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{
"metadata": {
"name": "",
"signature": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 4, Electrical Features of lines - 1"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.1 : page 104"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log, pi\n",
"import math\n",
"#Given Data :\n",
"r=1.213/2 #in cm\n",
"f=60 #in Hz\n",
"ds=0.77888*r #in cm\n",
"spacing=1.25 #in meter\n",
"L=4*10**-7*log(spacing*100/ds) #in H/m\n",
"L*=1000 # in H/km\n",
"print \"Inductance = %0.2e H/km\" %L\n",
"XL=2*pi*f*L #in ohm/km\n",
"XL*=60 # ohm per 60 km\n",
"print \"Inductive reactance for 60 km line = %0.1f ohm\" %XL"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance = 2.23e-03 H/km\n",
"Inductive reactance for 60 km line = 50.5 ohm\n"
]
}
],
"prompt_number": 105
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.2 : page 105"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import log\n",
"#Given Data : \n",
"l=20 # km (length of line)\n",
"d=2.8*100 #in cm(spacing)\n",
"r=0.5*1.5 #in cm\n",
"ds=0.77888*r #in cm\n",
"L=0.2*log(d/ds) #in H/m/phase\n",
"L*=l # mH for 20km line\n",
"print \"Inductance per phase for a 20 km line = %0.2f mH\" %L"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance per phase for a 20 km line = 24.69 mH\n"
]
}
],
"prompt_number": 106
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.3 : page 105"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import log\n",
"#Given Data :\n",
"a=1.5 #in cm**2\n",
"d=8 #in meter(spacing)\n",
"r=39.8/2 #in mm\n",
"l=1*10**5 #in cm\n",
"rho=1.73*10**-6 #in ohm-cm\n",
"R=rho*l/a #in ohm/km\n",
"print \"Resistance of line = %0.4f ohms/km\" %R\n",
"ds=0.77888*r #in cm\n",
"L=0.2*log(d/(ds*10**-3)) #in mH/km/phase\n",
"print \"Inductance per phase for a 1 km line = %0.3f mH/km\" %L"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Resistance of line = 0.1153 ohms/km\n",
"Inductance per phase for a 1 km line = 1.249 mH/km\n"
]
}
],
"prompt_number": 107
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.4 : page 106"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"#Given Data :\n",
"Cs=1/3 #in uF\n",
"Cc=(0.6-Cs)/2 #in uF\n",
"#Part (a) :\n",
"C1=(3/2)*Cc+(1/2)*Cs #in uF(between any two conductor)\n",
"print \"Capacitance between any two conductor = %0.3f uF\" %C1\n",
"#Part (b) :\n",
"C2=2*Cc+2*Cs/3\n",
"print \"Capacitance between any shorted conductors = %0.3f uF\" %C2"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Capacitance between any two conductor = 0.367 uF\n",
"Capacitance between any shorted conductors = 0.489 uF\n"
]
}
],
"prompt_number": 108
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.5 : page 107"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"#Given Data :\n",
"d1=3 #in meter\n",
"d2=3 #in meter\n",
"d3=d1+d2 #in meter\n",
"d=378 #in cm\n",
"dia=2.5 #in cm\n",
"r=dia/2 #in cm\n",
"epsilon_o=8.854*10**-12 #constnt\n",
"L=(0.5+2*log10(d/r))*10**-7 #in H/m\n",
"L*=60*1000*1000 # mH per 60 km\n",
"print \"Inductance for 60 km line %0.2f mH\" %L\n",
"C=2*pi*epsilon_o/log(d/r) #in F/m\n",
"C*=60*10**3*10**6 # uF per 60 km line\n",
"print \"Capacitnce for 60 km line = %0.4f uF\" %C\n",
"# Answer is not accurate in the textbook."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance for 60 km line 32.77 mH\n",
"Capacitnce for 60 km line = 0.5844 uF\n"
]
}
],
"prompt_number": 109
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.6 : page 107"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log10\n",
"#Given Data : \n",
"dinner=6 #in meter\n",
"douter=12 #in meter\n",
"d=(dinner**2*douter)**(1/3) #in meter\n",
"r=2.8 #in meter\n",
"ds=0.7788*r #in cm\n",
"L=2*log10(d*100/ds) #in mH/phase/km\n",
"L*=100 # mH per 100 km\n",
"print \"Inductance for 100 km line %0.f mH\" %L"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance for 100 km line 508 mH\n"
]
}
],
"prompt_number": 110
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.7 : page 108"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import log\n",
"#Given Data :\n",
"dia=5 #in mm\n",
"d=1.5 #in meter(spacing)\n",
"r=dia/2 #in mm\n",
"r=r*10**-3 #in meter\n",
"epsilon_o=8.854*10**-12 #constnt\n",
"C=pi*epsilon_o/log(d/r) #in Farad per meter\n",
"C*=50*1000 # F per 50km line\n",
"print \"Capacitance for 50 km line = %0.2e F\" %C\n",
"#Note : answer is not accurate in the book. "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Capacitance for 50 km line = 2.17e-07 F\n"
]
}
],
"prompt_number": 111
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.8 : page 108"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import log\n",
"#Given Data :\n",
"d=300 #in cm(spacing)\n",
"r=1 #in cm\n",
