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{
"metadata": {
"name": "",
"signature": "sha256:260bb8beffe2e4d2155fdaec0c7462f8cf5127d60c79f0bddb469ea9aad62673"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 26: Neutral Grounding"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 26.1, Page Number: 599"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"import math\n",
"\n",
"#Variable declaration:\n",
"f = 50 #Supply frequency(Hz)\n",
"C = 4.5*10**-6 #Line to earth capacitance(F)\n",
"\n",
"\n",
"#Calculation:\n",
"XL = 1/(3*2*math.pi*f*C) #ohm\n",
"\n",
"\n",
"#Result:\n",
"print \"The reactance of Peterson coil is\",round(XL,1),\"ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The reactance of Peterson coil is 235.8 ohm\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 26.2, Page Number: 599"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"import math\n",
"\n",
"#Variable declaration:\n",
"l = 200 #length of transmission line(km)\n",
"f = 50 #Supply frequency(Hz)\n",
"c = 0.02*10**-6 #Line to earth capacitance(F/km)\n",
"V = 230 #voltage rating of line(kV)\n",
"\n",
"\n",
"#Calculation:\n",
"C = c*l #capacitance of coil(F)\n",
"L = round(1/(3*(2*3.14*f)**2*C),2) #Required inductance of Peterson coil(H)\n",
"Vph = round(V*1000/1.732) #Voltage across Peterson coil(kV)\n",
"IF = math.ceil(Vph/(2*3.13*f*L)) #Current through Peterson coil(A)\n",
"kVA = Vph*IF/1000 #Rating of Peterson coil\n",
"\n",
"\n",
"\n",
"#Calculation:\n",
"print \"Inductance of Peterson coil is\",L,\"H\"\n",
"print \"Rating of Peterson coil is\",round(kVA),\"kVA\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance of Peterson coil is 0.85 H\n",
"Rating of Peterson coil is 66397.0 kVA\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 26.3, Page Number: 600"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"import math\n",
"\n",
"#Variable declaration:\n",
"f = 50 #fequency of supply(Hz)\n",
"C = 1.2*10**-6 #line-to-earth capacitance(F)\n",
"\n",
"\n",
"#Calculation:\n",
"#(i) To neutralize capacitance of 100% of the length of the line,\n",
"#Inductive reactance of the coilis given by\n",
"XL1 = 1/(3*2*math.pi*f*C) #ohm\n",
"\n",
"#(ii) To neutralize capacitance of 90% of the length of the line,\n",
"#Inductive reactance of the coilis given by\n",
"XL2 = 1/(3*2*math.pi*f*0.9*C) #ohm\n",
"\n",
"\n",
"#(iii) To neutralize capacitance of 80% of the length of the line,\n",
"#Inductive reactance of the coilis given by\n",
"XL3 = 1/(3*2*math.pi*f*0.8*C) #ohm\n",
"\n",
"\n",
"#Result:\n",
"print \"(i) Inductive reactance of the coil to neutralize capacitance\"\n",
"print \" of 100% of the length of the line is\",round(XL1,2),\"ohm\"\n",
"print \"\\n(ii) Inductive reactance of the coil to neutralize capacitance\"\n",
"print \" of 100% of the length of 90% of the line is\",round(XL2,2),\"ohm\"\n",
"print \"\\n(iii)Inductive reactance of the coil to neutralize capacitance\"\n",
"print \" of 100% of the length of 80% of the line is\",round(XL3,2),\"ohm\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(i) Inductive reactance of the coil to neutralize capacitance\n",
" of 100% of the length of the line is 884.19 ohm\n",
"\n",
"(ii) Inductive reactance of the coil to neutralize capacitance\n",
" of 100% of the length of 90% of the line is 982.44 ohm\n",
"\n",
"(iii)Inductive reactance of the coil to neutralize capacitance\n",
" of 100% of the length of 80% of the line is 1105.24 ohm\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 26.4, Page Number: 600"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"import math\n",
"\n",
"#Variable declaration:\n",
"r = 0.01 #radius of conductor(m)\n",
"d = 4 #conductor spacing(m)\n",
"V = 132 #voltage of the line(kV)\n",
"f = 50 #supply frequency(Hz)\n",
"l = 200 #line length(km)\n",
"\n",
"\n",
"#Calculation:\n",
"c = round(2*math.pi*8.885/math.log(d/r),1)*10**-12 #capacitance per unit length(F/m)\n",
"C = c*l*1000 #Capacitance between phase and earth for 200 km line(F)\n",
"L = round(1/(3*(2*math.pi*f)**2*C),2) #required inductance L of the arc suppression coil(H)\n",
"IF = V*1000/(10*math.ceil(3**0.5*2*math.pi*f*L/10)) #Current through the coil(A)\n",
"kVA = V/3**0.5*IF #kVA\n",
"\n",
"\n",
"#Result:\n",
"print \"The inductance of the coil is\",L,\"H\"\n",
"print \"Rating of the coil is\",round(kVA),\"kVA\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The inductance of the coil is 1.82 H\n",
"Rating of the coil is 10060.0 kVA\n"
]
}
],
"prompt_number": 6
}
],
"metadata": {}
}
]
}
|
