diff options
Diffstat (limited to '3802/CH10')
24 files changed, 408 insertions, 0 deletions
diff --git a/3802/CH10/EX10.1/Ex10_1.jpg b/3802/CH10/EX10.1/Ex10_1.jpg Binary files differnew file mode 100644 index 000000000..0c5ad6ab9 --- /dev/null +++ b/3802/CH10/EX10.1/Ex10_1.jpg diff --git a/3802/CH10/EX10.1/Ex10_1.sce b/3802/CH10/EX10.1/Ex10_1.sce new file mode 100644 index 000000000..607f85489 --- /dev/null +++ b/3802/CH10/EX10.1/Ex10_1.sce @@ -0,0 +1,26 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_1.sce
+
+clc;
+clear;
+f=50;
+p=4;
+
+printf("\n (a)")
+Ns=(120*f)/p;
+printf("\n Synchronous speed=%d r.p.m \n",Ns)
+
+printf("\n (b)")
+s=0.04;
+N=Ns-(s*Ns);
+printf("\n The rotor speed=%d r.p.m \n",N)
+
+printf("\n (c)")
+N=600;
+s=(Ns-N)/Ns;
+fs=s*f;
+printf("\n The rotor frequency=%d Hz",fs)
diff --git a/3802/CH10/EX10.10/Ex10_10.jpg b/3802/CH10/EX10.10/Ex10_10.jpg Binary files differnew file mode 100644 index 000000000..d328dd451 --- /dev/null +++ b/3802/CH10/EX10.10/Ex10_10.jpg diff --git a/3802/CH10/EX10.10/Ex10_10.sce b/3802/CH10/EX10.10/Ex10_10.sce new file mode 100644 index 000000000..1d9d2e551 --- /dev/null +++ b/3802/CH10/EX10.10/Ex10_10.sce @@ -0,0 +1,40 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//EX10_10.sce.
+clc;
+clear;
+sf=0.04;
+If=37.5;
+f=50;
+p=4;
+V=400;
+P_in_HP=25;
+z=2.8;
+P_in_watt=P_in_HP*735.5;
+Nf=((120*f)/p)*(1-sf);
+nf=Nf/60;
+Tf=P_in_watt/(2*%pi*nf);
+Isc_phase=V/z;
+Isc=sqrt(3)*Isc_phase;
+
+printf("\n (i) Using Direct switching")
+Ist=Isc;
+printf("\n \t The starting current=%3.2f A",Ist)
+Tst=(Isc/If)^2*sf*Tf;
+printf("\n \t The starting torque=%3.1f Nm \n",Tst)
+
+printf("\n (ii) Using Star delta connector")
+Ist=(1/3)*Isc;
+printf("\n \t The starting current=%3.2f A",Ist)
+Tst=(1/3)*(Isc/If)^2*sf*Tf;
+printf("\n \t The starting torque=%3.1f Nm \n",Tst)
+
+printf("\n (iii) Using auto transformer")
+k=0.7;
+Ist=k^2*Isc;
+printf("\n \t The starting current=%3.2f A",Ist)
+Tst=k^2*(Isc/If)^2*sf*Tf;
+printf("\n \t The starting torque=%3.1f Nm \n",Tst)
diff --git a/3802/CH10/EX10.11/Ex10_11.jpg b/3802/CH10/EX10.11/Ex10_11.jpg Binary files differnew file mode 100644 index 000000000..f56d5db18 --- /dev/null +++ b/3802/CH10/EX10.11/Ex10_11.jpg diff --git a/3802/CH10/EX10.11/Ex10_11.sce b/3802/CH10/EX10.11/Ex10_11.sce new file mode 100644 index 000000000..e8d974b7d --- /dev/null +++ b/3802/CH10/EX10.11/Ex10_11.sce @@ -0,0 +1,26 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_11.sce
+
+clc;
+clear;
+
+
+P_in_HP=25;
+s=0.04;
+p=4;
+f=50;
+Ns=(120*f)/p;
+ns=Ns/60;
+nf=(1-s)*ns;
+P_in_watt=P_in_HP*735.5;
+Tf=P_in_watt/(2*%pi*nf);
+sf=s;
+sp=2-s; //At the time of plugging the slip is 200%
+a=4;
+X2_by_R2=a;
+Tp=(sp/sf)*((1+(sf^2*X2_by_R2^2))/(1+(sp^2*X2_by_R2^2)))*Tf;
