{ "metadata": { "name": "", "signature": "sha256:1ed2c66761e5c24becdae0bef9d3fd6079b2eecb8e7b4c62bdcfe4d4af9edc70" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 10 - MECHANICAL DESIGN OF TRANSMISISON LINES" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E1 - Pg 246" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate maximum sag\n", "import math\n", "#Given data :\n", "L=200.#**m\n", "w=0.7#**kg\n", "T=1400.#**kg\n", "S=w*L**2./(8.*T)#**,m\n", "print '%s %.2f' %(\"maximum sag(m) :\",S)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "maximum sag(m) : 2.50\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E2 - Pg 247" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Height above the ground\n", "import math\n", "#Given data :\n", "W=680.##kg/km\n", "L=260.##m\n", "U_strength=3100.##kg\n", "SF=2.##safety factor\n", "Clearance=10.##m\n", "T=U_strength/SF##kg\n", "w=W/1000.##kg\n", "S=w*L**2./(8.*T)##,m\n", "h=Clearance+S##m\n", "print '%s %.1f' %(\"Height above the ground(m) :\",h)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Height above the ground(m) : 13.7\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E3 - Pg 247" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Horizontal component of tension,Maximum sag,Sag will be half at the point where x coordinate(in m) will be\n", "import math\n", "import numpy \n", "from numpy import roots\n", "#Given data :\n", "w=700./1000.##kg/m\n", "L=300.##m\n", "Tmax=3500.##kg\n", "\n", "S_T0=w*L**2./8.##,m\n", "#Tmax=T0+w*S\n", "#T0**2-T0*Tmax-w*S_T0=0\n", "polynomial=([1, -Tmax, -w*S_T0])#\n", "T0=numpy.roots(polynomial)##kg\n", "T0=T0[0]##+ve sign taken\n", "print '%s %.2f' %(\"Horizontal component of tension in kg is : \",T0)#\n", "S=S_T0/T0##m\n", "print '%s %.4f' %(\"Maximum sag in m : \",S)#\n", "y=S/2.##m\n", "x=math.sqrt(2.*y*T0/w)##m\n", "print '%s %.f' %(\"Sag will be half at the point where x coordinate(in m) will be : \",x)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Horizontal component of tension in kg is : 3501.57\n", "Maximum sag in m : 2.2490\n", "Sag will be half at the point where x coordinate(in m) will be : 106\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E4 - Pg 248" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Maximum sag \n", "import math\n", "#Given data :\n", "L=150.##m\n", "wc=1.##kg\n", "A=1.25##cm**2\n", "U_stress=4200.##kg/cm**2\n", "Pw=100.##kg/m**2(Wind pressure)\n", "SF=4.##factor of safety\n", "W_stress=U_stress/SF##kg/cm**2\n", "T=W_stress*A##kg\n", "d=math.sqrt(A/(math.pi/4.))##cm\n", "w_w=Pw*d*10.**-2##kg\n", "wr=math.sqrt(wc**2.+w_w**2.)##kg\n", "S=wr*L**2./8./T##m\n", "print '%s %.2f' %(\"Maximum sag(m)\",S)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum sag(m) 3.45\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E5 - Pg 248" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Sag(meter)\n", "import math\n", "#Given data :\n", "L=160.##m\n", "d=0.95##cm\n", "wc=0.65##kg/m\n", "U_stress=4250.##kg/cm**2\n", "Pw=40.##kg/m**2(Wind pressure)\n", "SF=5.