diff options
Diffstat (limited to '3784')
136 files changed, 3536 insertions, 0 deletions
diff --git a/3784/CH1/EX1.1/Ex1_1.sce b/3784/CH1/EX1.1/Ex1_1.sce new file mode 100644 index 000000000..7a9b5298e --- /dev/null +++ b/3784/CH1/EX1.1/Ex1_1.sce @@ -0,0 +1,27 @@ +clc
+// Va r i a b l e I n i t i a l i z a t i o n
+Vm=230 //Supply Voltage in Volts
+af=0 // Firing Angle of Converters in Field
+Rf=200 //Field Resistance in ohm
+T=50 //Load Torque in N-m
+Kt=0.8 //Torque Constant in N-m/A^2
+N=900 //Motor Speed in rpm
+Ra=0.3 // Armature Resistance in ohm
+
+//Solution
+Vf=Vm*(1+cos(af))*(1/%pi)*1.414 //Voltage across Field in Volts
+If=Vf/Rf //Field Current in Amp
+Ia=T/(Kt*If) //Armature Current in Amp
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+Eb=Kt*If*w //Back Emf in Volts
+Va=Eb+Ia*Ra // Voltage across Armature
+A=%pi*Va*(1/Vm)*(1/1.414)
+aa=acosd(A-1) //Firing Angle of Semi Converter in Armature Circuit
+VaIa=Va*Ia //Power output of Converters in Armature Circuit in Watts
+I=sqrt((180-aa)*(1/180))*Ia //Input Current
+VA=Vm*I //Input VA
+pf=VaIa/VA //Input Power Factor
+//Result
+printf('\n\n The Field Current=%0.1f Amp\n\n',If)
+printf('\n\n The Firing Angle of Semi Converter in Armature Circuit=%0.1f degree\n\n',aa)
+printf('\n\n The Power Factor of Semi Converter in Armature Circuit=%0.1f\n\n',pf)
diff --git a/3784/CH1/EX1.10/Ex1_10.sce b/3784/CH1/EX1.10/Ex1_10.sce new file mode 100644 index 000000000..058e70909 --- /dev/null +++ b/3784/CH1/EX1.10/Ex1_10.sce @@ -0,0 +1,26 @@ +clc
+// Variable Initialization
+Vm=230 //Supply Voltage in Volts
+R=0.25//Combined Field and Armature circuit resistance in Ohm
+N=1000 //Motor speed in Rpm
+Kaf=0.03 //Constant in N-m/A^2
+Krcs=0.075 //Constant in V-S/Rad
+a=30 //firing angle in Degree
+
+//Solution
+//For a full converter controlled dc motor drive
+W=(2*%pi*N)/60 //Angular speed in Rad/sec
+Ia=((((2*Vm*1.414)/%pi)*cosd(a))-(Krcs*W))/(R+(Kaf*W)) //Armature current in Amp
+T=Kaf*(Ia^2) //Torque in N-m
+Va=(2*Vm*1.414)*cosd(a)*(1/%pi)//Average voltage in volts
+Po=Va*Ia //Output power in Watt
+Irms=Ia*sqrt((180-a)/180) //Rms Current in Amp
+Pi=Vm*Irms
+pf=Po/Pi //Power factor
+
+//Results
+printf('\n\n The motor Current =%0.1f Amp \n\n',Ia)
+printf('\n\n The motor Torque=%0.1f N-m \n\n',T)
+printf('\n\n The Supply Power Factor=%0.1f Lag\n\n',pf)
+//The answers vary due to round off error
+
diff --git a/3784/CH1/EX1.11/Ex1_11.sce b/3784/CH1/EX1.11/Ex1_11.sce new file mode 100644 index 000000000..13a778e84 --- /dev/null +++ b/3784/CH1/EX1.11/Ex1_11.sce @@ -0,0 +1,42 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.5//Armature circuit resistance in Ohm
+Irms=25 //Armature current in Amp
+Nr=800 //Motor speed in Rpm
+Kaf=0.172 //Motor Voltage Constant in V/rpm
+a=60//firing angle in Degree
+
+//Solution
+//CASE:A
+//For motoring action
+Ka=(Kaf*60)/(2*%pi)//Constant in V-s/rad
+T=Ka*Irms //Torque of motor in N-m
+Va=(2*Vm*1.414)*cosd(a)*(1/%pi)//Average voltage in Volts
+Eb=Va-(Irms*Ra)//Back Emf in Volts
+N=Eb/Kaf//Speed of motor in Rpm
+//The supply current is square wave if motor current is constant and ripple-free with Amplitude 25A
+P=Vm*Irms //Supply VA in Watt
+//Power from supply is real power if losses in converter are neglected
+Ps=Va*Irms //Power in Watt
+pf=Ps/P //Power factor lag
+
+//CASE:B
+//For polarity reversal (regeneration action)
+Eb1=-Eb //Back emf in Volts
+Va1=Eb1+(Irms*Ra)
+af=acosd((Va1*%pi)/(2*Vm*1.414))//Firing angle in Degree
+//Power fed from DC Machine
+Pdc=Eb*Irms //Power in watt
+//Power lost in armature resistance
+PL=((Irms)^2)*Ra //Power in Watt
+//Power fed back to ac supply is
+PF=Pdc-PL //Power in watt
+
+//Results
+printf('\n\n The motor Torque=%0.1f N-m \n\n',T)
+printf('\n\n The motor Speed =%0.1f RPM \n\n',N)
+printf('\n\n The Supply Power Factor=%0.1f Lag\n\n',pf)
+printf('\n\n The Firing Angle=%0.1f Degree\n\n',af)
+printf('\n\n The Power fed back to Supply=%0.1f Watt\n\n',PF)
+//The answers vary due to round off error
diff --git a/3784/CH1/EX1.12/Ex1_12.sce b/3784/CH1/EX1.12/Ex1_12.sce new file mode 100644 index 000000000..8ef38d764 --- /dev/null +++ b/3784/CH1/EX1.12/Ex1_12.sce @@ -0,0 +1,23 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.3//Armature circuit resistance in Ohm
+I=18 //Rated current in Amp
+Nr=1500 //Motor speed in Rpm
+a=45//firing angle in Degree
+Vs=220 //input in volts
+
+//Solution
+Va=(2*Vm*1.414)*cosd(a)*(1/%pi)//Average voltage in Volts
+Eb=Va-(I*Ra)//Back emf in volts
+//When the polarity of the back emf is reversed ,the machine would act as generator and hence the governing equation
+Va=-Eb+(I*Ra) //Armature voltage in volts
+af=acosd((Va*%pi)/(2*Vs*sqrt(2)))//Firing angle in Degree(This value is Wrongly calculated in Textbook)
+Pg=Eb*I //Power generated in Watt
+Pl=((I)^2)*Ra //Power loss in armature in Watt
+P=Pg-Pl //Power fed to the supply in Watt
+
+//Results
+printf('\n\n The Firing Angle=%0.1f Degree\n\n',af)
+printf('\n\n The Power fed back to Supply=%0.1f Watt\n\n',P)
+//The answer provided in the textbook is wrong(1st answer)
diff --git a/3784/CH1/EX1.13/Ex1_13.sce b/3784/CH1/EX1.13/Ex1_13.sce new file mode 100644 index 000000000..378937223 --- /dev/null +++ b/3784/CH1/EX1.13/Ex1_13.sce @@ -0,0 +1,29 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=1//Armature circuit resistance in Ohm
+I=12 //Rated current in Amp
+Nr=1500 //Motor speed in Rpm
+Va=210 //Motor voltage in volts
+N1=1200 //Speed in RPM
+
+//Solution
+Eb=Va-(I*Ra) //Back emf in volts
+N=(Nr*2*%pi)/60 //Speed in Rad/sec
+Ka=Eb/N //Constant
+//Current at rated torque
+ //At 1200 Rpm
+ Eb1=(N1*Eb)/Nr
+ af=acosd((((I*Ra)+Eb1)*%pi)/(2*Vm*1.414))//Firing angle in Degree
+ //At Eb=-198 V at speed 1500 RPM
+ af1=acosd((((I*Ra)-Eb)*%pi)/(2*Vm*1.414))//Firing angle in Degree
+ //But reversal of field of armature forward regeneration is obtained
+ Ka1=-Ka
+ W=-Eb/Ka1 //Angular speed in Rad/sec(Wrongly calculated in book,wrong value of Eb is taken)
+ N1=(W*60)/(2*%pi) //Speed in Rpm
+
+ //Results
+printf('\n\n The Firing Angle=%0.1f Degree\n\n',af)
+printf('\n\n The Firing Angle=%0.1f Degree\n\n',af1)
+printf('\n\n The motor Speed =%0.1f RPM \n\n',N1)
+//The answer provided in the textbook is wrong(3rd answer omly)
diff --git a/3784/CH1/EX1.14/Ex1_14.sce b/3784/CH1/EX1.14/Ex1_14.sce new file mode 100644 index 000000000..c3e70dbca --- /dev/null +++ b/3784/CH1/EX1.14/Ex1_14.sce @@ -0,0 +1,29 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.75//Armature circuit resistance in Ohm
+I=8 //Armature current in Amp
+Nr=1200 //Motor speed in Rpm
+Va=220//Rated voltage of motor in Volts
+a=45//firing angle in Degree
+T=8 //Motor torque in N-m
+Nr1=800 //Speed in Rpm
+
+
+//Solution
+N=(Nr*2*%pi)/60 //Speed in Rad/sec
+Kaf=(Va-I*Ra)/N //Motor Constant
+//(A) For torque of 8 N-m
+Ia=T/Kaf //Armature Current in Amp
+V=(2*Vm*1.414)*cosd(a)*(1/%pi)//Average voltage in Volts
+W=(V-Ia*Ra)/Kaf //Angular speed in Rad/sec
+N=(W*60)/(2*%pi) //Speed in Rpm
+//(B) a=45 Degree
+N1=(Nr1*2*%pi)/60 //Speed in Rad/sec
+Ia1=(V-Kaf*N1)/Ra //armature current in amp
+T1=Kaf*Ia1 //Torque in N-m
+
+//Results
+printf('\n\n The motor Speed =%0.1f RPM \n\n',N)
+printf('\n\n The motor Torque=%0.1f N-m \n\n',T1)
+//The answers vary due to round off error
diff --git a/3784/CH1/EX1.15/Ex1_15.sce b/3784/CH1/EX1.15/Ex1_15.sce new file mode 100644 index 000000000..472fbae4a --- /dev/null +++ b/3784/CH1/EX1.15/Ex1_15.sce @@ -0,0 +1,30 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.2//Armature circuit resistance in Ohm
+I=80 //Rated current in Amp
+Nr=1200 //Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=150//firing angle in Degree
+Nr1=-700 //Speed in Rpm
+
+//Solution
+N=(Nr*2*%pi)/60 //Speed in Rad/sec
+Kaf=(V-I*Ra)/N //Motor Constant inN-m/A
+//(A)For rated motor torque
+Va=(2*Vm*1.414)*cosd(a)*(1/%pi)//Average voltage in Volts
+N1=(Nr1*2*%pi)/60 //Speed in Rad/sec
+af=acosd(((Kaf*N1)+(I*Ra))*%pi/(2*Vm*1.414))//Firing angle in Degree
+Eb1=V-(I*Ra)//Back emf in Volts
+Eb2=(Nr1/Nr)*Eb1 //Back emf in Volts
+Va1=Eb2+(I*Ra)//Armature voltage in volts
+af1=acosd((Va1*%pi)/(2*Vm*1.414))//Firing angle in Degree
+//(B) Half rated Torque
+Ia=(1/2)*I //Armature current in Amp
+W=(Va-(Ia*Ra))/Kaf //Angular speed in Rad/sec
+N=(W*60)/(2*%pi) //Speed in Rpm
+
+ //Results
+printf('\n\n The Firing Angle=%0.1f Degree\n\n',af1)
+printf('\n\n The motor Speed=%0.1f RPM \n\n',N)
+//The answers vary due to round off error(2nd only)
diff --git a/3784/CH1/EX1.16/Ex1_16.sce b/3784/CH1/EX1.16/Ex1_16.sce new file mode 100644 index 000000000..7e45cbe12 --- /dev/null +++ b/3784/CH1/EX1.16/Ex1_16.sce @@ -0,0 +1,62 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.05//Armature circuit resistance in Ohm
+L=0.85e-3//Inductance in mH
+N=750//Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=60//firing angle in Degree
+La=0.75e-3//External Inductance in mH
+I=175 //motor current in Amp
+f=50 //source Frequency in Hz
+
+//Solution
+P=atand((2*%pi*f*L)/Ra) // In Degree
+Z=sqrt((Ra^2)+((2*%pi*f*L)^2)) //Impedance In Ohm
+Eb=V-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w
+Cot_P=1/(tand(P))
+A=exp(-%pi*Cot_P)
+AA=(Ra*Vm*1.414)/(K*Z)
+Wmc=AA*sind(a-P)*((1+A)/(A-1))//Critical Speed in rad/Sec
+Wrpm=(Wmc*60)/(2*%pi) //speed in rpm
+//Since the motor Speed is greater than critical Value Wmc ,The drive is operating under discontinuous conduction
+//At N=600 Rpm
+N1=600 //Speed in Rpm
+Eb1=(N1/N)*Eb//Back emf in Volts
+//By trial and error method
+b=201.45//Bita in Degree
+Va=((Vm*1.414)*(cosd(a)-cosd(b))+(%pi+(a-b)*(%pi/180))*(Eb1))*(1/%pi) //Armature voltage in Volts
+Ia=(Va-Eb1)/Ra //Armature current in Amp
+T=K*Ia//Torque in N-m
+
+//La=2.85 mH
+N2=-400
+a1=120
+P1=atand((2*%pi*f*La)/Ra) // In Degree
+Cot_P1=1/(tand(P1))
+Eb2=(N2/N)*Eb//Back emf in Volts
+Z1=sqrt((Ra^2)+((2*%pi*f*La)^2)) //Impedance In Ohm
+AA1=(Ra*Vm*1.414)/(K*Z1)
+A1=exp(-%pi*Cot_P1)
+Wmc1=AA1*sind(a1-P1)*((1+A1)/(A1-1))//Critical Speed in rad/Sec
+Wrpm1=(Wmc1*60)/(2*%pi) //speed in rpm
+//By trial and error method
+b1=297.5//Bita in Degree
+Va1=((Vm*1.414)*(cosd(a1)-cosd(b1))+(%pi+(a1-b1)*(%pi/180))*(Eb2))*(1/%pi) //Armature voltage in Volts
+Ia1=(Va1-Eb2)/Ra //Armature current in Amp
+T1=K*Ia1//Torque in N-m
+
+//Since the motor speed (-600 rpm) is less than critical speed (-409.17 Rpm) the drive's opertion is continuous condition
+N3=-600
+Va2=(2*1.414*Vm)*(cosd(a1))*(1/%pi)
+Eb3=(N3/N)*Eb//Back emf in Volts
+Ia2=(Va2-Eb3)/Ra //Armature current in Amp
+T2=K*Ia2//Torque in N-m
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T1)
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T2)
+//The answers vary due to round off error
diff --git a/3784/CH1/EX1.17/Ex1_17.sce b/3784/CH1/EX1.17/Ex1_17.sce new file mode 100644 index 000000000..06f475a7f --- /dev/null +++ b/3784/CH1/EX1.17/Ex1_17.sce @@ -0,0 +1,55 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=2//Armature circuit resistance in Ohm
+L=50e-3//Inductance in mH
+N=1500//Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=60//firing angle in Degree
+a1=120//firing angle in Degree
+I=10//motor current in Amp
+f=50 //source Frequency in Hz
+
+//Solution
+P=atand((2*%pi*f*L)/Ra) // In Degree
+Z=sqrt((Ra^2)+((2*%pi*f*L)^2)) //Impedance In Ohm
+Eb=V-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w//value obtain is 1.2732395 approximating to 1.27
+K=1.27//Approximation of K as per book and our obtained value
+//At No Load
+Wo=(Vm*1.414)/K//Angular Speed in rad/sec(For 0<a<%pi/2)
+No=Wo*(60/(2*%pi))//Speed in Rpm
+Cot_P=1/(tand(P))
+A=exp(-%pi*Cot_P)
+AA=(Ra*Vm*1.414)/(K*Z)
+Wmc=AA*sind(a-P)*((1+A)/(A-1))//Critical Speed in rad/Sec
+Wrpm=(Wmc*60)/(2*%pi) //speed in rpm
+Eb1=(Wrpm*Eb)/N
+//By trial and error method
+b=240.45//Beta in Degree
+bx=249.45//Beta in Degree
+Va=((Vm*1.414)*(cosd(a)-cosd(bx))+(%pi+(a-b)*(%pi/180))*(Eb1))*(1/%pi) //Armature voltage in Volts
+Ia=(Va-Eb1)/Ra //Armature current in Amp
+T=K*Ia//Torque in N-m
+
+//At a1=120
+Wmc1=AA*sind(a1-P)*((1+A)/(A-1))//Critical Speed in rad/Sec
+Wrpm1=(Wmc1*60)/(2*%pi) //speed in rpm
+Wo1=(Vm*1.414*sind(a1))/1.273//Angular Speed in rad/sec(For 0<a<%pi/2)&K=1.273
+No1=Wo1*(60/(2*%pi))//Speed in Rpm
+Eb2=(Wrpm1*Eb)/N
+//By trial and error method
+b1=217.2//Beta in Degree
+Va1=((Vm*1.414)*(cosd(a1)-cosd(b1))-((%pi+((a1-b1)*(1/180))*%pi)*Eb2))*(1/%pi) //Armature voltage in Volts
+Ia1=(Va1-Eb2)/Ra //Armature current in Amp
+T1=K*Ia1//Torque in N-m
+
+//Results
+printf('\n\n The motor No load Speed =%0.1f RPM \n\n',No)
+printf('\n\n The motor Critical Speed =%0.1f RPM \n\n',Wrpm)
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor No load Speed =%0.1f RPM \n\n',No1)
+printf('\n\n The motor Critical Speed =%0.1f RPM \n\n',Wrpm1)
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T1)
+//The answers vary due to round off error
diff --git a/3784/CH1/EX1.18/Ex1_18.sce b/3784/CH1/EX1.18/Ex1_18.sce new file mode 100644 index 000000000..d39d8472a --- /dev/null +++ b/3784/CH1/EX1.18/Ex1_18.sce @@ -0,0 +1,44 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=1.8//Armature circuit resistance in Ohm
+L=32e-3//Inductance in mH
+N=1200//Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=60//firing angle in Degree
+I=15 //motor current in Amp
+f=50 //source Frequency in Hz
+
+//Solution
+P=atand((2*%pi*f*L)/Ra) // In Degree
+Z=sqrt((Ra^2)+((2*%pi*f*L)^2)) //Impedance In Ohm
+Eb=V-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w
+Cot_P=1/(tand(P))
+A=exp(-%pi*Cot_P)
+AA=(Ra*Vm*1.414)/(K*Z)
+Wmc=AA*sind(a-P)*((1+A)/(A-1))//Critical Speed in rad/Sec
+Wrpm=(Wmc*60)/(2*%pi) //speed in rpm
+//Since the motor Speed is greater than critical Value Wmc ,The drive is operating under discontinuous conduction
+//At N=600 Rpm
+N1=450 //Speed in Rpm
+Eb1=(N1/N)*Eb//Back emf in Volts
+//By trial and error method
+b=239.4//Bita in Degree
+Va=((Vm*1.414)*(cosd(a)-cosd(b))*(%pi+(a-b)*(%pi/180))*(Eb1))*(1/%pi) //Armature voltage in Volts
+Ia=(Va-Eb1)/Ra //Armature current in Amp
+T=K*Ia//Torque in N-m
+//Since the motor Speed is greater than critical Value Wmc ,The drive is operating in discontinuous mode at
+N2=1500
+Eb2=(N2/N)*Eb//Back emf in Volts
+//By trial and error method
+b1=172.2//Bita in Degree
+Va1=((Vm*1.414)*(cosd(a)-cosd(b))*(%pi+(a-b)*(%pi/180))*(Eb2))*(1/%pi) //Wromg calculation in book they have taken value of beta as 17.2 instead of 172.2
+Ia1=(Va1-Eb2)/Ra //Armature current in Amp
+T1=K*Ia1//Torque in N-m
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)//The answers vary due to round off error
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T1)
+//The answer provided in the textbook is wrong
diff --git a/3784/CH1/EX1.19/Ex1_19.sce b/3784/CH1/EX1.19/Ex1_19.sce new file mode 100644 index 000000000..cfa6186c0 --- /dev/null +++ b/3784/CH1/EX1.19/Ex1_19.sce @@ -0,0 +1,44 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.05//Armature circuit resistance in Ohm
+La=3e-3//Inductance in mH
+N=750//Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=60//firing angle in Degree
+I=175 //motor current in Amp
+f=50 //source Frequency in Hz
+
+//La=2.85 mH
+N2=-400
+a1=120
+P1=atand((2*%pi*f*La)/Ra) // In Degree
+Eb=V-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w
+Cot_P1=1/(tand(P1))
+Eb1=(N2/N)*Eb//Back emf in Volts
+Z1=sqrt((Ra^2)+((2*%pi*f*La)^2)) //Impedance In Ohm
+AA1=(Ra*Vm*1.414)/(K*Z1)
+A1=exp(-%pi*Cot_P1)
+Wmc1=AA1*sind(a1-P1)*((1+A1)/(A1-1))//Critical Speed in rad/Sec
+Wrpm1=(Wmc1*60)/(2*%pi) //speed in rpm
+Eb2=(Wrpm1*Eb)/N
+a2=150
+Va=(2*1.414*Vm)*(cosd(a2))*(1/%pi)
+Ia=(Va-Eb2)/Ra
+T=K*Ia//Torque in N-m
+//As the torque of 400 N-m is greater than T ,hence the opertion is in Continuous conduction mode
+T1=400
+Ia1=T1/K
+Eb3=Va-(Ia1*Ra)
+Ns=(Eb3*N)/Eb
+//As the torque of 400 N-m is less than T ,hence the opertion is in Discontinuous conduction mode
+Z=0.2716
+q=V*1.414/Z
+//nothing is solved in textbook using numericals
+//By Trial and error method beta is calculated
+b=233.240
+
+//Results
+printf('\n\n The motor Speed =%0.1f rpm \n\n',Ns)
diff --git a/3784/CH1/EX1.2/Ex1_2.sce b/3784/CH1/EX1.2/Ex1_2.sce new file mode 100644 index 000000000..c74318d3b --- /dev/null +++ b/3784/CH1/EX1.2/Ex1_2.sce @@ -0,0 +1,29 @@ +clc
+// variable Initialization
+Vm=208 //Supply Voltage In Volts
+af=0 //Firing Angle Of Converters In Field
+Rf=147 //Field Resistance In Ohm
+Ra=0.25 //Armature Resistance In Ohm
+T=45 //Load Torque In N-m
