|
구분 |
R [%/km] |
X [%/km] |
|
1800mm 완금 |
2400mm 완금 |
|
ACSR 160mm² |
3.86 |
6.89 |
7.42 |
|
ACSR 150mm² |
4.05 |
7.11 |
7.46 |
|
ACSR 95mm² |
7.71 |
8.80 |
9.24 | |
|
※ 22.9kV - Y 다중접지 계통의 가공전선 임피던스 참고값(표 1) |
|
|
|
|
<표>3 Typical Reactance Values for Induction and
Synchronous |
|
Machines, in per-Unit of Machine kVA Ratings
* |
|
|
|
|
|
Turbine generators † |
|
|
|
2 poles |
0.09 |
0.15 |
|
4 poles |
0.15 |
0.23 |
|
Salient-pole generators with damper
windings † |
|
|
|
12 poles or less |
0.16 |
0.33 |
|
14 poles or more |
0.21 |
0.33 |
|
Synchronous motors |
|
|
|
6 poles |
0.15 |
0.23 |
|
8-14 poles |
0.20 |
0.30 |
|
16 poles or more |
0.28 |
0.40 |
|
Synchronous condensers† |
0.24 |
0.37 |
|
Synchronous converters† |
|
|
|
600 V direct current |
0.20 |
- |
|
250 V direct current |
0.33 |
- |
|
Individual large induction motors, |
|
|
|
usually above 600 V |
|
0.17 |
|
Smaller motors, usually 600 V and below |
표 4 참고 |
| |
| Note : Approximate synchronous motor kVA
bases can be found from motor |
| horsepower ratings as follows; |
|
0.8 power factor motor - kVA base = hp
rating |
|
1.0 power factor motor - kVA base = 0.8 · hp
rating |
|
*
Use manufacture's specified values if available |
|
† Xd' not normally used in
short-circuit calculations | |
|
<그림 3>
X/R Ratio of Transformer (Based on ANSI/IEEE
C37.010-1979 [2])
|
|
<그림 4>
X/R Range for Small
Generators and Synchronius Motors
(Solid Rotor and Salient
Pole)
(From ANSI/IEEE C37.010-1979 [2]) |
|
 |
|
<그림 5>
X/R Range for
Three-Phase Induction Motors
(From ANSI/IEEE C37.010-1979
[2])
|
|
<표 4> Rotating-Machine Reactance (or impedance)
Multipliers
|
Type turbine generator : all hydroenerators
with |
Fist-Cycle |
Interrupting |
|
Machine |
Network |
Network | |
|
All turbine generator : all hydrogenerators with |
1.0 X "d |
1.0 X "d |
|
amortisseur windings, all condensers |
|
|
|
Hydrogenerators without amortisseur windings |
0.75 X 'd |
0.75 X 'd |
|
All synchronous motors |
|
|
|
All synchronous motors |
1.0 X "d |
1.5 X "d |
|
Above 1000 Hp at 1800 r/min or less |
1.0 X "d |
1.0 X "d |
|
Induction motors |
|
|
|
Above 250 Hp at 3600 r/min |
1.0 X "d |
1.0 X "d |
|
All others, 50 Hp and above |
1.2 X "d |
1.2 X "d |
|
All smaller then 50Hp |
Neglect |
Neglect | |
From ANSI/IEEE C37.010-1979 [2] and ANSI/IEEE
C37.5-1979
[3] |
케이블 및 전선
]로
Data가 주어지므로 이를 %Z나 Zp.u로 환산하여야 한다.