulate transfer functions of simulated systems) to control them:

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Gs = 1/((2*s+1)*(16*s+1)),  Gs = 1/((1*s+1)*(30*s+1)) ...

and so on.
Self Tuner identify (output parametres of Self Tuner) this system correctly, for example:

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system Gs = 1/((2*s+1)*(16*s+1))

is identified as

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Gs = 0,9881/((2,4763*s+1)*(16,2319*s+1)). 

Then Self Tuner computes parametres of PI and PID regulator.
Parametres of PI regulator: P: 2,765, I: 9,821.
Parametres of PID regulator: P: 32,265, I: 5,076, D: 1,228.
This parametres are represents in FB 41 like this:

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Gr = P(1+1/(Is)+Ds)

Behavior of PI regulator is very good, but PID regulator has big overshoots and regulation circuit oscilatted because of big P constant. I have tried a lot of transfer functions, but still one conclusion: good PI and PID regulator bad .
But status design and status heating on the end of the process of self tuning is good (status design=2, status heating=2),
so its still ideal case of tuning

My qustions:
1) have everybody some experiences with PID Self Tuner ? How does it work in your case ?
2) do you know where I can get some documents how Self Tuner works (except official help of self tuner ...) ?

Thanks a lot!!

[bit.hunter]

Do you have a WINMOD? What cofiguration do you have? Can you share with us?

[Georgio]

I have WINMOD in my work only (version 5). Unfortunately WINMOD requires hardware key. I dont know how to run it without this hardware key

[bit.hunter]

In my Work we use SIMIT and SIMBAPRO and they have hardkey too.

Thanks anyway.

[Georgio]

I have found an article which describes theory of PID Sel Tuner. But unfortunatelly this article is in German paper and is written in German language. Name of the paper is ATP - Automatisierungtechnische Praxis, the article is in print 11 from 1998 year. I cant speak German very much but equations are same in all languages. I have tried to compare theory and equations in this article with my practical results but the result of this comparison is poor. There is a problem with versions of Self Tuner maybe. In the article is not mentioned in which version of the Self Tuner is the theory implemented. And in fact it is ten years from publishing of this article to nowadays. Authors of the article: Dr.-Ing. Bernd-Markus Pfeiffer and Dipl.-Ing Dieter Mohr maybe know more. I will try to contact them and I will see