summaryrefslogtreecommitdiff
path: root/2642/CH7
diff options
context:
space:
mode:
Diffstat (limited to '2642/CH7')
-rwxr-xr-x2642/CH7/EX7.1/Ex7_1.sce27
-rwxr-xr-x2642/CH7/EX7.2/Ex7_2.sce29
-rwxr-xr-x2642/CH7/EX7.3/Ex7_3.sce25
-rwxr-xr-x2642/CH7/EX7.4/Ex7_4.sce29
-rwxr-xr-x2642/CH7/EX7.5/Ex7_5.sce31
-rwxr-xr-x2642/CH7/EX7.6/Ex7_6.sce33
-rwxr-xr-x2642/CH7/EX7.7/Ex7_7.sce35
-rwxr-xr-x2642/CH7/EX7.8/Ex7_8.sce24
8 files changed, 233 insertions, 0 deletions
diff --git a/2642/CH7/EX7.1/Ex7_1.sce b/2642/CH7/EX7.1/Ex7_1.sce
new file mode 100755
index 000000000..cd74940ef
--- /dev/null
+++ b/2642/CH7/EX7.1/Ex7_1.sce
@@ -0,0 +1,27 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.1
+
+clc;clear; // clears the console and command history
+
+// Given data
+V = 230 // supply voltage in V
+P = 4 // number of poles
+f = 50 // frequecny Hz
+N_l = 1445 // speed in rpm
+
+// caclulations
+N_s = 120*f/P // synchronous speed in rpm
+s = (N_s-N_l)/N_s // slip
+f_r = s*f // rotor frequency in Hz
+
+// display the result
+disp("Example 7.1 solution");
+printf(" \n Synchronous speed \n N_s = %.1f rpm \n", N_s);
+printf(" \n Slip \n s = %.4f \n", s);
+printf(" \n Rotor frequency \n f_r = %.1f Hz \n", f_r);
+
diff --git a/2642/CH7/EX7.2/Ex7_2.sce b/2642/CH7/EX7.2/Ex7_2.sce
new file mode 100755
index 000000000..588142d29
--- /dev/null
+++ b/2642/CH7/EX7.2/Ex7_2.sce
@@ -0,0 +1,29 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.2
+
+clc;clear; // clears the console and command history
+
+// Given data
+E_BR = 120 // voltage found under blocked condition in V
+P = 4 // number of poles
+f = 50 // frequecny in Hz
+N_l = 1450 // speed in rpm
+
+// caclulations
+N_s = 120*f/P // synchronous speed in rpm
+s = (N_s-N_l)/N_s // slip
+f_r = s*f // rotor frequency in Hz
+E_r = s*E_BR // Rotor voltage in V
+
+// display the result
+disp("Example 7.2 solution");
+printf(" \n Synchronous speed \n N_s = %.1f rpm \n", N_s);
+printf(" \n Slip \n s = %.3f \n", s);
+printf(" \n Rotor frequency \n f_r = %.2f Hz \n", f_r);
+printf(" \n Rotor voltage \n E_r = %.2f V \n", E_r);
+
diff --git a/2642/CH7/EX7.3/Ex7_3.sce b/2642/CH7/EX7.3/Ex7_3.sce
new file mode 100755
index 000000000..e68296e89
--- /dev/null
+++ b/2642/CH7/EX7.3/Ex7_3.sce
@@ -0,0 +1,25 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.3
+
+clc;clear; // clears the console and command history
+
+// Given data
+V_0 = 230 // supply voltage in V
+P = 4 // number of poles
+T_0 = 230 // original torque in N-m
+V_s = 150 // stator voltage in V
+I_0 = 560 // starting cuurent in A
+
+// caclulations
+T_st = (V_s/V_0)^2*T_0 // starting torque in N-m
+I_st = I_0*(V_s/V_0) // starting current in A
+
+// display the result
+disp("Example 7.3 solution");
+printf(" \n Starting torque \n T_st = %.1f N-m \n", T_st);
+printf(" \n Starting current \n I_st = %.1f A \n", I_st);
diff --git a/2642/CH7/EX7.4/Ex7_4.sce b/2642/CH7/EX7.4/Ex7_4.sce
new file mode 100755
index 000000000..42025d507
--- /dev/null
+++ b/2642/CH7/EX7.4/Ex7_4.sce
@@ -0,0 +1,29 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.4
+
+clc;clear; // clears the console and command history
+
+// Given data
+f = 50 // frequency in Hz
+P = 8 // number of poles
+a = 0.03 // full load slip
+R_2 = 0.01 // rotor resistance in ohm
+X_2 = 0.1 // standstill resistance in ohm
+
+// caclulations
+N_s = 120*f/P // synchronous speed in rpm
+s = R_2/X_2 // slip at maximum torque
+N_l = (1-s)*N_s // rotor maximum speed in rpm
+T = (2*a*s)/(s^2+a^2) // ratio of full load torque to maximum torque
+T_ratio = 1/T // ratio of maximum torque to full load torque
+
+// display the result
+disp("Example 7.4 solution");
+printf(" \n Rotor speed at maximum torque \n N_l = %.0f rpm \n", N_l);
+printf(" \n Ratio of maximum torque to full load torque \n T_ratio = %.2f \n", T_ratio);
+
diff --git a/2642/CH7/EX7.5/Ex7_5.sce b/2642/CH7/EX7.5/Ex7_5.sce
new file mode 100755
index 000000000..8ca3d77d0
