{
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"CHAPTER 11: SPECIALIZED DYNAMOS"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 11.1, Page number 372"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable declaration\n",
"#Given Torque-Speed relations shown in Fig.11-3b page no-371 for a dc servomotor\n",
"\n",
"#Calculation\n",
"#Case(a)\n",
"S = 800.0 #Motor speed at point x(rpm). Extrapolating to load line point x\n",
"V = 60.0 #Armature voltage at point x(V)\n",
"#Case(b)\n",
"T = 4.5 #At standstill, 60 V yields 4.5 lb-ft of starting torque\n",
"#Case(c)\n",
"P_c = T*S/5252 #Power delivered to the load(hp). From case(a)\n",
"P_c_watt = P_c*746 #Power delivered to the load(W)\n",
"#Case(d)\n",
"T_d = 1.1 #Torque for continuous duty without cooling fan(lb-ft). At point o\n",
"S_d = 410.0 #Maximum load speed(rpm)\n",
"#Case(e)\n",
"T_e = 2.4 #Torque for continuous duty with cooling fan(lb-ft). At point w\n",
"S_e = 900.0 #Maximum load speed(rpm)\n",
"#Case(f)\n",
"P_d = T_d*S_d/5252 #Power delivered to the load(hp). From case(d)\n",
"P_d_watt = P_d*746 #Power delivered to the load(W)\n",
"#Case(g)\n",
"P_e = T_e*S_e/5252 #Power delivered to the load(hp). From case(e)\n",
"P_e_watt = P_e*746 #Power delivered to the load(W)\n",
"#Case(h)\n",
"A = 65.0 #Upper limit of power range A(W)\n",
"B = 305.0 #Upper limit of power range B(W)\n",
"\n",
"#Result\n",
"print('Case(a): Motor speed when load torque is 2.1 lb-ft at point x , S = %.f rpm' %S)\n",
"print(' Armature voltage when load torque is 2.1 lb-ft at point x , V = %.f V' %V)\n",
"print('Case(b): Motor starting torque using the voltage found in part(a) , T_st = %.1f lb-ft' %T)\n",
"print('Case(c): Power delivered to the load under conditions given in part(a) , P = %.3f hp = %.f W' %(P_c,P_c_watt))\n",
"print('Case(d): Maximum load speed for continuous duty without cooling fan , S = %.f rpm' %S_d)\n",
"print(' Torque for continuous duty without cooling fan , T = %.1f lb-ft' %T_d)\n",
"print('Case(e): Maximum load speed for continuous duty with cooling fan , S = %.f rpm' %S_e)\n",
"print(' Torque for continuous duty with cooling fan , T = %.1f lb-ft' %T_e)\n",
"print('Case(f): Power delivered to load in part(d) , P = %.4f hp = %.1f W' %(P_d,P_d_watt))\n",
"print('Case(g): Power delivered to load in part(e) , P = %.3f hp = %.f W' %(P_e,P_e_watt))\n",
"print('Case(h): Upper limit of power range , A = %.f W' %A)\n",
"print(' Upper limit of power range , B = %.f W' %B)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Case(a): Motor speed when load torque is 2.1 lb-ft at point x , S = 800 rpm\n",
" Armature voltage when load torque is 2.1 lb-ft at point x , V = 60 V\n",
"Case(b): Motor starting torque using the voltage found in part(a) , T_st = 4.5 lb-ft\n",
"Case(c): Power delivered to the load under conditions given in part(a) , P = 0.685 hp = 511 W\n",
"Case(d): Maximum load speed for continuous duty without cooling fan , S = 410 rpm\n",
" Torque for continuous duty without cooling fan , T = 1.1 lb-ft\n",
"Case(e): Maximum load speed for continuous duty with cooling fan , S = 900 rpm\n",
" Torque for continuous duty with cooling fan , T = 2.4 lb-ft\n",
"Case(f): Power delivered to load in part(d) , P = 0.0859 hp = 64.1 W\n",
"Case(g): Power delivered to load in part(e) , P = 0.411 hp = 307 W\n",
"Case(h): Upper limit of power range , A = 65 W\n",
" Upper limit of power range , B = 305 W\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 11.2, Page number 379"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable declaration\n",
"n = 3.0 #Number of stacks or phases\n",
"P_a = 16.0 #Number of rotor teeth\n",
"P_b = 24.0 #Number of rotor poles\n",
"\n",
"#Calculation\n",
"alpha_a = 360/(n*P_a) #Stepping angle(degree/step) \n",
"alpha_b = 360/(n*P_b) #Stepping angle(degree/step)\n",
"\n",
"#Result\n",
"print('Case(a): Stepping angle , \u03b1 = %.1f\u00b0/step' %alpha_a)\n",
"print('Case(b): Stepping angle , \u03b1 = %.1f\u00b0/step' %alpha_b)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Case(a): Stepping angle , \u03b1 = 7.5\u00b0/step\n",
"Case(b): Stepping angle , \u03b1 = 5.0\u00b0/step\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 11.3, Page number 381"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable declaration\n",
"P = 50.0 #Number of rotor teeth\n",
"\n",
"#Calculation\n",
"alpha = 90/P #Stepping length(degrees)\n",
"\n",
"#Result\n",
"print('\u03b1 = %.1f\u00b0 ' %alpha)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\u03b1 = 1.8\u00b0 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 11.4, Page number 388"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable declaration\n",
"tou = 0.1 #Pole pitch of a double-sided primary LIM(m)\n",
"f = 60.0 #Frequency applied to the primary LIM(Hz)\n",
"\n",
"#Calculation\n",
"v_s = 2*f*tou #Synchronous velocity(m/s)\n",
"\n",
"#Result\n",
"print('Synchronous velocity , v_s = %.f m/s' %v_s)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Synchronous velocity , v_s = 12 m/s\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 11.5, Page number 388"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable declaration\n",
"v_s = 12.0 #Synchronous velocity(m/s)\n",
"v = 10.0 #Linear velocity of secondary sheet(m/s)\n",
"\n",
"#Calculation\n",
"s = (v_s-v)/v_s #Slip of the DSLIM\n",
"\n",
"#Result\n",
"print('Slip of the DSLIM , s = %.3f' %s)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Slip of the DSLIM , s = 0.167\n"
]
}
],
"prompt_number": 1
}
],
"metadata": {}
}
]
}