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diff --git a/3574/CH9/EX9.10/EX9_10.png b/3574/CH9/EX9.10/EX9_10.png Binary files differnew file mode 100644 index 000000000..8cd2c84bd --- /dev/null +++ b/3574/CH9/EX9.10/EX9_10.png diff --git a/3574/CH9/EX9.10/EX9_10.sce b/3574/CH9/EX9.10/EX9_10.sce new file mode 100644 index 000000000..0adf55f18 --- /dev/null +++ b/3574/CH9/EX9.10/EX9_10.sce @@ -0,0 +1,68 @@ +// Example 9.10 +// Repeat the example 9.9 assuming 90 % leading power factor +// Determine (a) Excitation voltage (b) Power angle (c) No load voltage, +// assuming the field current is not changed (d) Voltage regulation (e) No load +// voltage if the field current is reduced to 80% of its value at rated load. +// Page 372 + +clc; +clear; +close; + +// Given data +V=4800; // Voltage of synchronous generator +PF=0.900; // Lagging power factor +S_Mag=1000000/3; +Xa_Mag=13.80; // Synchronous reactance +Xa_Ang=90; +Vt_Ang=0; + +// (a) Excitation voltage +Vt=V/sqrt(3); +Theta=acosd(PF); // Angle +Ia_Magstar=S_Mag/Vt; // Magnitude of curent +Ia_Angstar=Theta-0; // Angle of current +Ia_Mag=Ia_Magstar; +Ia_Ang=Ia_Angstar; + +// Ef=Vt+Ia*j*Xa +// First compute Ia*Xa +IaXa_Mag=Ia_Mag*Xa_Mag; +IaXa_Ang=Ia_Ang+Xa_Ang; +// Polar to Complex form for IaXa +IaXa_R=IaXa_Mag*cos(-IaXa_Ang*%pi/180); // Real part of complex number +IaXa_I=IaXa_Mag*sin(IaXa_Ang*%pi/180); // Imaginary part of complex number +// Vt term in polar form +Vt_Mag=Vt; +Vt_Ang=Vt_Ang; +// Polar to Complex form for Vt +Vt_R=Vt_Mag*cos(-Vt_Ang*%pi/180); // Real part of complex number +Vt_I=Vt_Mag*sin(Vt_Ang*%pi/180); // Imaginary part of complex number +// Ef in complex form +Ef_R=IaXa_R+Vt_R; +Ef_I=IaXa_I+Vt_I; +Ef=Ef_R+%i*Ef_I; +// Complex to Polar form for Ef +Ef_Mag=sqrt(real(Ef)^2+imag(Ef)^2); // Magnitude part +Ef_Ang= atan(imag(Ef),real(Ef))*180/%pi; // Angle part
 + +// (b) Power angle +PA=Ef_Ang; + +// (c) No load voltage, assuming the field current is not changed +// From figure 9.23 (b) +VolAxis=Vt_Mag/30; // The scale at the given voltage axis +Ef_loc=Ef_Mag/VolAxis; // Location of Ef voltage +Vnl=29*VolAxis; // No load voltage + +// (d) Voltage regulation +VR=(Vnl-Vt)/Vt*100; + + +// Display result on command window +printf("\n Excitation voltage = %0.0f V ",Ef_Mag); +printf("\n Power angle = %0.1f deg ",PA); +printf("\n No load voltage = %0.0f V ",Vnl); +printf("\n Voltage regulation = %0.2f Percent ",VR); +disp('The leading power factor resulted in a negativr voltage regulation') + |