From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2642/CH6/EX6.6/Ex6_6.sce | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100755 2642/CH6/EX6.6/Ex6_6.sce (limited to '2642/CH6/EX6.6') diff --git a/2642/CH6/EX6.6/Ex6_6.sce b/2642/CH6/EX6.6/Ex6_6.sce new file mode 100755 index 000000000..924048f2b --- /dev/null +++ b/2642/CH6/EX6.6/Ex6_6.sce @@ -0,0 +1,40 @@ +// FUNDAMENTALS OF ELECTICAL MACHINES +// M.A.SALAM +// NAROSA PUBLISHING HOUSE +// SECOND EDITION + +// Chapter 6 : CONTROL AND STARTING OF A DC MOTORS +// Example : 6.6 + +clc;clear; // clears the console and command history + +// Given data +V_t = 220 // shunt motor supply voltage in V +P_0 = 3550 // o/p power in W +n = 0.85 // efficiency +// condition given : starting current of the motor should not exceed twice the load current + +// caclulations +P_in = P_0/n // i/p power in W +P_tloss = P_in-P_0 // total loss in W +I_a = P_in/V_t // neglet the field current then armature current in A +P_cu = P_tloss/2 // copper loss in W +R_a = P_cu/I_a^2 // armature resistance in ohm +I_1 = 2*I_a // maximum starting current in A +R_1 = V_t/I_1 // maximum resistance in ohm +k = (R_1/R_a)^(1/4) // constant +R_2 = R_1/k // other value of resistance in ohm +R_3 = R_2/k // other value of resistance in ohm +R_4 = R_3/k // other value of resistance in ohm +R_5 = R_4/k // other value of resistance in ohm +R_1step = R_1-R_2 // resistance of the 1st step in ohm +R_2step = R_2-R_3 // resistance of the 1st step in ohm +R_3step = R_3-R_4 // resistance of the 1st step in ohm +R_4step = R_4-R_5 // resistance of the 1st step in ohm + +// display the result +disp("Example 6.6 solution"); +printf(" \n resistance of the 1st step in ohm \n R_1step = %.1f ohm \n", R_1step); +printf(" \n resistance of the 2nd step in ohm \n R_2step = %.2f ohm \n", R_2step); +printf(" \n resistance of the 3rd step in ohm \n R_3step = %.2f ohm \n", R_3step); +printf(" \n resistance of the 4th step in ohm \n R_3step = %.2f ohm \n", R_4step); -- cgit