+Kv=0.7032 //Motor Voltage Constant
+N=1000 //Motor Speed In Rpm
+
+//Solution
+Vf=Vm*(1+cos(af))*(1/%pi)*1.414 //Voltage Across Field In Volts
+If=Vf/Rf //Field Current In Amp
+Ia=T/(Kv*If) //Armature Current In Amp
+w=(2*%pi*N)/60 //Angular Speed In Rad/Sec
+Eb=Kv*If*w //Back Emf In Volts
+Va=Eb+Ia*Ra //Voltage Across Armature In Volts
+A=%pi*Va*(1/Vm)*(1/1.414)
+aa=acosd(A-1) //Delay Angle Of Semi Converter In Armature Circuit
+VaIa=Va*Ia //Power Output Of Converters In Armature Circuit In Watts
+I=sqrt((180-aa)*(1/180))*Ia //Input Current
+VA=Vm*I //Input VA
+Pf=VaIa/VA //Input Power Factor
+
+//Result
+printf('\n\n The Field Current=%0.1f Amp\n\n',If)
+printf('\n\n The Delay Angle Of Semi Converter In Armature Circuit=%0.1f degree\n\n',aa)
+printf('\n\n The Power Factor Of Semi Converter In Armature Circuit=%0.1f\n\n',Pf)
+//The answers vary due to round off error(2nd and 3rd)
diff --git a/3784/CH1/EX1.20/Ex1_20.sce b/3784/CH1/EX1.20/Ex1_20.sce new file mode 100644 index 000000000..ea056e3da --- /dev/null +++ b/3784/CH1/EX1.20/Ex1_20.sce @@ -0,0 +1,26 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.25//Combined Field and Armature circuit resistance in Ohm
+N=1000 //Motor speed in Rpm
+V=210//Rated voltage of motor in Volts
+a=30//firing angle in Degree
+Kaf=0.03 //Constant in N-m/A^2
+Kres=0.075 //Constant in V-s/Rad
+
+//Solution
+//For semi-converter controlled Dc Drive
+W=(2*%pi*N)/60 //angular speed in Rad/sec
+Ia=(((Vm*1.414)/%pi)*(1+cosd(a))-(Kres*W))*(1/(Ra+Kaf*W))//Armature current in Amp
+T=Kaf*(Ia)^2//Torque in N-m
+Va=(Vm*1.414)*(1+cosd(a))*(1/%pi)//Average voltage in VoltsI
+Irms=Ia*((180-a)/180)^(1/2)//RMS Current in Amp
+Pa=Va*Ia //Power in Watt
+Pi=Vm*Irms //Input power in Watt
+Pf=(Pa/Pi)//Power Factor in Lag
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Current =%0.1f Amp \n\n',Irms)
+printf('\n\n The Supply Power Factor =%0.1f Lag \n\n',Pf)
+
diff --git a/3784/CH1/EX1.21/Ex1_21.sce b/3784/CH1/EX1.21/Ex1_21.sce new file mode 100644 index 000000000..19f561f41 --- /dev/null +++ b/3784/CH1/EX1.21/Ex1_21.sce @@ -0,0 +1,27 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.75//Combined Field and Armature circuit resistance in Ohm
+N=1300 //Motor speed in Rpm
+V=210//Rated voltage of motor in Volts
+a=45//firing angle in Degree
+Kaf=0.03 //Constant in N-m/A^2
+Kres=0.075 //Constant in V-s/Rad
+
+//Solution
+//For semi-converter controlled Dc Drive
+W=(2*%pi*N)/60 //angular speed in Rad/sec
+Ia=(((Vm*1.414)/%pi)*(1+cosd(a))-(Kres*W))*(1/(Ra+Kaf*W))//Armature current in Amp
+T=Kaf*(Ia)^2//Torque in N-m
+I=(T/Kaf)^(1/2)//motor current in Amp
+Va=(Vm*1.414)*(1+cosd(a))*(1/%pi)//Average voltage in Volts
+//Input Power if losses are neglected
+Ps=Va*I //Power loss in Watt
+Pi=Vm*I*(5/6)^0.5 //power input in watt
+Pf=(Ps/Pi)//Power Factor in Lag
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Current =%0.1f Amp \n\n',I)
+printf('\n\n The Supply Power Factor =%0.1f Lag \n\n',Pf)
+
diff --git a/3784/CH1/EX1.22/Ex1_22.sce b/3784/CH1/EX1.22/Ex1_22.sce new file mode 100644 index 000000000..217ed861e --- /dev/null +++ b/3784/CH1/EX1.22/Ex1_22.sce @@ -0,0 +1,19 @@ +clc
+// Variable Initialization
+Vm=240//Supply Voltage in Volts
+Ra=0.9//Combined Field and Armature circuit resistance in Ohm
+N=900 //Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=45//firing angle in Degree
+Kaf=0.035 //Constant in N-m/A^2
+
+//Solution
+//For semi-converter controlled Dc Drive
+Va=(Vm*1.414)*(1+cosd(a))*(1/%pi)//Average voltage in Volts
+W=(2*%pi*N)/60 //angular speed in Rad/sec
+Ia=Va/(Ra+W*Kaf)//Current in Amp
+T=Kaf*(Ia)^2//Torque in N-m
+
+//Results
+printf('\n\n The motor Current =%0.1f Amp \n\n',Ia)
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
diff --git a/3784/CH1/EX1.23/Ex1_23.sce b/3784/CH1/EX1.23/Ex1_23.sce new file mode 100644 index 000000000..0fc1d1776 --- /dev/null +++ b/3784/CH1/EX1.23/Ex1_23.sce @@ -0,0 +1,22 @@ +clc
+// Variable Initialization
+Vm=250//Supply Voltage in Volts
+Ra=0.3//Combined Field and Armature circuit resistance in Ohm
+N=900 //Motor speed in Rpm
+V=220//Rated voltage of motor in Volts
+a=30//firing angle in Degree
+Kaf=0.03 //Constant in N-m/A^2
+Kres=0.075 //Constant in V-s/Rad
+
+//Solution
+W=(2*%pi*N)/60 //angular speed in Rad/sec
+Ia=(((Vm*1.414)/%pi)*(1+cosd(a))-(Kres*W))*(1/(Ra+Kaf*W))//Armature current in Amp
+T=Kaf*(Ia)^2//Torque in N-m
+I=(T/Kaf)^(1/2)//motor current in Amp
+//The motor Terminal voltage would be given by the output voltage of the converter
+Va=(Vm*1.414)*(1+cosd(a))*(1/%pi)//Output voltage in Volts
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Current =%0.1f Amp \n\n',I)
+printf('\n\n The motor output voltage =%0.1f Volts\n\n',Va)
diff --git a/3784/CH1/EX1.24/Ex1_24.sce b/3784/CH1/EX1.24/Ex1_24.sce new file mode 100644 index 000000000..512646cdb --- /dev/null +++ b/3784/CH1/EX1.24/Ex1_24.sce @@ -0,0 +1,26 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.25//Combined Field and Armature circuit resistance in Ohm
+N=1000//Motor speed in Rpm
+V=210//Rated voltage of motor in Volts
+a=30//firing angle in Degree
+Kaf=0.03 //Constant in N-m/A^2
+Kres=0.075 //Constant in V-s/Rad
+
+//Solution
+//For Full-converter controlled Dc Drive
+W=(2*%pi*N)/60 //angular speed in Rad/sec
+Ia=(((2*Vm*1.414)/%pi)*(cosd(a))-(Kres*W))*(1/(Ra+Kaf*W))//Armature current in Amp
+T=Kaf*(Ia)^2//Torque in N-m
+Va=(2*Vm*1.414)*(cosd(a))*(1/%pi)//Average voltage in Volts
+//Input Power if losses are neglected
+Ps=Va*Ia //Power loss in Watt
+Pi=Vm*Ia//power input in watt
+Pf=(Ps/Pi)//Power Factor in Lag
+
+//Results
+printf('\n\n The motor Current =%0.1f Amp \n\n',Ia)
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The Supply Power Factor =%0.1f Lag \n\n',Pf)//The answers vary due to round off error
+
diff --git a/3784/CH1/EX1.25/Ex1_25.sce b/3784/CH1/EX1.25/Ex1_25.sce new file mode 100644 index 000000000..b8d6fe18f --- /dev/null +++ b/3784/CH1/EX1.25/Ex1_25.sce @@ -0,0 +1,17 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=2//Combined Field and Armature circuit resistance in Ohm
+Kaf=0.23 //Constant in H
+TL=20 //Load Torque in N-m
+a=65//firing angle in Degree
+
+//Solution
+Ia=(TL/Kaf)^(1/2)//Average Armature current in Amp
+V=(2*Vm*1.414)*cosd(a)*(1/%pi)//Average voltage in Volts
+W=(V-Ia*Ra)/(Kaf*Ia) //Angular speed in Rad/sec
+N=(W*60)/(2*%pi) //Speed in Rpm
+
+//Results
+printf('\n\n The motor Average Armature Current =%0.1f Amp \n\n',Ia)
+printf('\n\n The motor Average Speed =%0.1f RPM \n\n',N)//The answers vary due to round off error
diff --git a/3784/CH1/EX1.26/Ex1_26.sce b/3784/CH1/EX1.26/Ex1_26.sce new file mode 100644 index 000000000..d621cb164 --- /dev/null +++ b/3784/CH1/EX1.26/Ex1_26.sce @@ -0,0 +1,25 @@ +clc
+// Variable Initialization
+Vm=230//Supply Voltage in Volts
+Ra=0.75//Combined Field and Armature circuit resistance in Ohm
+N=1300//Motor speed in Rpm
+V=210//Rated voltage of motor in Volts
+a=45//firing angle in Degree
+Kaf=0.03 //Constant in N-m/A^2
+Kres=0.075 //Constant in V-s/Rad
+
+//Solution
+//For Full-converter controlled Dc Drive
+W=(2*%pi*N)/60//angular speed in Rad/sec
+Ia=(((2*Vm*1.414)/%pi)*(cosd(a))-(Kres*W))*(1/(Ra+Kaf*W))//Armature current in Amp
+T=Kaf*(Ia)^2//Torque in N-m
+I=(T/Kaf)^(1/2)//motor current in Amp
+Va=(2*Vm*1.414)*(cosd(a))*(1/%pi)//Average voltage in Volts
+//Input Power if losses are neglected
+Ps=Va*I//Power loss in Watt
+Pi=Vm*I//power input in watt
+Pf=(Ps/Pi)//Power Factor in Lag
+
+//Result
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The Supply Power Factor =%0.1f Lag \n\n',Pf)
diff --git a/3784/CH1/EX1.3/Ex1_3.sce b/3784/CH1/EX1.3/Ex1_3.sce new file mode 100644 index 000000000..60ac898eb --- /dev/null +++ b/3784/CH1/EX1.3/Ex1_3.sce @@ -0,0 +1,14 @@ +clc
+//Variable Initialization
+V=120 //Supply Voltage In Volts
+Vm=120*1.414 //Max. Voltage In Volts
+Ra=10 //Armature Resistance In Ohm
+af=0 //Firing Angle Of Converter
+Eb=60 //Back Emf In Volts
+
+//Solution
+Va=Vm*(1+cos(af))*(1/%pi)//Voltage Across armature In Volts
+Ia=(Va-Eb)/Ra //Average Value Of Armature Current In Amp
+
+//Result
+printf('\n\n The Average Value Of Armature Current=%0.1f Amp\n\n',Ia)
diff --git a/3784/CH1/EX1.4/Ex1_4.sce b/3784/CH1/EX1.4/Ex1_4.sce new file mode 100644 index 000000000..861617910 --- /dev/null +++ b/3784/CH1/EX1.4/Ex1_4.sce @@ -0,0 +1,19 @@ +clc
+//Variable Initialization
+Vm=320 //Input Voltage In Volts
+Eb=100 //Back Emf In Volts
+Ra=5 //Armature Resistance In Ohm
+af=45 // Firing Angle Of SCR In Degree
+N=1200 //Speed Of Motor In RPM
+
+//Solution
+Va=Vm* (1/%pi)* (1+cosd(af)) //Voltage Across Armature In volts
+Ia=(Va-Eb)/Ra //Armature Current Amp
+W=(2*%pi*N)/60 //Angular Speed In rad/Sec.
+K=Eb/W //Voltage Constant In V-rad/Sec
+T=K*Ia //Torque Of Motor In N-m
+
+//Result
+printf('\n\n The Armature Current=%0.1f Amp\n\n',Ia)
+printf('\n\n The Motor Torque=%0.1f N-m\n\n',T)
+//The answers vary due to round off error
diff --git a/3784/CH1/EX1.5/Ex1_5.sce b/3784/CH1/EX1.5/Ex1_5.sce new file mode 100644 index 000000000..da641f6c7 --- /dev/null +++ b/3784/CH1/EX1.5/Ex1_5.sce @@ -0,0 +1,28 @@ +clc
+//variable Initialization
+Vm=230//Input Voltage In Volts
+Ra=0.5 //Armature Resistance In Ohm
+Rf=190 //Field resistace in Ohm
+N=1400 //Speed Of Motor In RPM
+Ka=0.8 //Motor voltage constant in V/A-rad/sec
+T=50 //Load Torque In N-m
+
+//Solution
+W=(2*%pi*N)/60 //Angular Speed In rad/Sec.
+//Since the maximum field voltage and current is obtained at a Firing Angle of '0'degree
+af=0 //Firing Angle Of SCR In Degree
+Vf=(Vm*1.414)*(1+cosd(af))*(1/%pi) //field Voltage In volts
+If=Vf/Rf //Field Current In Amp.
+Ia=T/(Ka*If) //Armature current in Amp.
+Eb=(Ka*If*W)//this value is wrongly calculated in book
+Vdc=Eb+Ia*Ra //Voltage across armature in volts
+//for the semi converter fed dc motor the armature voltage is given by...
+A=%pi*Vdc*(1/Vm)*(1/1.414)
+aa=acosd(A-1) //slight change occurs in ans as Eb is wrongly calculated in book
+
+//Results
+printf('\n\n The field Current =%0.1f Amp\n\n',If)
+printf('\n\n The firing Angle Of Armature=%0.1f Degree\n\n',aa)
+//The answer provided in the textbook is wrong(2nd answer)
+
+
diff --git a/3784/CH1/EX1.6/Ex1_6.sce b/3784/CH1/EX1.6/Ex1_6.sce new file mode 100644 index 000000000..9360fe65c --- /dev/null +++ b/3784/CH1/EX1.6/Ex1_6.sce @@ -0,0 +1,42 @@ +clc
+// Variable Initialization
+Vm=200 //Supply Voltage in Volts
+N=1000 //speed of motor in RPM
+I=13 //Motor current in Ampere
+Ra=3 //Armature circuit resistance in Ohm
+L=100e-3 //Armature circuit Inductance in mH
+V=230 //Ac Source voltage in Volts
+f=50 //source Frequency in Hz
+a=30
+aa=(30*%pi)/180 //in rad/sec
+N2=400
+//Solution
+P=atand((2*%pi*f*L)/Ra) // In Degree
+Cot_P=1/(tand(P))
+A=exp(-%pi*Cot_P)
+B=exp((-aa)*Cot_P)
+Z=sqrt((Ra^(2))+((2*%pi*f*L)^2)) //Impedance In Ohm
+Eb=Vm-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w
+AA=(Ra*V*1.41)/(K*Z)
+Wmc=AA*((sind(P)*B)-(sind(a-P)*A))*(1/(1-A)) //Critical Speed in rad/Sec
+Wrpm=(Wmc*60)/(2*%pi) //speed in rpm
+//As the motor speed of 400 rpm is less than the critical speed ,the drive is operating under continuous conduction mode
+af=30 //firing angle in Degree
+Va=(V*1.414)*(1+cosd(af))*(1/%pi) //Armature voltage in volts
+//At 400 RPM
+Eb1=Eb*(N2/N) //This Value Is Wrongly Calculated in Textbook
+T=K*(Va-Eb1)*(1/Ra) //Torque in N-m
+//Motor back emf for critical speed equal to 1149.67 rpm
+Ec=(Wrpm*Eb)/N //critical emf in volts
+Tc=K*(Va-Ec)*(1/Ra) //Critical Torque in N-m
+//Since the motor torque of 70 N-m is greater than the critical torque Tc ,the drive is operating in continuous conduction
+Ia=T/K //Armature current in Amp
+Eb2=Va-(Ia*Ra) // Back emf in Volts
+Nm=(Eb2*N)/161 //Answer changed due wrong value is taken in book of Eb1
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Speed =%0.1f RPM \n\n',Nm)
+//The answer provided in the textbook is wrong
diff --git a/3784/CH1/EX1.7/Ex1_7.sce b/3784/CH1/EX1.7/Ex1_7.sce new file mode 100644 index 000000000..5d906c2e2 --- /dev/null +++ b/3784/CH1/EX1.7/Ex1_7.sce @@ -0,0 +1,54 @@ +clc
+// Variable Initialization
+Vm=230 //Supply Voltage in Volts
+N=650//speed of motor in RPM
+I=100//Motor curent in Ampere
+Ra=0.08 //Armature circuit resistance in Ohm
+L=8e-3 //Armature circuit Inductance in mH
+V=230 //Ac Source voltage in Volts
+f=50 //source Frequency in Hz
+a=60
+aa=(60*%pi)/180 //in rad/sec
+a1=120
+aa1=(120*%pi)/180 //in rad/sec
+N2=400
+T=1000
+
+//Solution
+P=atand((2*%pi*f*L)/Ra) // In Degree
+Cot_P=1/(tand(P))
+A=exp(-%pi*Cot_P)
+B=exp((-aa)*Cot_P)
+Z=sqrt((Ra^2)+((2*%pi*f*L)^2)) //Impedance In Ohm
+Eb=Vm-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w
+AA=(Ra*Vm*1.414)/(K*Z)
+Wmc=AA*((sind(P)*B)-(sind(a-P)*A))*(1/(1-A)) //Critical Speed in rad/Sec
+Wrpm=(Wmc*60)/(2*%pi) //speed in rpm
+//motor back emf for critical speed of 148 RPM
+Ec=(Wrpm*Eb)/N //Critical emf in Volts
+Va=(V*1.414)*(1+cosd(a))*(1/%pi) //Armature voltage in volts
+Tc=K*(Va-Ec)*(1/Ra) //Critical Torque in N-m
+//The check condition is
+Ia=T/K //Armature current in Amp
+Eb2=Va-(Ia*Ra) // Back emf in Volts
+Nm=(Eb2*N)/Eb//Motor speed in Rpm
+
+B1=exp((-aa1)*Cot_P)
+Wmc1=AA*((sind(P)*B1)-(sind(a1-P)*A))*(1/(1-A)) //Critical Speed in rad/Sec
+Wrpm1=(Wmc1*60)/(2*%pi) //speed in rpm
+//motor back emf for critical speed of 154 RPM
+Ec1=(Wrpm1*Eb)/N //Critical emf in Volts
+Va1=(V*1.414)*(1+cosd(a1))*(1/%pi) //Armature voltage in volts
+Tc1=K*(Va1-Ec1)*(1/Ra) //Critical Torque in N-m
+//The check condition is
+Ia1=-T/K //Armature current in Amp
+Eb3=Va1-(Ia1*Ra) // Back emf in Volts
+Nm1=(Eb3*N)/Eb//Motor speed in Rpm
+
+//Results
+printf('\n\n The motor Speed =%0.1f RPM \n\n',Nm)
+printf('\n\n The motor Speed =%0.1f RPM \n\n',Nm1)
+//The answers vary due to round off error(1st answer)
+
diff --git a/3784/CH1/EX1.8/Ex1_8.sce b/3784/CH1/EX1.8/Ex1_8.sce new file mode 100644 index 000000000..4ae12281d --- /dev/null +++ b/3784/CH1/EX1.8/Ex1_8.sce @@ -0,0 +1,48 @@ +clc
+// Variable Initialization
+Vm=230 //Supply Voltage in Volts
+N=650//speed of motor in RPM
+I=100//Motor curent in Ampere
+Ra=0.08 //Armature circuit resistance in Ohm
+L=8e-3 //Armature circuit Inductance in mH
+V=230 //Ac Source voltage in Volts
+f=50 //source Frequency in Hz
+a=60
+aa=(60*%pi)/180 //in rad/sec
+N2=200
+
+//Solution
+P=atand((2*%pi*f*L)/Ra) // In Degree
+Cot_P=1/(tand(P))
+A=exp(-%pi*Cot_P)
+B=exp((-aa)*Cot_P)
+Z=sqrt((Ra^2)+((2*%pi*f*L)^2)) //Impedance In Ohm
+Eb=Vm-(I*Ra) //back emf in Volts
+w=(2*%pi*N)/60 //Angular Speed in rad/sec
+K=Eb/w
+AA=(Ra*Vm*1.414)/(K*Z)
+Wmc=AA*((sind(P)*B)-(sind(a-P)*A))*(1/(1-A)) //Critical Speed in rad/Sec
+Wrpm=(Wmc*60)/(2*%pi) //speed in rpm
+//since the speed of 200 rpm is less than the critical speed ,the drive is operating under continuous conduction .Hence
+Va=(V*1.414)*(1+cosd(a))*(1/%pi) //Armature voltage in volts
+Ec=(N2*Eb)/N //Critical emf in Volts
+T=K*(Va-Ec)*(1/Ra) //Critical Torque in N-m
+
+//For
+a1=120
+aa1=(120*%pi)/180 //in rad/sec
+B1=exp((-aa1)*Cot_P)
+Wmc1=AA*((sind(P)*B1)-(sind(a1-P)*A))*(1/(1-A)) //Critical Speed in rad/Sec
+Wrpm1=(Wmc*60)/(2*%pi) //speed in rpm
+//since the motor speed of 200 RPM is greater than the critical speed the drive is operating under discontinuous condition for which
+AA1=(Ra*Vm*1.414)/(Ec*Z)
+e1=AA1*((sind(P)*A)-(sind(a1-P)*B1))+B1
+b=(log(e1))/Cot_P
+b=117.38
+Va1=((Vm*1.41*(1+cosd(a1))+(%pi+((a1-b)*%pi/180))*Ec))/%pi//square root of 2 is rounded off as 1.4
+T1=K*(Va1-Ec)/Ra //Critical Torque in N-m
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Torque=%0.1f N-m \n\n',T1)
+//The answers vary due to round off error
diff --git a/3784/CH1/EX1.9/Ex1_9.sce b/3784/CH1/EX1.9/Ex1_9.sce new file mode 100644 index 000000000..163d88682 --- /dev/null +++ b/3784/CH1/EX1.9/Ex1_9.sce @@ -0,0 +1,25 @@ +clc
+// Variable Initialization
+Vm=230 //Supply Voltage in Volts
+Ia=50//Motor Armature current in Ampere
+Ra=0.25//Armature circuit resistance in Ohm
+Rf=200 // Field circuit resistance in Ohm
+f=50 //source Frequency in Hz
+a=45 //Firing angle in the armature circuit in degree
+Vd=1 //Brush contact drop V/brush
+af=0 //Firing angle in the field circuit in degree
+Kf=1.1 //Torque and voltage constant
+
+//Solution
+Vf=(2*Vm*1.414)*cosd(af)*(1/%pi) //Voltage in field circuit in Volts
+//When a=45 degree
+Va=(2*Vm*1.414)*cosd(a)*(1/%pi) //Voltage in Armature circuit in Volts
+If=Vf/Rf //Field current in Amp.
