# 3 Phase Y Connected Generator

1. Nov 25, 2012

### richardknox

1. The problem statement, all variables and given/known data

A Y connected, 400V (line), 100KVA rated, stand alone generator is operating at 80kW at rated current with a lagging power factor and rated terminal voltage. The synchronous reactance is 2Ω.

Draw the per phase equivalent circuit and calculate:

(i) The Phase Current (Iph)
(ii) The Power Factor
(iii) The Reactive Power
(iv) The Voltage drop across the Synchronous Reactance (VXS)

2. Relevant equations

$V_{ph} = V_{line}/√3$
$P = IV$
$P = IVcosθ$
$Q = Ssinθ$
$S_{ph} = S/√3$
$V_{xs} = I_{ph} * jXs$

3. The attempt at a solution
$V_{ph} = 400/√3 = 230.9V$
$S_{ph} = 57735W$
$S = IV$
$I = S/V = 57735/230.9 = 250A$

$P = IVcosθ$
$cosθ = 0.8$

$Q = Ssinθ = 60VAr$

$V_{xs} = jXs * I_{ph} = 500V$

Not sure where I go wrong but I'm assuming I can't have a voltage drop of 500V over a component when I only have 230.9V of phase voltage!