In [3]:

```
#Question:
"""Finding the voltage across the secondary of the transformer."""
#Variable Declaration:
E_p=6400 #Primary voltage(in Volts)
f=50 #Frequency of primary supply(in Hertz)
N1=480 #Number of turns in the primary of the transformer
#Calculations:
flux_m=E_p/(4.44*f*N1)
N2=20.0
Es=4.44*f*N2*flux_m
#Result:
print "(a)The peak value of the flux produced in the core is %.2f Wb." %(flux_m)
print "(b)The voltage across the secondary winding if it has 20 turns is %.2f V." %(Es)
```

In [4]:

```
#Question:
"""Finding the peak value of the flux density in the core."""
#Variable Declaration:
f=50.0 #Operating frequency of the transformer(in Hertz)
N1=30.0 #Number of turns in the primary of transformer
N2=350.0 #Number of turns in the secondary of transformer
A=250e-04 #Cross-sectional area of the core(in square-metres)
E1=230.0 #Voltage of the supply(in Volts)
#Calculations:
flux_m=E1/(4.44*f*N1)
B_m=flux_m/A
E2=E1*(N2/N1)
I2=100.0
I1=I2*(N2/N1)
#Result:
print "(a)The peak value of flux density in the core is %.2f T." %(B_m)
print "(b)The voltage induced in the secondary winding is %e V." %(E2)
print "(c)The primary current when the secondary current is 100 A is %e A." %(I1)
```

In [5]:

```
#Question:
"""Finding the turns-ratio of the transformer."""
from math import sqrt
#Variable Declaration:
Req=50.0 #Output resistance of the source(in Ohms)
R_L=800.0 #Load resistance(in Ohms)
#Calculations:
K=sqrt(R_L/Req)
#Result:
print "The turns-ratio of the transformer to be used for maximising the load power is %d." %(K)
```

In [6]:

```
#Question:
"""Finding the load current in the ac circuit."""
from cmath import rect,phase
from math import degrees
#Calculations:
V=rect(30,0)
Ip=V/(20+20*1j+(pow(2,2)*(2-10*1j)))
I_L=2.0*Ip
#Result:
print "The load current is %.3f A at a phase angle of %.3f degrees." %(abs(I_L),degrees(phase(I_L)))
```

In [7]:

```
#Question:
"""Finding the output of the transformer in kVA."""
#Variable Declaration:
B_m=1.1 #Maximum magnetic flux density(in Weber per square-metre)
A=150e-04 #Cross-sectional area of the core(in square-metres)
#Calculations:
flux_m=B_m*A
N2=66
f=50
Z_L=4.0
E2=4.44*N2*f*flux_m
V2=E2
I2=V2/Z_L
output=(I2*V2)/1000.0
#Result:
print "The output when connected to a load of 4 Ohms impedance is %.3f kVA." %(output)
```

In [8]:

```
#Question:
"""Finding the number of turns in each winding of the transformer."""
#Variable Declaration:
A=9e-04 #Cross-sectional area of the core(in square-metre)
E1=230.0 #Primary Voltage(in Volts)
E2=110.0 #Secondary Voltage(in Volts)
E3=6.0 #Tertiary Voltage(in Volts)
f=50.0 #Operating frequency of the transformer(in Hertz)
Bm=1.0 #Maximum magnetic flux density(in Tesla)
#Calculations:
flux_m=Bm*A
N3_half=E3/(4.44*f*flux_m)
N3=2*N3_half
N1=N3_half*(E1/E3)
N2=N3_half*(E2/E3)
#Result:
print "The total number of turns on the primary winding is %d turns." %(N1)
print "The total number of turns on the secondary winding is %d turns." %(N2)
print "The total number of turns on the tertiary winding is %d turns." %(N3)
```

