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TMS320F2800137: Digital PFC theory

Nicolas UHL
Prodigy 100 points
Part Number: TMS320F2800137


Tool/software:

Hello,

I'm developping power electronic control on different TMS320F280xxx devices.

I have to tune a cassical PFC stage (single phase).

I know the principle of PFC control (votage loop / feed forward / current loop).

But I would like to know if there is a document in TI describing the way to define the regulator of the current loop.

What are the simple steps to calculate the PI controller ?

I've aleady browsed the Power Suite, the reference design, the totem pole PFC, etc...

But this is never clearly explained.

I sense the input values (I/Vin/Vout) and I normalize all of them

So, I have the input data I/Imax, Vbus/Vbusmax , Vin / Vin max

Then how I calculate the PI (for the current loop) to set the duty cycle.

Thanks in advance

Best regards

  • 0
    TI__Expert 3825 points

    Hi Nicholas,

    Did not get your question, are you asking what is the input to the PI compensator or how to calculate co-efficient?

    Best regards, Pawan

  • 0 in reply to Pawan Nayak
    Prodigy 100 points

    Hello Pawan,

    Thanks for your support.

    My question is :

    What are the simple steps to calculate the PI controller  for the current loop in a digital PFC?

    How to calculate co-efficient?

    I know what the input of the current compensator is (voltage loop output x input voltage x ...).

    I know how a PFC stage works.

    But I need to calculate the PI coefficient for the current loop.

    What are the steps to follow ?

    I read many docs from TI but none of them gives a clear picture.

    In particular the SPRA902A is totally impossible to understand..

    Thanks and best regards

    Nicolas UHL

  • 0 in reply to Nicolas UHL
    TI__Expert 3825 points

    Designing compensator involves deriving the plant transfer function and the compensator transfer function. Then tuning the compensation co-efficients to achieve desired gain and phase margins for stability and dynamic performance (transient, settling time etc). The below guide gives a high-level overview and tools which can make the job easier. 

    C2000Tm Software Frequency Response Analyzer (SFRA) Library User’s Guide (Rev. A)