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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 22 : Power System Voltage Stability"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22.2, Page No 725"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"Vb=500.0\n",
"Sb=1000.0\n",
"\n",
"#Calculations\n",
"Zb=Vb**2/Sb\n",
"Xpu=.35*100/Zb\n",
"Zth=1000/5000.0\n",
"X=Xpu+Zth\n",
"V=1.0\n",
"Q=0\n",
"P=1.0\n",
"Eth=V+(Q*X/V)+complex(P*X/V)\n",
"Q=0.75\n",
"Eth1=V+(Q*X/V)+complex(P*X/V)\n",
"\n",
"#Results\n",
"print(\"(i) For p.f unity , Eth= {0:.5f}+{1:.5f}i\".format(Eth.real, Eth.imag))\n",
"print(\"(i) For p.f .8 , Eth= {0:.5f}+{1:.5f}i\".format(Eth1.real, Eth1.imag))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(i) For p.f unity , Eth= 1.34000+0.00000i\n",
"(i) For p.f .8 , Eth= 1.59500+0.00000i\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22.3, Page No 726"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"X=.625\n",
"P=1.0\n",
"Q=0.6\n",
"V=1.0\n",
"\n",
"#Calculations\n",
"Eth=V+(Q*X/V)+complex(P*X/V)\n",
"Phase_Eth=math.degrees(math.atan(Eth.imag/Eth.real))\n",
"\n",
"#Results\n",
"print(\"Eth=%.2f at an angle %.0f degrees\" %(abs(Eth),Phase_Eth))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Eth=2.00 at an angle 0 degrees\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22.4, Page No 732"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"P=0.5\n",
"toff=4.0\n",
"\n",
"#Calculations\n",
"ton=(P*toff-0*toff)/(0.8-P)\n",
"\n",
"#Results\n",
"print(\"Toff= 4min .\")\n",
"print(\"ton(min.)=%.3f min.\" %ton)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Toff= 4min .\n",
"ton(min.)=6.667 min.\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22.6 Page No 739"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"V=1.0\n",
"Qload=1.0*V\n",
"Qcap=-0.75*V**2\n",
"\n",
"#Calculations\n",
"Qnet=Qload+Qcap\n",
"VS=1-0.75*2*V # voltage sensitivity\n",
"\n",
"#Results\n",
"print(\"Voltage sensitivity=%.3f\" %VS)\n",
"print(\"since the voltage sensitivity is negative,\\nvoltage regulation by tap changing will reduce net reactive load and improive voltage stability \")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Voltage sensitivity=-0.500\n",
"since the voltage sensitivity is negative,\n",
"voltage regulation by tap changing will reduce net reactive load and improive voltage stability \n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22.7, Page No 740"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"Y=complex(-10)\n",
"n=1+0.1\n",
"\n",
"#Calculations\n",
"Y1=n*(n-1)*Y\n",
"Y2=(1-n)*Y\n",
"\n",
"#Results\n",
"print(\"Y1= {0:.2f}+{1:.2f}i\".format(Y1.real, Y1.imag))\n",
"print(\"Y2= {0:.2f}+{1:.2f}i\".format(Y2.real, Y2.imag))\n",
"print(\"The shunt elements equal to a reactor of 1.1V1^2 size oin the primary side and a capacitive of sixe 1V2**2 on the secondary side\")"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Y1= -1.10+0.00i\n",
"Y2= 1.00+-0.00i\n",
"The shunt elements equal to a reactor of 1.1V1^2 size oin the primary side and a capacitive of sixe 1V2**2 on the secondary side\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 22.8, Page No 745"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"P=1.0\t\t#assuming\n",
"S1=P/.95\t#For pf .95\n",
"S2=P/.8\t\t#For pf .8\n",
"\n",
"#Calculations\n",
"dMVA=(S2-S1)*100.0/P\t\t#Increase in MVA rating \n",
"Q1=P*math.tan(math.radians(math.degrees(math.acos(0.95))))\t\t#Q for pf .95\n",
"Q2=P*math.tan(math.radians(math.degrees(math.acos(0.8))))\t\t#Q for pf .8\n",
"dPc=(Q2-Q1)*100.0/Q1\t\t#Percent additional Reactive Power Capability \n",
"\n",
"#Results\n",
"print(\"Percent additional Reactive Power Capability is %.2f\" %dPc)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Percent additional Reactive Power Capability is 128.18\n"
]
}
],
"prompt_number": 6
}
],
"metadata": {}
}
]
}
|
