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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
{
"metadata": {
"name": "",
"signature": "sha256:63415a109c6989d49d84f5199fa0cd1f338b44376604f4b24df855330c3cb38a"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 7: D.C. Machines"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 7.1, Page 243"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable declaration\n",
"Rf = 200; # The resistance of field winding of a shunt generator, ohm\n",
"Po = 80e+03; # Power delivered by the machine, watt\n",
"V = 450; # The terminal voltage, volt\n",
"E = 475; # The generated emf, volt\n",
"\n",
"\n",
"#Calculations\n",
"# Part (a)\n",
"# Po = V*I_L, solving for I_L\n",
"I_L = Po/V; # Load current, A\n",
"I_f = V/Rf; # Current through field resistor, A\n",
"I_a = I_L + I_f; # Current through armature resistance, A\n",
"# As I_a*Ra = E - V, solving for Ra\n",
"Ra = 25/I_a; # Armature resistance, ohm\n",
"\n",
"# Part (b)\n",
"Po = 50e+03; # Output power delivered by the machine, watt\n",
"V = 460; # The terminal voltage, volt\n",
"I_L = Po/V; # Load current, A\n",
"I_f = V/Rf; # Current through field resistor, A\n",
"I_a = I_L + I_f; # Current through armature resistance, A\n",
"# As I_a*Ra = E - V, solving for E\n",
"E = V + I_a*Ra; # The generated voltage, volt\n",
"\n",
"#Results\n",
"print \"The armature resistance = %5.3f ohm\"%Ra\n",
"print \"The value of generated emf = %5.1f V\"%E\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The armature resistance = 0.139 ohm\n",
"The value of generated emf = 475.4 V\n"
]
}
],
"prompt_number": 1
}
],
"metadata": {}
}
]
}
|
