summaryrefslogtreecommitdiff
path: root/3681/CH11/EX11.11/Ex11_11.sce
diff options
context:
space:
mode:
Diffstat (limited to '3681/CH11/EX11.11/Ex11_11.sce')
-rw-r--r--3681/CH11/EX11.11/Ex11_11.sce26
1 files changed, 26 insertions, 0 deletions
diff --git a/3681/CH11/EX11.11/Ex11_11.sce b/3681/CH11/EX11.11/Ex11_11.sce
new file mode 100644
index 000000000..58deef421
--- /dev/null
+++ b/3681/CH11/EX11.11/Ex11_11.sce
@@ -0,0 +1,26 @@
+// Calculating the length of air gap
+clc;
+disp('Example 11.11, Page No. = 11.35')
+// Given Data
+// 3 phase silient pole alternator
+kVA = 500;// kVA rating
+V = 3.3;// Voltage rating (in kV)
+f = 50;// Frequency (in Hz)
+rpm = 600;// R.p.m.
+Tph = 180;// Turns per phase
+Bav = 0.54;// Average flux density (in Wb per meter square)
+SCR = 1.2;// Short circuit ratio
+Kw = 0.955;// Winding factor
+Kg = 1.15;// Gap constraction factor
+Kf = 0.65;// Since field form factor is equal to the ratio of pole arc to pole pitch
+// Calculation of the length of air gap
+ns = rpm/60;// Synchronous speed (in r.p.s.)
+p = 2*f/ns;// Number of poles
+Iph = kVA*1000/(3^(1/2)*V*1000);// Armature diameter (in meter)
+ATa = 2.7*Iph*Tph*Kw/p;// Armature mmf per pole (in A)
+AT_f0 = SCR*ATa;// No load field mmf per pole
+Bg = Bav/Kf;// Maximum flux density in air gap (in Wb per meter square)
+lg = 0.8*AT_f0/(800000*Bg*Kg);// Length of air gap
+// Since mmf required for gap is 80% of no load field mmf
+disp(lg*1000,'Length of air gap (mm)=');
+//in book answer is 5.2 mm. The answers vary due to round off error