Current Angle More Than Ninety Degrees

[jaus tail]

Hi,
I'm studying Sync Generators. In one problem I got Ia as 1.59 angle of -159.9 degrees.

How do you calculate power factor for such a current?
Book says Ia leads Terminal Voltage by 23.13 degrees.
I guess they got that value by 180 - 159.9
But why?

 

[Tom.G]

Capacitive load versus Inductive load.

 

[jaus tail]

But in capacitive and inductive the phase angle is from 0 to 90 degrees.
I'm not able to understand what does angle more than 90 mean.

Mathematically i used 159 degrees by
I angle 159
= I cos 159 + j I sin 159
and that equals I angle -23

 

[Tom.G]

I fail to see a reason for 159 degrees. The phase angle has already been given:

Book says Ia leads Terminal Voltage by 23.13 degrees.

Pay attention to the book quote above as to which is leading, Voltage or Current, and to the fourth and fifth sentences in this tutorial. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/phase.html

It is customary to use the angle by which the voltage leads the current. This leads to a positive phase for inductive circuits since current lags the voltage in an inductive circuit.[i/]

 

[jaus tail]

I got the phase angle as 159 degrees. In sync alternator I = (E - V)/X
E is 2.341 pu angle + 90
V = 1 angle 0
X = j1.6

 

[Tom.G]

Sorry we are not making progress. Your problem can likely be better answered in the Homework forum. Be sure to fill in the information in the template there so people here get a better idea of the question details.

Paging @russ_watters to assist in this redirection.