1 files changed, 16 insertions, 0 deletions
diff --git a/3760/CH5/EX5.7/Ex5_7.sce b/3760/CH5/EX5.7/Ex5_7.sce
new file mode 100644
index 000000000..d74e6e665
--- /dev/null
+++ b/3760/CH5/EX5.7/Ex5_7.sce
@@ -0,0 +1,16 @@
+clc;
+v=2300; // rated voltage of motor
+xs=12 ; // per phase synchronous reactance
+p=200000; // VA rating of motor
+l1=120000; // initial load
+l2=60000; // final load
+vt=v/sqrt(3); // rated per phase voltage
+ia=l1/(3*vt); // minimum armature current
+ia1=1.5*ia; // armature current at reduced load (50% increment)
+pf=1/1.5; // power factor
+Ef=sqrt((vt*pf)^2+(vt*sqrt(1-pf^2)+ia1*xs)^2); // excitation EMF
+de=asind((l2*xs)/(3*vt*Ef)); // new load angle
+ia2=(sqrt(vt^2+Ef^2-2*Ef*vt*cosd(de)))/xs; // new armature current
+printf('New value of armature current is %f A\n',ia2);
+pfn=l2/(3*vt*ia2); 
+printf('Power factor at new armature current is %f leading',pfn);