blob: dfcfc864a11a65cc95de952482dadb873044bcaa (
plain)
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
|
// Electric Machinery and Transformers
// Irving L kosow
// Prentice Hall of India
// 2nd editiom
// Chapter 12: POWER,ENERGY,AND EFFICIENCY RELATIONS OF DC AND AC DYNAMOS
// Example 12-3
clear; clc; close; // Clear the work space and console.
// Given data
V = 240 ; // Voltage rating of the dc shunt motor in volt
P_hp = 25 ; // Power rating of the dc shunt motor in hp
S = 1800 ; // Speed in rpm of the shunt generator
I_L = 89 ; // Full-load line current
R_a = 0.05 ; // Armature resistance in ohm
R_f = 120 ; // Field resistance in ohm
// Calculations
// case a
V_f = V ; // Field voltage in volt
I_f = V_f / R_f ; // Field current in A
I_a = I_L - I_f ; // Armature current in A
V_a = V ;
E_c = V_a - I_a*R_a ; // Armature voltage to be applied to the motor when motor
// is run light at 1800 rpm during stray power test
// case b
Ia = 4.2 ; // Armature current in A produced by E_c
Va = E_c ; // Armature voltage in volt
P_r = Va*Ia ; // Stray power in W ,when E_c produces I_a = 4.2 A at speed of 1800 rpm
// Display the results
disp("Example 12-3 Solution : ");
printf(" \n a: Field current :\n I_f = %d A \n ",I_f );
printf(" \n Armature current :\n I_a = %d A \n ",I_a );
printf(" \n Armature voltage to be applied to the motor when motor is run");
printf(" \n light at %d rpm during stray power test :\n ",S );
printf(" \n E_c = %.2f V \n ",E_c );
printf(" \n b: Stray power :\n P_r = %.1f W ",P_r );
|
