// Example 1.24 clear; clc; close; format('v',7); // Given data VL=400;//in volt f=50;//in Hz P=6;//no. of poles Z1=0.3+%i*0.4;//in ohm Z2dash=0.2+%i*0.4;//in ohm X0=20;//Magnetic reactance in ohm R0=100;//resistance for core loss in ohm S=4;//in % StatorLoss=2;//in KW MechLoss=2;//in KW //Calculations R1=real(Z1);//in ohm R2dash=real(Z2dash);//in ohm X1=imag(Z1);//in ohm X2dash=imag(Z2dash);//in ohm S=S/100;//slip V1=VL/sqrt(3);//in volt Ns=120*f/P;//in rpm Ri=R2dash*(1-S)/S;//in ohm R1e=R1+R2dash;//in ohm X1e=X1+X2dash;//in ohm I2rdash=V1/(R1e+Ri+%i*X1e);//in Ampere Ic=V1/R0;//in Ampere Im=V1/(%i*X0);//in Ampere I0=(Ic+Im);//in Ampere CoreLoss=Ic^2*R0;//Core loss per phase in Watts I1=I0+I2rdash;//in Ampere Istator=abs(I1);//in Ampere cosfi=cosd(atand(imag(I1)/real(I1)));//lagging power factor Pc=3*abs(I2rdash)^2*R2dash;//in Watts //Here P2:P0:Pm=1:S:1-S Pm=Pc*(1-S)/S;//in watts Pout=Pm-MechLoss*1000;//in watts StatorCuLoss=3*abs(I1)^2*R1;//in watts TotLoss=CoreLoss*3+StatorCuLoss+Pc+MechLoss*1000;//in watts Eff=Pout/(Pout+TotLoss)*100;//in % N=Ns*(1-S);//in rpm disp(N,"(a) Motor Speed in rpm : "); disp(Istator,"(b) Stator current in Ampere : "); disp(cosfi,"(c) Power factor lagging : "); disp(Pout,"(d) Motor Output in Watts : "); disp(Eff,"(d) Efficiency in % : "); //Answer of Pout is wrong in the book.