+T=Kf*Ia*If //Torque in N-m
+Eb=Va-(Ia*Ra)-Vd*2 //Back emf in Volts
+W=Eb/(Kf*If) //Angular speed in Rad/sec
+N=W*60/(2*%pi) //Motor speed in RPM
+
+//Results
+printf('\n\n The motor Torque =%0.1f N-m \n\n',T)
+printf('\n\n The motor Speed=%0.1f RPM \n\n',N)
diff --git a/3784/CH2/EX2.1/Ex2_1.sce b/3784/CH2/EX2.1/Ex2_1.sce new file mode 100644 index 000000000..f6a4828be --- /dev/null +++ b/3784/CH2/EX2.1/Ex2_1.sce @@ -0,0 +1,34 @@ +clc
+//variable initialisation
+a1=0//Initial Firing Angle of Converter
+Vl=460//Line to Line Voltage in Volts
+Ia=170//armature Current in Ampere
+Ra=0.0999//Armature Resistance in ohm
+K=0.33
+a2=30
+N1=1750//Rotor Speed in rpm
+
+//solution
+Vm=(sqrt(2)/sqrt(3))*Vl
+Va=(3*sqrt(3)/%pi)*Vm*cosd(a1)
+Ia1=17
+Eb1=Va-(Ia1*Ra)
+N0=Eb1/K//no load Speed in rpm
+Va2=Va*cosd(a2)//For alpha=30
+Eb2=Va2-(Ia1*Ra)
+N01=Eb2/K//No load speed at alpha=30
+Eb3=K*N1//For Full load Condition
+Va3=Eb3+(Ia*Ra)
+a3=acosd(Va3/Va)
+P=Va3*Ia
+Irms=Ia*sqrt(((180-a3)/180))
+Vph=Vl/sqrt(3)
+pf=P/(3*Vph*Irms)//Power Factor
+Eb4=Va3-(Ia1*Ra)
+N4=Eb4/K
+R=(N4-N1)*100/N1//Speed Regulation
+printf('\n\n No load speed at alpha 0=%0.1f rpm\n\n',N0)
+printf('\n\n No load speed at alpha 30=%0.1f rpm\n\n',N01)
+printf('\n\n The Firing Angle for rated speed=%0.1f\n\n',a3)
+printf('\n\n Power Factor at rated speed=%0.1f\n\n',pf)
+printf('\n\n Speed Regulation=%0.1f\n\n',R)
diff --git a/3784/CH2/EX2.10/Ex2_10.sce b/3784/CH2/EX2.10/Ex2_10.sce new file mode 100644 index 000000000..0f0243c31 --- /dev/null +++ b/3784/CH2/EX2.10/Ex2_10.sce @@ -0,0 +1,17 @@ +clc
+//variable initialization
+P=80e+3 //power in Watt
+Va1=440 //voltage in volts
+N1=800 //speed in rpm
+N2=600 //speed in rpm
+Eb1=410 //Given back emf in volts
+Vrms=415 //voltage in volts
+
+//solution
+Eb2=Eb1*(N2/N1)
+Ia1=P/Va1
+Ra=(Va1-Eb1)/Ia1
+Ia2=0.75*Ia1//As motor is operating at 75% of rated torque
+Va2=Eb2+(Ia2*Ra)
+a=acosd(Va2*%pi/(3*sqrt(2)*Vrms))
+printf('\n\n The Triggering Angle=%0.1f\n\n',a)
diff --git a/3784/CH2/EX2.11/Ex2_11.sce b/3784/CH2/EX2.11/Ex2_11.sce new file mode 100644 index 000000000..f11d443e2 --- /dev/null +++ b/3784/CH2/EX2.11/Ex2_11.sce @@ -0,0 +1,18 @@ +clc
+//variable initialization
+P=100e+3 //power in W
+Va1=440 //Supply voltage in volts
+N1=1000 //speed in rpm
+N2=800 //speed in rpm
+Eb1=410 //given Back EMF in volts
+Vrms=415 //RMS voltage in volts
+f=50 //Supply frequency in Hz
+
+//solution
+Eb2=Eb1*(N2/N1)
+Ia1=P/Va1
+Ra=(Va1-Eb1)/Ia1
+Ia2=0.75*Ia1//At 75% of rated torque
+Va2=Eb2+(Ia2*Ra)
+a=acosd((Va2*%pi)/(3*sqrt(2)*Vrms))
+printf('\n\n The Firing Angle=%0.1f\n\n',a)
diff --git a/3784/CH2/EX2.12/Ex2_12.sce b/3784/CH2/EX2.12/Ex2_12.sce new file mode 100644 index 000000000..87c682161 --- /dev/null +++ b/3784/CH2/EX2.12/Ex2_12.sce @@ -0,0 +1,21 @@ +clc
+//variable initialization
+Php=100 //power in hp
+P=Php*735.5 //power in Watts
+Va1=440 //voltage in volts
+N1=1000 //speed in rpm
+N2=500 //speed in rpm
+Eb1=430//Given back EMF in volts
+Vrms=415 //RMS voltage in volts
+
+//solution
+Eb2=Eb1*(N2/N1)
+Ia1=P/Va1
+Ra=10/Ia1
+Ia2=0.85*Ia1
+Va2=Eb2+Ia2*Ra//At 85% load and 500 rpm
+a=acosd(Va2/(1.35*Vrms))
+printf('\n\n The Firing Angle=%0.1f\n\n',a)
+
+
+
diff --git a/3784/CH2/EX2.13/Ex2_13.sce b/3784/CH2/EX2.13/Ex2_13.sce new file mode 100644 index 000000000..82e87d517 --- /dev/null +++ b/3784/CH2/EX2.13/Ex2_13.sce @@ -0,0 +1,13 @@ +clc
+//variable initialisation
+Va=230 //Supply voltage in volts
+N1=1400 //speed in rpm
+N2=600 //speed in rpm
+N3=1400 //speed in rpm
+Vdrop=15//Voltage drop in Volts
+//solution
+Eb1=Va-15
+Eb2=Eb1*(N2/N1)
+Va1=Eb2+Vdrop
+a2=acosd(Va1/Va)
+printf('\n\n The Firing Angle=%0.1f\n\n',a2)
diff --git a/3784/CH2/EX2.2/Ex2_2.sce b/3784/CH2/EX2.2/Ex2_2.sce new file mode 100644 index 000000000..dcb84cf45 --- /dev/null +++ b/3784/CH2/EX2.2/Ex2_2.sce @@ -0,0 +1,36 @@ +clc
+//variable initialisation
+a1=0//Initial Firing Angle of Converter
+Vl=460//Line to Line Voltage in Volts
+Ia=150//armature Current in Ampere
+Ra=0.0999//Armature Resistance in ohm
+K=0.33
+N1=1650//Rotor Speed in rpm
+Ia1=15//armature Current for 2nd case in Ampere
+//solution
+Vm=(sqrt(2)/sqrt(3))*Vl
+Va=(3*sqrt(3)/%pi)*Vm*cosd(a1)
+Eb1=Va-(Ia*Ra)
+N0=Eb1/K//no load Speed in rpm
+a2=45
+Va2=Va*cosd(a2)
+Eb2=Va2-(Ia*Ra)
+N01=Eb2/K//No load speed at alpha=30
+Eb3=K*N1
+Va3=Eb3+(Ia*Ra)
+a3=acosd(Va3/Va)
+Irms=Ia*sqrt((180-a3)/180)
+P1=3*(Vl/sqrt(3))*Irms//Supply VA
+P=Va3*Ia//Power input to motor
+Pa=Va3*Ia
+pf=Pa/P//Power Factor
+Eb4=Va3-(Ia1*Ra)
+N4=Eb4/K
+R=(N4-N1)*100/N1//Speed Regulation
+printf('\n\n No load speed at alpha 0=%0.1f rpm\n\n',N0)
+printf('\n\n No load speed at alpha 45=%0.1f rpm\n\n',N01)
+printf('\n\n The Firing Angle for rated speed=%0.1f\n\n',a3)
+printf('\n\n Supply Power at rated speed=%0.1f watts\n\n',P)
+printf('\n\n Power Factor at rated speed=%0.1f\n\n',pf)
+printf('\n\n Speed Regulation=%0.1f\n\n',R)
+//The answers vary due to round off error
diff --git a/3784/CH2/EX2.3/Ex2_3.sce b/3784/CH2/EX2.3/Ex2_3.sce new file mode 100644 index 000000000..614de9609 --- /dev/null +++ b/3784/CH2/EX2.3/Ex2_3.sce @@ -0,0 +1,25 @@ +clc
+//variable initialisation
+Va=220 //supply voltage in volts
+N1=1500 //speed in rpm
+I=50 // current in ampere
+Ra=0.5 //armature resistance in ohm
+Vl=440 //line voltage in volts
+f=50 //frequency in Hz
+N2=1200 //speed in rpm
+
+//solution
+Vm=(Va*%pi)/(3*sqrt(3))
+Vph=(Vl*(sqrt(2)))/(sqrt(3))
+Xmer_ratio=Vph/Vm
+Eb1=Va-(Ra*I)
+Eb2=(N2/N1)*Eb1
+Va=Eb2+Ra*I
+a=acosd((Va*%pi)/(3*sqrt(3)*Vm))
+N3=800
+Eb3=(-N3/N1)*Eb1
+Va1=Eb3+(2*I*Ra)
+a1=acosd((Va1*%pi)/(3*sqrt(3)*Vm))
+printf('\n\n Transformer Turns Ratio=%0.1f\n\n',Xmer_ratio)
+printf('\n\n The Firing Angle=%0.1f\n\n',a)
+printf('\n\n The Firing Angle=%0.1f\n\n',a1)
diff --git a/3784/CH2/EX2.4/Ex2_4.sce b/3784/CH2/EX2.4/Ex2_4.sce new file mode 100644 index 000000000..f037999b6 --- /dev/null +++ b/3784/CH2/EX2.4/Ex2_4.sce @@ -0,0 +1,12 @@ +clc
+//variable initialisation
+Va=220 //supply voltage in volts
+N1=1500 //speed in rpm
+Ra=2 //armature resistance in ohm
+La=0.02836 //armature inductance in mH
+f=50 //frequency in Hz
+
+//solution
+Vl=(Va*%pi)/(3*sqrt(2))
+Vm=sqrt(2)*Vl
+printf('\n\n The Source Voltage Required=%0.1f Volts\n\n',Vm)
diff --git a/3784/CH2/EX2.5/Ex2_5.sce b/3784/CH2/EX2.5/Ex2_5.sce new file mode 100644 index 000000000..62786d27b --- /dev/null +++ b/3784/CH2/EX2.5/Ex2_5.sce @@ -0,0 +1,14 @@ +clc
+//variable initialisation
+V1=450 //terminal voltage in volts
+Vd=30 //voltage drop in volts
+V2=420 //input supply in volts
+f=50 //frequency in Hz
+a1=0//Firing Angle of Converter
+//solution
+Vt=V1+Vd
+V0_0=(3*sqrt(2))/(%pi)
+V0_a=480
+
+a2=acosd(V0_a/(V0_0*V2))
+printf('\n\n The Firing Angle=%0.1f\n\n',a2)
diff --git a/3784/CH2/EX2.6/Ex2_6.sce b/3784/CH2/EX2.6/Ex2_6.sce new file mode 100644 index 000000000..bbcd32c94 --- /dev/null +++ b/3784/CH2/EX2.6/Ex2_6.sce @@ -0,0 +1,16 @@ +clc
+//variable initialization
+N=800 //speed in rpm
+P=80000 //power in kw
+V=440 //Supply voltage in volts
+f=50 //Supply frequency in Hz
+Ra=0.8 //armature resistance in ohm
+k=0.2 //machine constant in V/rpm
+Ia=160 //rated current in ampere
+
+//solution
+Vp=V/(sqrt(3))//Phase Voltage
+Eb=k*N//Back emf in Volts
+V2=Eb+(Ia*Ra)
+a=acosd((V2*%pi)/(3*sqrt(6)*Vp))
+printf('\n\n The Firing Angle=%0.1f\n\n',a)
diff --git a/3784/CH2/EX2.7/Ex2_7.sce b/3784/CH2/EX2.7/Ex2_7.sce new file mode 100644 index 000000000..a58f9b693 --- /dev/null +++ b/3784/CH2/EX2.7/Ex2_7.sce @@ -0,0 +1,15 @@ +clc
+//variable initialisation
+N=900 //speed in rpm
+V=430 //Supply voltage in volts
+Ia=20 //current in ampere
+N1=900 //speed in rpm
+N2=450 //speed in rpm
+Ra=0.2 //armature resistance in ohm
+
+//solution
+Vl=V/1.35
+V2=((V-(Ia*Ra))/2)+Ia*Ra
+a=acosd(V2/V)
+printf('\n\n The RMS Voltage per phase=%0.1f Volts\n\n',V2)
+printf('\n\n The Firing Angle=%0.1f\n\n',a)
diff --git a/3784/CH2/EX2.8/Ex2_8.sce b/3784/CH2/EX2.8/Ex2_8.sce new file mode 100644 index 000000000..9765dc21a --- /dev/null +++ b/3784/CH2/EX2.8/Ex2_8.sce @@ -0,0 +1,31 @@ +clc
+//Variable Initialisation
+Vs=220//Supply Voltage in Volts
+N=600//Rotor Speed in rpm
+Ra=0.4//Armature Resistance in ohm
+Rf=150//Field Resistance in ohm
+af=0//Firing Angle for Maximum field current
+aa=0//Firing Angle for maximum Armature current
+N2=1200//Speed in rpm
+T=120//Torque in N-m
+K=1.4//Motor voltage Constant
+//Solution
+Vm=Vs/sqrt(3)
+W=2*%pi*N/60
+Vf1=3*sqrt(3)*sqrt(2)*Vm*cosd(af)/%pi
+If1=Vf1/Rf//Field Current in Amp
+Ia1=T/(K*If1)
+Eb1=K*If1*W
+Va1=Eb1+(Ia1*Ra)
+aa1=acosd(Va1*%pi/(3*sqrt(3)*sqrt(2)*Vm))
+Va2=3*sqrt(3)*sqrt(2)*Vm*cosd(aa)/%pi
+Eb2=Va2-(Ia1*Ra)
+N3=Eb2/(K*If1)//Speed in rad/s
+N3rpm=N3*60/(2*%pi)//Speed in Rpm
+W2=N2*2*%pi/60
+If2=Eb2/(K*W2)
+Vf2=If2*Rf
+af1=acosd(Vf2*%pi/(3*sqrt(3)*sqrt(2)*Vm))
+printf('\n\n The Firing Angle=%0.1f\n\n',aa1)
+printf('\n\n The Field Current=%0.1f Amp\n\n',N3rpm)
+printf('\n\n The Field Current=%0.1f Amp\n\n',af1)
diff --git a/3784/CH2/EX2.9/Ex2_9.sce b/3784/CH2/EX2.9/Ex2_9.sce new file mode 100644 index 000000000..aff594e50 --- /dev/null +++ b/3784/CH2/EX2.9/Ex2_9.sce @@ -0,0 +1,13 @@ +clc
+//variable initialisation
+V=440 //voltage in volts
+P=100e+3 //power in Watts
+N=900 //speed in rpm
+V1=415 //supply voltage in volts
+
+//solution
+k=(3*sqrt(2))/%pi
+a=acosd(V/(k*V1))
+V2=0.5*V//At 50% of rated speed
+a1=acosd(V2/(k*V1))
+printf('\n\n The Firing Angle=%0.1f\n\n',a1)
diff --git a/3784/CH3/EX3.1/Ex3_1.sce b/3784/CH3/EX3.1/Ex3_1.sce new file mode 100644 index 000000000..b372f1a54 --- /dev/null +++ b/3784/CH3/EX3.1/Ex3_1.sce @@ -0,0 +1,27 @@ +clc
+//variable initialization
+Vm= 220 //armature voltage in volts
+N= 1000 //speed in rpm
+N1= 900 // speed in rpm
+Ia= 60 //armature current in ampere
+Ra= 0.6 //armature resistance in ohm
+a= 0
+V= 165 //line voltage in volts
+
+//solution
+Eb1= Vm-Ia*Ra //back emf in volts
+Eb2= (N1/N)*Eb1 //back emf in volts
+Ea=Eb2+(Ia*Ra) //armature voltage in volts
+Em= V*sqrt(2)
+A=(((Ea*%pi)/(3*Em)))
+a1=acosd(A)
+a2=180-a1
+Ea1=V-(Ia*Ra) //armature voltage in volts
+cosa1=((Ea/Em)*(%pi/3))
+a11=acosd((Ea1*%pi)/(3*Em))
+a22=180-a1
+printf('\n\n Firing Angle for motoring operations at rated motor torqu and 900 or -900 rpm=%0.1f \n\n',a1)
+printf('\n\n Firing Angle for motoring operations at rated motor torqu and 900 or -900 rpm=%0.1f \n\n',a2)
+printf('\n\n Firing Angle for braking operations at rated motor torqu and 900 or -900 rpm=%0.1f \n\n',a11)
+printf('\n\n Firing Angle for braking operations at rated motor torqu and 900 or -900 rpm=%0.1f \n\n',a22)
+//The answers vary due to round off error
diff --git a/3784/CH3/EX3.2/Ex3_2.sce b/3784/CH3/EX3.2/Ex3_2.sce new file mode 100644 index 000000000..496b84a37 --- /dev/null +++ b/3784/CH3/EX3.2/Ex3_2.sce @@ -0,0 +1,21 @@ +clc
+// Variable Initiallization
+Vm=220 //armature voltage in volts
+f=50 //frequency in Hz
+Ra=10 //armature resistance in ohm
+Lr=50e-3 //circulating inductance in mH
+a1=30
+a2=150
+
+//solution
+w=2*%pi*f
+Em=sqrt(2)*220 //voltage in volts
+cosa1=cosd(a1)
+cosa2=cosd(a2)
+Irmax1=((2*Em)/(w*Lr))*(1-cosa1)
+Irmax2=((2*Em)/(w*Lr))*(1-cosa2)
+Ip=(Em/Ra)
+I1=Ip+Irmax1
+I2=Ip+Irmax2
+printf('\n\n Peak Current of Converter 1=%0.1f Amp\n\n',I1)
+printf('\n\n Peak Current of Converter 2=%0.1f Amp\n\n',I2)
diff --git a/3784/CH3/EX3.3/Ex3_3.sce b/3784/CH3/EX3.3/Ex3_3.sce new file mode 100644 index 000000000..c05d25941 --- /dev/null +++ b/3784/CH3/EX3.3/Ex3_3.sce @@ -0,0 +1,15 @@ +
+clc
+// Variable initialization
+F=50 //Supply Frequency In Hz
+Vm=400 //Supply Voltage In Volts
+Ip=20 //Peak Circulating Current In Ampere
+A=60 //firing angle
+
+// solution
+Ea=Vm/(sqrt(3))
+W=2*%pi*F
+Lr=[(3*sqrt(2)*Ea)/(W*Ip)]*(1-sind(A))
+Lr1=Lr*1000//Inductance in mH
+printf('\n\n Inductance Value Needed=%0.1f mH\n\n',Lr1)
+//The answer vary due to round off error
diff --git a/3784/CH3/EX3.4/Ex3_4.sce b/3784/CH3/EX3.4/Ex3_4.sce new file mode 100644 index 000000000..0f1194964 --- /dev/null +++ b/3784/CH3/EX3.4/Ex3_4.sce @@ -0,0 +1,15 @@ +clc
+// Variable Initiallization
+F=50 //Supply Frequency In Hz
+Erms=230 //RMS Voltage Per Phase In Volts
+L=0.015 //Inductance In Henry
+A1=60 //Firing Angle
+A2=120 //Firing Angle
+
+
+
+
+//solution
+W=2*%pi*F
+Icp=((3*sqrt(2)*Erms)/(W*L))*(1-sind(A1))
+printf('\n\n The Peak value of Circulating Current=%0.1f Amp\n\n',Icp)
diff --git a/3784/CH3/EX3.5/Ex3_5.sce b/3784/CH3/EX3.5/Ex3_5.sce new file mode 100644 index 000000000..16089b0da --- /dev/null +++ b/3784/CH3/EX3.5/Ex3_5.sce @@ -0,0 +1,15 @@ +clc
+// Variable Initiallization
+Vm=400 //Supply Voltage In Volt
+Ea1= 220// Voltage Of Motor In Volt
+Ia=200 //Line Current In Ampere
+Ra=0.05 //Armature Resistance In Ohm
+N1=750 //Speed Of Motor In rpm
+N2=600 //Speed Of Motor In rpm
+
+//solution
+Eb1=Ea1-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+Ea2=Eb2+(Ia*Ra)
+A=acosd((Ea2*%pi)/(Vm*3*sqrt(2)))
+printf('\n\n The Firing Angle of Rectifier=%0.1f\n\n',A)
diff --git a/3784/CH3/EX3.6/Ex3_6.sce b/3784/CH3/EX3.6/Ex3_6.sce new file mode 100644 index 000000000..59935f183 --- /dev/null +++ b/3784/CH3/EX3.6/Ex3_6.sce @@ -0,0 +1,23 @@ +clc
+// Variable Initiallization
+Ea=400 // Voltage Of MOtor In Volt
+Ia1=70 //Line Current In Ampere
+Ia2=90 //Line Current In Ampere
+Ra=0.3 //Armature Resistance In Ohm
+N1=750 //Speed Of Motor In rpm
+N2=300 //Speed Of Motor In rpm
+
+//Solution
+Eb1=Ea-(Ia1*Ra)
+Eb2=(N2/N1)*Eb1
+Rb=-((Eb2-Ea-Ia2*Ra)/Ia2)//Wrongly calculated in book,wrong value of Eb2 is taken
+W1=(2*%pi*N1)/60
+Kt1=Eb1/W1
+T1=Kt1*Ia1
+W2=(2*%pi*N2)/60
+Kt2=Eb2/W2//Wrongly computed in textbook
+T2=Kt2*Ia2//The answer provided in the textbook is wrong
+printf('\n\n External resistance to be added=%0.1f ohm\n\n',Rb)
+printf('\n\n Initial braking torque=%0.1f N-m\n\n',T1)
+printf('\n\n braking torque at 300 rpm=%0.1f N-m\n\n',T2)
+//The answer provided in the textbook is wrong(both)
diff --git a/3784/CH4/EX4.1/Ex4_1.sce b/3784/CH4/EX4.1/Ex4_1.sce new file mode 100644 index 000000000..d2d4226aa --- /dev/null +++ b/3784/CH4/EX4.1/Ex4_1.sce @@ -0,0 +1,41 @@ +clc
+//Variable Initialisation
+V=230//Input Voltage of motor in volts
+Vdc=240//Dc equivalent input to motor in Volts
+Po=746//Power rating of DC motor in Watt
+N=500//Rated Speed of Motor in rpm
+Ia=4.1//Armature Current in Ampere
+Ra=7.56//Armature resistance in ohm
+La=55e-3//Armature inductance in Henry
+f=500//Chopper Frequency
+Tmin=5//minimum load Torque in N-m
+//Solution
+T=(1/f)//Period of Chopper
+w=2*%pi*N*(1/60)
+Eb=V-(Ia*Ra)//Back emf in Volts
+k=Eb*(1/w)
+Pin=V*Ia//Armature Power Input
+L=Pin-Po-(Ia*Ia*Ra)//Rotational Loss
+Ta=L/w
+Ta1=Tmin+Ta//Average internal Torque in N-m
+Ia1=Ta1/k
+E0=Eb+(Ia1*Ra)
+ton=(E0/Vdc)*T
+ton11=ton*1000//ton in microseconds
+ta=(La/Ra)
+A=log(((Eb/Vdc)*(%e^(T/ta)-1))+1)
+ton1=A*ta
+ton12=ton1*1000//ton in microseconds
+E01=(ton1/T)*Vdc
+Ia2=(E01-Eb)/Ra
+Ta2=k*Ia2
+Tc=Ta2-Ta
+printf('\n\n ton for minimum load torque of 500rpm=%0.1f 10^(-3)sec\n\n',ton11)
+printf('\n\n ton for current is continuous at 500rpm=%0.1f 10^(-3)sec\n\n',ton12)
+if ton>ton1 then
+ disp("Current (Ia) is continuous")
+else
+ disp("Current (Ia) is not continuous")
+end
+printf('\n\n The coupling Torque for minimum value of ton obtain=%0.1f N-m\n\n',Tc)
+
diff --git a/3784/CH4/EX4.10/Ex4_10.sce b/3784/CH4/EX4.10/Ex4_10.sce new file mode 100644 index 000000000..c4631e041 --- /dev/null +++ b/3784/CH4/EX4.10/Ex4_10.sce @@ -0,0 +1,33 @@ +clc
+//Variable Initialisation
+V=230//Input Voltage of motor in volts
+f=300//Chopper Frequency
+Tl=40//Load Torque in N-m
+N1=900//Rated Speed of Motor in rpm
+Ra=0//Armature resistance in ohm
+La=12e-3//Inductance in Henry
+k=2//Motor Constant
+//Solution
+Ia=Tl/k
+W=2*%pi*N1/60
+Eb=k*W
+d=(Eb+(Ia*Ra))/V
+t1=1/f
+ton=d*t1
+toff=(1-d)*t1
+Z1=(V-Eb)/La
+Z2=-Eb/La
+A=Z1*ton //A=Imax-Imin
+B=2*Ia //B=Imax+Imin
+Imax=(A+B)/2
+Imin=(B-A)/2
+
+t=poly(0,'t');
+x=Imin+Z1*t
+y=Imax+Z2*t
