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Diffstat (limited to '1445/CH8/EX8.37/ch8_ex_37.sce')
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diff --git a/1445/CH8/EX8.37/ch8_ex_37.sce b/1445/CH8/EX8.37/ch8_ex_37.sce new file mode 100644 index 000000000..3cea8b20c --- /dev/null +++ b/1445/CH8/EX8.37/ch8_ex_37.sce @@ -0,0 +1,43 @@ +//CHAPTER 8- DIRECT CURRENT MACHINES +//Example 37 + +disp("CHAPTER 8"); +disp("EXAMPLE 37"); + +//VARIABLE INITIALIZATION +p_o=50*1000; //in Watts +v_t=250; //in Volts +loss1=5000; //total core loss in Watts +loss2=2000; //total core loss in Watts (when speed is reduced to half) +speed=125/100; + +//SOLUTION + +//solution (a) + +//W_h=A*N, where W_h=hysteresis loss, A=constant and N=speed +//W_e=B*(N^2), where W_e=eddy current loss, B=constant and N=speed +//W_h+(W_e^2)=loss1 =>W_h+W_e=5000 +//(W_h/2)+(W_e/4)=loss2 =>(0.5*W_h)+(0.25*W_e)=2000 (when speed reduces to half) +//So, we get two equations +//W_h+W_e=5000.......................eq(i) +//(0.5*W_h)+(0.25*W_e)=2000..........eq(ii) +//solving the equations by matrix method +A=[1 1;0.5 0.25]; +b=[5000;2000]; +x=inv(A)*b; +W_h1=x(1,:); //to access the 1st row of 2X1 matrix +W_e1=x(2,:); //to access the 2nd row of 2X1 matrix +disp("Solution (a)"); +disp(sprintf("The hysteresis loss at full speed is %d W",W_h1)); +disp(sprintf("The eddy current loss at full speed is %d W",W_e1)); + +//solution (b) +W_h2=speed*W_h1; +W_e2=(speed^2)*W_e1; +disp("Solution (b)"); +disp(sprintf("The hysteresis loss at 125%% of the full speed is %d W",W_h2)); +disp(sprintf("The eddy current loss at 125%% of the full speed is %d W",W_e2)); + +//END + |