In [9]:

```
#Question:
"""Finding the no-load power factor of the transformer."""
from math import sqrt,pow
#Variable Declaration:
VA=350.0 #Input at no-load(in Volt-Amperes)
V1=230.0 #Primary voltage(in Volts)
#Calculations:
Io=VA/V1
Pi=110.0
pf=Pi/(V1*Io)
Iw=Io*pf
Im=sqrt(pow(Io,2)-pow(Iw,2))
#Result:
print "The loss component of no-load current is given as %.4f A." %(Iw)
print "The magnetising component of no-load current is %.4f A." %(Im)
print "The no-load power factor is %.4f." %(pf)
```

In [10]:

```
#Question:
"""Finding the hysterisis and eddy-current losses of the transformer."""
#Variable Declaration:
f=50.0 #Operating frequency of the transformer(in Hertz)
eq1=100.0 #Iron loss at 60 Hz(in Watts)
eq2=60.0 #Iron loss at 40 Hz(in Watts)
#Calculations:
""" P_h=A*f ; P_e=B*f*f ;
P_i=P_h+P_e=(A*f)+(B*f*f); """
A=((eq2*36)-(eq1*16))/((40*36)-(60*16))
B=((eq1*4)-(eq2*6))/((3600*4)-(1600*6))
P_h=A*f
P_e=B*f*f
#Result:
print "The Hysteresis loss at 50 Hz is %.2f W." %(P_h)
print "The Eddy-current loss at 50 Hz is %.2f W." %(P_e)
```

In [11]:

```
#Question:
"""Finding the primary current snd the primary power factor."""
from math import acos,degrees,cos
from cmath import phase,rect
#Variable Declaration:
V1=440.0 #Primary voltage(in Volts)
V2=110.0 #Secondary voltage(in Volts)
I_0_mod=5.0 #No-load current(in Amperes)
I2=120.0 #Secondary current(in Amperes)
#Calculations:
phi_0=acos(0.2)
phi_2=acos(0.8)
K=V2/V1
I1_load_mod=K*I2
I1_load=rect(I1_load_mod,-phi_2)
I0=rect(I_0_mod,-phi_0)
I1_total=I0+I1_load
pf_primary=cos(phase(I1_total))
#Result:
print "The primary current is %.2f A at a phase angle of %.2f degrees." %(abs(I1_total),degrees(phase(I1_total)))
print "The primary power factor is %.3f lagging." %(pf_primary)
```

In [22]:

```
#Question:
"""Finding the equivalent resistance as referred to the primary and secondary."""
from math import sqrt
#Variable Declaration:
VA=50e03 #Power rating of the transformer(in Volt-Amperes)
V1=4400.0 #Primary voltage(in Volts)
V2=220.0 #Secondary voltage(in Volts)
R1=3.45 #Primary resistance(in Ohms)
R2=0.009 #Secondary resistance(in Ohms)
X1=5.2 #Leakage reactance of primary(in Ohms)
X2=0.015 #Leakage reactance of secondary(in Ohms)
#Calculations:
I1=VA/V1
I2=VA/V2
K=V2/V1
Re1=R1+(R2/(K*K))
Re2=(K*K*R1)+R2
Xe1=X1+(X2/(K*K))
Xe2=(K*K*X1)+X2
Ze1=sqrt((Re1*Re1)+(Xe1*Xe1))
Ze2=sqrt((Re2*Re2)+(Xe2*Xe2))
tot_copp_loss=(I1*I1*R1)+(I2*I2*R2)
tot_copp_eq_p=I1*I1*Re1
tot_copp_eq_s=I2*I2*Re2
#Result:
print "(a)The equivalent resistance as referred to the primary is %.2f Ohms." %(Re1)
print "(b)The equivalent resistance as referred to the secondary is %.4f Ohms." %(Re2)
print "(c)The equivalent reactance as referred to the primary is %.2f Ohms." %(Xe1)
print "(d)The equivalent reactance as referred to the secondary is %.3f Ohms." %(Xe2)
print "(e)The equivalent impedance as referred to the primary is %.2f Ohms." %(Ze1)
print "(f)The equivalent impedance as referred to the secondary is %.4f Ohms." %(Ze2)
print "(g)The total copper loss by using the individual resistances of the two windings is %.2f W." %(tot_copp_loss)
print " By considering equivalent resistances,"
print " Total copper loss(referred to primary equivalent resistance)=%.2f W." %(tot_copp_eq_p)
print " Total copper loss(referred to secondary equivalent resistance)=%.2f W" %(tot_copp_eq_s)
```