+
+disp (Imax ,"Maximum Armature Current in Amp is")
+disp (Imin ,"Minimum Armature Current in Amp is")
+disp (A ,"Armature Current Excursion in Amp is")
+disp (x ,"Armature Current During Ton in Amp is")
+disp (y ,"Armature Current During Toff in Amp is")
diff --git a/3784/CH4/EX4.11/Ex4_11.sce b/3784/CH4/EX4.11/Ex4_11.sce new file mode 100644 index 000000000..e5fdb8d66 --- /dev/null +++ b/3784/CH4/EX4.11/Ex4_11.sce @@ -0,0 +1,31 @@ +clc
+//Variable Initialisation
+Ea=200//Input Voltage of motor in volts
+Ra=0.12//Armature resistance in ohm
+La=12e-3//Armature Inductance in ohm
+K=2//Motor constant in V-s/rad
+Eb=150//Motor back EMF
+Ia=30//Armature Current in Ampere
+f=300//Chopper Frequency
+//Solution
+T=1/f
+d=(Eb+(Ia*Ra))/Ea
+ton=d*T
+toff=(1-d)*T
+t=Ra/La
+Ea1=Ea
+Imin=poly(0,'Imin');
+Ia1=((Ea1-Eb)/Ra)*(1-%e^(-ton*t))+(Imin*%e^(-ton*t))
+disp (Ia1 ,"Imax is")
+Ea2=0
+Imax=poly(0,'Imax');
+Ia2=((Ea2-Eb)/Ra)*(1-%e^(-toff*t))+(Imax*%e^(-toff*t))
+disp (Ia2 ,"Imin is")
+a=poly(0,'a');
+b=poly(0,'b');
+Imax1=(10.409+(0.975*(-9.96)))/(1-(0.975*0.992))//From above displayed values and rounding off
+Imin1=(-9.960)+(0.992*Imax1)
+Im=Imax1-Imin1//Armature Current Excursion
+printf('\n\n Maximum Armature Current=%0.1f Amp\n\n',Imax1)
+printf('\n\n Minimum Armature Current=%0.1f Amp\n\n',Imin1)
+printf('\n\n Armature Current Excursion=%0.1f Amp\n\n',Im)
diff --git a/3784/CH4/EX4.12/Ex4_12.sce b/3784/CH4/EX4.12/Ex4_12.sce new file mode 100644 index 000000000..10bb78ca1 --- /dev/null +++ b/3784/CH4/EX4.12/Ex4_12.sce @@ -0,0 +1,24 @@ +clc
+//Variable Initialisation
+V=440//Input Voltage of motor in volts
+Rf=100//Field resistance in ohm
+Il=50//Load Current in Ampere
+N1=900//Rated Speed of Motor in rpm
+N2=300//Rated Speed of Motor in rpm
+N3=400//Rated Speed of Motor in rpm
+N4=600//Rated Speed of Motor in rpm
+Ra=0.3//Armature resistance in ohm
+ton=4e-3//On period of Chopper in sec
+//Solution
+If=V/Rf//Motor Field Current in Amp
+Ia=Il-If//Armature Current in Amp
+Eb1=V-(Ia*Ra)//Back EMF of Motor
+Eb2=(N2/N3)*Eb1
+V2=Eb2+(Ia*Ra)//Required Terminal Voltage in volts
+T1=(V/V2)*ton//Chopping Period
+f1=1/T1///Chopping Period
+Eb3=(N4/N1)*Eb1//Back Emf at 600 rpm
+V3=Eb3+(Ia*Ra)//Required Terminal Voltage in volts
+T2=(V/V3)*ton//Chopping Period
+f2=1/T2//Chopping Period
+printf('\n\n Frequency of chopper=%0.1f Hz\n\n',f2)
diff --git a/3784/CH4/EX4.13/Ex4_13.sce b/3784/CH4/EX4.13/Ex4_13.sce new file mode 100644 index 000000000..d2a40868b --- /dev/null +++ b/3784/CH4/EX4.13/Ex4_13.sce @@ -0,0 +1,13 @@ +clc
+//Variable Initialisation
+ton=10//On time of Chopper
+toff=12//Off time of Chopper
+Ea=220//Input Voltage of motor in volts
+k=0.495//Motor Voltage constant
+W=146.60//Rated Speed of Motor in rad/sec
+Ra=2.87//Armature resistance in ohm
+//Solution
+d=ton/(ton+toff)//Duty cycle ratio
+Ia=((d*Ea)-(k*W))/Ra
+printf('\n\n Average load Current=%0.1f Amp\n\n',Ia)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.14/Ex4_14.sce b/3784/CH4/EX4.14/Ex4_14.sce new file mode 100644 index 000000000..0ff231f14 --- /dev/null +++ b/3784/CH4/EX4.14/Ex4_14.sce @@ -0,0 +1,25 @@ +clc
+//Variable Initialisation
+Ea=450//Input Voltage of motor in volts
+Ra=0.06//Armature resistance in ohm
+Kt=1.4//Motor Voltage Constant
+Ia=300//Armature Current in Ampere
+If=3.3//Motor Field Current in Amp
+d=0.7//Duty cycle of Converter
+//Solution
+Pin1=Kt*Ea*Ia//Input Power
+Re1=Ea/(Kt*Ia)//Equivalent Resistance
+E01=Kt*Ea
+Eb1=E01-(Ia*Ra)
+
+Pin2=d*Ea*Ia
+Re2=Ea/(d*Ia)
+E02=d*Ea
+Eb2=E02-(Ia*Ra)
+N1=Eb2/(Kt*If)
+N=N1*60/(2*%pi)
+T=Kt*Ia*If
+printf('\n\n Input Power=%0.1f KW\n\n',Pin1*10^-3)
+printf('\n\n Equivalent Resistance developed=%0.1f ohm\n\n',Re1)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N)
+printf('\n\n Motor Torque=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.15/Ex4_15.sce b/3784/CH4/EX4.15/Ex4_15.sce new file mode 100644 index 000000000..0399c672d --- /dev/null +++ b/3784/CH4/EX4.15/Ex4_15.sce @@ -0,0 +1,15 @@ +clc
+//Variable Initialisation
+Ea=210//Input Voltage of motor in volts
+Ia=25//Armature Current in Ampere
+Es=230
+N1=1500//Rated Speed of Motor in rpm
+Ra=3//Armature resistance in ohm
+N2=800//Rated Speed of Motor in rpm
+//Solution
+Ia2=1.5*Ia
+Eb=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb
+E0=Eb2+(Ia2*Ra)
+d=E0/Es
+printf('\n\n Duty Ratio=%0.1f\n\n',d)
diff --git a/3784/CH4/EX4.16/Ex4_16.sce b/3784/CH4/EX4.16/Ex4_16.sce new file mode 100644 index 000000000..d59f2ab41 --- /dev/null +++ b/3784/CH4/EX4.16/Ex4_16.sce @@ -0,0 +1,24 @@ +clc
+//Variable Initialisation
+Ea=200//Input Voltage of motor in volts
+Ia=20//Armature Current in Ampere
+Ra=0.33//Armature resistance in ohm
+La=11e-3//Armature Inductance in ohm
+N1=1200//Rated Speed of Motor in rpm
+N2=800//Rated Speed of Motor in rpm
+f=500//Chopper Frequency in Hz
+//Solution
+T=1/f
+t=Ra/La
+t1=1/t
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+E0=Eb2+(Ia*Ra)
+d=E0/Ea
+ton1=d*T
+A=log(1+((Eb2/Ea)*((%e^(T/t1))-1)))//Ia2=0 & A=ton2/t
+ton2=A*t1
+printf('\n\n Duty Cycle=%0.1f\n\n',ton2)
+//The answer provided in the textbook is wrong(answer given in textbook is in invalid range)
+if ton2<ton1 then disp('Current is Continuous')
+end
diff --git a/3784/CH4/EX4.17/Ex4_17.sce b/3784/CH4/EX4.17/Ex4_17.sce new file mode 100644 index 000000000..4bae4711b --- /dev/null +++ b/3784/CH4/EX4.17/Ex4_17.sce @@ -0,0 +1,18 @@ +
+clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+Ia=100//Armature Current in Ampere
+Ra=0.01//Armature resistance in ohm
+N1=1000//Rated Speed of Motor in rpm
+N2=500//Rated Speed of Motor in rpm
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+Ea2=Eb2+(Ia*Ra)
+d1=Ea2/Ea
+Ea3=Eb2-(Ia*Ra)
+d2=Ea3/Ea
+printf('\n\n Duty Ratio of Chopper in motoring operation=%0.1f\n\n',d1)
+printf('\n\n Duty Ratio of Chopper in breaking operation=%0.1f\n\n',d2)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.18/Ex4_18.sce b/3784/CH4/EX4.18/Ex4_18.sce new file mode 100644 index 000000000..8bd1e0450 --- /dev/null +++ b/3784/CH4/EX4.18/Ex4_18.sce @@ -0,0 +1,28 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+Ia=50//Armature Current in Ampere
+N1=800//Rated Speed of Motor in rpm
+Ra=0.4//Armature resistance in ohm
+d1=0.3//Duty ratio for Motoring Operation
+d2=0.6//Duty ratio for Motoring Operation
+d3=0.7//Duty ratio for Braking Operation
+d4=0.4//Duty ratio for Braking Operation
+//Solution
+E01=d1*Ea
+Eb1=Ea-(Ia*Ra)
+Eb2=E01-(Ia*Ra)
+N2=(Eb2/Eb1)*N1
+E02=d2*Ea
+Eb3=E02-(Ia*Ra)
+N3=(Eb3/Eb1)*N1
+E03=d3*Ea
+Eb4=E03+(Ia*Ra)
+N4=(Eb4/Eb1)*N1
+E04=d4*Ea
+Eb5=E04+(Ia*Ra)
+N5=(Eb5/Eb1)*N1
+printf('\n\n Motor speed for Motoring Operation 1 =%0.1f rpm\n\n',N2)
+printf('\n\n Motor speed for Motoring Operation 2=%0.1f rpm\n\n',N3)
+printf('\n\n Motor speed for Braking Operation 1=%0.1f rpm\n\n',N4)
+printf('\n\n Motor speed for Braking Operation 2=%0.1f rpm\n\n',N5)
diff --git a/3784/CH4/EX4.19/Ex4_19.sce b/3784/CH4/EX4.19/Ex4_19.sce new file mode 100644 index 000000000..5f0bd16d7 --- /dev/null +++ b/3784/CH4/EX4.19/Ex4_19.sce @@ -0,0 +1,16 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+d=0.95//Maximum Duty Ratio
+Ia1=100//Armature Current in Ampere
+Ia2=150//Armature Current in Ampere
+Ra=0.01//Armature resistance in ohm
+N1=1000//Rated Speed of Motor in rpm
+//Solution
+Eb1=Ea-(Ia1*Ra)
+E0=d*Ea
+Eb2=E0+(Ia2*Ra)
+N2=(Eb2/Eb1)*N1
+Pin=E0*Ia2
+printf('\n\n Maximum Permissible MOtor Speed=%0.1f rpm\n\n',N2)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.2/Ex4_2.sce b/3784/CH4/EX4.2/Ex4_2.sce new file mode 100644 index 000000000..83ffbe3cd --- /dev/null +++ b/3784/CH4/EX4.2/Ex4_2.sce @@ -0,0 +1,30 @@ +clc
+//Variable Initialisation
+V=230//Input Voltage of motor in volts
+N=1750//Rated Speed of Motor in rpm
+Ia=74//Armature Current in Ampere
+Ra=0.180//Armature resistance in ohm
+Vdc=240//Dc equivalent input to motor in Volts
+f=500//Chopper Frequency
+W0=2*f*%pi
+la=2.93*10^(-3)//Armature inductance in Henry
+//Solution
+T=1/f//Period of Chopper
+I0=Ia
+W=2*%pi*N/60
+Eb=V-(Ia*Ra)//Back EMF in Volts
+k=Eb/W
+Ea=Vdc/2//Average Voltage
+Eb1=Ea-(Ia*Ra)
+W1=Eb1/k
+N1=W1*(60/(2*%pi))
+ton=T/2
+Irms=((sqrt(2)*Vdc)/(%pi*W0*la))*sin(W0*ton/2)
+Irms1=sqrt((I0^2)+(Irms^2))
+k1=Irms/I0
+I01=Ia/2//Average Value of Source Current
+Irms2=sqrt(2)*Ia/%pi
+k2=Irms2/I01//Source Current Ripple Factor
+printf('\n\n The Motor Speed=%0.1f rpm\n\n',N1)
+printf('\n\n The RMS Armature Current=%0.1f Amp\n\n',Irms1)
+printf('\n\n The RMS and line current ripple factor=%0.1f\n\n',k2)
diff --git a/3784/CH4/EX4.20/Ex4_20.sce b/3784/CH4/EX4.20/Ex4_20.sce new file mode 100644 index 000000000..567f8414f --- /dev/null +++ b/3784/CH4/EX4.20/Ex4_20.sce @@ -0,0 +1,29 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+Ia=30//Armature Current in Ampere
+Ia2=60//Armature Current in Ampere
+N1=1000//Rated Speed of Motor in rpm
+N2=800//Rated Speed of Motor in rpm
+Ra=0.7//Armature resistance in ohm
+d2=0.6//Duty Ratio
+d3=0.9//Duty Ratio
+d4=0.9//Duty Ratio
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+E01=Eb2-(Ia*Ra)
+d1=E01/Ea
+E02=d2*Ea
+Eb3=E02+(Ia*Ra)
+N3=(Eb3/Eb1)*N1
+E03=d3*Ea
+Eb4=E03+(Ia2*Ra)
+N4=(Eb4/Eb1)*N1
+E04=d4*Ea
+Pin=E04*Ia2
+printf('\n\n Duty Ratio Of Chopper=%0.1f\n\n',d1)
+printf('\n\n Motor Speed for duty ratio 0.6=%0.1f rpm\n\n',N3)
+printf('\n\n Maximum Aloowable Speed=%0.1f rpm\n\n',N4)
+printf('\n\n Power Fed to Source=%0.1f KW\n\n',Pin*10^-3)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.21/Ex4_21.sce b/3784/CH4/EX4.21/Ex4_21.sce new file mode 100644 index 000000000..fe83bafda --- /dev/null +++ b/3784/CH4/EX4.21/Ex4_21.sce @@ -0,0 +1,26 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+Ia=150//Armature Current in Ampere
+Ra=0.06//Armature resistance in ohm
+N1=1000//Rated Speed of Motor in rpm
+N2=500//Rated Speed of Motor in rpm
+N4=1350//Rated Speed of Motor in rpm
+d3=0.91//Duty Ratio
+Ia2=2*Ia
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+E01=Eb2+(Ia*Ra)
+d1=E01/Ea
+E02=Eb2-(Ia*Ra)
+d2=E02/Ea
+E03=d3*Ea
+Eb3=E03+(Ia2*Ra)
+N3=(Eb3/Eb1)*N1
+Pin=E03*Ia2
+R=N1/N4 //Ratio of If1 and If2
+printf('\n\n Duty ratio for motoring operation=%0.1f\n\n',d1)
+printf('\n\n Duty ratio for braking operation=%0.1f\n\n',d2)
+printf('\n\n Maximum permissible motor Speed=%0.1f rpm\n\n',N3)
+printf('\n\n Ratio of If1 and If2=%0.1f\n\n',R)
diff --git a/3784/CH4/EX4.22/Ex4_22.sce b/3784/CH4/EX4.22/Ex4_22.sce new file mode 100644 index 000000000..06d643770 --- /dev/null +++ b/3784/CH4/EX4.22/Ex4_22.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+Ia=100//Armature Current in Ampere
+Ia2=1.5*Ia
+Ra=0.01//Armature resistance in ohm
+Rb=2
+N1=1000//Rated Speed of Motor in rpm
+N2=500//Rated Speed of Motor in rpm
+d2=0.5
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+d=(1-(((Eb2/Ia2)-Ra)/Rb))//Wrongly solved in textbook
+Eb3=Ia2*(((1-d2)*Rb)+Ra)
+N3=(Eb3/Eb1)*N1
+printf('\n\n Duty Ratio of chopper=%0.1f\n\n',d)//The answer provided in the textbook is wrong
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N3)
diff --git a/3784/CH4/EX4.23/Ex4_23.sce b/3784/CH4/EX4.23/Ex4_23.sce new file mode 100644 index 000000000..757503d64 --- /dev/null +++ b/3784/CH4/EX4.23/Ex4_23.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+Ia=150//Armature Current in Ampere
+Ia2=300 //torque is doubled
+Ra=0.06//Armature resistance in ohm
+Rb=2.2
+N1=1000//Rated Speed of Motor in rpm
+N2=700//Rated Speed of Motor in rpm
+d2=0.55
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+d=(1-(((Eb2/Ia2)-Ra)/Rb))
+Eb3=Ia2*(((1-d2)*Rb)+Ra)
+N3=(Eb3/Eb1)*N1
+printf('\n\n Duty Ratio Of Chopper=%0.1f\n\n',d)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N3)
diff --git a/3784/CH4/EX4.24/Ex4_24.sce b/3784/CH4/EX4.24/Ex4_24.sce new file mode 100644 index 000000000..fc5bd24cf --- /dev/null +++ b/3784/CH4/EX4.24/Ex4_24.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+N1=1200//Rated Speed of Motor in rpm
+N2=1000//Rated Speed of Motor in rpm
+Ia=15//Armature Current in Ampere
+Ia2=1.5*Ia
+Ra=1.2//Armature resistance in ohm
+Rb=20
+d2=0.5
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+d1=(1-(((Eb2/Ia2)-Ra)/Rb))
+Eb3=Ia*(((1-d2)*Rb)+Ra)
+N3=(Eb3/Eb1)*N1
+printf('\n\n Duty Ratio Of Chopper=%0.1f\n\n',d1)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N3)
diff --git a/3784/CH4/EX4.25/Ex4_25.sce b/3784/CH4/EX4.25/Ex4_25.sce new file mode 100644 index 000000000..20d1a2c57 --- /dev/null +++ b/3784/CH4/EX4.25/Ex4_25.sce @@ -0,0 +1,21 @@ +clc
+//Variable Initialisation
+Ia=180//Armature Current in Ampere
+Ra=0.06//Armature resistance in ohm
+Rb=8
+If=2//Field Current in Ampere
+d=0.5
+K=1.527
+//Solution
+E0=Ia*Rb*(1-d)
+Req=Rb*(1-d)+Ra
+Pb=(Ia^2)*(Rb*(1-d))
+Eb=E0+(Ia*Ra)
+W=Eb/(K*If)
+W1=(W*60)/(2*%pi)
+Ep=Ia*Rb
+printf('\n\n The Average Voltage across chopper=%0.1f Volts\n\n',E0)
+printf('\n\n Equivalent Resistance of motor=%0.1f ohm\n\n',Req)
+printf('\n\n Power dissipated in braking resistor=%0.1f KW\n\n',Pb*10^-3)
+printf('\n\n The Motor Speed=%0.1f rpm\n\n',W1)
+printf('\n\n Peak to Peak Voltage=%0.1f Volts\n\n',Ep)
diff --git a/3784/CH4/EX4.26/Ex4_26.sce b/3784/CH4/EX4.26/Ex4_26.sce new file mode 100644 index 000000000..d762ca71d --- /dev/null +++ b/3784/CH4/EX4.26/Ex4_26.sce @@ -0,0 +1,21 @@ +clc
+//Variable Initialisation
+Ea=440//Input Voltage of motor in volts
+d=0.5//Duty Ratio
+Ia=200//Armature Current in Ampere
+Ra=0.15//Armature resistance in ohm
+K=1//Motor Constant
+//Solution
+E0=(1-d)*Ea
+Pr=E0*Ia
+Wmin1=(Ia*Ra)/K
+Wmin=Wmin1*60/(2*%pi)
+Wmax1=(Ea+(Ia*Ra))/K
+Wmax=Wmax1*60/(2*%pi)
+Eb=E0+(Ia*Ra)
+Wm1=Eb/K
+Wm=Wm1*60/(2*%pi)
+printf('\n\n The Power Returned=%0.1f KW\n\n',Pr*10^-3)
+printf('\n\n Minimum braking Speed=%0.1f rpm\n\n',Wmin)
+printf('\n\n Maximum braking Speed=%0.1f rpm\n\n',Wmax)//The answers vary due to round off error
+printf('\n\n Speed during Regenerative Braking=%0.1f rpm\n\n',Wm)
diff --git a/3784/CH4/EX4.27/Ex4_27.sce b/3784/CH4/EX4.27/Ex4_27.sce new file mode 100644 index 000000000..ecf8f4767 --- /dev/null +++ b/3784/CH4/EX4.27/Ex4_27.sce @@ -0,0 +1,14 @@ +clc
+//Variable Initialisation
+Ia1=190//Armature Current in Ampere
+Ia2=0.9*Ia1
+Ra=0.08//Armature resistance in ohm
+Ri=0.05
+Ea=210//Input Voltage of motor in volts
+N1=950//Rated Speed of Motor in rpm
+N2=750//Rated Speed of Motor in rpm
+//Solution
+Eb1=Ea-(Ia1*Ra)
+Eb2=(N2/N1)*Eb1
+Vi=Eb2-(Ia2*(Ra+Ri))
+printf('\n\n Internal Voltage of Source=%0.1f Volts\n\n',Vi)
diff --git a/3784/CH4/EX4.28/Ex4_28.sce b/3784/CH4/EX4.28/Ex4_28.sce new file mode 100644 index 000000000..eaca7e805 --- /dev/null +++ b/3784/CH4/EX4.28/Ex4_28.sce @@ -0,0 +1,19 @@ +clc
+//Variable Initialisation
+Ea=210//Input Voltage of motor in volts
+Ia1=140//Armature Current in Ampere
+Ia2=2*Ia1
+Ra=0.08//Armature resistance in ohm
+N1=1100//Rated Speed of Motor in rpm
+N2=1200//Rated Speed of Motor in rpm
+//Solution
+Eb1=Ea-(Ia1*Ra)
+Eb2=(N2/N1)*Eb1
+Rb=((Eb2+Ea)/Ia2)-Ra
+W=(2*%pi*N2)/60
+T1=(Eb2*Ia2)/W
+Ia3=Ea/(Ra+Rb)
+T2=T1*(Ia3/Ia2)
+printf('\n\n Resistance to be placed=%0.1f ohm\n\n',Rb)
+printf('\n\n Braking torque=%0.1f N-m\n\n',T1)
+printf('\n\n torque=%0.1f N-m\n\n',T2)//The answers vary due to round off error
diff --git a/3784/CH4/EX4.29/Ex4_29.sce b/3784/CH4/EX4.29/Ex4_29.sce new file mode 100644 index 000000000..f597036e7 --- /dev/null +++ b/3784/CH4/EX4.29/Ex4_29.sce @@ -0,0 +1,31 @@ +clc
+//Variable Initialisation
+Ra=0.08//Armature resistance in ohm
+Rb=1.5
+Rf=12
+N=500//Rated Speed of Motor in rpm
+//Solution
+If0=poly(0,'If0')
+Eb0=poly(0,'Eb0')
+
+If=[4.16,6.2,8.33,10.5,12.5,14.6,16.6,18.8,20]
+Eb=[41.6,61.2,75,85,92,96.6,101,105,125]
+W=2*%pi*N/60
+Ia=((Rb+Rf)/Rb)*If0
+K=Eb0*(1/W)
+If1=12.6
+Eb1=102.2
+for If0=If1
+ disp(Ia)
+end
+for Eb0=Eb1
+ disp(K)
+end
+If2=12.6
+K2=1.75
+Eb2=102.2
+K1=Eb2*(1/W)
+Ia2=9*If2
+Eb3=(If2*Rf)+(Ia2*Ra)//Wrongly calculated in book
+N2=Eb3*60/(K1*2*%pi)
