Generator Capability Curve

[MD_10068523]

Can someone please explain how the right side (RHS) of the equation below represents active power (P)?

 Explain P: = PFUL*MVA + (MVA - PFUL*MVA) *i/N

given N = 2000, and

I run from zero to N.

[Fred_Kohlhepp]

Going to need more than that!

Is there a mathcad sheet with definitions of terms?

[MD_10068523]

PFUL stands for Upper Power factor.

MVA stands MVA of the generator.

Thanks.

[LucMeekes]

If "MVA" is "MVA of the generator", then "MVA" is "MVA of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator of the generator......"

In other words, a circular definition. That doesn't seem right.

So what is "MVA of the generator"?

Can you provide a source for the expression that you want to have explained?

Success!
Luc

[MD_10068523]

Once the Plag is calculated, is used to calculate Qlag as shown below: 

Which I have no problems with. 

Thanks 

[Fred_Kohlhepp]

Pick representative values for PFUL and MVA:

But this doesn't make sense,  See file attached.

[MD_10068523]

Hello Fred, 

Thanks for the support. 

I am actually looking for someone to confirm the Active Power expression. 

My thinking was the first expression is the initial active power, the incremental values are calculated using the expression in the brackets. 

Thanks 

[Fred_Kohlhepp]

I'm not sure what you're looking for.  You typed an expression that would generate a vector in Mathcad (i/N where i is a range variable creates a vector) and I showed you how to plot it.  Your dialog with LucMeekes indicates you're looking into active and reactive power in AC circuits.

Power Factor depends on circuit parameters and frequency of the AC power.  Attached is a short discussion of power factors, phase angles and AC circuit components.  I'm not sure it addresses what you're looking for, but it may shed some light, and it was fun to build!  Prime 4 Express.

[MD_10068523]

Hello Fred,

Thanks for the support.

My question was more of a programming issues than theory.

I was looking for the explanation of how the relation below gives real/active power :

Plag = MVA*PF + (MVA – MVA*PF)*(i/N) .

where PF is power factor

This is because as far as I can remember, P = S*PF, and (MVA – MVA*PF) is (MVA – P)*(i/N).

I cannot readily see how the term (MVA – P)*(i/N) adds to MVA* PF to give active/real power in the light of the expression S = P + jQ ,

Again, thanks much for all the support.

[Fred_Kohlhepp]

But that's not true:

[ppal]

[LucMeekes]

Yes, but:

and, suppose it's meant to sum over all i, then:

Luc

[Werner_E]

As you can see the helpers here are wildly guessing about the meaning of the formula.

One suggests "i" to be the index of sum (which is not shown in your post), another suggests it may be the imaginary unit.

So it sure would help if you provide a source for the formula as Liuc already demanded, so we could see how it really should look like and what the exact meaning of the used variables should be. Where does the formula stem from? Can you provide a link or the like?

[ppal · Accepted solution]

There Are Two Types Of People in this world: those who can extrapolate incomplete data