In [24]:

```
#Question:
"""Finding the full-load regulation for different load power factors."""
from math import cos,acos,sin
#Variable Declaration:
VA=40e03 #Power rating of the transformer(in Volt-Amperes)
V1=6600.0 #Primary voltage(in Volts)
V2=250.0 #Secondary voltage(in Volts)
R1=10.0 #Primary resistance(in Ohms)
R2=0.02 #Secondary resistance(in Ohms)
Xe1=35.0 #Equivalent leakage reactance as referred to the primary(in Ohms)
#Calculations:
K=V2/V1
I2=VA/V2
Re2=(K*K*R1)+R2
Xe2=(K*K*Xe1)
pf=1
phi=acos(pf)
per_reg_a=(((I2*Re2*pf)+(I2*Xe2*sin(phi)))/V2)*100
pf=0.8
phi=acos(pf)
per_reg_b=(((I2*Re2*pf)+(I2*Xe2*sin(phi)))/V2)*100
pf=0.8
phi=acos(pf)
per_reg_c=(((I2*Re2*pf)-(I2*Xe2*sin(phi)))/V2)*100
#Result:
print "(a)For unity power factor of the load:"
print "The full-load percentage regulation is %.3f percent." %(per_reg_a)
print "\n(b)For power factor of the load=0.8 lagging:"
print "The full-load percentage regulation is %.3f percent." %(per_reg_b)
print "\n(c)For power factor of the load=0.8 leading:"
print "The full-load percentage regulation is %.3f percent." %(per_reg_c)
```

In [17]:

```
#Question:
"""Finding the number of turns in each winding."""
from math import sqrt
#Variable Declaration:
f=50.0 #Operating frequency of the transformer(in Hertz)
E1=5000.0 #Primary voltage at no-load(in Volts)
E2=250.0 #Secondary voltage at no-load(in Volts)
VA_full=150e03 #Power rating of the transformer(in Volt-Ampere)
flux=0.06 #Maximum core flux(in Weber)
Pi=1500.0 #Core losses(in Watts)
Pc_FL=1800.0 #Full-load copper losses(in Watts)
#Calculations:
N2=E2/(4.44*f*flux)
N1=(E1/E2)*round(N2,0)
pf=1
Po=0.5*VA_full*pf
Pc=0.5*0.5*Pc_FL
effi_b=(Po/(Po+Pi+Pc))*100
pf=0.8
Po=VA_full*pf
Pc=Pc_FL
effi_c=(Po/(Po+Pi+Pc))*100
x=sqrt(Pi/Pc_FL)
VA_load=VA_full*x
#Result:
print "(a)The number of turns in the primary winding is %d." %(round(N1,0))
print " The number of turns in the secondary winding is %d." %(round(N2,0))
print "(b)The efficiency at half rated kVA and unity power factor is %.3f percent" %(effi_b)
print "(c)The efficiency at full load and 0.8 power factor lagging is %.3f percent." %(effi_c)
print "(d)The kVA load for maximum efficiency is %d kVA." %(round((VA_load/1000),0))
```