--- /dev/null
+++ b/2642/CH7/EX7.5/Ex7_5.sce
@@ -0,0 +1,31 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.5
+
+clc;clear; // clears the console and command history
+
+// Given data
+V = 440 // supply voltage in V
+P = 4 // number of poles
+P_ag = 1500 // rotor i/p in kW
+P_rcu = 250 // copper loss in W
+f = 50 // frequency in Hz
+
+// caclulations
+s = P_rcu/P_ag // slip
+N_s = 120*f/P // synchronous speed in rpm
+N_l = (1-s)*N_s // rotor maximum speed in rpm
+P_mech = (1-s)*P_ag // mechanical power developed in W
+
+// display the result
+disp("Example 7.5 solution");
+printf(" \n Slip \n s = %.3f \n", s);
+printf(" \n Synchronous speed \n N_s = %.f rpm \n", N_s);
+printf(" \n Rotor speed \n N_l = %.0f rpm \n", N_l);
+printf(" \n Mecahnical power developed \n P_mech = %.0f W \n", P_mech);
+
+// NOTE : small change in answer instead 1245 got 1250W
diff --git a/2642/CH7/EX7.6/Ex7_6.sce b/2642/CH7/EX7.6/Ex7_6.sce
new file mode 100755
index 000000000..33417cc13
--- /dev/null
+++ b/2642/CH7/EX7.6/Ex7_6.sce
@@ -0,0 +1,33 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.6
+
+clc;clear; // clears the console and command history
+
+// Given data
+V_1 = 150 // supply voltage in V
+P = 4 // number of poles
+f = 50 // frequency in Hz
+Z_1 = 0.12+%i*0.16 // per phase standstill stator impedance in ohm
+Z_2 = 0.22+%i*0.28 // per phase standstill rotor impedance in ohm
+R_2 = real(Z_2) // from Z_2
+
+// caclulations
+Z_eq = Z_1+Z_2 // equivalent impedance in ohm
+P_mech = 3*V_1^2/(2*(R_2+abs(Z_eq))) // maximum mechanical power developed in W
+s_mp = R_2/(abs(Z_eq)+R_2) // slip
+W_s = 2*%pi*2*f/P // since N_s = f/(P/2) and W_s = 2*%pi*N_s
+W = (1-s_mp)*W_s // speed of rotor in rad/s
+T_mxm = P_mech/W // miximum torque in N-m
+
+// display the result
+disp("Example 7.6 solution");
+printf(" \n maximum mechanical power developed \n P_mech = %.f W \n", P_mech);
+printf(" \n Maximum torque \n T_mxm = %.3f N-m \n", T_mxm);
+printf(" \n Maximum slip \n s_mp = %.2f \n", s_mp);
+printf(" \n NOTE : Error in calculation of P_mech and T_mxm ");
+
diff --git a/2642/CH7/EX7.7/Ex7_7.sce b/2642/CH7/EX7.7/Ex7_7.sce
new file mode 100755
index 000000000..8559c9eca
--- /dev/null
+++ b/2642/CH7/EX7.7/Ex7_7.sce
@@ -0,0 +1,35 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.7
+
+clc;clear; // clears the console and command history
+
+// Given data
+V = 440 // supply voltage in V
+P = 6 // number of poles
+f = 50 // frequency in Hz
+P_a = 45000 // i/p power
+N_l = 900 // speed in rpm
+P_tloss = 2000 // total power loss in W
+
+// caclulations
+N_s = 120*f/P // synchronous speed in rpm
+s = (N_s-N_l)/N_s // slip
+P_ag = (P_a-P_tloss) // air gap power in W
+P_rcu = s*P_ag // rotor copper loss in W
+P_mech = P_ag-P_rcu // mechanical power in W
+P_0 = P_mech-3000 // o/p power in W
+n = (P_0/P_ag)*100 // efficiency since n = P_o/P_in
+
+// display the result
+disp("Example 7.7 solution");
+printf(" \n Slip \n s = %.1f \n", s );
+printf(" \n Rotor copper loss \n P_rcu = %.f W \n", P_rcu );
+printf(" \n Out put power \n P_0 = %.f W \n", P_0 );
+printf(" \n Efficiency \n n = %.f percent \n", n );
+
+
diff --git a/2642/CH7/EX7.8/Ex7_8.sce b/2642/CH7/EX7.8/Ex7_8.sce
new file mode 100755
index 000000000..09744502c
--- /dev/null
+++ b/2642/CH7/EX7.8/Ex7_8.sce
@@ -0,0 +1,24 @@
+// FUNDAMENTALS OF ELECTICAL MACHINES
+// M.A.SALAM
+// NAROSA PUBLISHING HOUSE
+// SECOND EDITION
+
+// Chapter 7 : THREE-PHASE INDUCTION MOTOR
+// Example : 7.8
+
+clc;clear; // clears the console and command history
+
+// Given data
+v_s = 120 // train speed in km/h
+f = 50 // frequency in Hz
+
+// caclulations
+v_s = 120*1000/(60*60) // train speed in m/s
+w = v_s/(2*f) // length of the pole-pitch in m
+
+// display the result
+disp("Example 7.8 solution");
+printf(" \n Length of the pole-pitch lenear induction motor \n w = %.2f m \n", w );
+
+
+
generated by cgit (git 2.34.1) at 2025-01-08 00:51:49 +0000