+printf("\n Plugging torque at full load=%2.1f Nm",Tp)
diff --git a/3802/CH10/EX10.12/Ex10_12.jpg b/3802/CH10/EX10.12/Ex10_12.jpg Binary files differnew file mode 100644 index 000000000..c7e6efb34 --- /dev/null +++ b/3802/CH10/EX10.12/Ex10_12.jpg diff --git a/3802/CH10/EX10.12/Ex10_12.sce b/3802/CH10/EX10.12/Ex10_12.sce new file mode 100644 index 000000000..fd13ff34c --- /dev/null +++ b/3802/CH10/EX10.12/Ex10_12.sce @@ -0,0 +1,20 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_12.sce
+
+clc;
+clear;
+p=4;
+f=50;
+R2=0.25;
+N1=1425;
+N2=1275;
+
+Ns=(120*f)/p;
+s1=(Ns-N1)/Ns;
+s2=(Ns-N2)/Ns;
+R=(R2*(s2/s1))-R2;
+printf("\n External resistance per phase=%1.1f ohm per phase",R)
diff --git a/3802/CH10/EX10.13/Ex10_13.jpg b/3802/CH10/EX10.13/Ex10_13.jpg Binary files differnew file mode 100644 index 000000000..a999cda1e --- /dev/null +++ b/3802/CH10/EX10.13/Ex10_13.jpg diff --git a/3802/CH10/EX10.13/Ex10_13.sce b/3802/CH10/EX10.13/Ex10_13.sce new file mode 100644 index 000000000..f8a14a9a6 --- /dev/null +++ b/3802/CH10/EX10.13/Ex10_13.sce @@ -0,0 +1,38 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_13.sce
+
+clc;
+clear;
+p1=12;
+p2=8;
+f=50;
+printf("\n (a)")
+printf("\n \t (i)Speed when cumulatively cascaded:")
+N1=(120*f)/(p1+p2);
+printf("\n \t N=%d r.p.m",N1)
+printf("\n \t (ii)Speed when differentially cascaded:")
+N2=(120*f)/(p1-p2);
+printf("\n \t N=%d r.p.m \n",N2)
+
+printf("\n (b)")
+printf("\n The ratio of power shared by the two motors=%d/%d \n",p1,p2)
+
+printf("\n (c)")
+printf("\n \t(i)First motor:")
+Ns1=(120*f)/p1;
+s1=(Ns1-N1)/Ns1;
+sf1=s1*f;
+printf("\n Required frequency of voltage to be injected in rotor of first motor=%d Hz",sf1)
+printf("\n \t(ii)Second motor:")
+Ns2=(120*f)/p2;
+s2=(Ns2-N1)/Ns2;
+sf2=s2*f;
+printf("\n Required frequency of voltage to be injected in rotor of second motor=%d Hz",sf2)
+
+
+
+
diff --git a/3802/CH10/EX10.2/Ex10_2.jpg b/3802/CH10/EX10.2/Ex10_2.jpg Binary files differnew file mode 100644 index 000000000..de0ebf793 --- /dev/null +++ b/3802/CH10/EX10.2/Ex10_2.jpg diff --git a/3802/CH10/EX10.2/Ex10_2.sce b/3802/CH10/EX10.2/Ex10_2.sce new file mode 100644 index 000000000..d2933f79c --- /dev/null +++ b/3802/CH10/EX10.2/Ex10_2.sce @@ -0,0 +1,41 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_2.sce
+
+clc;
+clear;
+T1=120;
+T2=24;
+R2=0.013;
+X2=0.048;
+V=400;
+kd=0.96;
+kp=1.0;
+f=50;
+
+printf("\n (a)")
+phi=V/(4.44*kd*kp*f*T1);
+printf("\n The flux per pole=%1.6f Wb \n",phi)
+
+printf("\n (b)")
+E2=4.44*kd*kp*phi*f*T2;
+printf("\n The rotor emf induced at standstill on open circuit=%d V \n",E2)
+
+printf("\n (c)")
+s=0.04;
+Er=s*E2;
+printf("\n Rotor emf at a slip=%1.1f V",Er)
+Ir=Er/sqrt(R2^2+(s*X2)^2);