In [12]:

```
#Question:
"""Finding the all-day efficiency of a distribution transformer."""
#Variable Declaration:
kVA_FL=200.0 #Power rating of transformer at full-load(in Volt-Ampere)
Pc_FL=3.02 #Full-load copper losses(in kilo-Watts)
Pi=1.6 #Iron-losses(in kilo-Watts)
#Calculations:
Pi_24_hrs=24.0*Pi
""" For 80 kW load at unity power factor in 6 hrs:"""
Po_1=80
t1=6
pf_1=1
output_ene_1=Po_1*t1
kVA_1=Po_1/pf_1
Pc_1=pow((kVA_1/kVA_FL),2)*Pc_FL*t1
""" For 160 kW load at 0.8 power factor in 8 hrs:"""
Po_2=160
t2=8
pf_2=0.8
output_ene_2=Po_2*t2
kVA_2=Po_2/pf_2
Pc_2=pow((kVA_2/kVA_FL),2)*Pc_FL*t2
""" For no load period of 10 hrs:"""
Po_3=0
t3=10
output_ene_3=0
Pc_3=0
Po_total=output_ene_1+output_ene_2+output_ene_3
Pc_total=Pc_1+Pc_2+Pc_3
all_day_effi=Po_total/(Po_total+Pc_total+Pi_24_hrs)
#Result:
print "The all day efficiency of the distribution transformer is %.3f percent." %(all_day_effi*100)
```

In [10]:

```
#Question:
"""Finding the apparent power rating of an autotransformer."""
#Variable Declaration:
V_rated=120.0 #Voltage rating of the transformer(in Volts)
VA=12e03 #Power rating of the transformer(in Volt-Ampere)
#Calculations:
I1=VA/V_rated
I2=I1
input_app_pow=240*I1
output_app_pow=120*2*I1
#Result:
print "In auto-tranformer mode, the input apparent power is %d kVA and the output apparent power is %d kVA." %(round((input_app_pow/1000),0),round((output_app_pow/1000),0))
print "Thus, the apparent power capacity of the 12-kVA transformer is doubled by the auto-transformer connection."
print "In effect,half the apparent power is transformed and half is conducted directly to the secondary side."
```

In [7]:

```
#Question:
"""Finding the secondary line voltage on no load when the windings are connected(a)star/delta,(b)delta/star."""
from math import sqrt
#Variable Declaration:
V_L1=3300.0 #Supply voltage(in Volts)
Np=840.0 #Number of turns in the primary
Ns=72.0 #Number of turns in the secondary
#Calculations:
Vph_1a=V_L1/sqrt(3)
Vph_2a=Vph_1a*(Ns/Np)
V_L2a=Vph_2a
Vph_1b=V_L1
Vph_2b=Vph_1b*(Ns/Np)
V_L2b=Vph_2b*sqrt(3)
#Result:
print("(a)For star/delta connection: ")
print "The secondary line voltage on no load is %.2f V." %(V_L2a)
print("(b)For delta/star connection: ")
print "The secondary line voltage on no load is %.2f V." %(V_L2b)
```

In [2]:

```
#Question:
"""Finding the magnetising current and the core-loss current in a single-phase transformer."""
from math import sqrt
#Variable Declaration:
VA=12e03 #Power rating of the transformer(in Volt-Ampere)
Vp=400.0 #Primary voltage(in Volts)
Vs=200.0 #Secondary voltage(in Volts)
Wo=120.0 #Power in open-circuit test(in Watts)
V1=200.0 #Voltage in open-circuit test(in Volts)
I_0=1.3 #Current in open-circuit test(in Amperes)
Isc=30.0 #Current in short-circuit test(in Amperes)
Wsc=200.0 #Power in short-circuit test(in Watts)
Vsc=22.0 #Voltage in short-circuit test(in Volts)
#Calculations:
Iw=Wo/V1
Im=sqrt((I_0*I_0)-(Iw*Iw))
R_0=V1/Iw
X_0=V1/Im
K=Vs/Vp
I_FL=VA/Vp
Re1=Wsc/(Isc*Isc)
Ze1=Vsc/Isc
Xe1=sqrt((Ze1*Ze1)-(Re1*Re1))
Re2=K*K*Re1
Xe2=K*K*Xe1
#Result:
print "(a)The magnetising current is %.2f A and the core-loss current is %.2f A" %(Im,Iw)
print "(b)The parameters of equivalent circuit as referred to the low voltage winding(secondary winding) are: \n Re2=%.4f ohm \n Xe2=%.4f ohm" %(Re2,Xe2)
```