##factor of safety\n", "W_stress=U_stress/SF##kg/cm**2\n", "T=W_stress*math.pi/4.*d**2.##kg\n", "w_w=Pw*d*10.**-2##kg\n", "wr=math.sqrt(wc**2.+w_w**2.)##kg\n", "S=wr*L**2./8./T##m\n", "print '%s %.2f' %(\"Sag(meter)\",round(S))#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Sag(meter) 4.00\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E6 - Pg 248" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Sag in still air,Maximum Sag\n", "import math\n", "#Given data :\n", "L=180.##m\n", "D=1.27##cm\n", "Pw=33.7##kg/m**2(Wind pressure)\n", "r=1.25##cm\n", "wc=1.13##kg/cm**2\n", "U_stress=4220.##kg/cm**2\n", "SF=5.##factor of safety\n", "W_stress=U_stress/SF##kg/cm**2\n", "T=W_stress*math.pi/4.*D**2.##kg\n", "S=wc*L**2./8./T##msag in air\n", "print '%s %.2f' %(\"Sag in still air(meter)\",S)#\n", "w1=2890.3*r*10.**-2*(D+r)*10.**-2##kg/m\n", "w_w=Pw*(D+2.*r)*10.**-2##kg\n", "wr=math.sqrt((wc+w1)**2.+w_w**2.)##kg\n", "Smax=wr*L**2./8./T##msag in air\n", "print '%s %.3f' %(\"Maximum Sag(meter)\",Smax)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Sag in still air(meter) 4.28\n", "Maximum Sag(meter) 9.105\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E7 - Pg 249" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Maximum Sag \n", "import math\n", "#Given data :\n", "D=19.5##mm\n", "wc=0.85##kg/m\n", "L=275.##m\n", "Pw=39.##kg/m**2(Wind pressure)\n", "r=13.##mm\n", "U_stress=8000.##kg/cm**2\n", "SF=2.##factor of safety\n", "rho_i=910.##kg/m**3(density of ice)\n", "T=U_stress/SF##kg\n", "wi=rho_i*math.pi*r*10.**-3*(D+r)*10.**-3##kg\n", "w_w=Pw*(D+2.*r)*10.**-3##kg\n", "wr=math.sqrt((wc+wi)**2.+w_w**2)##kg\n", "Smax=wr*L**2./8./T##msag in air\n", "print '%s %.3f' %(\"Maximum Sag(meter)\",Smax)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum Sag(meter) 6.422\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E8 - Pg 249" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate \n", "import math\n", "#Given data :\n", "wc=1.##kg/m\n", "L=280.##m\n", "D=20.##mm\n", "r=10.##mm\n", "Pw=40.##kg/m**2(Wind pressure)\n", "rho_i=910.##kg/m**3(density of ice)\n", "U_stress=10000.##kg/cm**2\n", "SF=2.##factor of safety\n", "wi=rho_i*math.pi*r*10.**-3*(D+r)*10.**-3##kg\n", "w_w=Pw*(D+2.*r)*10.**-3##kg\n", "wr=math.sqrt((wc+wi)**2.+w_w**2.)##kg(Resultant force per m length of conductor)\n", "T=U_stress/SF##kg\n", "Smax=wr*L**2./8./T##msag in air\n", "print '%s %.1f' %(\"Maximum Sag(meter)\",Smax)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum Sag(meter) 4.8\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E9 - Pg 250" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Sag in inclined direction,Sag in vertical direction,Height of lowest cross arm\n", "import math\n", "#Given data :\n", "L=250.##m\n", "D=1.42##cm\n", "wc=1.09##kg/m\n", "Pw=37.8##kg/m**2(Wind pressure)\n", "r=1.25##cm\n", "Lis=1.43##m(insulator string length)\n", "Clearance=7.62##m\n", "rho_i=913.5##kg/m**3(density of ice)\n", "stress=1050.##kg/cm**2\n", "T=stress*math.pi/4.*D**2##kg\n", "wi=rho_i*math.pi*r*10.**-2*(D+r)*10.