+printf('\n\n Motor Speed at which load is hold by motor=%0.1f rpm\n\n',N2)//The answer provided in the textbook is wrong
diff --git a/3784/CH4/EX4.3/Ex4_3.sce b/3784/CH4/EX4.3/Ex4_3.sce new file mode 100644 index 000000000..9783db294 --- /dev/null +++ b/3784/CH4/EX4.3/Ex4_3.sce @@ -0,0 +1,25 @@ +clc
+//Variable Initialisation
+Ia=50//Armature Current in Ampere
+Ea=440//Input Voltage to armature in volts
+N=1000//Rated Speed of Motor in rpm
+Ra=0.5//Armature resistance in ohm
+Ra1=10.5//Armature resistance in ohm
+Rf=100//Field resistance in ohm
+N1=400//Speed of Motor in rpm
+N2=800//Speed of Motor in rpm
+ton=2*10^(-3)
+//Solution
+If=Ea/Rf
+Eb=Ea-(Ia*Ra)
+Eb1=(N1/N)*Eb
+E01=Eb1+(Ia*Ra1)
+t1=(Ea/E01)*2*10^3
+f1=1/t1
+Eb2=(N2/N)*Eb
+E02=Eb2+(Ia*Ra)
+t2=(Ea/E02)*ton
+f2=1/t2
+printf('\n\n The Chopping Frequency 1=%0.1f\n\n',f1)
+printf('\n\n The Chopping Frequency 2=%0.1f\n\n',f2)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.30/Ex4_30.sce b/3784/CH4/EX4.30/Ex4_30.sce new file mode 100644 index 000000000..f8cb031c1 --- /dev/null +++ b/3784/CH4/EX4.30/Ex4_30.sce @@ -0,0 +1,19 @@ +clc
+//Variable Initialisation
+Ra=0.08//Armature resistance in ohm
+T=300//Torque in N-m
+N=1000//Rated Speed of Motor in rpm
+Rf=12//Field Winding Resistor in ohm
+//Solution
+Eb=poly(0,'Eb')
+W=2*%pi*N/60
+Pd=T*W
+Ea=Eb-((Pd*Ra)/Eb)
+If=20//From previous Example
+Ea1=Rf*If
+Eb1=250//From previous Example
+Ia=(Eb1-Ea1)/Ra
+If1=Ea1/Rf
+Ir=Ia-If
+Rb=Ea1/Ir
+printf('\n\n Braking Resistance=%0.1f ohm\n\n',Rb)
diff --git a/3784/CH4/EX4.31/Ex4_31.sce b/3784/CH4/EX4.31/Ex4_31.sce new file mode 100644 index 000000000..9e0d880e9 --- /dev/null +++ b/3784/CH4/EX4.31/Ex4_31.sce @@ -0,0 +1,26 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+Ia=200//Armature Current in Ampere
+Ra=0.02//Armature resistance in ohm
+N1=960//Rated Speed of Motor in rpm
+N2=350//Rated Speed of Motor in rpm
+N4=1200//Rated Speed of Motor in rpm
+d3=0.95
+//Solution
+Ia2=2*Ia
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+E01=Eb2+(Ia*Ra)
+d1=E01/Ea
+Ea2=Eb2-(Ia*Ra)
+d2=Ea2/Ea
+Eam=d3*Ea
+P=Eam*Ia2
+Eb3=Eam+(Ia2*Ra)
+N3=(Eb3/Eb1)*N1
+Ifr=(N1/N4)
+printf('\n\n Duty ratio for motoring operation=%0.1f\n\n',d1)
+printf('\n\n Duty ratio for braking operation=%0.1f\n\n',d2)
+printf('\n\n Maximum permissible motor Speed=%0.1f rpm\n\n',N3)
+printf('\n\n Field Current as Ratio of its rated value=%0.1f\n\n',Ifr)
diff --git a/3784/CH4/EX4.32/Ex4_32.sce b/3784/CH4/EX4.32/Ex4_32.sce new file mode 100644 index 000000000..387b4245c --- /dev/null +++ b/3784/CH4/EX4.32/Ex4_32.sce @@ -0,0 +1,19 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+Ia=10//Armature Current in Ampere
+Ia2=2*Ia//Given condition for armature Current
+Ia3=2*Ia//Given condition for armature Current
+Ra=1.5//Armature resistance in ohm
+Rb=15//Braking Resistance in ohm
+N1=1500//Rated Speed of Motor in rpm
+N2=1200//Rated Speed of Motor in rpm
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+d1=1-(((Eb2/Ia2)-Ra)/Rb)
+d2=0.6//Duty ratio
+Eb3=Ia3*(((1-d2)*Rb)+Ra)
+N3=(Eb3/Eb1)*N1
+printf('\n\n Duty ratio =%0.1f\n\n',d1)
+printf('\n\n motor Speed=%0.1f rpm\n\n',N3)
diff --git a/3784/CH4/EX4.33/Ex4_33.sce b/3784/CH4/EX4.33/Ex4_33.sce new file mode 100644 index 000000000..978d42940 --- /dev/null +++ b/3784/CH4/EX4.33/Ex4_33.sce @@ -0,0 +1,23 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+Ia=50//Armature Current in Ampere
+Ra=0.4//Armature resistance in ohm
+N1=800//Rated Speed of Motor in rpm
+//Solution
+T=poly(0,'T')
+W=2*%pi*N1/60
+Eb=Ea-(Ia*Ra)
+K=Eb/W
+d1=0.3
+W1=((d1*Ea)/K)-(Ra/(K^2))*T
+d2=0.6
+W2=((d2*Ea)/K)-(Ra/(K^2))*T
+d3=0.7
+W3=((d3*Ea)/K)+(Ra/(K^2))*T
+d4=0.4
+W4=((d4*Ea)/K)+(Ra/(K^2))*T
+disp(W1,'Speed in terms of torque for motoring operation for duty ratio 0.3')
+disp(W2,'Speed in terms of torque for motoring operation for duty ratio 0.6')
+disp(W3,'Speed in terms of torque for Braking operation for duty ratio 0.7')
+disp(W4,'Speed in terms of torque for Braking operation for duty ratio 0.4')
diff --git a/3784/CH4/EX4.34/Ex4_34.sce b/3784/CH4/EX4.34/Ex4_34.sce new file mode 100644 index 000000000..71cc9576c --- /dev/null +++ b/3784/CH4/EX4.34/Ex4_34.sce @@ -0,0 +1,17 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+Ia=15//Armature Current in Ampere
+Ra=1.2//Armature resistance in ohm
+Rb=20//Braking Resistance in ohm
+Ia2=15*Ia
+N1=1200//Motor Speed in rpm
+//Solution
+Eb=Ea-(Ia*Ra)
+Eb1=Ea-(Ia2*Ra)
+d1=1-(((Eb1/Ia2)-Ra)/Rb)
+d2=0.5//Duty ratio
+Eb2=Ia*(((1-d2)*Rb)+Ra)
+N2=(Eb2/Eb)*N1
+printf('\n\n Duty ratio Of Chopper=%0.1f\n\n',d1)
+printf('\n\n Motor Speed=%0.1frpm\n\n',N2)
diff --git a/3784/CH4/EX4.35/Ex4_35.sce b/3784/CH4/EX4.35/Ex4_35.sce new file mode 100644 index 000000000..2f35e1d32 --- /dev/null +++ b/3784/CH4/EX4.35/Ex4_35.sce @@ -0,0 +1,19 @@ +clc
+//Variable Initialisation
+Ea=400//Input Voltage of motor in volts
+Ia=200//Armature Current in Ampere
+d=0.5//Duty Ratio
+Ra=0.03//Armature resistance in ohm
+Rs=0.05
+K=3e-3//Motor Constant
+//Solution
+E0=d*Ea
+Pin=E0*Ia//Input power in watt
+R=Ra+Rs
+Eb=E0-(Ia*R)
+Wm=Eb/(K*Ia)
+Wmrpm=Wm*30/%pi
+T=K*(Ia^2)
+printf('\n\n Input Power From Source=%0.1f KW\n\n',Pin*10^-3)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',Wmrpm)
+printf('\n\n Motor Torque=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.36/Ex4_36.sce b/3784/CH4/EX4.36/Ex4_36.sce new file mode 100644 index 000000000..ac38dc62f --- /dev/null +++ b/3784/CH4/EX4.36/Ex4_36.sce @@ -0,0 +1,16 @@ +clc
+//Variable Initialisation
+Ea=400//Input Voltage of motor in volts
+Ia=200//Armature Current in Ampere
+Ra=0.05//Armature resistance in ohm
+Rs=0.07
+d=0.5//Duty Ratio
+K=5e-3//Motor Constant
+//Solution
+E0=d*Ea
+Pin=E0*Ia
+Wm=((E0-Ia*(Ra+Rs))/(K*Ia))*(30/%pi)
+T=K*(Ia^2)
+printf('\n\n Input Power From Source=%0.1f KW\n\n',Pin*10^-3)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',Wm)
+printf('\n\n Motor Torque=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.37/Ex4_37.sce b/3784/CH4/EX4.37/Ex4_37.sce new file mode 100644 index 000000000..db0dea8fa --- /dev/null +++ b/3784/CH4/EX4.37/Ex4_37.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Ea=210//Input Voltage of motor in volts
+Ia1=80//Armature Current in Ampere
+N1=1200//Rated Speed of Motor in rpm
+Ra=0.08//Armature resistance in ohm
+Rf=0.08
+N2=1000
+//Solution
+T1=poly(0,'T1')
+T2=2*T1
+A=T2/T1
+Ia2=Ia1*(sqrt(2))//A=2
+Eb1=Ea-(Ia1*Ra)
+Eb2=Ia2*N2*Eb1/(Ia1*N1)
+Rb=(Eb2/Ia2)-Ra
+printf('\n\n Braking=%0.1f Amp\n\n',Ia2)
+printf('\n\n Braking Resistor=%0.1f ohm\n\n',Rb)
diff --git a/3784/CH4/EX4.38/Ex4_38.sce b/3784/CH4/EX4.38/Ex4_38.sce new file mode 100644 index 000000000..d3c0f78d2 --- /dev/null +++ b/3784/CH4/EX4.38/Ex4_38.sce @@ -0,0 +1,23 @@ +clc
+//Variable Initialisation
+Ea=500//Input Voltage of motor in volts
+Ra=0.06//Armature resistance in ohm
+Rf=0.09//Field Resistance in ohm
+K=35e-3//Motor Constant
+T=560//Rated Torque in N-m
+N1=0//Rated Speed of Motor in rpm
+d2=1//Duty ratio
+//Solution
+Ia=sqrt(T/K)//Armature Current in Ampere
+d1=(Ia*(Ra+Rf)+K*Ia*N1)/Ea
+N2=(d2*Ea-Ia*(Ra+Rf))/(K*Ia)
+N2rpm=N2*30/%pi
+d3=0.6
+N3=((d3*Ea-Ia*(Ra+Rf))/(K*Ia))*30/%pi
+d4=0.8
+N4=((d4*Ea-Ia*(Ra+Rf))/(K*Ia))*30/%pi
+d=[d1,d3,d4,d2]
+N=[N1,N3,N4,N2rpm]
+plot(d,N)
+ylabel("Speed in rpm", "fontsize", 2)
+xlabel("Duty Ratio", "fontsize", 2)
diff --git a/3784/CH4/EX4.39/Ex4_39.sce b/3784/CH4/EX4.39/Ex4_39.sce new file mode 100644 index 000000000..568d744b5 --- /dev/null +++ b/3784/CH4/EX4.39/Ex4_39.sce @@ -0,0 +1,20 @@ +clc
+//Variable Initialisation
+Ea=600//Input Voltage of motor in volts
+Ia=500//Armature Current in Ampere
+d1=0.6//Duty Ratio
+Ra=0.05//Armature resistance in ohm
+Rf=0.07//Field Resistance in ohm
+K=15.27e-3//Motor Constant
+//Solution
+E0=d1*Ea
+Pin=E0*Ia
+Re=Ea/(Ia*d1)
+Eb=E0-(Ia*(Ra+Rf))
+W=Eb/(Ia*K)
+N=W*60/(2*%pi)
+T=K*(Ia^2)
+printf('\n\n Input Power From Source=%0.1f KW\n\n',Pin*10^-3)
+printf('\n\n Equivalent Output Resistor=%0.1f ohm\n\n',Re)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N)
+printf('\n\n Motor Torque=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.4/Ex4_4.sce b/3784/CH4/EX4.4/Ex4_4.sce new file mode 100644 index 000000000..a29e12a5a --- /dev/null +++ b/3784/CH4/EX4.4/Ex4_4.sce @@ -0,0 +1,17 @@ +clc
+//Variable Initialisation
+V=230//Input Voltage of motor in volts
+Ra=1.5//Armature resistance in ohm
+La=1e-3//Armature inductance in ohm
+Ia=15//Armature Current in Ampere
+k=0.05//Voltage constant
+//Solution
+Eb=0 //when d=0
+Ea=Eb+(Ia*Ra)
+d=Ea/V
+Eb1=V-(Ia*Ra)
+//when d1=1
+N=Eb1/k
+printf('\n\n Range of speed control is from 0 to %0.1f\n\n',N)
+printf('\n\n The Duty Cycle is from%0.1f to 1\n\n',d)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.40/Ex4_40.sce b/3784/CH4/EX4.40/Ex4_40.sce new file mode 100644 index 000000000..95420d847 --- /dev/null +++ b/3784/CH4/EX4.40/Ex4_40.sce @@ -0,0 +1,17 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+N1=700//Rated Speed of Motor in rpm
+T1=247
+Ra=0.06//Armature resistance in ohm
+Rf=0.04
+d1=0.7
+T2=1.5*T1
+Ia1=133//Armature Current in Ampere
+//Solution
+K=T2/Ia1
+R=Ra+Rf
+Eb=(d1*Ea)-(Ia1*R)//Wrong value taken in book for Armature current
+W=Eb/K
+N2=W*60/(2*%pi)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N2)//The answer provided in the textbook is wrong
diff --git a/3784/CH4/EX4.41/Ex4_41.sce b/3784/CH4/EX4.41/Ex4_41.sce new file mode 100644 index 000000000..5019cf391 --- /dev/null +++ b/3784/CH4/EX4.41/Ex4_41.sce @@ -0,0 +1,13 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+Ia=125//Armature Current in Ampere
+Eb=60//Average Value of Back EMF
+f=200//Chopper Frequency
+Ra=0.025//Armature resistance in ohm
+Rf=0.015//Field resistance in ohm
+//Solution
+d1=(Eb+(Ia*(Ra+Rf)))/Ea
+T=(1/f)
+ton=d1*T
+printf('\n\n The Pulse Width=%0.1f msec\n\n',ton*10^3)
diff --git a/3784/CH4/EX4.42/Ex4_42.sce b/3784/CH4/EX4.42/Ex4_42.sce new file mode 100644 index 000000000..2f292b55f --- /dev/null +++ b/3784/CH4/EX4.42/Ex4_42.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+d1=0.8//Duty Ratio
+Ia1=300//Armature Current in Ampere
+Ra=0.04//Armature resistance in ohm
+N1=600//Rated Speed of Motor in rpm
+//Solution
+E0=d1*Ea
+Eb1=E0-(Ia1*Ra)
+Eb2=210
+N2=(Eb1/Eb2)*N1
+Ia3=310
+N3=500
+Eb3=142
+T=Eb3*Ia3/(2*%pi*N3/60)//Wrong calculated in book used N=520 instead of 500
+printf('\n\n The Motor Speed=%0.1f rpm\n\n',N2)
+printf('\n\n The Motor Torque=%0.1f N-m\n\n',T)//The answer provided in the textbook is wrong)
diff --git a/3784/CH4/EX4.43/Ex4_43.sce b/3784/CH4/EX4.43/Ex4_43.sce new file mode 100644 index 000000000..2b12a9e1d --- /dev/null +++ b/3784/CH4/EX4.43/Ex4_43.sce @@ -0,0 +1,22 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage of motor in volts
+d1=0.8//Duty Ratio
+Ia1=310//Armature Current in Ampere
+Ra=0.04//Armature resistance in ohm
+N4=1500//Rated Speed of Motor in rpm
+//Solution
+E0=d1*Ea
+Eb1=E0+(Ia1*Ra)
+N1=610//Motor speed in rpm
+Eb2=215
+N2=(Eb1/Eb2)*N1
+d2=0.95
+E02=d2*Ea
+Eb3=E02+(Ia1*Ra)
+N3=(Eb3/Eb2)*N1
+Eb4=(N4/N1)*Eb2
+Ra1=((Eb4-E02)/Ia1)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N2)
+printf('\n\n Maximum Allowable Speed=%0.1f rpm\n\n',N3)//The answers vary due to round off error
+printf('\n\n Resistance to be Inserted=%0.1f ohm\n\n',Ra1)
diff --git a/3784/CH4/EX4.44/Ex4_44.sce b/3784/CH4/EX4.44/Ex4_44.sce new file mode 100644 index 000000000..4783b1ee0 --- /dev/null +++ b/3784/CH4/EX4.44/Ex4_44.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Eb2=215//Average Value of Back EMF
+Ia=300//Armature Current in Ampere
+Ia1=310//Armature Current in Ampere
+Ra=0.04//Armature resistance in ohm
+N1=610//Rated Speed of Motor in rpm
+N2=750//Rated Speed of Motor in rpm
+dmin=0.05//Minimum Duty Ratio
+//Solution
+Eb1=(N2/N1)*Eb2
+Rbe=(Eb1/Ia)-Ra
+Rb=Rbe/(1-dmin)
+R=Rb*(1-dmin)+Ra
+K=Eb2/(2*%pi*N1/60)//The answer provided in the textbook is wrong
+T=K*Ia
+printf('\n\n Value of Braking Resistor=%0.1f ohm\n\n',Rb)
+printf('\n\n Maximum Available Motor Torque=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.45/Ex4_45.sce b/3784/CH4/EX4.45/Ex4_45.sce new file mode 100644 index 000000000..558f01076 --- /dev/null +++ b/3784/CH4/EX4.45/Ex4_45.sce @@ -0,0 +1,14 @@ +clc
+//Variable Initialisation
+Ra=0.4//Armature resistance in ohm
+Rf=0.4//Field resistance in ohm
+N1=400//Rated Speed of Motor in rpm
+N2=500//Rated Speed of Motor in rpm
+//Solution
+W1=2*%pi*N1/60
+W2=2*%pi*N2/60
+Ia=97.5
+K=15.8
+Eb=K*W2
+Rb=(Eb/Ia)-Ra
+printf('\n\n Resistance across motor terminal=%0.1f ohm\n\n',Rb)
diff --git a/3784/CH4/EX4.46/Ex4_46.sce b/3784/CH4/EX4.46/Ex4_46.sce new file mode 100644 index 000000000..e575169f3 --- /dev/null +++ b/3784/CH4/EX4.46/Ex4_46.sce @@ -0,0 +1,22 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+d1=0.8//Duty Ratio
+d2=0.75//Duty Ratio
+Ia1=80//Armature Current in Ampere
+Ra=0.25//Armature resistance in ohm
+N2=750//Rated Speed of Motor in rpm
+N3=600//Rated Speed of Motor in rpm
+Ia2=70
+Eb2=210//Average Value of Back EMF
+//Solution
+E01=d1*Ea
+Eb1=E01-(Ia1*Ra)
+N1=(Eb1/Eb2)*N2
+Ia2=86
+E02=d2*Ea
+Eb3=E02-(Ia2*Ra)
+Wm=2*%pi*N3/60
+T=Eb3*Ia2/Wm
+printf('\n\n Motor Speed=%0.1f rpm\n\n',N1)
+printf('\n\n Torque produced=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.47/Ex4_47.sce b/3784/CH4/EX4.47/Ex4_47.sce new file mode 100644 index 000000000..655110f0b --- /dev/null +++ b/3784/CH4/EX4.47/Ex4_47.sce @@ -0,0 +1,25 @@ +clc
+//Variable Initialisation
+Ea=230//Input Voltage of motor in volts
+d1=0.4//Duty Ratio
+Ia1=86//Armature Current in Ampere
+Ra=0.25//Armature resistance in ohm
+N1=850//Rated Speed of Motor in rpm
+N4=1300//Rated Speed of Motor in rpm
+Eb1=220//Average Value of Back EMF
+//Solution
+E01=d1*Ea
+Eb2=E01+(Ia1*Ra)
+N2=(Eb2/Eb1)*N1
+dmax=0.98//Maximum aloowable duty ratio
+E02=dmax*Ea
+Eb3=E02+(Ia1*Ra)
+N3=(Eb3/Eb1)*N1//Wrong value of N1 is taken in textbook
+Eb4=(N4/N1)*Eb1
+R=((Eb4-E02)/Ia1)-Ra
+E1=(N1/N4)*Eb3
+n=E1/Eb1
+printf('\n\n Motor speed=%0.1f rpm\n\n',N2)
+printf('\n\n Maximum allowable motor Speed=%0.1f rpm\n\n',N3)//The answer provided in the textbook is wrong
+printf('\n\n Resistance to be inserted=%0.1f ohm\n\n',R)
+printf('\n\n number of turns reduced to fraction=%0.1f\n\n',n)
diff --git a/3784/CH4/EX4.48/Ex4_48.sce b/3784/CH4/EX4.48/Ex4_48.sce new file mode 100644 index 000000000..3f274a09e --- /dev/null +++ b/3784/CH4/EX4.48/Ex4_48.sce @@ -0,0 +1,21 @@ +clc
+//Variable Initialisation
+Ia1=86//Armature Current in Ampere
+Ra=0.25//Armature resistance in ohm
+N1=1000//Rated Speed of Motor in rpm
+N2=850//Rated Speed of Motor in rpm
+Eb1=220//Average Value of Back EMF
+dmin=0.5//Minimum Duty Ratio
+dmax=0.95//Maximum Duty Ratio
+//Solution
+Eb2=(N1/N2)*Eb1
+Rbe=(Eb2/Ia1)-Ra
+Rb=Rbe/(1-dmin)
+R=Rb*(1-dmax)+Ra
+Eb3=Ia1*R
+Eb4=190
+Ia2=55
+K=Eb4/(2*%pi*N2/60)
+T=K*Ia2
+printf('\n\n Braking Resistor=%0.1f ohm\n\n',Rb)
+printf('\n\n Maximum Available Motor Torque=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.49/Ex4_49.sce b/3784/CH4/EX4.49/Ex4_49.sce new file mode 100644 index 000000000..7e515f116 --- /dev/null +++ b/3784/CH4/EX4.49/Ex4_49.sce @@ -0,0 +1,26 @@ +clc
+//Variable Initialisation
+Ea=500//Input Voltage of motor in volts
+d1=0.65//Duty Ratio
+Ra=0.06//Armature resistance in ohm
+Ia=300//Armature Current in Ampere
+Rf=0.08//Field resistance in ohm
+K=15.27e-3//Motor Constant
+//Solution
+E0=(1-d1)*Ea
+R=Ra+Rf
+Req=(1-d1)*(Ea/Ia)+R
+Pgen=E0*Ia
+Wmin=R/K
+Wminr=Wmin*(30/%pi)
+Wmax=(Ea/(K*Ia))+(R*Ia/(K*Ia))
+Wmaxr=Wmax*(30/%pi)
+Eb=E0+(Ia*Ra)
+W=Eb/(K*Ia)
+Wr=W*(30/%pi)
+printf('\n\n Voltage across Chopper=%0.1f Volts\n\n',E0)
+printf('\n\n Equivalent Resistance of Motor=%0.1f ohm\n\n',Req)
+printf('\n\n Power Generated=%0.1f KW\n\n',Pgen*10^-3)
+printf('\n\n Maximum Permissible Braking Speed=%0.1f rpm\n\n',Wmaxr)
+printf('\n\n Minimum Permissible Braking Speed=%0.1f rpm\n\n',Wminr)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',Wr)