In [3]:

```
#Question:
"""Finding the secondary emf in a transformer."""
#Variable Declaration:
VA=25.0e03 #Power rating of the transformer(in VA)
N1=500.0 #Number of turns in the primary winding
N2=40.0 #Number of turns in the secondary winding
V1=3e03 #Voltage of the supply connected to primary(in Volts)
f=50.0 #Frequency of the supply(in Hertz)
#Calculations:
K=N2/N1
E2=K*V1
I1=VA/V1
I2=I1/K
flux=V1/(4.44*f*N1)
#Result:
print "(a)The secondary emf is %.2f V." %(E2)
print "(b)The primary current on full-load is %.2f A and the secondary current on full-load is %.2f A." %(I1,I2)
print "(c)The maximum flux in the core is %.4f Wb." %(flux)
```

In [8]:

```
#Question:
"""Finding the active cross-sectional area of the core."""
from math import sqrt
#Variable Declaration:
N1=50.0 #Number of turns in the primary winding
B=1.0 #Maximum flux density(in Tesla)
f=50.0 #Frequency rating of the transformer(in Hertz)
V=230.0 #Voltage rating of the transformer(in Volts)
#Calculations:
E1=V
flux=E1/(4.44*f*N1)
A=flux/B
"""Due to the insulation of laminations from each other,the gross area is about 10% greater than the active area."""
gross=1.1*A
a=sqrt(gross)
#Result:
print "(a)The active cross sectional area of the core is %.5f square m." %(A)
print "(b)The side of a square core is %.2f m." %(a)
```

In [9]:

```
#Question:
"""Finding the output of the transformer in kVA."""
#Variable Declaration:
A=150e-04 #Cross-sectional area of the core(in square metres)
Bm=1.1 #Maximum flux density(in Tesla)
f=50.0 #Frequency of the supply(in Hertz)
N2=66.0 #Number of turns in the secondary winding
Z_L=4.0 #Load impedance(in Ohms)
#Calculations:
flux=Bm*A
E2=4.44*flux*f*N2
I2=E2/Z_L
kVA=(E2*I2)/1000.0
#Result:
print "The output in kVA when connected to a 4 Ohms load impedance is %.2f kVA." %(kVA)
```

In [11]:

```
#Question:
"""Finding the magnetising current and the iron loss."""
#Variable Declaration:
I0=1.0 #No-load primary current(in Amperes)
pf=0.24 #Power factor
V1=11e03 #Primary voltage(in Volts)
V2=400 #Secondary voltage(in Volts)
#Calculations:
Iw=I0*pf
Im=sqrt((I0*I0)-(Iw*Iw))
Pi=V1*I0*pf
#Result:
print "(a)The core-loss current is %.2f A." %(Iw)
print "(b)The magnetising current is %.3f A." %(Im)
print "(c)The iron loss is %.2f W." %(Pi)
```

