EmonLib - V and I are good but Pf is wrong

Hardware
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1

Hello guys,

I am working with an ESP32 arduino (Heltec) using CT013 000 sensor and a AC/AC 9V transformer.

Everything works perfectly in my EmonLib implementation, my calcVI gives me a perfect voltage and a perfect intensity.

However, the powerfactor is wrong and thus the reactive power too.

Actually, I have tested using a wattmeter and my home power factor is around 0.9. However, the PF calculated in emonlib is around 0.7. Have a look at my power factors graph calculated using emonlib :

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image2517×421 59.1 KB

What could be wrong ? I am really annoyed because i have a solar production and solar injection and i want to use this power factor to know if I am consuming (PF > 0) or producing (PF < 0)…

Can someone help me ? Thanks a lot.

2

Did you follow the calibration procedure in the ‘Learn’ section?

Over what range did you try to adjust the phase error correction (PHASECAL)?

Real power is a much more reliable indicator, because as real and apparent powers tend towards zero, power factor becomes increasingly error-prone, because 0 ÷ 0 has no meaning.

3

Yes I follow the calibration procedure.

My PHASECAL is currently at 1.7.

Since I am on this issue for weeks, I’ve tried almost everything before sending a post here. Including trying to set PHASECAL to various values (between 0 and 2 with 0.01 increment).

And yes, I’ll use the real power insteaf of PF. you are right.

5

EmonLib was designed for speeds at which the Atmel '328P works, and your ESP32 will be very different.

I don’t have an ESP32 Arduino, so I need more information about yours. In particular, I need to know the time between the voltage and current readings and the speed at which it reads and processes pairs of values - because the value for phasecal depends on both of those.

Can you time say 1000 loops of:

{
    sampleV = analogRead(inPinV);            //Read in raw voltage signal
    sampleI = analogRead(inPinI);            //Read in raw current signal
}

so that I can calculate the actual time between samples, and
calcVI( ) running for say 100 half-cycles and 1100 half-cycles (this is so that I calculate the time to read the samples and do the immediate maths, but not the final calculations, i.e. the while loop at line 97).