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Diffstat (limited to '3871/CH7/EX7.8/Ex7_8.sce')
| -rw-r--r-- | 3871/CH7/EX7.8/Ex7_8.sce | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/3871/CH7/EX7.8/Ex7_8.sce b/3871/CH7/EX7.8/Ex7_8.sce new file mode 100644 index 000000000..d7746901c --- /dev/null +++ b/3871/CH7/EX7.8/Ex7_8.sce @@ -0,0 +1,42 @@ + //============================================================================
+//Chapter 7 Example 8
+
+
+clc;
+clear all;
+
+//variable declaration
+theta1 =1; //pressure coil phase angle in °
+theta2 =2; //pressure coil phase angle in °
+P1 = 700; //wattmeter reading in W
+P2 = 620; //wattmeter reading in W
+V = 240; //voltage in V
+
+
+//calculations
+x = P1/P2;
+//P1 =P*cos(theta2)*cos(phi-theta2)/cos(phi)
+//P2 = P*cos(theta1)*cos(phi-theta1)/cos(phi)
+//P1/P2 = cos(theta2)*cos(phi-theta2)/cos(phi)/cos(theta1)*cos(phi-theta1)/cos(phi)
+//x = cos(theta2)*cos(phi-theta2)/cos(phi)/cos(theta1)*cos(phi-theta1)/cos(phi)
+//x = (cos(theta2)/cos(theta1))*(cos(phi-theta2)/cos(phi-theta1))
+//x = y*(cos(phi-theta2)/cos(phi-theta1))
+//(cos(phi-theta2)/cos(phi-theta1)) = x/y
+y = (cos(theta2*%pi/180)/cos(theta1*%pi/180));
+z = x/y;
+//(cos(phi-theta2)/cos(phi-theta1)) = ((cos(thet2*%pi/180))*cos(phi))+(sin(thet2*%pi/180))*sin(phi))/((cos(theta1*%pi/180))*cos(phi))+(sin(thet1*%pi/180))*sin(phi))
+//z = ((cos(thet2*%pi/180))*cos(phi))+(sin(thet2*%pi/180))*sin(phi))/((cos(theta1*%pi/180))*cos(phi))+(sin(thet1*%pi/180))*sin(phi))
+t = ((z*cos(theta1*%pi/180))-(cos(theta2*%pi/180)))/((sin(theta2*%pi/180))-(z*sin(theta1*%pi/180)));
+phi = (atan(t))*180/%pi;
+pf = cos(phi*%pi/180);
+C = (phi-theta2)
+c = cos(C*%pi/180);
+a = (cos(theta2*%pi/180));
+b = a*c;
+B = P1*pf;
+P = B/b;
+I = P/(V*pf);
+
+//result
+mprintf("actual power = %3.3f W",P);
+mprintf("\ncurrent drawn = %3.2f A",I);
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