initial commit / add all books

1 files changed, 90 insertions, 0 deletions

diff --git a/1092/CH8/EX8.4/Example8_4.sce b/1092/CH8/EX8.4/Example8_4.sce
new file mode 100755
index 000000000..d3af817aa
--- /dev/null
+++ b/1092/CH8/EX8.4/Example8_4.sce
@@ -0,0 +1,90 @@
+// Electric Machinery and Transformers

+// Irving L kosow 

+// Prentice Hall of India

+// 2nd editiom

+

+// Chapter 8: AC DYNAMO TORQUE RELATIONS - SYNCHRONOUS MOTORS

+// Example 8-4

+

+clear; clc; close; // Clear the work space and console.

+

+// Given data

+// Y-connected synchronous dynamo

+P = 2 ; // No. of poles

+hp = 1000 ; // power rating of the synchronous motor in hp

+V_L = 6000 ; // Line voltage in volt

+f = 60 ; // Frequency in Hz

+R_a = 0.52 ; // Effective armature resistance in ohm

+X_s = 4.2 ; // Synchronous reactance in ohm

+P_t = 811 ; // Input power in kW

+PF = 0.8 ; // Power factor leading

+

+// Calculations

+V_p = V_L / sqrt(3); // Phase voltage in volt

+

+// case a

+cos_theta = PF ; // Power factor leading

+I_L = (P_t*1000) / ( sqrt(3) * V_L * cos_theta); // Line armature current in A

+I_ap = I_L ; // Phase armature current in A

+

+// case b

+Z_p = R_a + %i * X_s ; // Impedance per phase in ohm

+Z_p_m = abs(Z_p);//Z_p_m=magnitude of Z_p in ohm

+Z_p_a = atan(imag(Z_p) /real(Z_p))*180/%pi;//Z_p_a=phase angle of Z_p in degrees

+

+// case c

+Ia_Zp = I_L * Z_p_m ; 

+E_r = Ia_Zp ; 

+

+// case d

+theta = acosd(0.8); // Power factor angle in degrees

+

+// case e

+funcprot(0); // Use  to avoid this message "Warning : redefining function: beta"                    . 

+beta = Z_p_a ; // 

+deba = beta + theta // Difference angle at 0.8 leading PF in degrees

+

+// case f

+//  Generated voltage/phase in volt 

+E_gp_f = sqrt( (E_r)^2 + (V_p)^2 - 2*E_r*V_p*cosd(deba) );

+

+// case g

+//  Generated voltage/phase in volt 

+E_gp_g = ( V_p + Ia_Zp * cosd(180-deba) ) + %i * ( Ia_Zp * sind(180-deba) ); 

+E_gp_g_m = abs(E_gp_g);//E_gp_g_m=magnitude of E_gp_g in volt

+E_gp_g_a = atan(imag(E_gp_g) /real(E_gp_g))*180/%pi;//E_gp_g_a=phase angle of E_gp_g in degrees

+

+// case h

+IaZp = Ia_Zp * expm(%i * Z_p_a * (%pi/180) ); // voltage generated by alternator 1 in volt

+IaZp_m = abs(IaZp);//IaZp_m=magnitude of IaZp in A

+IaZp_a = atan(imag(IaZp) /real(IaZp))*180/%pi;//IaZp_a=phase angle of IaZp in degrees

+IaRa = IaZp_m*cosd(IaZp_a); // Real part of IaZp

+IaXs = IaZp_m*sind(IaZp_a); // Imaginery part of IaZp

+

+cos_theta = PF ; //

+sin_theta = sqrt( 1 - (cos_theta)^2 );

+//  Generated voltage/phase in volt 

+E_gp_h = ( V_p * cos_theta - IaRa ) + %i * ( V_p * sin_theta + IaXs);

+E_gp_h_m = abs(E_gp_h);//E_gp_h_m=magnitude of E_gp_h in volt

+E_gp_h_a = atan(imag(E_gp_h) /real(E_gp_h))*180/%pi;//E_gp_h_a=phase angle of E_gp_h in degrees

+

+// Display the results

+disp("Example 8-4 Solution : ");

+printf(" \n a: I_L = %.2f \n    I_ap = %.2f A \n", I_L, I_ap );

+

+printf(" \n b: Z_p in ohm = ");disp(Z_p);

+printf(" \n    Z_p = %.3f <%.2f ohm \n ", Z_p_m , Z_p_a );

+

+printf(" \n c: IaZp = %.1f V \n    E_r = %.1f V \n ",Ia_Zp , E_r );

+

+printf(" \n d: Power factor angle,\n    theta = %.2f degrees leading \n ", theta );

+

+printf(" \n e: Difference angle,\n    deba = %.2f degrees \n ", deba );

+

+printf(" \n f: E_gp = %.f V \n ", E_gp_f );

+ 

+printf(" \n g: E_gp in V = ");disp(E_gp_g );

+printf(" \n    E_gp = %d <%.2f V \n",E_gp_g_m , E_gp_g_a );

+

+printf(" \n h: E_gp in V = ");disp(E_gp_h);

+printf(" \n    E_gp = %.f <%.2f V",E_gp_h_m, E_gp_h_a );