diff --git a/3784/CH4/EX4.5/Ex4_5.sce b/3784/CH4/EX4.5/Ex4_5.sce new file mode 100644 index 000000000..dc497ae3e --- /dev/null +++ b/3784/CH4/EX4.5/Ex4_5.sce @@ -0,0 +1,15 @@ +clc
+//Variable Initialisation
+Ea=220//Input Voltage to armature in volts
+N1=1000//Rated Speed of Motor in rpm
+N2=500//Speed of Motor in rpm
+Ia=24//Armature Current in Ampere
+Ra=2//Armature resistance in ohm
+Es=230//Source voltage in Volts
+//Solution
+Eb1=Ea-(Ia*Ra)
+Eb2=(N2/N1)*Eb1
+E0=Eb2+(1.2*Ia*Ra)
+d=E0/Es
+printf('\n\n The Duty Ratio=%0.1f\n\n',d)
+//The answers vary due to round off error
diff --git a/3784/CH4/EX4.50/Ex4_50.sce b/3784/CH4/EX4.50/Ex4_50.sce new file mode 100644 index 000000000..c6f99366f --- /dev/null +++ b/3784/CH4/EX4.50/Ex4_50.sce @@ -0,0 +1,26 @@ +clc
+//Variable Initialisation
+Ea=500//Input Voltage of motor in volts
+Ra=0.06//Armature resistance in ohm
+Rf=0.09//Field resistance in ohm
+K=12e-3//Motor Constant
+Ia=400//Armature Current in Ampere
+d1=0.6//Duty Ratio
+//Solution
+E0=(1-d1)*Ea
+Pin=E0*Ia
+R=Ra+Rf
+Req=(E0/Ia)+R
+Wmin=R/K
+Wminr=Wmin*30/%pi
+Wmax=(R/K)+(Ea/(K*Ia))
+Wmaxr=Wmax*30/%pi
+Eb=E0+(Ia*R)
+W=Eb/(K*Ia)
+Wr=W*30/%pi
+printf('\n\n Voltage across Converter=%0.1f Volts\n\n',E0)
+printf('\n\n Power Generated=%0.1f KW\n\n',Pin*10^-3)
+printf('\n\n Equivalent Resistance of Motor=%0.1f ohm\n\n',Req)
+printf('\n\n Maximum Permissible Braking Speed=%0.1f rpm\n\n',Wmaxr)
+printf('\n\n Minimum Permissible Braking Speed=%0.1f rpm\n\n',Wminr)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',Wr)
\ No newline at end of file diff --git a/3784/CH4/EX4.51/Ex4_51.sce b/3784/CH4/EX4.51/Ex4_51.sce new file mode 100644 index 000000000..0ab06dcea --- /dev/null +++ b/3784/CH4/EX4.51/Ex4_51.sce @@ -0,0 +1,22 @@ +clc
+//Variable Initialisation
+Ia=300//Armature Current in Ampere
+Rb=8//Braking resistance in ohm
+Ra=0.05//Armature resistance in ohm
+Rf=0.08//Field resistance in ohm
+d=0.5//Duty Ratio
+K=14e-3//Motor Constant
+//Solution
+E0=(1-d)*Ia*Rb
+Pin=(Ia^2)*Rb*(1-d)
+R=Ra+Rf
+Req=Rb*(1-d)+R
+Eb=E0+(Ia*R)
+W=Eb/(K*Ia)
+Wr=W*30/%pi
+Ep=Ia*Rb
+printf('\n\n Voltage across Converter=%0.1f Volts\n\n',E0)
+printf('\n\n Power dissipated=%0.1f KW\n\n',Pin*10^-3)
+printf('\n\n Equivalent Resistance of Motor=%0.1f ohm\n\n',Req)
+printf('\n\n Motor Speed=%0.1f rpm\n\n',Wr)
+printf('\n\n Peak to Peak Voltage of Converter=%0.1f Volts\n\n',Ep)
diff --git a/3784/CH4/EX4.6/Ex4_6.sce b/3784/CH4/EX4.6/Ex4_6.sce new file mode 100644 index 000000000..07e4fed85 --- /dev/null +++ b/3784/CH4/EX4.6/Ex4_6.sce @@ -0,0 +1,20 @@ +clc
+//Variable Initialisation
+Ea=500//Input Voltage to armature in volts
+Ra=0.09//Armature resistance in ohm
+If=3//Field Current in Ampere
+K=1.527//Voltage constant
+T=560//Torque Developed in N-m
+N1=0//Speed of Motor in rpm
+d2=1//duty ratio
+//Solution
+Ia=T/(K*If)
+Eb=K*N1
+d1=(Eb+(Ia*Ra))/Ea
+N2=((d2*Ea)-(Ia*Ra))/(K*If)
+N2r=N2*60/(2*%pi)
+d3=[0.2,0.4,0.6,0.8,1.0]
+N3r=[556.56 ,1181.92,1807.28 ,2432.6,3058.0]
+plot(d3,N3r)
+xlabel ('Duty Interval')
+ylabel ('Speed in RPM')
diff --git a/3784/CH4/EX4.7/Ex4_7.sce b/3784/CH4/EX4.7/Ex4_7.sce new file mode 100644 index 000000000..ed02af6ef --- /dev/null +++ b/3784/CH4/EX4.7/Ex4_7.sce @@ -0,0 +1,18 @@ +clc
+//Variable Initialisation
+Ra=0.08//Armature resistance in ohm
+Ea=450//Input Voltage to armature in volts
+Ia=275//Armature Current in Ampere
+If=3//Field Current in Ampere
+K=1.527//Voltage constant
+d=0.65//Duty ratio
+//Solution
+Pin=d*Ea*Ia
+E0=d*Ea
+Eb=E0-(Ia*Ra)
+W=Eb/(K*If)
+N=W*60/(2*%pi)
+T=K*If*Ia
+printf('\n\n The Input power from Generator Source=%0.1f Watt\n\n',Pin)
+printf('\n\n The Speed of Motor=%0.1f rpm\n\n',N)
+printf('\n\n The Torque developed=%0.1f N-m\n\n',T)
diff --git a/3784/CH4/EX4.8/Ex4_8.sce b/3784/CH4/EX4.8/Ex4_8.sce new file mode 100644 index 000000000..10b027ff9 --- /dev/null +++ b/3784/CH4/EX4.8/Ex4_8.sce @@ -0,0 +1,14 @@ +clc
+//Variable Initialisation
+ton=15
+toff=10
+Ea=220//Input Voltage to armature in volts
+Km=0.4//Voltage constant
+N=1400//Rated Speed of Motor in rpm
+Ra=2//Armature resistance in ohm
+//Solution
+d=ton/(ton+toff)
+E0=d*Ea
+W=2*%pi*N/60
+Ia=(E0-(Km*W))/Ra
+printf('\n\n The Average load Current=%0.1f Amp\n\n',Ia)
diff --git a/3784/CH4/EX4.9/Ex4_9.sce b/3784/CH4/EX4.9/Ex4_9.sce new file mode 100644 index 000000000..08949fe50 --- /dev/null +++ b/3784/CH4/EX4.9/Ex4_9.sce @@ -0,0 +1,16 @@ +clc
+//Variable Initialisation
+Ea=200//Input Voltage to armature in volts
+Ia=20//Armature Current in Ampere
+Ra=0.4//Armature resistance in ohm
+k=0.1
+N1=0//Speed of Motor in rpm
+//Solution
+Eb1=k*N1
+d1=(Eb1+(Ia*Ra))/Ea
+d2=1
+Eb2=d2*Ea-(Ia*Ra)
+N2=Eb2/k
+printf('\n\n Range of speed control from 0 to %0.1f\n\n',N2)
+printf('\n\n Range of duty cycle from %0.1f to 1\n\n',d1)
+//The answers vary due to round off error
diff --git a/3784/CH5/EX5.1/Ex5_1.sce b/3784/CH5/EX5.1/Ex5_1.sce new file mode 100644 index 000000000..939485dfc --- /dev/null +++ b/3784/CH5/EX5.1/Ex5_1.sce @@ -0,0 +1,17 @@ +clc
+//Variable Initilisation
+Ns=1500 //Speed of Squirrel Cage Induction Motor in RPM
+N1=1460 //Speed of Squirrel Cage Induction Motor in RPM
+N2=1350 //Speed of Squirrel Cage Induction Motor in RPM
+
+// At 1460 rpm the speed slip is given by
+S1=(Ns-N1)/Ns //Slip
+I=(sqrt(1/3)*(2/3))/(sqrt(S1)*(1-S1))
+// At 1350 rpm the speed slip is given by
+S2=(Ns-N2)/Ns //Slip
+I1=(sqrt(1/3)*(2/3))/(sqrt(S2)*(1-S2))
+
+
+//Results
+printf('\n\n The motor maximum Current in terms of rated current at the above speed =%0.1f \n\n',I)
+printf('\n\n The motor maximum Current in terms of rated current at the above speed =%0.1f \n\n',I1)
diff --git a/3784/CH5/EX5.10/Ex5_10.sce b/3784/CH5/EX5.10/Ex5_10.sce new file mode 100644 index 000000000..8834b94c7 --- /dev/null +++ b/3784/CH5/EX5.10/Ex5_10.sce @@ -0,0 +1,31 @@ +clc
+//variable initialisation
+Vm=400 //Rated Voltage of motor in volt
+Vs=440 //Supply Voltage of motor in volt
+F=50 //Supply frequency in hrtz
+P=4 //Number Of Poles
+N1=1475 //Speed OF Motor In rpm
+R1=0.35 //Resistance of stator in ohm
+R2=0.18 //Resistance of rotor in ohm
+X1=0.9 //Reactance of Motor in ohm
+X2=0.7 //Reactance of Motor in ohm
+Xm=25 //Reactance of Motor in ohm
+
+//Solution
+Vph1=Vs/(sqrt(3))
+Vph2=Vm/(sqrt(3))
+Ns=(120*F)/(P)
+S=(Ns-N1)/Ns
+I2=(Vph2)/sqrt(((R1+(R2/S))^2)+((X1+X2)^2))
+Pg=3*(I2^2)*(R2/S)
+Sm=R2/sqrt((R1)^2+((X1+X2)^2))
+Wms=(2*%pi*Ns)/60
+Tm=3*(Vph1^2)/((2*Wms)*(R1+sqrt((R1)^2+((X1+X2)^2))))
+Zi=%i*(Xm*((R1+(R2/S))+%i*(X1+X2)))/(R1+(R2/S)+%i*(X1+X2+Xm))
+Z=abs(Zi)
+printf('\n\n The Slip=%0.1f\n\n',S)
+printf('\n\n The Air gap Power Angle=%0.1f Watts\n\n',Pg)
+printf('\n\n The Slip for maximum torque=%0.1f\n\n',Sm)
+printf('\n\n The Maximum Torque=%0.1f N-m\n\n',Tm)
+printf('\n\n The Input Impedance=%0.1f\n\n',Z)
+//The answers vary due to round off error
diff --git a/3784/CH5/EX5.11/Ex5_11.sce b/3784/CH5/EX5.11/Ex5_11.sce new file mode 100644 index 000000000..2c3d8aa5d --- /dev/null +++ b/3784/CH5/EX5.11/Ex5_11.sce @@ -0,0 +1,42 @@ +clc
+//variable Initialisation
+Vm=240 //Terminal Voltage Of Motor In Volt
+F=50 //Supply Frequency Of Motor
+P=4 //Number Of Pole
+R1=0.25 //Resistance Of Motor in Ohm
+R2=0.60 //Resistance Of Motor in Ohm
+X1=0.36//Reactance in Ohm
+X2=0.36//Reactance in Ohm
+Xm=17.3//Reactance In Ohm
+Nr1=1400 //Speed Of Rotor In RPM
+Nr2=600 //Speed Of Rotor In RPM
+
+//Solution
+#Case=1
+W=((2*%pi)/60)*(Nr1)
+Ns=(120*F)/(P)
+S1=(Ns-Nr1)/Ns
+S2=(Ns-Nr2)/Ns
+Zr=(R2/S1)+%i*(X2)
+Zs=R1+%i*(X1)
+Zt=Zr+Zs
+Zin=(%i*(Xm)*(Zt))/(%i*(Xm)+(Zt))
+Tl=1.4*((10)^-3)*(W)^2
+n=Nr1/60
+I2=sqrt((S1*Tl*2*%pi*n)/(3*R2*(1-S1)))
+#Case=2
+Zr1=(R2/S2)+%i*(X2)
+Zs1=R1+%i*(X1)
+Zt1=Zr1+Zs1
+Zin1=(%i*(Xm)*(Zt1))/(%i*(Xm)+(Zt1))
+W1=((2*%pi)/60)*(Nr2)
+Tl1=1.4*((10)^-3)*(W1)^2
+n1=Nr2/60
+I3=sqrt((S2*Tl1*2*%pi*n1)/(3*R2*(1-S2)))
+//Given base currents in Amp
+Ib1=17.55
+Ib2=100.27
+Ip1=I2/Ib1
+Ip2=I3/Ib2
+printf('\n\n The per unit rotor Current for case 1=%0.1f\n\n',Ip1)
+printf('\n\n The per unit rotor Current for case 2=%0.1f\n\n',Ip2)
diff --git a/3784/CH5/EX5.12/Ex5_12.sce b/3784/CH5/EX5.12/Ex5_12.sce new file mode 100644 index 000000000..8eaf176d4 --- /dev/null +++ b/3784/CH5/EX5.12/Ex5_12.sce @@ -0,0 +1,23 @@ +clc
+//variable Initialisation
+Vm=400 //Terminal Voltage Of Motor In Volt
+F=50 //Supply Frequency Of Motor
+P=6 //Number Of Pole
+R1=0.2 //Resistance Of Motor in Ohm
+R2=0.2 //Resistance Of Motor in Ohm
+X1=0.5 //Reactance in Ohm
+X2=0.5 //Reactance in Ohm
+Xm=15 //Reactance In Ohm
+S=0.05 //Slip Of Motor
+
+//Solution
+Ns=(120*F)/(P)
+Ws=((2*%pi)/60)*(Ns)
+Vph=Vm/sqrt(3)
+S1=2-S
+I2=(Vph)/sqrt(((R1+(R2/S1))^2)+((X1+X2)^2))
+Im=Vph/Xm
+I1=Im+I2
+Tb=((3*((I2)^2))/(Ws))*(R2/S1)
+printf('\n\n The Primary Current=%0.1f Amp\n\n',I1)
+printf('\n\n The Braking Torque=%0.1f N-m\n\n',Tb)
diff --git a/3784/CH5/EX5.13/Ex5_13.sce b/3784/CH5/EX5.13/Ex5_13.sce new file mode 100644 index 000000000..305213f39 --- /dev/null +++ b/3784/CH5/EX5.13/Ex5_13.sce @@ -0,0 +1,29 @@ +clc
+//variable Initialisation
+Vm=400 //Terminal Voltage Of Motor In Volt
+F=50 //Supply Frequency
+P=6 //Number Of Pole
+R1=1.5 //Resistance Of Motor in Ohm
+R2=1.5 //Resistance Of Motor in Ohm
+X1=2.5//Reactance in Ohm
+X2=2.5//Reactance in Ohm
+Nr1=900 //Speed Of Rotor In RPM
+Nr2=400 //Speed Of Rotor In RPM
+
+//Solution
+Vph=Vm/sqrt(3)
+Ns=(120*F)/(P)
+S=(Ns-Nr1)/Ns
+I2=(Vph)/sqrt(((R1+(R2/S))^2)+((X1+X2)^2))
+Ws=((2*%pi)/60)*(Ns)
+T=((3*((I2)^2))/(Ws))*(R2/S)
+//At Braking
+Sb=2-S
+I2b=(Vph)/sqrt(((R1+(R2/Sb))^2)+((X1+X2)^2))
+Tb=((3*((I2b)^2))/(Ws))*(R2/Sb)
+S1=(Ns+Nr2)/Ns
+I3=(Vph)/sqrt(((R1+(R2/S1))^2)+((X1+X2)^2))
+T1=((3*((I3)^2))/(Ws))*(R2/S1)
+printf('\n\n The Full load Torque=%0.1f N-m\n\n',T)
+printf('\n\n The Initial braking Torque=%0.1f N-m\n\n',Tb)
+printf('\n\n The braking Torque at 400 rpm=%0.1f N-m\n\n',T1)
diff --git a/3784/CH5/EX5.14/Ex5_14.sce b/3784/CH5/EX5.14/Ex5_14.sce new file mode 100644 index 000000000..42fc74bbf --- /dev/null +++ b/3784/CH5/EX5.14/Ex5_14.sce @@ -0,0 +1,27 @@ +
+clc
+//variable Initialisation
+Vm=400 //Terminal Voltage Of Motor In Volts
+Pout=3 //Output Of Motor In KW
+F=50 //Supply Frequency
+P=4 //Number Of Pole
+R1=2.5 //Resistance Of Motor in Ohm
+R2=4.5 //Resistance Of Motor in Ohm
+X1=6 //Reactance in Ohm
+X2=6 //Reactance in Ohm
+Nr1=1400 //Speed Of Rotor In RPM
+Nr2=1300 //Speed Of Rotor In RPM
+
+//Solution
+Ns=(120*F)/(P)
+S=(Ns-Nr1)/Ns
+Vph=Vm/sqrt(3)
+I2=(Vm)/sqrt(((R1+(R2/S))^2)+((X1+X2)^2))
+Ws=((2*%pi)/60)*(Ns)
+Tl=((3*((I2)^2))/(Ws))*(R2/S)
+K=Tl/((1-S)^2)
+S1=(Ns-Nr2)/Ns
+Tl1=K*((1-S1)^2)
+Vs=sqrt(Tl1*S1*Ws*(((R1+(R2/S1))^2)+((X1+X2)^2))/((3)*(R2)))//Wrongly calculated in textbook
+printf('\n\n The Voltage To be Applied=%0.1f Volts\n\n',Vs)
+//The answer provided in the textbook is wrong
diff --git a/3784/CH5/EX5.15/Ex5_15.sce b/3784/CH5/EX5.15/Ex5_15.sce new file mode 100644 index 000000000..280a9a677 --- /dev/null +++ b/3784/CH5/EX5.15/Ex5_15.sce @@ -0,0 +1,35 @@ +clc
+//variable Initialisation
+Vm=400 //Terminal Voltage Of Motor In Volt
+F=50 //Supply Frequency
+P=6 //Number Of Pole
+R1=0.6 //Resistnce Of Motor in Ohm
+R2=0.5 //Resistnce Of Motor in Ohm
+X1=1.3 //Reactance in Ohm
+X2=1.3 //Reactance in Ohm
+Xm=50 //Reactance In Ohm
+Nr=950 //Speed Of Rotor In RPM
+
+//Solution
+Ns=(120*F)/(P)
+Wms=((2*%pi)/60)*(Ns)
+S=(Ns-Nr)/Ns
+Vph=Vm/sqrt(3)
+I2=(Vph)/sqrt(((R1+(R2/S))^2)+((X1+X2)^2))
+Im=Vph/Xm
+I1=Im+I2
+Z1=(%i*(Xm)*((R2/S)+%i*(X2)))/((R2/S)+(%i*(X2+Xm)))
+Zf=R1+%i*(X1)+(Z1)
+Z2=%i*Xm*((R2/(2-S))+(%i*(X2)))/((R2/(2-S))+(%i*(X2+Xm)))
+Zb=R1+%i*(X1)+(Z2)
+Z3=Zf+Zb
+Znew=abs(Z3)
+I=Vph/Znew
+Tp=(3*((I)^2)*((Xm)^2)*(R2/S))/((Wms)*(((R2/S)^2)+((X2+Xm)^2)))
+Tn=-((3*((I)^2)*((Xm)^2)*(R2/(2-S)))/((Wms)*(((R2/(2-S))^2)+((X2+Xm)^2))))
+T=Tp+Tn
+Wm=Wms*(1-S)
+Tl=(8.4/1000)*(Wm^2)//Given
+printf('\n\n The Motor Speed=%0.1f rpm\n\n',Ns)
+printf('\n\n The motor Current=%0.1f Amp\n\n',I)
+disp("Since T=Tl,Motor will run Safely")
diff --git a/3784/CH5/EX5.2/Ex5_2.sce b/3784/CH5/EX5.2/Ex5_2.sce new file mode 100644 index 000000000..631b76f01 --- /dev/null +++ b/3784/CH5/EX5.2/Ex5_2.sce @@ -0,0 +1,45 @@ +clc
+//variable Initialisation
+V=415//Voltage Input in Volts
+f=50//supply frequency in Hz
+P=4//No of Poles
+N1=1450//Rotor Speed in rpm
+N2=1290//Rotor Speed in rpm for case II
+R1=1.01
+R2=0.69
+X1=1.08
+X2=1.60
+Xm=36
+Tl=42//Rated torque in N-m
+//Solution
+Vph=V/sqrt(3)
+Ns=120*f/P
+Ws=2*%pi*Ns/60
+Wm=2*%pi*N1/60
+K=Tl/(Wm^2)
+s=(Ns-N2)/Ns//Slip
+Wm2=Ws*(1-s)
+Tl=K*(Wm2^2)//Load Torque in N-m
+Tl2=Tl*Wm2//Torque in Synchronous Watts
+I2=sqrt((Tl2*s)/(3*R2*(1-s)))
+Z=R1+(R2/s)+(%i*(X1+X2))//Impedance at slip s
+V2=I2*abs(Z)//Voltage applied in Volts/Phase
+Im=V2/(%i*Xm)
+Im1=abs(Im)
+Ir=V2/Z//Rotor Current
+Is=Ir+Im//Stator Current
+a=atand(imag(Is)/real(Is))
+Pin=3*V2*abs(Is)*cosd(a)//Input Power
+Smax=1/3//Smax is obtain theorotically
+I2max=Ws*sqrt(Smax)*(1-Smax)*sqrt(K*Ws/(3*R2))
+Nr=Ns*(1-Smax)//Speed at maximum Current
+Wmax=2*%pi*Nr/60
+T=3*(I2max^2)*R2*(1-Smax)/(Smax*Wmax)//Torque at maximum Current
+printf('\n\n The Load torque=%0.1f N-m\n\n',Tl)
+printf('\n\n The Rotor Current=%0.1f Amp\n\n',Ir)
+printf('\n\n The Stator Supply Voltage=%0.1f Volts\n\n',V2)
+printf('\n\n The Motor input current=%0.1f Amp\n\n',Is)
+printf('\n\n The Motor input power=%0.1f Watt\n\n',Pin)//The answer provided in the textbook is wrong
+printf('\n\n Maximum rotor Current=%0.1f Amp\n\n',I2max)
+printf('\n\n The speed at maximum current=%0.1f rad/sec\n\n',Wmax)
+printf('\n\n The torque at maximum current=%0.1f N-m\n\n',T)
diff --git a/3784/CH5/EX5.3/Ex5_3.sce b/3784/CH5/EX5.3/Ex5_3.sce new file mode 100644 index 000000000..2ac1d93ba --- /dev/null +++ b/3784/CH5/EX5.3/Ex5_3.sce @@ -0,0 +1,25 @@ +clc
+//variable Initialisation
+Vl=440//Voltage Input in Volts
+f1=50//supply frequency in Hz
+P=25e+3//power rating in Watts
+N1=950//Rotor Speed in rpm
+Z=0.1+(%i*3)//Rotor Impedance
+pole=6//No of poles
+f2=80//Supply 2 frequency in Hz
+//Solution
+V=Vl/sqrt(3)//Phase Voltage in Volts
+Wm=2*%pi*N1/60
+Tfl=P/Wm//Full load Torque in N-m
+Ns=120*f2/pole
+Ws=2*%pi*Ns/60
+Z2=Z*(f2/f1)//Rotor Impedance at 80 Hz
+S=3*(V^2)*0.5/(Ws*((abs(Z2))^2)*Tfl)
+Nr=Ns*(1-S)
+Rl=real(Z)
+Xl=imag(Z2)
+Smax=(Rl/Xl)
+Tmax=3*(V^2)/(Ws*2*Xl)
+printf('\n\n The Motor speed=%0.1f rpm\n\n',Nr)//The answers vary due to round off error
+printf('\n\n The Slip at which maximum torque occurs=%0.1f\n\n',Smax)
+printf('\n\n The maximum Torque=%0.1f\n\n',Tmax)
diff --git a/3784/CH5/EX5.4/Ex5_4.sce b/3784/CH5/EX5.4/Ex5_4.sce new file mode 100644 index 000000000..fa2505604 --- /dev/null +++ b/3784/CH5/EX5.4/Ex5_4.sce @@ -0,0 +1,24 @@ +clc
+//variable initialisation
+Vm=400 //Input Voltage in volt
+F=50 //supply frequency in Hz
+P1=4 //number of poles
+R1=0.15 //resistance of stator in ohm
+R2=0.12 //resistance of rotor in ohm
+X1=0.45 //reactance of Motor in ohm
+X2=0.45 //reactance of Motor in ohm
+Xm=28.5 //reactance of Motor in ohm
+S=0.04 //Slip Of Motor
+
+//Solution
+Rl=R2*((1/S)-1)
+Vph=Vm/sqrt(3)
+I2=Vph/((R1+R2+Rl)+%i*(X1+X2))
+I0=Vph/(%i*Xm)
+I1=I0+I2
+y=imag(I1)
+x=real(I1)
+phi=atand(y/x)
+pf=cosd(phi)
+printf('\n\n The Stator Current=%0.1f Amp\n\n',I1)
+printf('\n\n The Power Factor=%0.1f lag\n\n',pf)
diff --git a/3784/CH5/EX5.5/Ex5_5.sce b/3784/CH5/EX5.5/Ex5_5.sce new file mode 100644 index 000000000..3644a3841 --- /dev/null +++ b/3784/CH5/EX5.5/Ex5_5.sce @@ -0,0 +1,41 @@ +clc
+//variable initialisation
+Pout=37.3 //Motor Output In KW
+Vm=440 //Motor Input in volt
+F=50 //supply frequency in Hz
+I0=20 //NO Load Line Current Of Motor
+R1=0.1 //resistance of stator in ohm
+R2=0.15 //resistance of rotor in ohm
+X1=0.4 //reactance of Motor in ohm
+X2=0.44 //reactance of Motor in ohm
+S=0.03 //Slip Of Motor
+Ls=1250 //Stator Core Loses In Watt
+Lr=1000 //Rotational Losses In KW
+Ns=1500 // Synchronous Speed Of Motor
+
+//Solution
+Vph=Vm/sqrt(3)
+I2=Vph/((R1+(R2/S))+%i*(X1+X2))
+I21=abs(I2)
+I21=49.1//rounding off to avoid computational error
