// Example 3.6 // Determine the percent of the total bank-current drawn by each transformer // Page No. 109 clc; clear; close; // Given data ZaPU_R=0.0158; // Transformer A impedance real part ZaPU_I=0.0301; // Transformer A impedance imaginary part ZbPU_R=0.0109; // Transformer B impedance real part ZbPU_I=0.0398; // Transformer B impedance imaginary part SB=200000; // Transformer B rating VHSA=2400; // Voltage at the high side of transformer A VHSB=2400; // Voltage at the high side of transformer B RPUA=1.64; // Percent resistance of transformer A XPUA=3.16; // Percent reactance of transformer A RPUB=1.10; // Percent resistance of transformer B XPUB=4.03; // Percent reactance of transformer B // Base impedance of transformer A ZaPU=ZaPU_R+%i*ZaPU_I; // Complex to Polar form... ZaPU_Mag=sqrt(real(ZaPU)^2+imag(ZaPU)^2); // Magnitude part ZaPU_Ang=atan(imag(ZaPU),real(ZaPU))*180/%pi; // Angle part
 // Base impedance of transformer B ZbPU=ZbPU_R+%i*ZbPU_I; // Complex to Polar form... ZbPU_Mag=sqrt(real(ZbPU)^2+imag(ZbPU)^2); // Magnitude part ZbPU_Ang=atan(imag(ZbPU),real(ZbPU))*180/%pi; // Angle part
 // Admittance of transformer A YaPU_Mag=1/ZaPU_Mag; // Magnitude of equivalent admittance A YaPU_Ang=0-ZaPU_Ang; // Angle of equivalent admittance A // Polar to Complex form YaPU_R=YaPU_Mag*cos(-YaPU_Ang*%pi/180); // Real part of complex number YaPU_I=YaPU_Mag*sin(YaPU_Ang*%pi/180); //Imaginary part of complex number // Admittance of transformer B YbPU_Mag=1/ZbPU_Mag; // Magnitude of equivalent admittance B YbPU_Ang=0-ZbPU_Ang; // Angle of equivalent admittance B // Polar to Complex form YbPU_R=YbPU_Mag*cos(-YbPU_Ang*%pi/180); // Real part of complex number YbPU_I=YbPU_Mag*sin(YbPU_Ang*%pi/180); //Imaginary part of complex number // Parallel admittance YP=(YaPU_R-%i*YaPU_I)+(YbPU_R-%i*YbPU_I); // Complex to Polar form... YP_Mag=sqrt(real(YP)^2+imag(YP)^2); // Magnitude part YP_Ang=atan(imag(YP),real(YP))*180/%pi; // Angle part
 IA=YaPU_Mag/YP_Mag*100; // Percent current drawn by transformer A IB=100-IA; // Display the result on the command window printf("\n Percent of total bank current drawn by transformer A = %0.2f Percent ",IA); printf("\n Percent of total bank current drawn by transformer B = %0.2f Percent ",IB);