+printf("\n The rotor current=%3.2f A \n",Ir)
+
+printf("\n (d)\t(i)")
+s=0.04;
+phir=atand(s*(X2/R2));
+printf("\n The phase difference between rotor emf and current for 4 percentage slip=%2.2f degree",phir)
+printf("\n\t(ii)")
+s=1;
+phir=atand(s*(X2/R2));
+printf("\n The phase difference between rotor emf and current for 100 percentage slip=%2.2f degree",phir)
diff --git a/3802/CH10/EX10.3/Ex10_3.jpg b/3802/CH10/EX10.3/Ex10_3.jpg Binary files differnew file mode 100644 index 000000000..da1c7eda4 --- /dev/null +++ b/3802/CH10/EX10.3/Ex10_3.jpg diff --git a/3802/CH10/EX10.3/Ex10_3.sce b/3802/CH10/EX10.3/Ex10_3.sce new file mode 100644 index 000000000..42c1ca674 --- /dev/null +++ b/3802/CH10/EX10.3/Ex10_3.sce @@ -0,0 +1,41 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_3.sce
+
+clc;
+clear;
+Pin=40; // power in kW
+Ps=1.5; // power in kW
+Ns=100; //speed percentage value
+N=40; //speed percentage value
+power_loss=0.8; // power in kW
+
+printf("\n (a)")
+rotor_input_power=Pin-Ps;
+s=0.04;
+rotor_copper_loss=s*rotor_input_power;
+mec_power_developed=rotor_input_power-rotor_copper_loss;
+printf("\n Mechanical power developed by the rotor=%2.2f kW",mec_power_developed)
+printf("\n Rotor copper loss=%2.2f kW \n",rotor_copper_loss)
+
+printf("\n (b)")
+motor_output_power=mec_power_developed-power_loss;
+printf("\n Output of the motor=%2.2f kW \n",motor_output_power)
+
+printf("\n (c)")
+motor_efficiency=(motor_output_power/Pin)*100;
+printf("\n The motor efficiency=%2.1f percentage \n",motor_efficiency)
+
+printf("\n (d)")
+new_slip=(Ns-N)/Ns;
+total_rotor_copper_loss=new_slip*rotor_input_power;
+printf("\n Total rotor copper loss when speed reduced to 40percentage of synchronous speed=%2.1f kW \n",total_rotor_copper_loss)
+
+printf("\n (e)")
+total_rotor_loss=total_rotor_copper_loss+power_loss;
+motor_output_power=rotor_input_power-total_rotor_loss;
+motor_efficiency=(motor_output_power/Pin)*100;
+printf("\n Efficiency of motor when speed reduced to 40percentage of synchronous speed=%2.1f percentage",motor_efficiency)
diff --git a/3802/CH10/EX10.4/Ex10_4.jpg b/3802/CH10/EX10.4/Ex10_4.jpg Binary files differnew file mode 100644 index 000000000..12923d51b --- /dev/null +++ b/3802/CH10/EX10.4/Ex10_4.jpg diff --git a/3802/CH10/EX10.4/Ex10_4.sce b/3802/CH10/EX10.4/Ex10_4.sce new file mode 100644 index 000000000..4d1282ce1 --- /dev/null +++ b/3802/CH10/EX10.4/Ex10_4.sce @@ -0,0 +1,56 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_4.sce
+
+clc;
+clear;
+
+f=50;
+p=4;
+V=400;
+E2=190;
+R1=0.5;
+X1=2.5;
+R2=0.06;
+X2=0.3;
+
+printf("\n (a)")
+Ns=(120*f)/p;
+printf("\n Synchronous speed=%d r.p.m \n",Ns)
+
+printf("\n (b)")
+s=(R2/X2)*100;
+printf("\n Slip at which maximum torque occurs=%d percentage \n",s)