**-2##kg\n", "w_w=Pw*(D+2.*r)*10.**-2##kg\n", "wr=math.sqrt((wc+wi)**2+w_w**2.)##kg(Resultant force per m length of conductor)\n", "Smax=wr*L**2./8./T##max sag in air\n", "print '%s %.4f' %(\"Sag in inclined direction(meter)\",Smax)#\n", "Sdash=Smax*(wc+wi)/wr##max sag in air\n", "print '%s %.2f' %(\"Sag in vertical direction(meter)\",Sdash)#\n", "h=Clearance+Sdash+Lis##m\n", "print '%s %.2f' %(\"Height of lowest cross arm(m)\",h)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Sag in inclined direction(meter) 11.8756\n", "Sag in vertical direction(meter) 9.62\n", "Height of lowest cross arm(m) 18.67\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E10 - Pg 250" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Distance of lowest point,minimum point of catenary above the ground\n", "import math\n", "#Given data :\n", "wc=0.35##kg/m\n", "stress=800.##kg/cm**2\n", "L=160.##m\n", "SF=2.##safety factor\n", "h=70.-65.##m\n", "T=stress/SF##kg\n", "x=L/2.+T*h/(wc*L)##m\n", "print '%s %.2f' %(\"Distance of lowest point(m)\",x)#\n", "S1=wc*x**2/SF/T##max sag in air\n", "xmin=70.-S1##m\n", "print '%s %.4f' %(\"minimum point of catenary above the ground(m)\",xmin)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Distance of lowest point(m) 115.71\n", "minimum point of catenary above the ground(m) 64.1420\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E11 - Pg 251" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Slant sag,Vertical Sag\n", "import math\n", "#Given data :\n", "L=200.##m\n", "h=10.##m\n", "D=2.##cm\n", "wc=2.3##kg/m\n", "Pw=57.5##kg/m**2(wind pressure)\n", "SF=4.##safety factor\n", "stress=4220.##kg/cm**2\n", "w_w=Pw*D*10.**-2##kg\n", "wr=math.sqrt(wc**2.+w_w**2.)##kg\n", "f=stress/SF##kg/cm**2\n", "T=f*math.pi/4.*D**2.##kg\n", "x=L/2.-T*h/(wr*L)##m\n", "S1=wr*x**2./2./T##max sag in air\n", "print '%s %.4f' %(\"Slant sag(m)\",S1)#\n", "Sdash=wc*x**2./2./T##vertical sag\n", "print '%s %.4f' %(\"Vertical Sag(meter)\",Sdash)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Slant sag(m) 0.4904\n", "Vertical Sag(meter) 0.4386\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E12 - Pg 251" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Vertical Sag\n", "import math\n", "#Given data :\n", "wc=1.925##kg/m\n", "A=2.2##cm**2\n", "f=8000.##kg/cm**2\n", "L=600.##m\n", "h=15.##m\n", "D=2.##cm\n", "SF=5.##safety factor\n", "wi=1.##kg(load)\n", "w=wi+wc##kg\n", "T=f*A/SF##kg\n", "x=L/2.-T*h/(w*L)##m\n", "S2=w*(L-x)**2./2./T##m\n", "print '%s %.2f' %(\"Vertical Sag(meter)\",S2)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Vertical Sag(meter) 45.27\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E13 - Pg 252" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Mid point P is \"+string(Point_P)+\" meter below point B or \"+string(80-Point_P)+\" meter above the water level\n", "import math\n", "#Given data :\n", "h=80.-50.##m\n", "L=300.##m\n", "T=2000.##kg\n", "w=0.844##kg/m\n", "x=L/2.-T*h/(w*L)##m\n", "d_PO=L/2.-x##m\n", "d_BO=L-x##m\n", "Smid=w*(L/2.