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Diffstat (limited to '1445/CH10/EX10.14/ch10_ex_14.sce')
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diff --git a/1445/CH10/EX10.14/ch10_ex_14.sce b/1445/CH10/EX10.14/ch10_ex_14.sce new file mode 100644 index 000000000..c9dddcdad --- /dev/null +++ b/1445/CH10/EX10.14/ch10_ex_14.sce @@ -0,0 +1,52 @@ +//CHAPTER 10- THREE-PHASE INDUCTION MACHINES +//Example 14 + +disp("CHAPTER 10"); +disp("EXAMPLE 14"); + +//VARIABLE INITIALIZATION +p=10*1000; //in Watts +I_nl=8; //no load line current in Amperes +p_ni=660; //input power at no load in Watts +I_fl=18; //full load current in Amperes +p_fi=11.20*1000; //input power at full load in Watts +r=1.2; //stator resistance per phase in Ohms +loss=420; //friction and winding loss in Watts + +//SOLUTION + +//solution (a) +I1=I_nl/sqrt(3); +i_sq_r1=(I1^2)*r*3; //stator (I^2*R) loss at no load +s_loss=p_ni-loss-i_sq_r1; +disp(sprintf("(a) The stator core loss is %f W",s_loss)); + +//solution (b) +I2=I_fl/sqrt(3); +i_sq_r2=(I2^2)*r*3; +p_g=p_fi-s_loss-i_sq_r2; +r_loss=p_g-p; +disp(sprintf("(b) The total rotor loss at full load is %f W",r_loss)); + +//solution (c) +o_loss=r_loss-loss; +disp(sprintf("(c) The total rotor ohmic loss at full load is %f W",o_loss)); + +//solution (d) +s_fl=o_loss/p_g; //full load slip +N_s=1500; +N_r=N_s*(1-s_fl); +disp(sprintf("(d) The full load speed is %f rpm",N_r)); + +//solution (e) +w=(2*%pi*N_s)/60; +T_e=p_g/w; +disp(sprintf("(e) The internal torque is %f N-m",T_e)); +T_sh=p/(w*(1-s_fl)); +disp(sprintf(" The shaft torque is %f N-m",T_sh)); +eff=p/p_fi; +disp(sprintf(" The motor efficiency is %f %%",eff*100)); + +//The answers may be slightly different due to precision of floating point numbers + +//END |