1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
|
// ELECTRIC POWER TRANSMISSION SYSTEM ENGINEERING ANALYSIS AND DESIGN
// TURAN GONEN
// CRC PRESS
// SECOND EDITION
// CHAPTER : 4 : OVERHEAD POWER TRANSMISSION
// EXAMPLE : 4.15 :
clear ; clc ; close ; // Clear the work space and console
// GIVEN DATA
D_12 = 26 ; // distances in feet
D_23 = 26 ; // distances in feet
D_31 = 52 ; // distances in feet
d = 12 ; // Distance b/w 2 subconductors in inches
f = 60 ; // frequency in Hz
kv = 345 ; // voltage base in kv
p = 100 ; // Power base in MVA
l = 200 ; // length of line in km
// CALCULATIONS
// For case (a)
D_S = 0.0435 ; // from A.3 Appendix A . Geometric mean radius in feet
D_bS = sqrt(D_S * 0.3048 * d * 0.0254) ; // GMR of bundled conductor in m .[1 ft = 0.3048 m ; 1 inch = 0.0254 m]
D_eq = (D_12 * D_23 * D_31 * 0.3048^3)^(1/3) ; // Equ GMR in meter
L_a = 2 * 10^-7 * log(D_eq/D_bS); // Inductance in H/meter
// For case (b)
X_L = 2 * %pi * f * L_a ; // inductive reactance/phase in ohms/m
X_L0 = X_L * 10^3 ; // inductive reactance/phase in ohms/km
X_L1 = X_L0 * 1.609 ;// inductive reactance/phase in ohms/mi [1 mi = 1.609 km]
// For case (c)
Z_B = kv^2 / p ; // Base impedance in Ω
X_L2 = X_L0 * l/Z_B ; // Series reactance of line in pu
// For case (d)
r = 1.293*0.3048/(2*12) ; // radius in m . outside diameter is 1.293 inch given in A.3
D_bsC = sqrt(r * d * 0.0254) ;
C_n = 55.63 * 10^-12/log(D_eq/D_bsC) ; // capacitance of line in F/m
// For case (e)
X_C = 1/( 2 * %pi * f * C_n ) ; // capacitive reactance in ohm-m
X_C0 = X_C * 10^-3 ; // capacitive reactance in ohm-km
X_C1 = X_C0/1.609 ; // capacitive reactance in ohm-mi
// DISPLAY RESULTS
disp("EXAMPLE : 4.15 : SOLUTION :-") ;
printf("\n (a) Average inductance per phase , L_a = %.4e H/m \n",L_a) ;
printf("\n (b) Inductive reactance per phase , X_L = %.4f Ω/km \n",X_L0) ;
printf("\n Inductive reactance per phase , X_L = %.4f Ω/mi \n",X_L1) ;
printf("\n (c) Series reactance of line , X_L = %.4f pu \n",X_L2) ;
printf("\n (d) Line-to-neutral capacitance of line , C_n = %.4e F/m \n",C_n);
printf("\n (e) Capacitive reactance to neutral of line , X_C = %.3e Ω-km \n",X_C0) ;
printf("\n Capacitive reactance to neutral of line , X_C = %.3e Ω-mi \n",X_C1) ;
|