"#Formula : L=10**-7*[mu_r+4*log10(d/r)] #in H/m\n",
"#Part (i) : mu_r=1\n",
"mu_r=1 #constant\n",
"L=10**-4*(mu_r+4*log(d/r)) #in H/m\n",
"L*=1000 # mh per km\n",
"print \"Loop inductance per km for copper %0.2f mH\" %L\n",
"#Part (ii) : mu_r=100\n",
"mu_r=100 #constant\n",
"L=10**-4*(mu_r+4*log(d/r)) #in H/m\n",
"L*=1000 # mH per km\n",
"print \"Loop inductance per km for steel = %0.2f mH\" %L\n",
"# Answer not calculated completely and calculation mistake."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Loop inductance per km for copper 2.38 mH\n",
"Loop inductance per km for steel = 12.28 mH\n"
]
}
],
"prompt_number": 112
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.9 : page 109"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from math import log\n",
"#Given Data :\n",
"d1=100 #in cm(spacing)\n",
"d2=100 #in cm(spacing)\n",
"d3=100 #in cm\n",
"r=1 #in cm\n",
"L=10**-7*(0.5+2*log((d1*d2*d3)**(1/3)/r)) #in H/m\n",
"L=L*1000*1000 #in mH/km\n",
"print \"Inductance per km = %0.2f mH\" %L\n",
"#Note : Answer in the book is wrong due to calculation mistake.\n",
"#Note : In the last line it should be multiply by 10**6 to convert from H/m to mH/km instead of 10**8."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance per km = 0.97 mH\n"
]
}
],
"prompt_number": 113
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.10 : page 109"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log\n",
"#Given Data : \n",
"d1=2 #in cm\n",
"d2=2.5 #in cm\n",
"d3=4.5 #in cm\n",
"r=1.24/2 #in cm\n",
"L=10**-7*(0.5+2*log((d1*d2*d3)**(1/3)/r)) #in H/m\n",
"L=L*1000*1000 #in mH/km\n",
"print \"Inductance per km per phase = %0.2f mH\" %L\n",
"#Note : Answer in the book is wrong(calculation mistake)."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance per km per phase = 0.35 mH\n"
]
}
],
"prompt_number": 114
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.11 : page 110"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log\n",
"#Given Data :\n",
"r=0.75*10 #in mm\n",
"d=1.5*10**3 #in mm\n",
"ds=0.7788*r #in mm\n",
"L=4*10**-7*log(d/ds) #in H/m\n",
"L=L*10**6 #in mH/km\n",
"print \"Inductance of line = %0.2f mH/km\" %L"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance of line = 2.22 mH/km\n"
]
}
],
"prompt_number": 115
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.12 : page 110"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log\n",
"#Given Data :\n",
"d1=4*100 #in cm\n",
"d2=5*100 #in cm\n",
"d3=6*100 #in cm\n",
"r=1 #in cm\n",
"ds=0.7788*r #in cm\n",
"L=(0.2*log((d1*d2*d3)**(1/3)/ds)) #in mH\n",
"L*=10**3 # uH\n",
"print \"Inductance per km = %0.2f uH\" %L\n",
"#Note : answer in the book is wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Inductance per km = 1290.20 uH\n"
]
}
],
"prompt_number": 116
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.13 : page 110"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log\n",
"#Given Data :\n",
"d=300 #in cm(spacing)\n",
"r=1 #in cm\n",
"epsilon_o=8.854*10**-12 #constnt\n",
"C=pi*epsilon_o/log(d/r) #in Farad per meter\n",
"C*=30*1000*10**6 # uF per 30k km line\n",
"print \"Capacitance for 30 km line = %0.2f uF\" %C"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Capacitance for 30 km line = 0.15 uF\n"
]
}
],
"prompt_number": 117
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.14 : page 111"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from __future__ import division\n",
"from numpy import log\n",
"#Given Data :\n",
"d=2.5*100 #in cm(spacing)\n",
"r=2/2 #in cm\n",
"epsilon_o=8.854*10**-12 #constnt\n",
"C=2*pi*epsilon_o/log(d/r) #in Farad per meter\n",
"C*=10*1000*10**6 # uF per 10 km line\n",
"print \"Capacitance for 10 km line = %0.2f uF\" %C\n",
"#Note : answer given in the book is wrong but calculated is right."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Capacitance for 10 km line = 0.10 uF\n"
]
}
],
"prompt_number": 119
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 4.15 : page 111"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Given Data :\n",
"VL=33 #in KV\n",
"f=50 #in hz\n",
"d1=4 #in meter\n",
"d2=4 #in meter\n",
"d3=8 #in meter\n",
"d=(d1*d2*d3)**(1/3) #in meter\n",
"epsilon_o=8.854*10**-12 #constnt\n",
"d=d*100 #in cm\n",
"r=0.62 #in cm\n",
"C=2*pi*epsilon_o/log(d/r) #in Farad per meter\n",
"C*=50*1000*10**6 # uF per m line\n",
"print \"Capacitance for 50 km line %0.3f uF\" %C\n",
"Vp=VL/sqrt(3) #in KV\n",
"Vp=Vp*10**3 #in volt\n",
"Ic=2*pi*f*(C*10**-6)*Vp #in Ampere\n",
"print \"The charging current = %0.2f Ampere\" %Ic"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Capacitance for 50 km line 0.415 uF\n",
"The charging current = 2.48 Ampere\n"
]
}
],
"prompt_number": 120
}
],
"metadata": {}
}
]
}
|