I am working on a metering application where I have STPM10 metering IC. I am connected to the IC via SPI interface, I am able to read RMS Voltage and Current values along with the Line Frequency successfully. The device is also capable of readings Active Apparent and Reactive Energies, however it is not very clear to me how these reading can be read as there are internal energy up/down counters which hold a very small energy value and it has to be further integrated inside the application.
If there is anyone her who has experience with this device, please share your experience.
Hi Owais
It looks like that the 2 values you are trying to find
are a calculation of the 2 values you have.
eg:Apparent Power
Apparent Power is measured in volt-amperes (VA) and is the voltage on an AC system multiplied by all the current that flows in it. It is the vector sum of the active and the reactive power.
I am actually doing this calculation already to find the RMS Power consumed by simple multiplying the RMS Voltage and Current.
Maybe I didn't explain myself correctly, I would like to interpret the Energy not Power by reading the internal counters of the device STPM10. The device has internal 20 bit counters for Active Reactive and Apparent Energies which have to be integrated inside the application further to get the Energies in Wh, VARh and VAh respectively.
I am also attaching an application note for the device which tries to explain the procedure to interpret the above values. Please feel free to go through it and let me know what you think.