ADE7758 line-cycle accumulation mode

Hello,

On the ADE7758 datasheet, it is written that for calibration with line-cycle accumulation mode, the RSTREAD of the LCYCMODE register must not be set.

But In this case, how to be sure that after the Lenergy IRQ, the content of the Energy registers are OK. Does the internal 41-bit active registers are automatically reset to 0 after each n zeor crossing detection (defined in the LINCYC register)?

Thank you for reply

  • 0
    •  Analog Employees 
    on Oct 18, 2013 4:06 PM

    Hi Arnaud31,

    When using line-cycle accumulation, there is an internal accumulation for only the set number of line-cycles specified in the LINECYC register. That value is held in the xWATTHR register until the next value has accumulated for the number of line-cycles and then updated.  Whenever the xWATTHR register is read, it will always hold the value of the last line-cycle accumulation.  If read with reset is turned on then the reading will get reset  every time the register is read which can cause a jumpy and inconsistent reading.

    Best Regards,

    Dlath

  • Hi Dlath,

    Thank you for this information which wasn't written clearly in the

    datasheet (or i didn't see it)

    I also didn't see how to calibrate VRMS gain, IRMS gain, V_LSB and I_LSB.

    is it the same way as for the ADE7754?

    Best regards.

    Arnaud

    Le 18/10/2013 14:07, dlath a écrit :

    >

      EngineerZone <http://ez.analog.com/index.jspa>

    >

          Re: ADE7758 line-cycle accumulation mode

    created by dlath <http://ez.analog.com/people/dlath> in /Energy

    Monitoring and Metering/ - View the full discussion

    <http://ez.analog.com/message/120680#120680>

  • 0
    •  Analog Employees 
    on Feb 10, 2014 8:05 PM

    Hi Arnaud31,

    I apologize for the late response, there seemed to have been some issue with my notifications on this discussion. Is this still an open issue because I would be more than happy to help solve the problem.

    Your question was concerning calibrating VRMS and IRMS gain, these calibrations would be similar to the ADE7754 to match the RMS registers of the different phases. Equation 11 on Page 30 of the ADE7758 data sheet is useful in understanding the gain relationship. The gain can be adjusted +/-50% to match the VRMS and IRMS registers. With this, the RMS registers can be gained to the same Volts/LSB and Amps/LSB.

    Pleae let me know if I can help with anything further and I will respond as soon as possible.

    Best Regards,

    Dlath

  • 0
    •  Analog Employees 
    on Aug 2, 2018 2:29 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin
  • Hello, I have a problem related to energy reading with the line cycles. When I measure with 60 half cycles, the AWATTHR value is constant, and then when I measure with 120 half cycles or more, the AWATTHR value varies and the AEHF bit of half full register is set. The constant voltage of phase A used is 120 Vrms and 10 A of current. My question is, the register AWATTHR overflows after the 0.5 seconds that the data sheet says?