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TIDA-01604: How to determine the grid frequency in reference design TIDA-01604?

Expert 2590 points

Replies: 6

Views: 299

Part Number: TIDA-01604

Dear team:

How to determine the grid frequency in reference design TIDA-01604? I only see the phase-locked section in the reference manual.

http://www.ti.com/lit/ug/tidue54a/tidue54a.pdf 

Best regards

  • Expert 2590 points

    Wait for your reply.

    Best regards

  • In reply to F.F:

    Because the software need change low frequency SR switch and main switch, so there will have zero cross detect. you can get the frequency from two zero cross time. But i don't understand why using spll there, the current ref can get from Instantaneous Vac,you know ,spll need amount of calculation.

  • In reply to user4584317:

    1. The PLL was added to provide the following

    a. It allows for vector based cancellation techniques for power factor improvement

    b. It adds robustness against noise which can also result in wrong changes to the totempole bridge

    The phase locked loop provides a frequency output as well, but it will change wuite often as it is also used for the lock. You may have to add some aditional filter on it. In addition to that the sine analyzer also outputs frequency information from the zero crossing information.  

  • In reply to Manish Bhardwaj:

    Dear Manish:

    I've heard so much about you, thank you for your reply! But i have some questions:

    1:what's the meaning of "vector based cancellation techniques". why use spll' result sinQ instead of instantaneous ac voltage?

    2:can i get frequency from pll? i think it just lock the phase, it is not fll.

    I am looking forward to your reply.

    best wishes!

  • In reply to user4584317:

    1. We published a paper here

    Improving light load power factor for GaN based Totem Pole bridgeless PFC using digital phase locked loop based vector cancellation & tracking error compensation

    Also it is covered in the UG for TIDM-1007 which is a lower power version of the same topology  see

    http://www.ti.com/lit/ug/tidud61b/tidud61b.pdf 3.1.2.6.1

    2. Please see the module

     float32_t   fo;         //!< Output frequency of PLL(Hz)

    f0 is the output frequency, but you will need to put a low pass filter on it as it will oscialte due to PLL action.

    How fast does the frequecy read needs to be ? Can it tolerate some latency?

  • In reply to Manish Bhardwaj:

    Thank you very much for your reply. I have benefited a lot from it

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