"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from __future__ import division\n",
"import math\n",
"#initializing the variables:\n",
"f = 50;# in ohm\n",
"V = 240;# in Volts\n",
"pf = 0.6;# power factor\n",
"Im = 50;# in amperes\n",
"\n",
"#calculation:\n",
"phi = math.acos(pf)\n",
"phid = phi*180/math.pi\n",
"Ic = Im*math.sin(phi)\n",
"I = Im*math.cos(phi)\n",
"\n",
"\n",
"#Results\n",
"print \"\\n\\n Result \\n\\n\"\n",
"print \"\\n (a)the capacitor current Ic must be \",round(Ic,2),\" A for the power factor to be unity. \"\n",
"print \"\\n (b)Supply current I = \",round(I,2),\" A \""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
"\n",
" Result \n",
"\n",
"\n",
"\n",
" (a)the capacitor current Ic must be 40.0 A for the power factor to be unity. \n",
"\n",
" (b)Supply current I = 30.0 A "
]
}
],
"prompt_number": 1
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"
Example 12, page no. 253
"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"from __future__ import division\n",
"import math\n",
"#initializing the variables:\n",
"Pout = 4800;# in Watt\n",
"eff = 0.8# effficiency\n",
"f = 50;# in ohm\n",
"V = 240;# in Volts\n",
"pf1 = 0.625;# power factor\n",
"pf2 = 0.95;# power factor\n",
"\n",
"#calculation:\n",
"Pin = Pout/eff\n",
"Im = Pin/(V*pf1)\n",
"phi1 = math.acos(pf1)\n",
"phi1d = phi1*180/math.pi\n",
"phi2 = math.acos(pf2)\n",
"phi2d = phi2*180/math.pi\n",
"Imh = Im*math.cos(phi1)\n",
" #Ih = I*cos(phi2)\n",
"Ih = Imh\n",
"I = Ih/math.cos(phi2)\n",
"Imv = Im*math.sin(phi1)\n",
"Iv = I*math.sin(phi2)\n",
"Ic = Imv - Iv\n",
"C = Ic/(2*math.pi*f*V)\n",
"kvar = V*Ic/1000\n",
"\n",
"\n",
"#Results\n",
"print \"\\n\\n Result \\n\\n\"\n",
"print \"\\n (a)current taken by the motor, Im = \",round(Im,2),\" A\"\n",
"print \"\\n (b)supply current after p.f. correction, I = \",round(I,2),\" A \"\n",
"print \"\\n (c)magnitude of the capacitor current Ic = \",round(Ic,0),\" A\"\n",
"print \"\\n (d)capacitance, C = \",round((C/1E-6),0),\" uF \"\n",
"print \"\\n (d)kvar rating of the capacitor = \",round(kvar,2),\" kvar \""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n",
"\n",
" Result \n",
"\n",
"\n",
"\n",
" (a)current taken by the motor, Im = 40.0 A\n",
"\n",
" (b)supply current after p.f. correction, I = 26.32 A \n",
"\n",
" (c)magnitude of the capacitor current Ic = 23.0 A\n",
"\n",
" (d)capacitance, C = 305.0 uF \n",
"\n",
" (d)kvar rating of the capacitor = 5.52 kvar "
]
}
],
"prompt_number": 4
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"