Discrete Time Model

[ryangilmour]

Hi again @chetangk94

I am working on the PID control of the model developed. I want to ask about the completeness of the current version of the discrete time plant model, and how representative this is of the system.

The discrete time model has an unstable step response (below):

And when combined with the voltage divider, the problem is not solved (below).

As I understand it, the PID control will allow the stable plant system to use feedback and react more quickly to perturbations. Since the current model of the plant is unstable, designing the correct feedback using simple Ziegler Nichols tuning techniques is not possible.

So, is the plant model incorrect (perhaps due to being incomplete?), or is there some other issue I am not considering?

Thanks,

Ryan

[chetangk94]

Hi Ryan, The present model is based on the literature which is quoted in matlab code and it was just model on matlab. The code works perfectly well for the system parameter given in that literature. The system parameter for libre solar has to be decided and then fed to the matlab model which gives you the plant model and soon. Plant model for your system has to analysed before proceeding to PID design. As I am not from Control theory background, I stopped my work up to that point . Regards, Chetan Govind Kulkarni M.Sc Microelectronics and Microsystems +4917643837154 www.linkedin.com/in/chetangk

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On Thu, Jan 23, 2020 at 6:15 PM ryangilmour ***@***.***> wrote: Hi again @chetangk94 <https://github.com/chetangk94> I am working on the PID control of the model developed. I want to ask about the completeness of the current version of the discrete time plant model, and how representative this is of the system. The discrete time model has an unstable step response (below): [image: image] <https://user-images.githubusercontent.com/53762848/73006991-84ad5f00-3e03-11ea-9555-1f9b3afbfa6f.png> And when combined with the voltage divider, the problem is not solved (below). [image: image] <https://user-images.githubusercontent.com/53762848/73006951-6cd5db00-3e03-11ea-8bfa-66f97d0ed388.png> As I understand it, the PID control will allow the stable plant system to use feedback and react more quickly to perturbations. Since the current model of the plant is unstable, designing the correct feedback using simple Ziegler Nichols tuning techniques is not possible. So, is the plant model incorrect (perhaps due to being incomplete?), or is there some other issue I am not considering? Thanks, Ryan — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#4?email_source=notifications&email_token=AMLM4PGJZEHNZHTCGNI7BDDQ7HGEFA5CNFSM4KKZ72FKYY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4IIJ3DIQ>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AMLM4PB5VO632CTB6FMB4WDQ7HGEFANCNFSM4KKZ72FA> .