-x)**2./2./T##m\n", "S2=w*(L-x)**2./2./T##m\n", "Point_P=S2-Smid##m\n", "print '%s %.3f %s %.3f %s' %(\"Mid point P is \",Point_P,\" meter below point B or \",80-Point_P,\" meter above the water level.\")#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mid point P is 19.747 meter below point B or 60.253 meter above the water level.\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E14 - Pg 252" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Stringing Tension\n", "import math\n", "#Given data :\n", "S1=25.##m\n", "S2=75.##m\n", "Point_P=45.##m\n", "L1=250.##m\n", "L2=125.##m(mid point)\n", "w=0.7##kg/m\n", "h1=S2-S1##m(for points A & B)\n", "h2=Point_P-S1##m(for points A & B)\n", "#h1=w*L1/2/T*[L1-2*x]\n", "#h2=w*L2/2/T*[L2-2*x]\n", "x=(L1-h1/h2/L1*L2*L2)/(-h1/h2/L1*L2*2.+2.)##m\n", "T=(L1-2.*x)/(h1/w/L1*2.)##kg\n", "print '%s %.2f' %(\"Stringing Tension(kg)\",T)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Stringing Tension(kg) 1093.75\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E15 - Pg 253" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Clearance of the lowest point from ground,Minimum clearance\n", "import math\n", "#Given data :\n", "L=300.##m\n", "slope=1./20.#\n", "w=0.80##kg/m\n", "hl=30.##m\n", "T0=1500.##kg\n", "CD=L##m\n", "tan_alfa=slope#\n", "ED=CD*tan_alfa##m\n", "AC=hl##m\n", "BE=hl##m\n", "BD=BE+ED##m\n", "#S1=w*x1**2/2/T0##m\n", "#S2=w*(L-x1)**2/2/T0##m\n", "h=15.##m\n", "ED=h##m\n", "x1=L/2.-T0*h/w/L##m\n", "S1=w*x1**2./2./T0##m\n", "S2=w*(L-x1)**2./2./T0##m\n", "OG=AC-S1-x1*tan_alfa##m\n", "Clearance=OG##m\n", "print '%s %.5f' %(\"Clearance of the lowest point from ground(m)\",Clearance)#\n", "#y=x*tan_alfa-OG##m\n", "#C1=w*x**2/2/T0-(x/20-OG)\n", "x=T0/20./w##m(Byy putting dC1/dx=0)\n", "C1=w*x**2./2./T0-(x/20.-OG)##m\n", "print '%s %.2f' %(\"Minimum clearance(m)\",C1)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Clearance of the lowest point from ground(m) 26.34375\n", "Minimum clearance(m) 24.00\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example E16 - Pg 255" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Sag at erection\n", "import math\n", "import numpy\n", "from numpy import roots\n", "#Given data :\n", "L=250.##m\n", "D=19.5##mm\n", "A=2.25*10.**-4##m**2.\n", "wc=0.85##kg/m\n", "t1=35.##degree C\n", "t2=5.##degree C\n", "Pw=38.5##kg/m**2\n", "alfa=18.44*10.**-6##per degree C\n", "E=9320.##kg/mm**2\n", "E=9320.*10.**6.##kg/m**2\n", "Breaking_Load=8000.##kg\n", "SF=2.##Safety factor\n", "T1=Breaking_Load/SF##kg\n", "f1=T1/A##kg/m**2\n", "w_w=Pw*D*10.**-2##kg\n", "w1=math.sqrt(wc**2.+w_w**2.)##kg\n", "w2=wc#\n", "#f2**2.*[(f2-f1)+w1*L**2.*E/24./f1**2./A**2.+(t2-t1)*E]=w2*L**2.*E/24./A**2.\n", "#f2**3-f2**2.*f1-w2*L**2.*E/24./A**2.=0\n", "P=([1, -1.0674*10.**7, 0, -3463.84*10.**17.])#\n", "f2=numpy.roots(P)#\n", "f2=numpy.real(f2[0])##kg/m**2\n", "S=w2*L**2./8./f2/A##m\n", "print '%s %.1f' %(\"Sag at erection(m)\",S)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Sag at erection(m) 2.3\n" ] } ], "prompt_number": 15 } ], "metadata": {} } ] }