Built-in electricity meter with ADE7953?

[Javert]

For a machine with significant electricity consumption, I would like the operator to know how much electricity the machine consumed for a given production cycle
On the one hand, due to the recalculation of costs, and then also, the change in consumption is a function of the wear of some machine components. the operator knows better when parts need to be changed
To cut a long story short, I decided to design my own board that could communicate with the control computer and was able to reduce consumption and could be connected without interfering with the machine's power line,

Here is the result of my hard thinking today.

The heart is the ADE7953.
Voltage measurement:
resistive divider 1000:1 3x 1206 330k from 240V RMS is on ADE 240mV RMS. Actual catalog connection supplemented with Varistor 275V and SMD 1206 ferrite bead
Current measurement:
ADE can measure the current on both L and N, I will probably never use it, but if it can ...
I will use a current transformer something like the Talema AP2500
For primary current 16A is sec current 6,4mA
If use 2x13 ohm burned resisito willl be voltage on current input 166,4mV Vpp. PGA=2

ADE7953 is in the catalog connection CF1 is used purely so that something flashes there and you can see from the view whether it works or not.
Communication with computer SPI isolated ISO6762. Power supply from secondary DC/DC converter. 24bit ADCs should have a precise power supply, so the power supply is +5V and the low nose LDO is 3.3V

Nothing complicated really, but I'd be interested in your opinion and any ideas you might have. I worked with ADE circuits 10 years ago and I tend to overlook something.

Thank you

 

[KlausST]

Hi,

the ferrite bead will be useless, since your "load" is about 1 MOhm .. the ferrite impedance will not go anywhere near this.

I see there is an RCRC in the current measurement but only an RC in the voltage measurement.
I recommend to treat both paths very identically, because amplitude vs frequency and also phase vs frequency should be equal for voltage and current to get the true power reading and phase shift (cos phi) reading correct.

Klaus

 

[Javert]

> Different filter orders
I noticed that too, but I took it from Evaluation Board for the ADE7953 Single Phase Energy Metering IC.
and I was not alone see for example

>Induction in voltage input
.In normal operation (voltage in the order of hundreds of V) you are right.
If a voltage in the order of tens of thousands of volts with a sufficiently steep edge reaches the input
SMD resistors even size 1206 will lose their resistance and a spark will jump over their surface.
The varistor won't prevent it, it's slow and it will happen before it starts to conduct
Ferrite has a small DC resistance of 0.2 ohms, it should be much more resistant to sparking, it should reduce dV/dt. By doing so, under certain conditions and with the help of God, increase the resistance of the entry. It is an SMD form of a ferrite core on a power cable.
And maybe it's just a matter of faith, but HP used a similar solution for expensive meters, i.e. their voltage inputs and prome space on the PCB cost nothing,

 

[carpenter]

it's like this with filters.
For current transformer or shunt resisort a first-order filter as on the voltage input is sufficient.
A second order filter is required for rogowski coils.