For what loads, active power turns negative?

[alphacat]

And what is the meaning of negative active power?

Thank you.

 

[Willbe]

For an arc, it may mean when an incremental increase in V brings an incremental decrease in I.

 

[alphacat]

Could you please give a practical example that I'd really measure negative active power on a certain load?

 

[crutschow]

Don't really understand your question. Where have you found the term "negative active power"? Are you referring to a "negative power factor"?

 

[Willbe]

Could you please give a practical example that I'd really measure negative active power on a certain load?

Nah, that was my best shot. . .

 

[Sceadwian]

The only thing that makes sense is a generator.
Negative active power is when the 'load' is an electrical generator.

 

[Janis1279]

If you mean great inductive loads, you need read some about reactive power , reactive power compensation. May be it's no the better article :VOLTAGE COLLAPSE IN POWER SYSTEMS - AN INTRODUCTION - Article by Suresh Kumar K.S

 

[alphacat]

Don't really understand your question. Where have you found the term "negative active power"? Are you referring to a "negative power factor"?

If AP = V*I * PF, where V*I >=0, then AP < 0 if and only if PF < 0.
Didnt think i'd need to explain it.

 

[alphacat]

The only thing that makes sense is a generator.
Negative active power is when the 'load' is an electrical generator.

SO any load would give possitive active power?

 

[Tesla23]

If AP = V*I * PF, where V*I >=0, then AP < 0 if and only if PF < 0.
Didnt think i'd need to explain it.

If the power factor is negative then the average power is flowing the wrong way. As Sceadwian says, the load is a generator (or at least something capable of supplying power).

e.g. your electricity company supplying power to your house would see a negative power factor if you have a solar supply and it is supplying power to the grid.

 

[Willbe]

Basic Electricity - Google Book Search
Look for the yellow highlights

 

[Sceadwian]

Alphacat, any electric motor under the right conditions can produce energy rather than use it, so any electric motor as a load in theory can produce power rather than use it. Under any normal circumstances however motors draw power not generate it.