import math
from math import sqrt
S1=2.0 #value of slip in percentage of slip ring induction motor
Ns=1000.0 #value of stator speed in rpm
Nr=500.0 #value of rotor speed in rpm
S2=(Ns-Nr)*100/Ns #valu of slip in percentage of motor
print 'value of slip of motor=S2=',S2,'percentage'
I1=50.0 #stator current in amps
I2=I1*sqrt(S2/S1)
print 'value of new stator current=I2=',I2,'Amp'
import math
Imr=50.0 #motor field rating in amp//
Icr=1.5*Imr #converter rated current in amp
print 'value of converter rated current=Icr=',Icr,'amp'
Vdc=100.0 #converter dc rating in volts
Vac=Vdc/1.35 #converter ac rating voltage required
Vac=round(Vac,2)
print 'value of converter rated ac voltage=Vac=',Vac,'volts'
Pkva=(1.05*100*75)/1000 #KVA rating of the transformer
print 'KVA rating of transformer=Pkva=',Pkva,'KVA'
import math
S1=0.04 #value of slip in of induction motor
Ns=1500.0 #value of initial speed in rpm
N2=1300.0 #value of speed reduced to in rpm
N1=Ns*(1-S1) #value of speed N1 in rpm
print 'value of speed N1=',N1,'rpm'
f=(Ns-N1)/(Ns-N2)
print 'value of f=',f
T1=2000.0 #developing torque in induction motor in watts
T2=T1/f #new value of torque developed by the motor in watts
T2=round(T2,1)
print 'value of new torque developed=T2=',T2,'Watts'
import math
f1a=50.0 #initial frequency in hertz
f1b=75.0 #value of frequency increased to in hertz
Ta=1500.0 #developing torque in induction motor in watts
Tb=Ta*f1a/f1b #new value of torque developed by the motor in watts
print 'value of new torque developed=Tb=',Tb,'Watts'
import math
V=415.0 #operating input voltage of induction motor in volts
S=0.04 #input slip
r2=1.0 #rotor resistance referred to stator in ohms
T=(S*V**2)/r2 #torque developed by motor in watts
print 'torque developed by motor=T=',T,'watts'
f1=75.0 #input stator frequency in hertz
f2=S*f1 #rotor frequency in hertz
print 'value of rotor frequency=f2=',f2,'hertz'
import math
f1a=50.0 #intial frequency in hertz
f1b=30.0 #value of frequency reduced to in hertz
Va=415.0 #operating voltage of induction motor in volts
Vb=Va*f1b/f1a #input voltage to the motor in volts
print 'value of input voltage to the motor=Vb=',Vb,'volts'
Pa=100.0 #operating power of induction motor in KVA
Pb=Pa*f1b/f1a #input power to the motor in KVA
print 'value of input power to the motor=Pb=',Pb,'KVA'
import math
f1a=40.0 #intial frequency in hertz
Pa=200.0 #input power of squirrel cage motor in KVA
Pb=150.0 #input power to the motor after change in speed in KVA
f1b=f1a*Pb/Pa #frequency changed to in hertz
print 'value of frequency changed to f1b=',f1b,'hz'
Nsa=1200.0 #motor initial syncronous speed in rpm
Nsb=Nsa*f1b/f1a
Sb=0.04
Nb=Nsb*(1-Sb) #speed in rpm at 4% slip
print 'speed at 4 percent slip=Nb=',Nb,'rpm'
Va=325 #operating voltage of induction motor in volts
Vb=Va*f1b/f1a #stator voltage to the motor in volts
print 'value of stator voltage to the motor=Vb=',Vb,'volts'
Pag=150.0 #power transferred from stator to rotor at 30 hz in KVA
Ws=2*3.14*Nsb/60
T=Pag*1000/Ws #torque if stator drop is negligible in watts
T=round(T,2)
print 'torque if stator drop is negligible=T=',T,'watts'
P2=Sb*Pag #rotor copper loss in KVA
print 'rotor copper loss=P2=',P2,'KVA'
import math
from math import sqrt
f1a=50.0 #i n t i a l input frequency in hertz
Ta=2000.0 #developing torque in induction motor in watts
Tb=1500.0 #new value of torque reduced to in watts
f1b=f1a*sqrt(Ta/Tb) #value of stator frequency increased to in hertz
f1b=round(f1b,2)