In [14]:

```
#Question:
"""Finding the supply voltage and the power factor."""
from cmath import rect,phase
from math import degrees,radians
#Variable Declaration:
K=0.5 #Turns ratio of the step-down transformer
R1=2.5 #Resistance of the primary winding(in Ohms)
X1=6.0 #Reactance of the primary winding(in Ohms)
R2=0.25 #Resistance of the secondary winding(in Ohms)
X2=1 #Reactance of the secondary winding(in Ohms)
Im=51.5e-03 #Magnetising current(in Amperes)
Iw=20.6e-03 #Core-loss current(in Amperes)
Z_L=rect(25,radians(30)) #Load impedance(in Ohms)
Vo=50.0 #Output voltage(in Volts)
#Calculations:
Z1=R1+1j*X1
Z2=R2+1j*X2
V2=rect(Vo,0)
I2=V2/Z_L
E2=V2+(I2*Z2)
E1=E2/K
E1_minus=-E1
I1_a=-I2*K
"""Im lags -E1 by 90 degrees and Iw is in phase with -E1."""
Im_com=rect(Im,(phase(E1_minus)-radians(90)))
Iw_com=rect(Iw,phase(E1_minus))
I1=I1_a+Im_com+Iw_com
V1=E1_minus+(I1*Z1)
pf_ang=phase(V1)-phase(I1)
pf=cos(pf_ang)
#Result:I
print "The supply voltage is %.4f V at a phase angle of %.2f degrees." %(abs(V1),degrees(phase(V1)))
print "The current drawn from the supply is %.4f A at a phase angle of %.2f degrees." %(abs(I1),degrees(phase(I1)))
print "The power factor is %.3f lagging." %(pf)
```

In [13]:

```
#Question:
"""Finding the copper loss in the transformer."""
#Variable Declaration:
K=0.25 #Turns ratio of the step-down transformer
R1=1.4 #Resistance of the primary(in Ohms)
X1=5.5 #Reactance of the primary(in Ohms)
R2=0.06 #Resistance of the secondary(in Ohms)
X2=0.04 #Reactance of the secondary(in Ohms)
Vsc=24.0 #Voltage of the HV winding(in Volts)
#Calculations:
Re1=R1+(R2/(K*K))
Xe1=X1+(X2/(K*K))
Ze1=sqrt((Re1*Re1)+(Xe1*Xe1))
Isc=Vsc/Ze1
I1=Isc
I2=I1/K
P=I1*I1*Re1
pf=P/(Vsc*I1)
#Result:
print "(a)The current in the LV winding is %.3f A." %(I2)
print "(b)The copper loss in the transformer is %.2f W." %(P)
print "(c)The power factor is %.4f." %(pf)
```

In [20]:

```
#Question:
"""Finding the regulation and efficiency."""
from math import acos
#Variable Declaration:
VA=20e03 #Power rating of the transformer(in Volt-Amperes)
V1=2200.0 #Voltage of the primary winding(in Volts)
V2=220.0 #Voltage of the secondary winding(in Volts)
f=50.0 #Frequency rating of the transformer(in Hertz)
Vsc=86.0 #Voltage measured during short-circuit test(in Volts)
Isc=10.5 #Current measured during short-circuit test(in Amperes)
Psc=360.0 #Power measured during short-circuit test(in Watts)
Voc=220.0 #Voltage measured during open-circuit test(in Volts)
Ioc=4.2 #Current measured during open-circuit test(in Amperes)
Poc=148.0 #Power measured during open-circuit test(in Watts)
pf=0.8 #Lagging power factor
#Calculations:
Ze1=Vsc/Isc
Re1=Psc/(Isc*Isc)
Xe1=sqrt((Ze1*Ze1)-(Re1*Re1))
I1=VA/V1
reg=(I1*((Re1*pf)+(Xe1*sin(acos(pf)))))/V1
Pc=(I1/Isc)*(I1/Isc)*Psc
Pi=Poc
Po=VA*pf
effi=Po/(Po+Pc+Pi)
pf_sc=Re1/Ze1
#Result:
print "(a)The regulation at 0.8 pf lagging at full load is %.2f per cent." %(reg*100)
print " The efficiency is %.2f per cent." %(effi*100)
print "(b)The power factor on short circuit is %.3f lagging." %(pf_sc)
```

