Vdq decoupling terms

DIJO PAULSON

Other Parts Discussed in Thread: CONTROLSUITE

Hi,

1) How do we set PI current and speed controller saturation levels in FOC ?

2) Does adding decoupling terms to the controller outputs improve the current waveforms ? I did a simulation of it, but didn't find any significant improvement. What is the purpose of removing the cross coupling terms?

Regards,

Dijo Paulson

over 10 years ago

0 Ramesh Ramamoorthy over 10 years ago

TI__Mastermind 27240 points

1. These are already given in the example code at controlSUITE. Typically, the machine flux is mostly aligned on D axis and will contribute to more back emf on Q axis. Therefore, Vq should be chosen closer to +/1 1.0. Typically Vd could be chosen around +/- 0.5

2. Agree, I also did not see their impact like in ACIM. They are supposed to make the controller look linear.

0 DIJO PAULSON over 10 years ago in reply to Ramesh Ramamoorthy

Intellectual 710 points

If i am correct there are no decoupling terms in the sample code of PMSM FOC.
Adding it to the PI outputs would be enough right ? Will it introduce any slight improvement? Or else is it worhtless ?

0 Aditya Gadekar over 10 years ago

Intellectual 385 points

Dear Dijo,
You should get significant improvement in response by decoupling
Decoupling will give you the faster dynamic response of the machine

0 DIJO PAULSON over 10 years ago in reply to Aditya Gadekar

Intellectual 710 points

Does it improve the current waveforms ?

0 Aditya Gadekar over 10 years ago in reply to DIJO PAULSON

Intellectual 385 points

Yes if its decoupled it should improve current waveforms

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Vdq decoupling terms