print 'value of stator frequency increased to f1b=',f1b,'hertz'
import math
from math import pi,sqrt
Vom1=sqrt(2)*41.5 #starting rms value of output voltage
Vom2=sqrt(2)*166 #ending rms value of output voltage
V=415.0 #operating voltage of cyclo converter
A1=(math.acos(Vom1/(1.35*V)))*180/pi #firing angle starts from
A1=round(A1,1)
print 'firing angle starts from A1=',A1,'degrees'
A2=(math.acos(Vom2/(1.35*V)))*180/pi #f i r i n g angle ends at
A2=round(A2,1)
print 'firing angle ends at A2=',A2,'degrees'
PFl=0.8 #load power factor
IPF=math.cos(pi*7/15)*PFl/sqrt(2) #input power factor
DF=0.7 #input displacement factor
IPF=round(IPF,4)
print 'input power factor=IPF=',IPF
Mh=math.cos(pi*0.3627)*PFl/(sqrt(2)*DF)
Mh=round(Mh,4)
print 'distortion factor=Mh=',Mh
import math
from math import sqrt,pi
Vo5m=sqrt(2)*41.5 #rms value of output voltage
V=415.0 #operating voltage of cyclo converter
A5=(math.acos(Vo5m/(1.35*V)))*180/pi #trigger angle ranges from
A5=round(A5,2)
print 'trigger angle ranges fromA5=',A5,'degrees'
A51=180.0-A5 #trigger angle ranges upto
A51=round(A51,2)
print 'trigger angle ranges upto A51=',A51,'degrees'
LPF=0.9 #load power factor
CA15=0.3132 #maximum cosine value corresponding to operating frequency 15hz
HIPF=CA15*LPF/sqrt(2) #highest value of input power factor
HIPF=round(HIPF,2)
print 'highest value of input power factor=HIPF=',HIPF
LIPF=math.cos(A5*pi/180)*LPF/sqrt(2) #lowest value of input power factor
LIPF=round(LIPF,2)
print 'lowest value of input power factor=LIPF=',LIPF
IDF=0.75 #input displacement factor
HDF=CA15*LPF/(sqrt(2)*IDF) #highest value of distortion factor
HDF=round(HDF,2)
print 'highest value of distortion factor=HDF=',HDF
LDF=HDF*math.cos(A5*pi/180)/CA15 #lowest value of distortion factor
LDF=round(LDF,2)
print 'lowest value of distortion factor=LDF=',LDF
import math
from math import sqrt
PFm=0.5 #highest value of input factor
Am=3.14/6 #highest value of input powerfactor occurs at 30 degrees
A=math.cos(Am) #highest value of cosAm if firingangle ranging from 30 to 150
A=round(A,3)
print 'highest value of cosAm=',A
PFl=(sqrt(2)*PFm)/A
PFl=round(PFl,3)
print 'laod power factor of cyclo converter=',PFl
import math
PFi=0.6 #input powerfactor
DF=0.7 #distortion factor
IDF=PFi/DF #input displacement factor
IDF=round(IDF,3)
print 'input displacement factor=',IDF
import math
from math import sqrt
PFi=0.1 #input powerfactor
PFl=0.9 #load powerfactor
A=(math.acos(sqrt(2)*PFi/PFl))*180/3.14 #firing angle indegrees
A=round(A,2)
print 'firing angle of cyclo converter drive=A=',A,'degrees'
IDF=0.7 #leading input displacement factor
DF=PFi/IDF #distortion factor
DF=round(DF,3)
print 'distortion factor=DF=',DF
import math
Ap=30.0 #triggering angle of positive group in degrees
An=180-Ap #triggering angle of negative group in degrees
print 'triggering angle of negative group=An=',An,'degrees'
import math
from math import pi,sqrt
V=415.0 #input operating voltage of cycloconverter in volts
Pi=50.0 #input power of the cycloconverter in KVA
PF=0.8 #input power factor
A=0.785 #firing angle in radians
I=(Pi*1000*sqrt(2))/(3*V*PF*math.cos(A)) #input current to the converter in amp
I=round(I,3)
print 'input current to the converter=I=',I,'amp'
import math
Vo=200.0 #input operating voltage of cycloconverter in volts
Po=50*10**3 #input power of the cycloconverter in VA
Io=100.0 #drawing current from motor in amp
PF=Po/(3*Vo*Io) #load power factor
PF=round(PF,2)
print 'load power factor of motor=PF=',PF