Units of Harmonic and Fundamental power

[alphacat]

Hello.
I wanted to verify that i'm not wrong.
Is it correct:
[Harmonic active power] = [Fundamental active power] [Instantaneous active power] = Watt
[Harmonic reactive power] = [Fundamental reactive power] = [Instantaneous recative power] = VAR

Thanks.

 

[Hayato]

Yes. Active is always in Watts, Reactive in VAr and Apparent in VA, it does not matter if it is from the fundamental or the harmionics.

 

[alphacat]

Thank you very much Hayato

 

[Jony130]

But only fundamental harmonics (1st harmonic) "transfer" the real power in Watts.

 

[Hayato]

No. Every harmonic transfers power.

Think about a 60Hz squarewave, if only the 1st harmonic would transfer power, we could calculate the transfered power same way we would calculate for a sine wave. Which is not right.

 

[MrAl]

Hello,


Well, every frequency has the ability to power something, so yes every frequency harmonic has the ability to power a load. This is sometimes a problem when we want to limit harmonic power.
The OP seemed to be asking the general question if other harmonics can produce power so yes that is correct.

When we talk about power 'transfer' however that's a little different because sometimes we are honing in on one harmonic only and usually that is the fundamental. Sometimes we want to know how much fundamental frequency power is transferred because we wont be using for example the third harmonic for any useful purpose. On the other hand, sometimes we (for example) might only want to know the third harmonic power transferred, and then we would be ignoring the fundamental.
I dont think the OP was talking about power transferred though but he can clarify this if he wants to.