+
+printf("\n (c)")
+E=E2/sqrt(3);
+Ir=(s*E)/(sqrt(2)*R2*100);
+pf=1/sqrt(2);
+Pi=sqrt(3)*E2*Ir*pf;
+P0=(1-s/100)*Pi;
+Tm=Pi/(2*%pi*Ns/60);
+printf("\n Maximum Torque=%3.2f synchronous watt \n",Tm)
+
+printf("\n (d)")
+Tfl=(1/2)*Tm;
+//(2/1)=(R2^2+sf^2*X2^2)/(2*X2*R2*sf)
+//From this equation we get sf^2-0.8*sf+0.04=0;
+a=1;
+b=-0.8;//a,b,c are coefficient values taken from the above second order equation
+c=0.04;
+sf=(-b-sqrt(b^2-(4*a*c)))/(2*a);
+sf_percentage=sf*100;
+Nf=Ns*(1-sf);
+Pf=2*%pi*(Nf/60)*Tfl;
+printf("\n Full load torque=%3.2f synchronous watt",Tfl)
+printf("\n Full load slip=%1.1f percentage",sf_percentage)
+printf("\n Speed at full load=%d r.p.m",Nf)
+printf("\n Power output=%2.2f kW \n",Pf/1000)
+//Answer vary dueto round off error
+
+printf("\n (e)")
+f_at_fullload=sf*f;
+printf("\n The rotor frequency at full load=%1.1f Hz",f_at_fullload)
diff --git a/3802/CH10/EX10.5/Ex10_5.jpg b/3802/CH10/EX10.5/Ex10_5.jpg Binary files differnew file mode 100644 index 000000000..6d182aa5f --- /dev/null +++ b/3802/CH10/EX10.5/Ex10_5.jpg diff --git a/3802/CH10/EX10.5/Ex10_5.sce b/3802/CH10/EX10.5/Ex10_5.sce new file mode 100644 index 000000000..509b16d7f --- /dev/null +++ b/3802/CH10/EX10.5/Ex10_5.sce @@ -0,0 +1,32 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_5.sce
+
+clc;
+clear;
+f=50;
+N=285;
+Ns=300; //which is near the value of N as slip lies b/w 0.03 to 0.05
+
+printf("\n (a)")
+p=(120*f)/Ns;
+printf("\n Number of poles=%d \n",p)
+
+printf("\n (b)")
+s=(Ns-N)/Ns;
+s_percentage=s*100;
+printf("\n Slip at full load=%d percentage \n",s_percentage)
+
+printf("\n (c)")
+//slip is proportional to rotor resistance
+s=2*s_percentage;
+printf("\n Slip at full load if rotor resistance is doubled=%d percentage \n",s)
+
+printf("\n (d)")
+//copper loss=I^2*R; so copper loss doubles if rotor resistance doubles
+Pcu=280;
+Pcu_new=2*Pcu;
+printf("\n The new value of rotor copper loss=%d watt \n",Pcu_new)
diff --git a/3802/CH10/EX10.6/Ex10_6.jpg b/3802/CH10/EX10.6/Ex10_6.jpg Binary files differnew file mode 100644 index 000000000..27b9192b3 --- /dev/null +++ b/3802/CH10/EX10.6/Ex10_6.jpg diff --git a/3802/CH10/EX10.6/Ex10_6.sce b/3802/CH10/EX10.6/Ex10_6.sce new file mode 100644 index 000000000..46b910f7c --- /dev/null +++ b/3802/CH10/EX10.6/Ex10_6.sce @@ -0,0 +1,13 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_6.sce
+
+clc;
+clear;
+s=0.05; //Full load slip of 5 percentage
+Iss_by_Isf=5; //Taken from question statement
+Ts_by_Tf=s*(Iss_by_Isf)^2;
+printf("\n Starting torque interms of full load torque=%1.2f*Tf",Ts_by_Tf)
