%**********************************************************
%
% Synchronous Generator
%
% ECE 520  Initial Torque Angle for a Round Rotor S/G
%
% April 29, 2008
%
%**********************************************************

clc;
clear;

%**********************************************************
% I. Machine Parameters

H = 2.5;
w_eB = 2*60*pi;
T_max = 2.1;
T_m = 0.7;

%---------------------------------------------------------------------
% Use Newton-Raphson to solve for delta_0

% Initial guess
delta_0 = pi/4;
ftn = T_m - T_max*sin(delta_0);

a = 1;
while abs(ftn) > 1.0e-014
    J = -T_max*cos(delta_0);
    Delta_delta = -ftn/J;
    delta_0 = delta_0 + Delta_delta;
    ftn = T_m - T_max*sin(delta_0);
    a = a+1;
    if a>100
        Err = 0;
        'Newton-Raphson unable to Solve for delta_0'
    end
end

%---------------------------------------------------------------------
% Output Results


OPF = fopen('RoundRotor.dat','w');

fprintf(OPF,'\n\n delta_0 = %5.4f radians \n', delta_0);
fprintf(OPF,' delta_0 = %5.4f degrees \n\n', delta_0*180/pi);

fclose(OPF);