+I0=1.78-(%i*19.9)//Taken in book for No load motor current
+I1=I0+I2
+y=imag(I1)
+x=real(I1)
+phi=atand(y/x)
+pf=cosd(phi)
+P2=3*((I21)^2)*(R2/S)
+Tg=(9.55*P2)/Ns
+Pm=(1-S)*P2
+Pout1=Pm+Lr
+Lcs=3*((I21)^2)*R1//Wrong value of I2 is taken in textbook
+Lcr=S*P2
+Lt=Ls+Lr+Lcs+Lcr
+Pin=Lt+Pout1
+n=Pout1/Pin
+printf('\n\n The input line Current=%0.1f Amp\n\n',I1)
+printf('\n\n The power factor=%0.1f lag\n\n',pf)
+printf('\n\n The Electromagnetic Torque Developed=%0.1f N-m\n\n',Tg)
+printf('\n\n The output=%0.1f Watts\n\n',Pm)
+printf('\n\n The efficiency of Motor=%0.1f\n\n',n)
+//The answers vary due to round off error
diff --git a/3784/CH5/EX5.6/Ex5_6.sce b/3784/CH5/EX5.6/Ex5_6.sce new file mode 100644 index 000000000..24c55c7a1 --- /dev/null +++ b/3784/CH5/EX5.6/Ex5_6.sce @@ -0,0 +1,19 @@ +clc
+//variable initialisation
+Vm=400 //Supply Voltage in volt
+F=50 //supply frequency in hrtz
+P=6 //Number Of Poles
+R1=0.15 //resistance of stator in ohm
+R2=0.15 //resistance of rotor in ohm
+X1=0.8 //reactance of Motor in ohm
+X2=0.8 //reactance of Motor in ohm
+S=0.04 //Slip Of Motor
+
+//Solution
+Ns=(120*F)/P
+Ws=((2*%pi)/60)*1000
+Sr=2-S
+Vph=Vm/(sqrt(3))
+I2=Vph/(sqrt(((R1+(R2/((2-S))))^2)+((X1+X2)^2)))
+Tsb=(3*((I2)^2)*(R2/(2-S)))/(Ws)
+printf('\n\n The Initial Braking Torque=%0.1f N-m\n\n',Tsb)
diff --git a/3784/CH5/EX5.7/Ex5_7.sce b/3784/CH5/EX5.7/Ex5_7.sce new file mode 100644 index 000000000..55ac6056e --- /dev/null +++ b/3784/CH5/EX5.7/Ex5_7.sce @@ -0,0 +1,32 @@ +clc
+//variable initialisation
+Pout=7.5 // Output Of Motor In KW
+Vm=230 //Supply Voltage in volt
+F=50 //supply frequency in hrtz
+R1=0.36 //resistance of stator in ohm
+R2=0.222 //resistance of rotor in ohm
+X1=0.47 //reactance of Motor in ohm
+X2=0.47 //reactance of Motor in
+Xm=15.5 //reactance of Motor in ohm
+S=0.4723 //Slip Of Motor
+P=4 //Number Of Poles
+
+//Solution
+Vph=Vm/sqrt(3)
+Z=((R1+(R2/S))+(%i*(X1+X2)))
+I2=Vph/Z
+I2r=abs(I2)
+Lcr=3*((I2r)^2)*R2
+P2=Lcr/S
+Ns=(120*F)/P
+Tst=(9.55*P2)/Ns
+Sm=R2/X2
+Z1=(R1+R2)+%i*(X1+X2)
+Z2=abs(Z1)
+I3=Vph/Z2
+I4=abs(I3)
+P3=3*((I4)^2)*R2
+Tst1=(9.55*P3)/(Ns)
+printf('\n\n The Maximum Internal Torque=%0.1f N-m\n\n',Tst)
+printf('\n\n Slip at Maximum Torque=%0.1f\n\n',Sm)
+printf('\n\n The Starting Torque=%0.1f N-m\n\n',Tst1)
diff --git a/3784/CH5/EX5.8/Ex5_8.sce b/3784/CH5/EX5.8/Ex5_8.sce new file mode 100644 index 000000000..f18ed19ec --- /dev/null +++ b/3784/CH5/EX5.8/Ex5_8.sce @@ -0,0 +1,32 @@ +clc
+//variable initialisation
+Vm=400 //input of motor in volt
+F=50 //supply frequency in hrtz
+P=4 //Number Of Poles
+R1=1 //resistance of stator in ohm
+R2=0.4 //resistance of rotor in ohm
+X1=1 //reactance of Motor in ohm
+X2=1 //reactance of Motor in ohm
+Xm=50 //reactance of Motor in ohm
+Vc=231 //Constant Voltage Source In Volt
+I1=28//Current from Constant Current Source in Amp
+//Solution
+Xe=(X1*Xm)/(X2+Xm)
+Sm=R2/(Xe+X2)
+Sm1=R2/(X2+Xm)
+Ve=(Vc*Xm)/(X1+Xm)
+Ws=(4*%pi*F)/(P)
+Test=(3/Ws)*(((Ve)^2)/(R2^2+(X2+Xe)^2))*R2
+Tem=(3/Ws)*(((Ve)^2)/(2*(X2+Xe)))
+Test1=(3/Ws)*(((I1*Xm)^2)/(R2^2+(X2+Xm)^2))*R2
+Tem1=(3/Ws)*(((I1*Xm)^2)/(2*(X2+Xm)))
+Im=I1*((R2/Sm1)+(%i*X2))/((R2/Sm1)+%i*(X2+Xm))
+V1=sqrt(3)*abs(Im)*Xm
+printf('\n\n The Slip for maximum torque for Voltage source=%0.1f\n\n',Sm)
+printf('\n\n The Slip for maximum torque for current source=%0.1f\n\n',Sm1)
+printf('\n\n The Starting Torque for Voltage source=%0.1f N-m\n\n',Test)
+printf('\n\n The Maximum Torque for Voltage Source=%0.1f N-m\n\n',Tem)
+printf('\n\n The Starting Torque for Current Source=%0.1f N-m\n\n',Test1)
+printf('\n\n The Maximum Torque for Current Source=%0.1f N-m\n\n',Tem1)
+printf('\n\n The Supply voltage required=%0.1f Volt\n\n',V1)
+//The answers vary due to round off error
diff --git a/3784/CH5/EX5.9/Ex5_9.sce b/3784/CH5/EX5.9/Ex5_9.sce new file mode 100644 index 000000000..7591a0679 --- /dev/null +++ b/3784/CH5/EX5.9/Ex5_9.sce @@ -0,0 +1,42 @@ +clc
+//variable initialisation
+Vph=2200 //Supply Voltage in volt
+F=50 //supply frequency in Hz
+Pout=2600 // Output Of Motor In KW
+P=8 //Number Of Poles
+N1=735 //Speed OF Motor In rpm
+Rs=0.075 //Resistance of stator in ohm
+Rr=0.1 //Resistance of rotor in ohm
+Xs=0.45 //Reactance of Motor in ohm
+Xr=0.55 //Reactance of Motor in ohm
+
+//Solution
+Ns=(120*F)/P
+S=(Ns-N1)/Ns
+Iph=Vph/sqrt((Rs+((Rr/S)^2))+((Xs+Xr)^2))
+Il=sqrt(3)*Iph
+Wms=(2*%pi*Ns)/60
+Tl=(3*((Iph)^2))/(S*(Wms))
+Ilm=Vph/(sqrt(3)*sqrt(((Rs+Rr)^2)+((Xs+Xr)^2)))
+S2=1
+Tst=(3*(((Ilm)^2)*0.1))/(S2*Wms)
+r1=Tst/Tl//ratio of Tst and Tl
+Tmax=(3/(2*Wms))*(((Vph/sqrt(3))^2)/((Rs+sqrt((Rs^2)+((Xs+Xr)^2)))))
+r2=Tmax/Tl//ratio of Tmax and Tl
+Rr2=0.15
+Xr2=0.9
+Il1=(sqrt(3)*Vph)/(sqrt(((Rs+Rr)^2)+((Xs+Xr2)^2)))
+Iph1=Il1/(sqrt(3))
+Tst1=(3*((Iph1)^2)*(Rr))/(Wms)
+Rs1=Rs/3
+Rr1=Rr/3
+Xs1=Xs/3
+Xr1=Xr/3
+Inew=2*Il
+X=sqrt(((Vph/(sqrt(3)*Inew))^2)-((Rs1+Rr1)^2))
+Xe=X-Xs1-Xr1
+printf('\n\n Ratio of starting torque and load torque=%0.1f \n\n',r1)//The answer provided in the textbook is wrong
+printf('\n\n Ratio of maximum torque and load torque=%0.1f \n\n',r2)
+printf('\n\n The Maximum line current during starting=%0.1f Amp\n\n',Il1)//The answer provided in the textbook is wrong
+printf('\n\n The maximum torque at starting=%0.1f N-m\n\n',Tst1)//The answer provided in the textbook is wrong
+printf('\n\n The required value of reactor=%0.1f ohm\n\n',Xe)
diff --git a/3784/CH6/EX6.1/Ex6_1.sce b/3784/CH6/EX6.1/Ex6_1.sce new file mode 100644 index 000000000..8335db30f --- /dev/null +++ b/3784/CH6/EX6.1/Ex6_1.sce @@ -0,0 +1,48 @@ +clc
+//variable initialization
+Vm=415 //input of motor in volt
+F1=50 //supply frequency in hrtz
+F2=35 //supply frequency in hrtz
+F3=10 //supply frequency in hrtz
+N=1460 //speed of motor in rpm
+P=4 //number of poles
+R1=0.65 //resistance of stator in ohm
+R2=0.35 //resistance of rotor in ohm
+X1=0.95 //reactance of Motor in ohm
+X2=1.43 //reactance of Motor in ohm
+Xm=28 //reactance of Motor in ohm
+
+
+
+//Solution
+V1ph=Vm/sqrt(3)
+Ns1=(120*F1)/P
+Wsm1=(2*%pi/60)*Ns1
+Sm1=R2/sqrt((R1^2)+(X1+X2)^2)//Slip for maximum torque
+Nr1=Ns1*(1-Sm1)
+Tm1=3*((V1ph)^2)/(2*Wsm1*(R1+sqrt((R1)^2+(X1+X2)^2)))
+
+V2ph=Vm/sqrt(3)
+X3=X1*(F2/F1)
+X4=X2*(F2/F1)
+Sm2=R2/sqrt((R1^2)+(X3+X4)^2)//Slip for maximum torque
+Ns2=(120*F2)/P
+Wsm2=(2*%pi/60)*Ns2
+Nr2=Ns2*(1-Sm2)
+Tm2=3*((V2ph*F2/F1)^2)/(2*Wsm2*(R1+sqrt((R1)^2+(X3+X4)^2)))
+
+V3ph=Vm/sqrt(3)
+X5=X1*(F3/F1)
+X6=X2*(F3/F1)
+Sm3=R2/(sqrt((R1^2)+((X5+X6)^2)))//Slip for maximum torque
+Ns3=(120*F3)/P
+Wsm3=(2*%pi/60)*Ns3
+Nr3=Ns3*(1-Sm3)
+Tm3=3*((V3ph*F3/F1)^2)/(2*Wsm3*(R1+sqrt((R1)^2+(X5+X6)^2)))
+printf('\n\n speed at which maximum torque occurs for 50 Hz=%0.1f rpm\n\n',Nr1)
+printf('\n\n maximum torque for 50 Hz=%0.1f N-m\n\n',Tm1)
+printf('\n\n speed at which maximum torque occurs for 35 Hz=%0.1f rpm\n\n',Nr2)
+printf('\n\n maximum torque for 35 Hz=%0.1f N-m\n\n',Tm2)
+printf('\n\n speed at which maximum torque occurs for 10 Hz=%0.1f rpm\n\n',Nr3)
+printf('\n\n maximum torque for 10 Hz=%0.1f N-m\n\n',Tm3)
+
diff --git a/3784/CH6/EX6.2/Ex6_2.sce b/3784/CH6/EX6.2/Ex6_2.sce new file mode 100644 index 000000000..fd1098844 --- /dev/null +++ b/3784/CH6/EX6.2/Ex6_2.sce @@ -0,0 +1,25 @@ +clc
+//variable initialization
+Pout=50 //output of induction motor in kilowatt
+Vm=400 //input of motor in volt
+F0=50 //supply frequency in hrtz
+N1=1470 //speed of motor in rpm
+P=4 //number of pole
+Rs=0.42 //resistance of stator in ohm
+Rr=0.23 //resistance of rotor in ohm
+Xs=0.95 //reactance of stator in ohm
+Xr=0.85 //reactance of rotor in ohm
+Xm=28 //reactance of motor in ohm
+Sm=0.12 //slip of motor
+//Solution
+Vs=Vm/sqrt(3)
+W0=2*%pi*F0
+K=Rr/(Sm*(Xs+Xr))
+F=K*F0//Supply Frequency
+Tdm=3*P*Vs^2/(2*(K^2)*W0(Xs+Xr))
+Ws=(K*W0*2)/(P)
+Wm=Ws*(1-Sm)
+N2=Wm*60/(2*%pi)
+printf('\n\n Supply Frequency=%0.1f Hz\n\n',F)
+printf('\n\n The Breakdown Torque=%0.1f N-m\n\n',Tdm)
+printf('\n\n The Speed at maximum torque=%0.1f rpm\n\n',N2)
diff --git a/3784/CH6/EX6.3/Ex6_3.sce b/3784/CH6/EX6.3/Ex6_3.sce new file mode 100644 index 000000000..0dc3292fe --- /dev/null +++ b/3784/CH6/EX6.3/Ex6_3.sce @@ -0,0 +1,31 @@ +clc
+//variable initialization
+Pout=50 //output of induction motor in kilowatt
+Vm=400 //input of motor in volt
+F0=50 //supply frequency in hrtz
+N1=1475 //speed of motor in rpm
+P=4 //number of poles
+Rs=0.42 //resistance of stator in ohm
+Rr=0.23 //resistance of rotor in ohm
+Xs=0.95 //reactance of stator in ohm
+Xr=0.85 //reactance of rotor in ohm
+Xm=30 //reactance of motor in ohm
+Tdm=225 //Breakdown Torque In N-m
+K=poly(0,'K')
+
+
+
+
+//Solution
+W0=2*%pi*F0
+Vp=Vm/sqrt(3)
+K=sqrt((3*2*(Vp^2))/(2*Tdm*W0*(Xs+Xr)))
+W1=K*W0
+F1=W1/(2*%pi)
+Sm=Rr/(K*(Xs+Xr))
+Ws=2*K*W0/(P)
+Wm=Ws*(1-Sm)
+N=Wm*60/(2*%pi)
+printf('\n\n The Supply Frequency=%0.1f Hz\n\n',F1)
+printf('\n\n The slip at maximum torque=%0.1f\n\n',Sm)
+printf('\n\n The speed at maximum torque=%0.1f rpm\n\n',N)
diff --git a/3784/CH6/EX6.4/Ex6_4.sce b/3784/CH6/EX6.4/Ex6_4.sce new file mode 100644 index 000000000..4e01f940b --- /dev/null +++ b/3784/CH6/EX6.4/Ex6_4.sce @@ -0,0 +1,27 @@ +clc
+//variable initialization
+Pout=50 //output of induction motor in kilowatt
+Vm=420 //input of motor in volt
+F0=50 //supply frequency in hrtz
+F1=58 // frequency in hrtz
+N1=1475 //speed of motor in rpm
+P=4 //number of poles
+Rs=0.4 //resistance of stator in ohm
+Rr=0.21 //resistance of rotor in ohm
+Xs=0.95 //reactance of stator in ohm
+Xr=0.85 //reactance of rotor in ohm
+Xm=32 //reactance of motor in ohm
+
+//Solution
+Vp=Vm/sqrt(3)
+K=F1/F0
+W0=2*%pi*F0
+W=W0*K
+Sm=Rr/(K*(Xs+Xr))
+Ws=2*K*W0/P
+Wm=Ws*(1-Sm)
+N=Wm*60/(2*%pi)
+Tdm1=(3*2*(Vp^2))/(2*(K^2)*W0*(Xs+Xr))
+printf('\n\n The Slip at maximum torque=%0.1f\n\n',Sm)
+printf('\n\n The Speed at maximum torque=%0.1f rpm\n\n',N)//The answers vary due to round off error
+printf('\n\n The Breakdown torque=%0.1f N-m\n\n',Tdm1)
diff --git a/3784/CH6/EX6.5/Ex6_5.sce b/3784/CH6/EX6.5/Ex6_5.sce new file mode 100644 index 000000000..39180d16e --- /dev/null +++ b/3784/CH6/EX6.5/Ex6_5.sce @@ -0,0 +1,34 @@ +clc
+//variable initialization
+Pout=30 //output of induction motor in kilowatt
+Vm=400 //input of motor in volt
+F0=50 //supply frequency in hrtz
+F1=40 // frequency in hrtz
+P=4 //number of poles
+Rs=0.33 //resistance of stator in ohm
+Rr=0.22 //resistance of rotor in ohm
+Xs=0.9 //reactance of stator in ohm
+Xr=0.9 //reactance of rotor in ohm
+
+//Solution
+Vs=Vm/sqrt(3)
+Sm=Rr/(sqrt((Rs^2)+((Xs+Xr)^2)))
+Ir=Vs/sqrt(((Rs+(Rr/Sm))^2)+((Xs+Xr)^2))
+cos_P=cosd(atand((Xs+Xr)/(Rs+(Rr/Sm))))
+Pi=sqrt(3)*Vm*Ir*cos_P
+P0=3*(Ir^2)*Rr*((1/Sm)-1)
+n=(P0/Pi)*100
+
+K=F1/F0//for frequency of 40 Hz
+Xs2=K*Xs
+Xr2=K*Xr
+Sm2=Rr/(sqrt((Rs^2)+((Xs2+Xr2)^2)))
+Vs2=K*Vs
+Ir2=Vs2/sqrt(((Rs+(Rr/Sm2))^2)+((Xs2+Xr2)^2))
+cos_p2=cosd(atand((Xs2+Xr2)/(Rs+(Rr/Sm2))))
+Pi2=3*Vs2*Ir2*cos_p2
+P02=3*(Ir2^2)*Rr*((1/Sm2)-1)
+n2=(P02/Pi2)*100
+printf('\n\n The Efficiency at breakdown torque with 50Hz=%0.1f\n\n',n)
+printf('\n\n The Efficiency at breakdown torque with 40Hz=%0.1f\n\n',n2)
+//The answers vary due to round off error
diff --git a/3784/CH6/EX6.6/Ex6_6.sce b/3784/CH6/EX6.6/Ex6_6.sce new file mode 100644 index 000000000..2906dbf36 --- /dev/null +++ b/3784/CH6/EX6.6/Ex6_6.sce @@ -0,0 +1,20 @@ +clc
+//variable initialization
+Vm=400 //input of motor in volt
+F=50 //supply frequency in hrtz
+N=1500 //speed of motor in rpm
+P=6 //number of poles
+R1=2 //resistance of stator in ohm
+R2=3 //resistance of rotor in ohm
+X1=4 //reactance of Motor in ohm
+X2=4 //reactance of Motor in ohm
+S=1 //Slip Of Motor
+
+//Solution
+Ns=(120*F)/P
+Ws=(2*%pi/60)*Ns
+Vph=Vm/sqrt(3)
+Tst=(3/Ws)*((Vph^2)/((R1+(R2/S))^2+(X1+X2)^2))*R2
+Ist=Vph/sqrt((R1+R2)^2+(X1+X2)^2)
+printf('\n\n The Starting Torque=%0.1f N-m\n\n',Tst)
+printf('\n\n The starting Current=%0.1f Amp\n\n',Ist)
diff --git a/3784/CH7/EX7.1/Ex7_1.sce b/3784/CH7/EX7.1/Ex7_1.sce new file mode 100644 index 000000000..e361813e2 --- /dev/null +++ b/3784/CH7/EX7.1/Ex7_1.sce @@ -0,0 +1,28 @@ +clc
+//variable initialization
+V=440 //voltage in volts
+P=6 //number of poles
+f=50 //frequency in Hz
+R=0.3 //rotor resistance in ohm
+X=1 //leakage reactance in ohm
+s=0.03 //slip
+N=800 //speed in rpm
+K=2.2 //stator to rotor ratio
+
+//solution
+Ns=(120*f)/6
+w=(2*%pi/60)*Ns
+Tf=(3/w)*((V^(2))*(R/s))*(1/(((R/s)^(2))+(X^(2))))
+k=Tf/((Ns*(1-s))^(2))
+Tl=k*(N^(2))
+s1=((Ns-N)/Ns)
+Re=(X^(2))*(s*Tl*w)*(1/(3*(V^(2))-(Tl*w)))
+X1=14.78
+X2=0.07
+Ree=(X1*0.2)-0.3
+Ree1=(X2*0.2)-0.3
+//since negative value of resistance is not feasible
+Ree=2.656
+//Rotor -referred value of external resistance
+Rex=Ree/K^(2)
+printf('\n\n The Resistance to be inserted in rotor circuit=%0.1f ohm\n\n',Rex)
diff --git a/3784/CH7/EX7.10/Ex7_10.sce b/3784/CH7/EX7.10/Ex7_10.sce new file mode 100644 index 000000000..14d53a898 --- /dev/null +++ b/3784/CH7/EX7.10/Ex7_10.sce @@ -0,0 +1,50 @@ +clc
+//Variable initialisation
+V=400//Supply voltage in volts
+f=50//Supply Frequency in Hz
+P=6//No of poles
+Rs=0.2//stator resistance in ohm
+Rr=0.07//Rotor resistance in ohm
+Xs=0.4//Stator impedance in ohm
+Xr=0.4//Rotor impedance in ohm
+Sm1=0.25//Maximum Slip at 25% speed range
+N1=750//Speed in rpm
+a1=130
+am=150//maximum Firing Angle
+n=2//Stator to rotor turns ratio
+Rd=0.02//Dc link resistance in ohm
+N2=950//Speed in rpm
+N3=850//Speed in rpm
+//Solution
+V1=V/sqrt(3)
+Ns=120*f/P//Synchronous speed in rpm
+Wms=Ns*2*%pi/60
+a=-Sm1/cosd(am)//At 25% speed Range
+m=2/a//Transformer Turns Ratio
+S1=(Ns-N1)/Ns
+Vd11=3*sqrt(6)*S1*V1/(%pi*n)
+Vd21=3*sqrt(6)*V1*cosd(a1)/(%pi*m)
+Rs1=Rs/(n^2)
+Rr1=Rr/(n^2)
+Id1=(Vd11+Vd21)/(2*((S1*Rs1)+Rr1)+Rd)//The answers vary due to round off error
+T1=abs(Vd21)*Id1/(S1*Wms)//The answers vary due to round off error
+S2=(Ns-N2)/Ns
+Tr=(3/Wms)*V1^2*(Rr/S2)/((Rs+(Rr/S2))^2+(Xs+Xr)^2)//Rated torque in N-m
+Thr=Tr/2//Half rated Torque in N-m
+S3=(Ns-N3)/Ns
+X=poly(0,'X')//let X=cos(a2)
+Vd12=3*sqrt(6)*S3*V1/(%pi*n)
+Vd22=3*sqrt(6)*V1*X/(%pi*m)
+Id2=(Vd12+Vd22)/(2*((S3*Rs1)+Rr1)+Rd)
+T2=abs(Vd22)*Id2/(S3*Wms)
+//Equating T2 to Thr
+0==5547.31*X^2-2878.788*X+349.52//Polynomial Equation in X
+X1=(2878.788+sqrt((2878.788^2)-4*5547.31*349.52))/(2*5547.31)//Roots of polynomial eqn
+X2=(2878.788-sqrt((2878.788^2)-4*5547.31*349.52))/(2*5547.31)//Roots of polynomial eqn
+a11=acosd(-X1)
+a22=acosd(-X2)
+printf('\n\n Transformer Turns Ratio=%0.1f \n\n',m)
+printf('\n\n Torque for 750rpm and alpha 130=%0.1f N-m\n\n',T1)
+printf('\n\n The Field Current=%0.1f \n\n',a11)
+printf('\n\n The Field Current=%0.1f \n\n',a22)
+//The answers vary due to round off error
diff --git a/3784/CH7/EX7.11/Ex7_11.sce b/3784/CH7/EX7.11/Ex7_11.sce new file mode 100644 index 000000000..b8063e620 --- /dev/null +++ b/3784/CH7/EX7.11/Ex7_11.sce @@ -0,0 +1,28 @@ +clc
+//variable initialization
+V=380 //line voltage in volts
+P=8 //number of poles
+f=50 //frequency in Hz
+n=1.25
+N1=600 //speed in rpm
+N2=400 //speed in rpm
+
+//solution
+Ns=(120*f/P)
+s=(Ns-N1)/Ns
+Vd1=(3*sqrt(6)*s*(V/sqrt(3)))/(%pi*n)
+m=(3*sqrt(6)*(V/sqrt(3)))/(%pi*Vd1)
+a=acosd(-(s*(n/m)))
+s1=(Ns-N2)/Ns
+s1=0.4//TRo avoid further Computational errors
+Vdc=(3*sqrt(6)*s1*(V/sqrt(3))/%pi)/n
+Vd2=(3*sqrt(6)*s1*(V/sqrt(3)))/(%pi*n)
+m1=(((3*sqrt(6))/%pi)*(V/sqrt(3)))/Vd2
+a1=acosd(s1/(m1/n))
+w1=(2*%pi*Ns)/60
+w2=w1/(1+(m/n))//Speed in rad/sec
+w21=w2*60/(2*%pi)
+printf('\n\n The Firing Angle for 600rpm=%0.1f\n\n',a)
+printf('\n\n The Firing Angle for 400rpm=%0.1f\n\n',a1)
+printf('\n\n Minimum Possible Speed=%0.1f rpm\n\n',w21)
+//The answers vary due to round off error
diff --git a/3784/CH7/EX7.12/Ex7_12.sce b/3784/CH7/EX7.12/Ex7_12.sce new file mode 100644 index 000000000..85a567383 --- /dev/null +++ b/3784/CH7/EX7.12/Ex7_12.sce @@ -0,0 +1,46 @@ +clc
+//variable initialisation
+V=440 //Supply voltage in volts
+p=6 //number of poles
+f=50 //Supply frequency in Hz
+N1=970 //speed in rpm
+N2=750 //speed in rpm
+N3=850 //speed in rpm
