//Caption:In a single phase transformer Calculate the efficiency at full load unity power factor and At half full load 0.8 power factor lag also determine the load for maximum efficiency //Exam:3.29 clc; clear; close; KVA=25;//Rating of the transformer(in KVA) P_c=400;//Full load copper loss(in Watt) P_c1=P_c/1000;//Full load copper loss(in KW) P_i=350;//Iron loss(in Watt) P_i1=P_i/1000;//Iron loss (in KW) P_f=1;//Power factor unity P_f1=0.8;//Power factor 0.8 lagging O_p1=KVA*P_f;//Output at full load and unity power factor(in KW) P_t1=P_c1+P_i1;//Total losses at full load and unity power factor(in KW) I_p1=O_p1+P_t1;//Input at full load and unity power factor(in KW) E_f1=(O_p1/I_p1)*100;//Efficiency of the transformer at full load and unity power factor(in KW) disp(E_f1,'Efficiency of the transformer at full load and unity power factor(in KW)='); O_p2=(1/2)*KVA*P_f1;//Output At half full load, 0.8 power factor lag.(in KW) P_c2=((1/2)^2)*P_c1;//Copper loss At half full load, 0.8 power factor lag.(in KW) P_t2=P_c2+P_i1;//Total loss At half full load, 0.8 power factor lag.(in KW) I_p2=O_p2+P_t2;//Input At half full load, 0.8 power factor lag.(in KW) E_f2=(O_p2/I_p2)*100;//Efficiency of the transformer at half full load and 0.8 lagging power factor(in KW) disp(E_f2,'Efficiency of the transformer at half full load and 0.8 lagging power factor(in KW)='); //Maximum efficiency occurs when Copper loss = Iron loss,let the maximum efficiency occcur at x times full load x=(P_i/P_c)^(1/2); L=x*KVA;//load in KVA corresponding to maximum efficiency disp(L,'the load for maximum efficiency(in KVA)=');