In [21]:

```
#Question:
"""Finding the efficiency at half of full-load current."""
#Variable Declaration:
VA=200e03 #Power rating of the transformer(in VA)
effi_FL=0.98 #Full-load efficiency of the transformer
pf=0.8 #Lagging power factor
x=0.75 #Fraction of load at which maximum efficiency occurs
#Calculations:
Po=VA*pf
Pin=Po/effi_FL
tot_loss=Pin-Po
Pc=tot_loss/(1+(x*x))
Pi=tot_loss-Pc
x_new=0.5
P1=(x_new*x_new*Pc)+Pi
effi_half=(Po/2.0)/((Po/2.0)+P1)
#Result:
print "The efficiency at half of full-load current is %.3f per cent." %(effi_half*100)
```

In [30]:

```
#Question:
"""Finding the efficiency at different rated kVAs."""
#Variable Declaration:
VA=150e03 #Power rating of the transformer(in Volt-Amperes)
V1=5000.0 #Voltage of the primary winding(in Volts)
V2=250.0 #Voltage of the secondary winding(in Volts)
f=50.0 #Frequency rating of the transformer(in Hertz)
Pc=1.8e03 #Full-load copper losses(in Watts)
Pi=1.5e03 #Core losses(in Watts)
flux=60e-03 #Maximum core flux(in Webers)
pf=0.8 #Lagging power factor
#Calculations:
N2=V2/(4.44*f*flux)
N1=round(N2,0)*(V1/V2)
"""Case 1:"""
Po=(VA*pf)
effi_a=Po/(Po+Pi+Pc)
"""Case 2:"""
pf=1.0
Po=0.5*VA*pf
Pc_new=0.5*0.5*Pc
effi_b=Po/(Po+Pi+Pc_new)
x=sqrt(Pi/Pc)
VA_max_effi=x*VA
#Result:
print "(a)The number of turns in the primary winding is %d turns." %(round(N1,0))
print " The number of turns in the secondary winding is %d turns." %(round(N2,0))
print "(b)The efficiency at full rated kVA with 0.8 pf lagging is %.2f percent." %(effi_a*100)
print "(c)The efficiency at half rated kVA with unity pf is %.2f percent." %(effi_b*100)
print "(d)The kVA load for maximum efficieny is %d kVA." %(round((VA_max_effi/1000),0))
```

In [3]:

```
#Question:
"""Finding the impedance on the high voltage side."""
#Variable Declaration:
VA=50e03 #Power rating of the transformer(in VA)
V1=2400.0 #Voltage of primary winding(in Volts)
V2=240.0 #Voltage of secondary winding(in Volts)
f=50.0 #Frequency rating of the transformer(in Hertz)
LV=240.0 #Low tension voltage(in Volts)
#Calculations:
I2=VA/V2
Z_L=V2/I2
K=V2/V1
Zeq=Z_L/(K*K)
I_high=K*I2
#Result:
print "(a)The load impedance connected to the LV side is %.3f Ohms." %(Z_L)
print "(b)The load impedance referred to to the high voltage side is %.2f Ohms." %(Zeq)
print "(c)The current referred to the high voltage side is %.3f A." %(I_high)
```

In [8]:

```
#Question:
"""Finding the kVA output of the transformer."""
#Variable Declaration:
VA=10e03 #Power rating of the transformer(in VA)
V1=2300.0 #Voltage of HT winding(in Volts)
V2=230.0 #Voltage of LT winding(in Volts)
f=50.0 #Frequency rating of the transformer(in Hertz)
#Calculations:
I_HT=VA/V1
I_LT=VA/V2
I2=I_HT+I_LT
I1=I_LT
kVA_out=(V1*I2)/1000.0
VA_c=(V1*I1)
VA_i=V1*(I2-I1)
K=V1/(V1+V2)
#Result:
print "(a)The current distribution in the windings: load current=%.2f A and the input current is %.2f A." %(I2,I1)
print "(b)The kVA output is %.2f kVA." %(kVA_out)
print "(c)The volt-amperes transferred conductively is %.2f kVA" %(VA_c/1000.0)
print " The volt-amperes transferred inductively is %.2f kVA" %(VA_i/1000.0)
print "(d)The saving in copper as compared to the two-winding transformer is %.2f per cent." %(K*100)
```