Sample Computations
Impedance Z
Rab=25 Ω
L
ab
=100 mH
f=60 Hz
Z
ab
=R
ab
+2π f L
ab
j
Z
ab
=25+2π
(
60
) (
100 m
)
j=25+1.2 πj Ω =25+3.77 πj Ω
Impedance Z in polar form
|
Z
ab
|
=
√
25
2
+1.2 π
2
=25.28 Ω
θ
ab
=tan
−1
1.2 π
25 =8.58 °
Z
ab
=25.28 Ω∠8.58 °
Current
IAB
Iab=Vab
Zab
I
ab
=33 0 ∠0°
25.28 Ω∠8. 58 °
I
ab
=33 0
25.28 ∠0−8.58 ° Ω =13.05∠−8. 58 ° A
Line Current
IAB
Z
AB
=13.05 ∠−8. 58 ° A
I
A
=
|
I
A
|
√
3∠(θ¿¿ ab−30 °)¿
I
A
=13.05
√
3∠(−8. 58−30 °)=22.61 ∠−38. 58 ° A
