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//===========================================================================
//chapter 7 example 14
clc;
clear all;
//variable declaration
V = 6000; //load voltage in V
I = 100; //load current in A
p = 0.5; //power factor cos(phi) lagging
theta = 0; //since wattmeter reads correctly
x1 = 20; // current transformers nominal ratio
x2 = 60; // potenetial transformers nominal ratio
e1 =-0.005; // ration error
e2 = 0.01; // ratio error
//calculations
P = V*I*p; //actual power consumed in W
phi =acos(p);
phi1 = (phi*180)/%pi;
d = -1; //phase angle in °
b = 2; //phase angle in °
g = phi1+d-theta1-b; //phase angle in °
theta1 =theta*180/%pi
g1 = g*180/%pi;
A =cos(phi1)
K = (cos(phi1*%pi/180))/((cos(theta1*%pi/180))*(cos(g*%pi/180)));
CT = x1*(1+e1); //actual transformation ratio of CT
PT = x2*(1+e2); //actual transformation ratio of PT
P1 = P/(K*CT*PT); //power indicated by wattmeter in kW
T = P/(x1*x2); //true reading of wattmeter in kW
e = ((P1-T)/T)*100; //percentage errror in %
//result
mprintf("phase angle between the currents in CC and PC of wattmeter %3.2f ° ",K);
mprintf("\npercentage error = %3.0f percentage ",e);
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