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TIDM-TWOPHASEMETER-I2040: Current Transformers ref. examples

Jose Fernandes
Prodigy 20 points
Part Number: TIDM-TWOPHASEMETER-I2040


hello,
I would like to start my AC energy meter investiganting the TIDM-TWOPHASEMETER-I2040 that appears to me very close what I need.
I would like to focus on the metrology MCU, since will not be used with a front-end processor to direct LCD whattage readings, instead will be used to
comunicate with a raspberry PI like computer viewing energy measurement parameters.
The reference design of two phase metrology is a exactly what I need, since that in my area
energy distribuition uses mains of 220V where L1=120v L2=120v + N.
Could you please give me some current transformers (CT) manufactures part numbers already used (compatible with the spec) in this project?
The ref. text has no mention on a exemple PN that cumplies with the spec for this component: 2000:1 ratio with a burden resistor of 13R for 919mV @ 100A (what is also exactly what I will limit in my EVM design).

Another questions relates to the suppressor inductors (just for better understanding of already acquired experiences of expert in this design).
The provided footprint initialy populated with 0R resistors can in some cases be populated with an inductor instead.
For what cases these indcutors was thought to be used?
What calculations was toke in place for its use instead of 0R resistors?
For the analog front-end we have the low-pass filter after supressors inductors too.
Same use case?

Thank you dor your support!

  • 0
    TI__Expert 7765 points
    Jose,

    The CTs were custom. They have an error of 0.05%, maximum current of 100 Amps, 5 Amp nominal current, and a turns ratio of 1:2000.

    The footprints you mentioned(along with other components) are typically used in e-meters with inductors/ferrite beads in order to obtain better performance for the EMC tests that e-meters are expected to pass. The low-pass filters help with this as well.

    Regards,
    Mekre
  • 0 in reply to Mekre Mesganaw
    Prodigy 20 points

    Hello Mekle!

    First of all  ... Thanks for your answer and  support.

    Well a custom component is not what we expect at the begining due to the timing for manufacturing, tests, etc.

    Perhaps you can take a look on this spec that I selected for the CT.

    What do you think and with your experience how can I mitigate risks and time to market, using a active PN like this one I attached, since your design is almost ready to go or at least ready to be adapted to our needs for an EVM.

    Best regards!

    Clamp Type AC Current Sensors TDK CCT Series.pdf

  • 0 in reply to Jose Fernandes
    TI__Mastermind 49692 points

    Hi Jose,

    Our EVMs can be used with other CTs. Depending on the current capacity, you'd want to size the burden resistor appropriately. The CT that you attached appears to be a clamp-style CT. This would measure current flow, but if you're designing an e-meter, you may want to consider CTs with solid cores. I don't have any specific manufacture or part number recommendations, but you should be able to find them online and contact the manufacturers.

    Hope this helps!

    Regards,

    James

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