Fundamental Question - I'm confused

[mityeltu]

First, I already feel as dumb as a bag of wet blonde hair, so please be nice.

I am looking at the power triangle and power factor.

I know that an inductive load has a lagging power factor, meaning that *current* lags *voltage*, right?

Ok, so, why is my inductive Q positive?

If the vectors rotate CCW and my reference is voltage than current should be in quadrant 4 (negative angle with respect to 0 degrees where the voltage vector is located). If the angle is for current is negative with respect to voltage then as they both rotate, current does in fact lag voltage.

So, back to the triangle. If inductive reactance is caused by lagging current, why is theta positive for Q but negative for I?

Like I said, I already feel stupid, here. Can anyone make this make sense? I assume I am simply missing some small piece, but I have not been able to find it.

 

[dkarst]

First, I already feel as dumb as a bag of wet blonde hair, so please be nice.

I am looking at the power triangle and power factor.

I know that an inductive load has a lagging power factor, meaning that *current* lags *voltage*, right?

Ok, so, why is my inductive Q positive?

If the vectors rotate CCW and my reference is voltage than current should be in quadrant 4 (negative angle with respect to 0 degrees where the voltage vector is located). If the angle is for current is negative with respect to voltage then as they both rotate, current does in fact lag voltage.

So, back to the triangle. If inductive reactance is caused by lagging current, why is theta positive for Q but negative for I?

Like I said, I already feel stupid, here. Can anyone make this make sense? I assume I am simply missing some small piece, but I have not been able to find it.

You are correct in which quadrants the current and voltage are in but you have to remember S = VI* so the conjugate of I puts it back in the first quadrant. They could have just as well defined S = P +jQ differently but they didn't so for an inductive load, S = VI* = P +jQ and Q ends up being positive. Hope this helps...

 

[mityeltu]

Yeah, I remember that. Thanks. Sheesh..... wet blonde hair....