• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 83 subscribers
  • Views 966 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TIDM-1000: Frequency up to 800Hz for TIDM-1000?

Antonio Faggio
Expert 8000 points
Part Number: TIDM-1000


Hi All,

I am hence contacting you for some more information on the TIDM-1000 board.

 

In particular, the question is whether you think it can work with a network frequency of 360-800Hz.

I looked at the documentation and found no limit in this regard even if you specify all the tests were done at 60Hz.

 

I have seen, however, that the FW platform allows the switching frequency to rise above 100KHz which we consider indispensable to manage a higher network frequency.

 

Who can please give me answers on this?

Obviously changing the frequency customer will surely have to change a bit of circuitry starting from the inductors but I am interested in knowing if the conditioning circuit (sensors and dsp) can manage higher frequencies.

 

In the past the E2E post for this topic for the same customer was the below: https://e2e.ti.com/support/power-management/f/196/p/851645/3151632#3151632

 

Many Thanks,

Antonio

 

  • 0
    TI__Genius 15935 points

    Hi Antonio,

    You have already covered the hardware side consideration.  From the software side, we have not tested in that freq range so we don't know whether it will work. Customer needs to be very careful about the test and it might damage the board.

    Some issues you might see:

    Theoretically, you can modify VIENNA_GRID_MAX_FREQ_HZ  and VIENNA_GRID_MIN_FREQ_HZ. The power analyzer considers it as a jitter if your input frequency is higher than the original max freq which is 110Hz.  So you probably could not get any Vrms value. But considering your input frequency is very high, I can imagine the accuracy of the parameter you get will be worse since the samples you get are less.

    And note that there might be other issues with this AC mains freq range.

    Regards,

    Chen

  • 0 in reply to Chen Jiang ti
    Prodigy 30 points

    Hi Chen,

    obviously we were not expecting to have the system working without any changes.

    We are expecting as minimum change to increase the switching frequency (probably around 100-120 KHz instead of 50KHz) so to change inductor and sampling frequency for acquisition.

    Which is the sampling freq for the TIDM-100 50KHz switching frequency?

    Which is the maximum sampling frequency supported by the platform?

    Alessandro

  • 0 in reply to Chen Jiang ti
    Prodigy 30 points

    Hi Chen,

    It's clear to us that TIDM-1000 cannot operate with 800Hz in input as is.
    We know we will have to change inductor and switching frequency (probably we will operate at 120KHz) and probably we will have to modify the SW.

    Our question are:

    - Is the PWM controller fast enough to handle a 120KHz as frequency switching?

    - Which is the max sampling rate for the input (current and voltage)?

    Thanks

    Alessandro 

  • 0 in reply to Alessandro Donati
    TI__Genius 15935 points

    Hi Alessandro,

    - Is the PWM controller fast enough to handle a 120KHz as frequency switching?

    That is totally fine. The PWM freq could go up to 1MHz with HRPWM in our reference design. PWM module is enough for 120kHz switching freq.

    - Which is the max sampling rate for the input (current and voltage)?

    That depends on multiple factors(for example, which device you are using, how you deal with oversampling with each ADC module,etc).

    Our ADC max sampling rate is 3.45-MSPS in f28004x. You could refer to the datasheet for other device information.

    In TIDM-1000, we over-sample four times( same trigger source, consecutive) in each switching cycle( 50KHz). 

    Regards,

    Chen