//CHAPTER 7- SINGLE PHASE TRANSFORMER //Example 39 disp("CHAPTER 7"); disp("EXAMPLE 39"); //220/440 v 50 Hz transformer //VARIABLE INITIALIZATION v1=220; //primary voltage in Volts v2=440; //secondary voltage in Volts f1=50; //rated frequency in Hz //loads V=110; f2=25; //frquency of the applied load //say, else computation may not be possible using computer Pout1=100; //in watt, just assumed for computational purposes for the 220V supply We1=0.01*Pout1; //in Watts at 220 V, eddy losses which are 1% of the output at 220V Wh1=0.01*Pout1; //in Watts at 220 V, hysteresis losses which are 1% of the output at 220V //Pc1=We1+Wh1; //Total iron losses which equals We+Wh due to eddy and hysteresis Pcu1=0.01*Pout1; //copper losses // //SOLUTION //since on connecting to half the power ie 110V, the output would get halved Pout2=Pout1/2; xPcu=Pcu1/Pout2; disp(sprintf("The copper losses at 110 V would be %.0f percent of the output",xPcu*100)); //now coming to frequency dependant losses ie eddy and hysteresis //since we know that We=kh.f.B^1.6 and Wh=Ke.Kf^2.f^2.B^2 //since all being constant exept frequency, we may take We2/We1=f2^2/f1^2 //and Wh2/Wh1=f2/f1 //find values for We2 and Wh2, whence Pc2=We2+Wh2 We2=f2^2*We1/f1^2; Wh2=f2*Wh1/f1; xWe=We2/Pout2; xWh=Wh2/Pout2; disp(sprintf("The eddy losses at 110 V would be %.2f percent of the output",xWe*100)); disp(sprintf("The hysteresis losses at 110 V would be %.2f percent of the output",xWh*100)); disp(" "); // //END