diff --git a/3802/CH10/EX10.7/Ex10_7.jpg b/3802/CH10/EX10.7/Ex10_7.jpg Binary files differnew file mode 100644 index 000000000..f304d104f --- /dev/null +++ b/3802/CH10/EX10.7/Ex10_7.jpg diff --git a/3802/CH10/EX10.7/Ex10_7.sce b/3802/CH10/EX10.7/Ex10_7.sce new file mode 100644 index 000000000..43d348166 --- /dev/null +++ b/3802/CH10/EX10.7/Ex10_7.sce @@ -0,0 +1,54 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_7.sce
+
+clc;
+clear;
+Vl_not=400; //No load voltage in volt
+Vl_sc=50; //Blocked rotor voltage in volt
+I_not=20; //No load current in Ampere
+Isc=60; //Blocked rotor currnet in Ampere
+W1_not=5e3; //watt meter readings for no load test in watt
+W2_not=-3.2e3; //watt meter readings for no load test in watt
+Wsc1=2.3e3; //watt meter readings for blocked rotor test in watt
+Wsc2=0.75e3; //watt meter readings for blocked rotor test in watt
+Vdc=18; //dc voltage in volt
+Idc=60; //dc line current in Ampere
+
+printf("\n (a)")
+R1=(Vdc/Idc)/2;
+printf("\n R1=%1.2f ohm",R1)
+P_not=W1_not+W2_not;
+V_not=Vl_not/sqrt(3);
+cos_phi_not=P_not/(3*V_not*I_not);
+R_not=V_not/(I_not*cos_phi_not);
+printf("\n R0=%2.3f ohm",R_not)
+//R_not answer vary dueto round off error in v_not and cos_phi_not
+X_not=V_not/(I_not*sqrt(1-cos_phi_not^2));
+printf("\n X0=%2.3f ohm",X_not)
+Psc=Wsc1+Wsc2;
+Vsc=Vl_sc/sqrt(3);
+cos_phi_sc=Psc/(3*Vsc*Isc);
+R2_dash=((Vsc/Isc)*cos_phi_sc)-R1;
+printf("\n R2dash=%1.3f ohm",R2_dash)
+X1=((Vsc/Isc)*sqrt(1-cos_phi_sc^2))/2;
+printf("\n X1=%1.3f ohm",X1)
+X2_dash=X1;
+printf("\n X2dash=%1.3f ohm \n",X2_dash)
+
+printf("\n (b)")
+ns=25;
+s=R2_dash/X2_dash; //Slip for maximum torque
+pf_max=1/sqrt(2);
+Ps=(3*V_not^2)/sqrt((R1+R2_dash/s)^2+(2*X1)^2);
+Pc=(3*V_not^2*(R1+R2_dash))/((R1+R2_dash/s)^2+(2*X1)^2); //Stator copper loss in kw
+Pin=Ps-Pc;
+T=Pin/(2*%pi*ns);
+printf("\n Slip for pullout torque=%g",s)
+printf("\n Magnitude of pullout torque=%3.2f Nm",T)
+//There is a mistake in the book solution in part (b)
+//The calculated Ps value is wrong
+//Hence T answer vary
diff --git a/3802/CH10/EX10.9/Ex10_9.jpg b/3802/CH10/EX10.9/Ex10_9.jpg Binary files differnew file mode 100644 index 000000000..df3599beb --- /dev/null +++ b/3802/CH10/EX10.9/Ex10_9.jpg diff --git a/3802/CH10/EX10.9/Ex10_9.sce b/3802/CH10/EX10.9/Ex10_9.sce new file mode 100644 index 000000000..a604c24a4 --- /dev/null +++ b/3802/CH10/EX10.9/Ex10_9.sce @@ -0,0 +1,21 @@ +//Book Name:Fundamentals of Electrical Engineering
+//Author:Rajendra Prasad
+//Publisher: PHI Learning Private Limited
+//Edition:Third ,2014
+
+//Ex10_9.sce
+
+clc;
+clear;
+P_in_HP=10;
+eta=0.9;
+pf=0.8;
+Vl=400;
+Vsc=160;
+Isc=7.2;
+P_in_watt=P_in_HP*735.5;
+If=P_in_watt/(sqrt(3)*Vl*pf*eta);
+Isc_400=Isc*Vl/Vsc;
+Ist=Isc_400/3;
+Ist_by_If=Ist/If;
+printf("\n The ratio value of starting current to full load current=%1.3f",Ist_by_If)
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