function ee340lab8(IMinput) I1 = IMinput(:,2)'; % Stator line current P1 = IMinput(:,3)'; % Wattmeter reading W1 P2 = IMinput(:,4)'; % Wattmeter reading W2 n = IMinput(:,5)'; % Speed in RPM Pull=IMinput(:,6)'; % Pull in Kg % Calculated data Pi = P1+P2; % Motor input power T=Pull*9.81*0.305; % Torque Eq. (7.11) w = 2*pi*n/60; % Speed in Rad/sec. Po=(w.*T); % Motor output power Eq. (8.17) Eff = (Po./Pi*100); % Motor efficiency th=atan(sqrt(3)*(P1-P2)./(P1+P2)); pf=cos(th); ns=input('Enter the synchronous speed in RPM, ns = '); S=((ns-n)/ns); % Slip fprintf('\n\n Table I: Measured Data \n') V = IMinput(:,1)'; % Line-to-line voltage fprintf(['\n V(V) I_1(A) P_1(W) P_2(W) n(RPM) Pull, kg\n']) fprintf('%10.2f %8.2f %11.2f %10.2f %11.2f %9.2f\n', [V; I1; P1; P2; n; Pull]); fprintf('\n\n Results for the Squirrel cage Induction Motor \n') fprintf(['\n P_i(W) T(N-m) P_0(W) Slip pf Eff\n']) fprintf('%9.2f %9.2f %11.2f %10.3f %10.3f %10.2f\n',[Pi; T; Po; S; pf; Eff]); % Current and Torque Vs. Speed plots nI= 2; nT=3; % Poly. order for curve fitting % if necessary change the order CI=polyfit(n, I1,nI); % Returns polynomial coefficients for I1/n curve Ifit=polyval(CI, n); % Evaluates the polynomial values for I1/n curve figure(1), plot(n, I1, 'xr', n, Ifit, 'r' ) CT=polyfit(n, T,nT); % Returns polynomial coefficients for T/n curve Tfit=polyval(CT, n); % Evaluates the polynomial values for T/n curve hold on figure(1), plot(n, T, 'xb', n, Tfit, 'b' ) figure(1), Legend('I_1', ' ','T', ' ', 3) figure(1),title('Stator current and Developed Torque Vs. Speed') figure(1), xlabel('n, RPM'), figure(1), ylabel('I_1 (A) & T (Nm)') hold off Eff=Eff/100; % Pf and efficiency Vs. Speed plots npf= 2; nE=2; % Poly. order for curve fitting % if necessary change the order Cpf=polyfit(n, pf,npf); % Returns polynomial coefficients for pf/n curve pffit=polyval(Cpf, n); % Evaluates the polynomial values for pf/n curve figure(2), plot(n, pf, 'xr', n, pffit, 'r' ) CE=polyfit(n, Eff,nE); % Returns polynomial coefficients for Eff/n curve Efit=polyval(CE, n); % Evaluates the polynomial values for Eff/n curve hold on figure(2), plot(n, Eff, 'xb', n, Efit, 'b' ) figure(2), Legend('pf', ' ','P.U. \eta',' ', 3) figure(2),title('Power factor and Per-unit Efficiency Vs. Speed') figure(2), xlabel('n, RPM'), figure(2), ylabel('pf & P.U. \eta') hold off