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
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 2: Transformers"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.1: Finding_power_factor_and_core_loss_current.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding power factor,core loss current\n",
"clear;\n",
"close;\n",
"clc;\n",
"alpha=acos(16/20);\n",
"pf=cos(alpha);//power factor\n",
"disp(pf,'power factor=');\n",
"\n",
"I_e=20/194;//exciting current\n",
"I_c=16/194;//core loss component\n",
"I_m=I_e*0.6;//magnetizing componentminimum magnet volume"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.3: Finding_peak_mmf_and_flux.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding peak mmf and flux\n",
"clear;\n",
"close;\n",
"clc;\n",
"function [F_peak]=mmf(k,N,m,I)\n",
" F_peak=(1.5*4*k*N*I)/(%pi*2*m);\n",
"endfunction\n",
"\n",
"f=mmf(.92,45,3,700);\n",
"U_o=4*%pi*10^-7;\n",
"B_peak=U_o*8.81*10^3/.01;//flux density\n",
"vel=25*0.5;//in m/s"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.4: Finding_regulation.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding regulation\n",
"clear;\n",
"close;\n",
"clc;\n",
"Z_eq=48/20.8;\n",
"R_eq=617/20.8^2;\n",
"X_eq=sqrt(Z_eq^2-R_eq^2);//in ohms\n",
"I_h=50000/2400;//full load high tension current\n",
"Loss=I_h^2*R_eq;\n",
"Input=40000+186+Loss;//in watts\n",
"Efficiency=1-803/Input;\n",
"disp(Efficiency,'efficiency is=');\n",
"\n",
"V_1h=2400+(20.8*(0.8-0.6*%i)*(1.42+1.82*%i));\n",
"Reg=((2446-2400)/2400)*100;\n",
"disp(Reg,'percentage regultion=')"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.5: Finding_kVA_rating.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding kVA rating\n",
"clear;\n",
"close;\n",
"clc;\n",
"I_h=50000/240;\n",
"V_h=2640;\n",
"kva=V_h*I_h/1000;\n",
"disp(kva,'kVA rating of transformer=')\n",
"\n",
"eff=1-803/(0.8*550000);//from ex 2.4\n",
"disp(eff,'efficiency is=')"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.7: Finding_current_in_feeder_wires.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding current in feeder wires\n",
"clear;\n",
"close;\n",
"clc;\n",
"V_s=2400/sqrt(3);\n",
"X_eqs=2.76/3;//per phase\n",
"X_eqr=1.82/3;//at recieving end\n",
"total_X=X_eqs+X_eqr+0.8;\n",
"I_win=594/sqrt(3);//at 2400V windings\n",
"I_feeder=1385/2.33;//at 2400V feeder"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.8: Finding_per_unit_system.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding per unit system\n",
"clear;\n",
"close;\n",
"clc;\n",
"Z_baseH=2400/20.8;\n",
"Z_baseX=240/208;\n",
"\n",
"I_x=5.41/208;//per unit at low voltage side\n",
"\n",
"Z_eqH=(1.42+%i*1.82)/115.2;//per unit\n",
"disp(Z_eqH,'equivalent impedence referred to high voltage side')"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 2.9: Finding_current_in_feeder_wires_in_per_unit.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Caption: Finding current in feeder wires in per unit\n",
"clear;\n",
"close;\n",
"clc;\n",
"V_base=2400/sqrt(3);//for 2400V feeder and line to neutral\n",
"I_base=50000/1385;//phase Y\n",
"Z_base=V_base/I_base;//phase Y\n",
"X_feeder=0.8/Z_base;//per unit\n",
"\n",
"SC_current=1.00/.0608;// short circuit current in per unit\n",
"disp(SC_current,'short circuit current in per unit=')"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Scilab",
"language": "scilab",
"name": "scilab"
},
"language_info": {
"file_extension": ".sce",
"help_links": [
{
"text": "MetaKernel Magics",
"url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
}
],
"mimetype": "text/x-octave",
"name": "scilab",
"version": "0.7.1"
}
},
"nbformat": 4,
"nbformat_minor": 0
}
|
