ADE7758: Line cycle energy accumulation method

Hi All,

I am using ADE7758 Poly phase energy metering IC for my project. I went through the data sheet of the ADE7758 IC, and some of the topics were quite confusing for me. Especially the "Energy accumulation mode" and "Line cycle energy accumulation mode".

What I could understand is, in Line cycle energy accumulation mode, the value in the value in Energy accumulation registers(eg. AWATTHR) gets updated gets updated when the number of half-line cycles becomes equal to the Line cycle (LINECYC) register count.

And in Energy accumulation mode, the value in Energy accumulation registers(eg. AWATTHR) gets updated at every 0.52 Sec.(WDIV=0).

Is this correct ?

In both the methods, before reading the Energy accumulation registers(eg. AWATTHR), do I have to wait for a Zero-cross detect for ensuring that the value has been updated ?

Or should I be waiting for the LENERGY interrupt to occur in Line cycle energy accumulation mode ?

Thanks & Regards,

Angel

Parents
• Hello Angelmary, I want to know that how you calculate the number of half-line cycles for line accumulation time. Because in datasheet page no. 49 step 4 they set it 0x1C. and in futher below examples they set line cycle by different numbers. but somehow i don't get it how they calculate it. In page no. 61 they said LINECYC is 16 bit. but how to set these bits?

• Half line cycle is exactly that.

If you have 50Hz the half cycle time is 10ms

Example

If you want 1sec of  accumulation set linecycle to  1/10ms = 100 half linecycles.

If you want 5 sec os accumulation set linecycle to 5/10ms = 500 half line cycles.

If your accumulation time is to long the energy will overflow. see Active Energy Calculation: pg 32

Make sure only one zx is enabled

SEE LCYCMODE ZXSEL bits  table 22 https://www.analog.com/media/en/technical-documentation/data-sheets/ADE7758.pdf pg 67

If more than one zx is selected the expected time with be 2 or 3 times faster.

• Half line cycle is exactly that.

If you have 50Hz the half cycle time is 10ms

Example

If you want 1sec of  accumulation set linecycle to  1/10ms = 100 half linecycles.

If you want 5 sec os accumulation set linecycle to 5/10ms = 500 half line cycles.

If your accumulation time is to long the energy will overflow. see Active Energy Calculation: pg 32

Make sure only one zx is enabled

SEE LCYCMODE ZXSEL bits  table 22 https://www.analog.com/media/en/technical-documentation/data-sheets/ADE7758.pdf pg 67

If more than one zx is selected the expected time with be 2 or 3 times faster.

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