+n=3.5//Turns Ratio
+R1=0.2
+R2=0.15
+X1=0.4
+X2=0.4
+aa1=170//Firing Angle
+aa2=140//Firing Angle
+s=0.3
+
+//solution
+Ns=(120*f)/p
+a=-(s/cosd(aa1))
+m=(n/a)
+s1=(Ns-N2)/Ns
+Vd1=(3*sqrt(6)*s1*(V/sqrt(3)))/(%pi*n)
+Vd2=(3*sqrt(6)*(V/sqrt(3)*cosd(aa2)))/(%pi*m)
+Vd2=-39.05//To avoid further computational errors assuming Vd2
+Rs1=R1*((1/n)^(2))
+R3=(R2*((1/n)^(2)))
+Rd=0
+Id=(Vd1+Vd2)/(2*((s1*Rs1)+R3)+Rd)
+w=Ns*((2*%pi)/60)
+Td=(abs(Vd2)*Id/(s1*w))
+s2=(Ns-N1)/N1
+Tr=(3/w)*((((V/sqrt(3))^(2))*(R2/s2))/(R1+(R2/s2))^(2)+(s2)^(2))
+s3=(Ns-N3)/Ns
+Vd3=(3*sqrt(6)*s3*(V/sqrt(3)))/(%pi*n)
+X=poly(0,'X')//X=-cos alpha
+0==1769.4*X^2-884.02*X+51.5//Polynomial Eqn obtained
+X1=(884.02+sqrt((884.02^2)-4*1769.4*51.5))/(2*1769.4)//Roots of polynomial eqn
+X2=(884.02-sqrt((884.02^2)-4*1769.4*51.5))/(2*1769.4)//Roots of polynomial eqn
+a11=acosd(-X1)
+a22=acosd(-X2)
+printf('\n\n Turns Ratio of Transformer=%0.1f\n\n',m)
+printf('\n\n The Torqye for 750rpm=%0.1f N-m\n\n',Td)
+printf('\n\n Firing Angle 1=%0.1f\n\n',a11)
+printf('\n\n Firing Angle 2=%0.1f\n\n',a22)
+//The answers vary due to round off error
diff --git a/3784/CH7/EX7.13/Ex7_13.sce b/3784/CH7/EX7.13/Ex7_13.sce new file mode 100644 index 000000000..4699f74c9 --- /dev/null +++ b/3784/CH7/EX7.13/Ex7_13.sce @@ -0,0 +1,34 @@ +clc
+//variable initialization
+Vm=600 //Voltage of motor in volt
+Pout=30000 // Output Of Motor In Watt
+F=50 //Supply frequency in hrtz
+P=4 //Number Of Poles
+N1=100 //Speed OF Motor In rpm
+N2=1000 //Speed OF Motor In rpm
+R1=0.05 //Resistance of stator in ohm
+R2=0.07 //Resistance of rotor in ohm
+R0=53 //Resistance of rotor in ohm
+X=0.153 //Reactance of Motor in ohm
+X0=23 //Reactance of Motor in ohm
+n=1.3 //Stator To Rotr Ratio
+N3=300 //Speed OF Motor In rpm
+
+
+//Solution
+Vph=Vm/(sqrt(3))
+a=1/n
+Ns=(120*F)/(P)
+S=(Ns-N2)/Ns
+Wm=(2*%pi)/60
+Tl=(Pout)/(Wm*N3)
+Id=(Tl*Wm*Ns)/(2.339*a*Vph)
+I0=Vph/(X0)
+I2=(sqrt(2/3))*(Id*a)
+Pi=Pout+(R1*((I2)^2))+(R2*((I2)^2))
+e=(Pout/Pi)*100
+theta=-(atand(Vph/(0.779*Id*a*X0)))
+pf=cosd(theta)
+printf('\n\n The Motor Efficiency=%0.1f\n\n',e)
+printf('\n\n The Power Factor=%0.1f lag\n\n',pf)
+//The answers vary due to round off error
diff --git a/3784/CH7/EX7.2/Ex7_2.sce b/3784/CH7/EX7.2/Ex7_2.sce new file mode 100644 index 000000000..db59d6fb6 --- /dev/null +++ b/3784/CH7/EX7.2/Ex7_2.sce @@ -0,0 +1,22 @@ +clc
+//variable initialisation
+V=440 //Supply voltage in volts
+P=4 //number of poles
+f=50 //Supply frequency in Hz
+R=0.2 //rotor resistance in ohm
+X=0.35 //leakage reactance in ohm
+N1=1450 //speed in rpm
+N2=1200 //speed in rpm
+S2=0.2
+//solution
+Vph=V/sqrt(3)
+Ns=(120*f)/P//Synchronous Speed
+Wms=2*%pi*Ns/60
+S=(Ns-N1)/Ns
+T=(3/Wms)*(Vph^2)*(R/S)/((R/S)^2+(X)^2)//The answer provided in the textbook is wrong
+K=T/(1-S)
+T2=K*(1-S2)
+Vph2=sqrt(T2*((R/S)^2+(X)^2)/((3/Wms)*(R/S)))
+Vl=Vph2*sqrt(3)
+printf('\n\n Torque=%0.1f N-m\n\n',T)//The answer provided in the textbook is wrong
+printf('\n\n Line Voltage to be imposed=%0.1f Volts\n\n',Vph2)
diff --git a/3784/CH7/EX7.3/Ex7_3.sce b/3784/CH7/EX7.3/Ex7_3.sce new file mode 100644 index 000000000..a95881064 --- /dev/null +++ b/3784/CH7/EX7.3/Ex7_3.sce @@ -0,0 +1,24 @@ +clc
+//variable initialization
+V=440 //voltage in volts
+P=6 //number of poles
+f=50 //frequency in Hz
+R1=2 //resistance in ohm
+R2=2 //resistance in ohm
+X1=3 //reactance in ohm
+X2=4 //reactance in ohm
+N1=945 //speed in rpm
+N2=800 //speed in rpm
+
+//solution
+Ns=(120*f)/P
+s=(Ns-N1)/Ns
+w=2*%pi*Ns/60
+T=(3/w)*((V^(2)*(R2/s))/(((R1+(R2/s))^(2))+(X1+X2)^(2)))
+k=T/(1-s)^2//The answer provided in the textbook is wrong
+s1=(Ns-N2)/Ns
+Tl=k*((1-s1)^(2))//The answer provided in the textbook is wrong
+V2=sqrt((Tl*w*(((R1+(R2/s1))^2)+((X1+X2)^2))/((R2/s1)*3)))//The answer provided in the textbook is wrong
+I=V2/((R1+(R2/s1))+(%i*(X1+X2)))//The answer provided in the textbook is wrong
+Il=sqrt(3)*I//The answer provided in the textbook is wrong
+printf('\n\n The Line Current=%0.1f Amp\n\n',Il)
diff --git a/3784/CH7/EX7.4/Ex7_4.sce b/3784/CH7/EX7.4/Ex7_4.sce new file mode 100644 index 000000000..9c9e841a4 --- /dev/null +++ b/3784/CH7/EX7.4/Ex7_4.sce @@ -0,0 +1,28 @@ +clc
+//variable initialisation
+V=400 //Supply voltage in volts
+P=24 //number of poles
+f=50 //frequency in Hz
+P1=100e+3 //power in Watt
+P2=100e+3 //power in Watt
+K=1.4 //Turns ratio
+R=0.03 //resistance in ohmm
+N1=240 //speed in rpm
+N2=180 //speed in rpm
+
+//solution
+Vp=V/sqrt(3)
+Ns=(120*f)/P
+s=(Ns-N1)/Ns
+w=(2*%pi*N1)/60
+T=P1/w
+R1=K^(2)*R
+X=sqrt((3*Vp^2*R1/(T*2*%pi*Ns*s/60))-((R1/s)^(2)))
+s1=(Ns-N2)/Ns
+T1=T*(N2/N1)^2
+A=(T*2*%pi*Ns*s1/60)/(3*(Vp^2))
+R22=poly(0,'R22')
+0==(R22^2)*(A/(s1^2))+(A*X^2)-R22//Polynomial equation obtained for R22
+R22=0.745//After solving equation value of Resistor
+R2=(R22-R1)/K^2
+printf('\n\n The Resistance to connect in series=%0.1f ohm\n\n',R2)
diff --git a/3784/CH7/EX7.5/Ex7_5.sce b/3784/CH7/EX7.5/Ex7_5.sce new file mode 100644 index 000000000..d5f3d4a86 --- /dev/null +++ b/3784/CH7/EX7.5/Ex7_5.sce @@ -0,0 +1,20 @@ +clc
+V= 100 //supply voltage in volts
+f=50 //frequency in Hz
+p=6 //number of poles
+Rs=0.6 //parameters in ohm
+Rr=0.45 //parameters in ohm
+Xr=1.2 //parameters in ohm
+Xs=1.2 //parameters in ohm
+Xm=45 //parameters in ohm
+Sm=1
+R=0.4495
+
+//solution
+Re=(((Rs^2)+(Xs+Xr)^2)*Sm-Rr) //external resistance in ohm
+Ns=1000
+N=poly(0,'N')
+a=1-(((((Rs^2)+(Xs+Xr)^2)*((Ns-N)/Ns)-Rr))/(4.5*R))
+printf('\n\n The Ratio of External Resistance=%0.1f\n\n',Re)
+disp(a,'Duty Ratio alpha is ')
+//The answer provided in the textbook is wrong
diff --git a/3784/CH7/EX7.6/Ex7_6.sce b/3784/CH7/EX7.6/Ex7_6.sce new file mode 100644 index 000000000..2d972e37f --- /dev/null +++ b/3784/CH7/EX7.6/Ex7_6.sce @@ -0,0 +1,19 @@ +clc
+//variable initialization
+p=4 //number of poles
+f=50 //frequency in Hz
+T1=40 // Torque in N-m
+s=0.04 //Average slip
+T=35 //Torque in N-m
+N0=1250
+
+//solution
+Tav=35 //average torque in N-m
+Ns=1500 //synchronous speed in rpm
+N1=(1-s)*Ns
+N2=sqrt(((Tav/T1)*(N1)^2))
+T2=T1*(N0^2)/(N1^2)
+Tratio=((Tav-T2)/(T1-Tav))
+printf('\n\n The Average Torque=%0.1f N-m\n\n',Tav)
+printf('\n\n The Speed=%0.1f rpm\n\n',N2)
+printf('\n\n The required ratio of torque=%0.1f\n\n',Tratio)
diff --git a/3784/CH7/EX7.7/Ex7_7.sce b/3784/CH7/EX7.7/Ex7_7.sce new file mode 100644 index 000000000..b769c6558 --- /dev/null +++ b/3784/CH7/EX7.7/Ex7_7.sce @@ -0,0 +1,9 @@ +clc
+I2=poly(0,'I2')//Defining I2
+R2=poly(0,'R2')//Defining R2
+R=poly(0,'R')//Defining R
+ra=(R2-0.3*R2)/0.3//Equation drawn by neglecting stator impedance
+Id=I2*sqrt(3/2)//From Copper Losses
+R=2*ra
+
+disp(R,'value of resistance = ')
diff --git a/3784/CH7/EX7.8/Ex7_8.sce b/3784/CH7/EX7.8/Ex7_8.sce new file mode 100644 index 000000000..199d5429c --- /dev/null +++ b/3784/CH7/EX7.8/Ex7_8.sce @@ -0,0 +1,19 @@ +clc
+// variable initiallitation
+T1=50 //torque in N-m
+s=0.3 //slip
+p=4 //number of poles
+f=50 //frequency in Hz
+V=400 //supply voltage in volts
+Toff=poly(0,'Toff')
+Ton=0.4*Toff
+//solution
+Tratio=0.4
+Ns=1500 //synchronous speed in rpm
+N1=Ns*(1-s)
+T2=40 //torque in N-m
+N2=sqrt((T2/T1)*(Ns)^2)
+Tav=((T1*Ton+T2*Toff)/(Ton+Toff))
+disp(Tav,'The Average Torque Developed')
+Tav=60/1.4
+printf('\n\n The Average Torque Developed=%0.1f N-m\n\n',Tav)
diff --git a/3784/CH7/EX7.9/Ex7_9.sce b/3784/CH7/EX7.9/Ex7_9.sce new file mode 100644 index 000000000..3401c09a5 --- /dev/null +++ b/3784/CH7/EX7.9/Ex7_9.sce @@ -0,0 +1,33 @@ +clc
+//Variable Initialisation
+V=400//Supply Voltage in Volts
+f=50//Supply Frequency in Hz
+P=4//No of Poles
+N=1460//Rotor Speed in rpm
+d1=0.2//Duty Ratio
+s1=0.13//Given Slip
+d2=0.6//Duty Ratio
+s2=0.04//Given Slip
+s3=0.0867//Slip of motor
+Rs=0.08//Motor Resistance in ohm
+Xs=0.95//Motor Reactance in ohm
+Rr1=0.055//Motor Resistance in ohm
+X21=0.5//Motor Reactance in ohm
+Rd=0.0114//Resistance of link Inductor in ohm
+K=2//Stator to Rotor Turns Ratio
+//Solution
+V1=V/sqrt(3)
+Ns=120*f/P
+Ws=2*%pi*Ns/60
+Sm=Rr1/(sqrt((Rs^2)+((Xs+X21)^2)))//Slip at maximum Torque
+X2=X21*(K^2)
+R2=Rs*(K^2)
+Rr=Rr1*(K)//Wrongly Calculated in Textbook
+Radd=R2-Rr
+Rw=(Radd-Rd)/(1-d1)//The answers vary due to round off error
+Radd2=Rd+Rw*(1-d2)
+R22=Radd2+Rr
+Td=3*(V1^2)*R22/(s2*Ws*(((Rs+(R22/s2))^2)+((Xs+X2)^2)))
+printf('\n\n External Resistance=%0.1f ohm\n\n',Rw)
+printf('\n\n Torque at given condition=%0.1f N-m\n\n',Td)
+//The answers vary due to round off error
diff --git a/3784/CH8/EX8.1/Ex8_1.sce b/3784/CH8/EX8.1/Ex8_1.sce new file mode 100644 index 000000000..b45c9526d --- /dev/null +++ b/3784/CH8/EX8.1/Ex8_1.sce @@ -0,0 +1,29 @@ +clc
+P=5e+6// power rating in Watts
+Vl=11e+3// line voltage in Volts
+f=50// frequency of motor in Hz
+p1=0
+N=6// no. of poles
+Rs=0// resistance of motor in ohm
+Xs=10// reactance of motor in ohm
+If=60// rated field current in amp
+
+//Solution
+Vph=Vl/sqrt(3)//phase voltage in Volts
+N1=750// speed of motor at rated motor current Is
+p2=36.869898//p2=acosd(0.8)
+Is=P/(sqrt(3)*Vl*cos(p1))
+E=Vph-(Is*Xs*%i)
+Ns=120*f/N// synchronous speed of motor
+f1=N1*f/Ns// freaquency of motor while running at N1
+Vph1=Vph*f1/(f)//phase voltage for speed N1 in V
+Xs1=(N1/Ns)*Xs//reactance of motor at speed N1 in ohm
+E2=Vph1-(Is*(cosd(p2)+%i*sind(p2))*(Xs1*%i))
+E1=E*N1/Ns//in V
+If1=abs(E2)*If/abs(E1)//field current at N1 in amp
+P1=3*Vph1*Is*cosd(p2)//output power in kW
+wm=N1*2*%pi/60//angular speed in rad/sec
+T=P1/wm//torque in Nm
+printf('\n\n The Field Current=%0.1f Amp\n\n',If1)
+printf('\n\n The Torque for Rated Armature Current=%0.1f N-m\n\n',T)
+//The answers vary due to round off error
diff --git a/3784/CH8/EX8.2/Ex8_2.sce b/3784/CH8/EX8.2/Ex8_2.sce new file mode 100644 index 000000000..075e87467 --- /dev/null +++ b/3784/CH8/EX8.2/Ex8_2.sce @@ -0,0 +1,32 @@ +clc
+P=500e+3//power of motor in Watts
+V=6.6e+3//rated voltage in Volts
+f=60//frequency in Hz
+n=6//no. of poles
+Rs=0//resistnce of motor in ohm
+Xm=78//reactance in ohm
+Xsr=3//reactance in ohm
+p=0//pf=1
+k=5
+
+//solution
+Xsr1=3*%i
+Vph=V/sqrt(3)
+Is=P/(3*Vph*cosd(p))
+E=Vph-(Is*%i*Xsr)
+E1=abs(E)
+d=asind((Is*1*Xsr/E1))
+Pm=3*Vph*E*sind(d)/Xsr
+Pm1=abs(Pm)//Power in watt
+Pm2=Pm1*10^(-3)//Power in Kw
+Ns=120*f/n
+N=Ns/k
+wm=N*2*%pi/60
+T=Pm1/wm
+If1=E/(%i*Xsr)
+Im=Is+abs(If1)
+printf('\n\n Power Pm=%0.1f Kw\n\n',Pm2)
+printf('\n\n Torque T=%0.1f N-m\n\n',T)
+printf('\n\n The Field Current=%0.1f Amp\n\n',abs(If1))
+printf('\n\n The motor Current=%0.1f Amp\n\n',Im)
+//The answers vary due to round off error
diff --git a/3784/CH8/EX8.3/Ex8_3.sce b/3784/CH8/EX8.3/Ex8_3.sce new file mode 100644 index 000000000..b5c0e483a --- /dev/null +++ b/3784/CH8/EX8.3/Ex8_3.sce @@ -0,0 +1,39 @@ +clc
+P=5e+5//rated power output in Watts
+P1=25e+4// power at half rated torque
+f=50//frequency in Hz
+If=10//rated firld current in amp
+Xs=10//reactance in ohm
+p=4//no.of poles
+Vl=33e+2//line voltage in volts
+
+Vph=Vl/sqrt(3)//phase voltage in volts
+Is=P/(sqrt(3)*Vl*0.8)//Current in amp
+theta1=acosd(0.8)
+E=Vph-(-%i*Xs*(Is*(%i*sind(theta1)+cosd(theta1))))
+y=imag(E)
+x=real(E)
+Er=sqrt((y^2)+(x^2))
+theta2=atand(y/x)
+d1=asind(P1*Xs/(3*Vph*(abs(E))))
+Is1=(Vph-Er*(cosd(d1)-%i*sind(d1)))/(%i*Xs)
+y1=imag(Is1)
+x1=real(Is1)
+Is1r=sqrt((y1^2)+(x1^2))
+theta3=atand(y1/x1)
+pf=cosd(theta3)
+Is2=P/(Vph*3)
+E2=Vph-(%i*Xs*(Is2*(%i*sind(0)+cosd(0))))
+If1=abs(E2)*If/E
+If1r=abs(If1)
+If3=15//field current in amp
+E3=If3*(Er)/If//in volts
+Is3=sqrt(((E3^2)-(Vph^2))/(Xs^2))
+P3=3*Vph*Is3*cosd(0)
+Ns=120*f/p//synchronous speed
+wm=Ns*2*%pi/f//in rad/sec
+T=P3/wm//in Nm
+printf('\n\n The Armature Current at half rated torque and rated field current=%0.1f Amp\n\n',Is1)
+printf('\n\n The power Factor=%0.1f\n\n',pf)
+printf('\n\n The Field Current=%0.1f Amp\n\n',abs(If1))
+printf('\n\n The Torque for upf operation for 15 amp field current=%0.1f N-m\n\n',T)
diff --git a/3784/CH8/EX8.4/Ex8_4.sce b/3784/CH8/EX8.4/Ex8_4.sce new file mode 100644 index 000000000..3a59cfcb6 --- /dev/null +++ b/3784/CH8/EX8.4/Ex8_4.sce @@ -0,0 +1,42 @@ +clc
+P=5e+5//rated power output in Watts
+P1=25e+4// power at half rated torque
+f=50//frequency in Hz
+If=10//rated firld current in amp
+Xs=10//reactance in ohm
+p=4//no.of poles
+Vl=33e+2//line voltage in volts
+N1=1500
+//Solution
+Vph=Vl/sqrt(3)//phase voltage in volts
+Is=P/(sqrt(3)*Vl*0.8)//Current in amp
+theta1=acosd(0.8)
+E=Vph-(-%i*Xs*(Is*(%i*sind(theta1)+cosd(theta1))))
+y=imag(E)
+x=real(E)
+Er=sqrt((y^2)+(x^2))
+theta2=atand(y/x)
+Ia=Is
+E2=Vph+(%i*Ia*Xs)
+y2=imag(E2)
+x2=real(E2)
+Er2=sqrt((y2^2)+(x2^2))
+theta3=atand(y2/x2)
+P=3*Vph*Er2*sind(-theta3)/Xs
+Wms=2*%pi*N1/f
+T=P/Wms
+If1=Er2*If/Er
+If2=12
+Er3=Er*If2/If
+P2=-500e+3
+d1=asind(P2*Xs/(3*Vph*Er3))
+Is=(Vph-Er3*(cosd(d1)+(%i*sind(d1))))/(%i*Xs)
+Isr=abs(Is)
+u=imag(Is)
+v=real(Is)
+pf=cosd(atand(u/v))
+printf('\n\n The Breaking Torque for machine operation at rated current and upf=%0.1f N-m\n\n',T)
+printf('\n\n The Field Current for machine operation at rated current and upf=%0.1f Amp\n\n',If1)
+printf('\n\n The Armature Current at 12 A Field Current=%0.1f Amp\n\n',Isr)
+printf('\n\n The power factor at 12 A Field Current=%0.1f lead\n\n',pf)
+//The answers vary due to round off error
diff --git a/3784/CH8/EX8.5/Ex8_5.sce b/3784/CH8/EX8.5/Ex8_5.sce new file mode 100644 index 000000000..9e0e6c2f7 --- /dev/null +++ b/3784/CH8/EX8.5/Ex8_5.sce @@ -0,0 +1,52 @@ +clc
+//Variable Initialisation
+Pm=5e+6//motor rating in Watt
+V=11e+3//Input voltage in Volts
+f1=50//Supply Frequency
+pf=0.9//power factor of motor
+N1=1000//rated speed
+Rs=0//resistance in ohm
+Xs=10//reactance in ohm
+N2=750
+N3=1500
+pf2=0.8
+If1=50//rated field current
+//Solution
+V1=V/sqrt(3)
+Is=Pm/(3*V1*pf)
+Is1=Is*(cosd(25.84)+(%i*sind(25.84)))
+E=V1-(Is1*%i*Xs)
+y=imag(E)
+x=real(E)
+Er=sqrt((y^2)+(x^2))
+theta=atand(y/x)
+theta1=acosd(0.8)
+f2=f1*N2/N1
+V2=V1*f2/f1
+Xs2=Xs*f2/f1
+Is2=Is*(cosd(theta1)+(%i*sind(theta1)))
+E2=V2-(Is2*%i*Xs2)
+t=imag(E2)
+u=real(E2)
+Er2=sqrt((t^2)+(u^2))
+theta3=atand(t/u)
+E3=Er*N2/N1
+If2=If1*Er2/E3
+P2=3*V2*Is*pf2
+W=2*%pi*N2/f1
+T=P2/W
+f3=f1*N3/N1
+Xs3=f3/f1*Xs
+E4=Er*f3/f1
+P3=0.75*Pm
+k=asind(Xs3*P3/(3*V1*E4))
+Is3=(V1-(E4*(cosd(k)+(%i*sind(k)))))/(Xs3*%i)
+y2=imag(Is3)
+x2=real(Is3)
+Is3r=sqrt((y2^2)+(x2^2))
+theta4=atand(y2/x2)
+pf3=cosd(theta4)
+printf('\n\n The torque for Rated armature current,750rpm,0.8pf=%0.1f N-m\n\n',T)
+printf('\n\n The Field Current for Rated armature current,750rpm,0.8pf=%0.1f Amp\n\n',If2)
+printf('\n\n The Armature Current for half the Rated torque,1500rpm,rated field current=%0.1f Amp\n\n',Is3r)
+printf('\n\n The power factor for half the Rated torque,1500rpm,rated field current=%0.1f\n\n',pf3)
diff --git a/3784/CH8/EX8.6/Ex8_6.sce b/3784/CH8/EX8.6/Ex8_6.sce new file mode 100644 index 000000000..06bd87f79 --- /dev/null +++ b/3784/CH8/EX8.6/Ex8_6.sce @@ -0,0 +1,38 @@ +clc
+//Variable Initialisation
+Vs=6.6e+3//Supply voltage in Volts
+f1=50//Supply Frequency
+Ns=1000//rated motor speed
+Rd=0.2//dc link inductor resistance in ohm
+Xs=2.6//Reactance in ohm
+P=10e+6//motor rating in Watt
+pf1=1
+al=150
+//solution
+V1=Vs/sqrt(3)
+Is=P/(3*V1*pf1)
+Id=Is*%pi/sqrt(6)
+phi=180-al
+N2=500
+f2=f1*N2/Ns
+Vph=V1*N2/Ns
+P2=3*Vph*Is*cosd(phi)
+Pd=P2*10^(-6)//Power delivered in mega watt
+Vdl=3*sqrt(6)*Vph*cosd(al)/%pi
+Vds=(Id*Rd)-Vdl
+A=Vds*%pi/(3*sqrt(6)*V1)
+as=acosd(A)
+N3=600
+f3=f1*N3/Ns
+Vph2=V1*N3/Ns
+P3=3*Vph2*Is*pf1
+Ps=P3-((Id^2)*Rd)
+Ps2=Ps*10^(-6)
+Vdl2=3*sqrt(6)*Vph2*pf1/%pi
+Vds2=(Id*Rd)-Vdl2
+B=Vds2*%pi/(3*sqrt(6)*V1)
+as2=acosd(B)
+printf('\n\n The Power Delivered by Motor=%0.1f MWatt\n\n',Pd)
+printf('\n\n The Firing angle for motoring operation=%0.1f\n\n',as)
+printf('\n\n The Power supplied to source =%0.1f MWatt\n\n',Ps2)
+printf('\n\n The Firing angle for regenerative braking operation=%0.1f\n\n',as2)
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