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Diffstat (limited to '3681/CH9/EX9.34')
| -rw-r--r-- | 3681/CH9/EX9.34/Ans9_34.PNG | bin | 0 -> 4629 bytes | |||
| -rw-r--r-- | 3681/CH9/EX9.34/Ex9_34.sce | 24 |
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diff --git a/3681/CH9/EX9.34/Ans9_34.PNG b/3681/CH9/EX9.34/Ans9_34.PNG Binary files differnew file mode 100644 index 000000000..29bc29fad --- /dev/null +++ b/3681/CH9/EX9.34/Ans9_34.PNG diff --git a/3681/CH9/EX9.34/Ex9_34.sce b/3681/CH9/EX9.34/Ex9_34.sce new file mode 100644 index 000000000..2982e6dc1 --- /dev/null +++ b/3681/CH9/EX9.34/Ex9_34.sce @@ -0,0 +1,24 @@ +// Calculating the total commutator losses
+clc;
+disp('Example 9.34, Page No. = 9.92')
+// Given Data
+P = 800;// Power rating (in kW)
+V = 400;// Voltage rating (in Volts)
+rpm = 300;// r.p.m.
+p = 10;// Number of poles
+Dc = 1;// Commutator diameter (in meter). Since 100 cm = 1 meter
+u = 0.23;// Co-efficient of friction
+Pb = 14.7;// Brush pressure (in kN per meter square)
+J = 0.075;// Current density in brushes (in A per mm square)
+Vcb = 2.2;// Total brush contact drop (in Volts)
+// Calculation of the total commutator losses
+n = rpm/60;// r.p.s.
+Ia = P*10^(3)/V;// Armature current (in Ampere)
+Ib = 2*Ia/p;// Current per brush arm (in Ampere)
+Ab = Ib/J;// Brush area per brush arm (in mm square)
+AB = p*Ab*10^(-6);// Total brush area on the commutator (in meter square)
+Vc = %pi*Dc*n;// Peripheral speed (in meter per second)
+Wcf = u*Pb*10^(3)*AB*Vc;// Brush friction loss (in Watts)
+Wcb = Ia*Vcb;// Brush contact loss (in Watts)
+disp(Wcf+Wcb,'Total commutator losses (Watts)=');
+//in book answer is 7230 Watts. The answers vary due to round off error
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