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// Example 3.5
// Determine (a) Rated high side current of each transformer (b) Percent of the
// total bank-current drawn by each transformer (c) Maximum load that can be
// handled by the bank without overloading by one of the transformer
// Page No. 107
clc;
clear;
close;
// Given data
SA=75000; // Transformer A rating
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
// (a) Rated high side current of each transformer
IArated=SA/VHSA; // High side rated current transformer A
IBrated=SB/VHSB; // High side rated current transformer B
// (b) Percent of the total bank-current drawn by each transformer
ZAper=RPUA+%i*XPUA; // Percent impadance for transformer A
// Complex to Polar form...
ZAper_Mag=sqrt(real(ZAper)^2+imag(ZAper)^2); // Magnitude part
ZAper_Ang=atan(imag(ZAper),real(ZAper))*180/%pi; // Angle part
ZBper=RPUB+%i*XPUB; // Percent impadance for transformer B
// Complex to Polar form...
ZBper_Mag=sqrt(real(ZBper)^2+imag(ZBper)^2); // Magnitude part
ZBper_Ang=atan(imag(ZBper),real(ZBper))*180/%pi; // Angle part
ZAbase=VHSA/IArated; // Base impedance of transformer A
ZBbase=VHSB/IBrated; // Base impedance of transformer A
ZeqA_Mag=ZAbase*ZAper_Mag/100; // Magnitude of equivalent impedance A
ZeqA_Ang=ZAper_Ang; // Angle of equivalent impedance A
ZeqB_Mag=ZBbase*ZBper_Mag/100; // Magnitude of equivalent impedance B
ZeqB_Ang=ZBper_Ang; // Angle of equivalent impedance B
YeqA_Mag=1/ZeqA_Mag; // Magnitude of equivalent admittance A
YeqA_Ang=0-ZeqA_Ang; // Angle of equivalent admittance A
// Polar to Complex form
YeqA_R=YeqA_Mag*cos(-YeqA_Ang*%pi/180); // Real part of complex number
YeqA_I=YeqA_Mag*sin(YeqA_Ang*%pi/180); //Imaginary part of complex number
YeqB_Mag=1/ZeqB_Mag; // Magnitude of equivalent admittance B
YeqB_Ang=0-ZeqB_Ang; // Angle of equivalent admittance B
// Polar to Complex form
YeqB_R=YeqB_Mag*cos(-YeqB_Ang*%pi/180); // Real part of complex number
YeqB_I=YeqB_Mag*sin(YeqB_Ang*%pi/180); //Imaginary part of complex number
YP=(YeqA_R - %i* YeqA_I)+(YeqB_R - %i* YeqB_I); // Parallel admittance
// 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=YeqA_Mag/YP_Mag; // Transformer A load
IB=YeqB_Mag/YP_Mag; // Transformer A load
IA=IA*100;
IB=IB*100;
// (c) Maximum load that can be handled by the bank without overloading by
// one of the transformer
Ibank=IArated/0.307;
// Display result on command window
printf("\n Rated high side current of transformer A = %0.2f A ",IArated);
printf("\n Rated high side current of transformer B = %0.3f A ",IBrated);
printf("\n Percent of total bank current drawn by transformer A = %0.0f Percent ",IA);
printf("\n Percent of total bank current drawn by transformer B = %0.0f Percent ",IB);
printf("\n Maximum load that can be handled by the bank = %0.2f A ", Ibank);
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