Unable to meet integration tolerances without reducing the step size below the smallest value allowed (1.776357e-15) at time t

My script consists of 4 ode eq's. Iam solving those using ode45 function.

syms theta

A = cos(theta).*[1 5 6 1 7; 5 0 2 9 3; 1 4 5 1 0; 0 0 0 1 0; 0 0 0 0 1];
B = tan(2*theta).*[8 5 1 7 5; 0 3 1 1 6; 3 1 2 4 7; 0 0 0 0 0; 0 0 0 0 0];
C = sin(2*theta).*[8 5 1; 0 1 6; 2 4 7];

myfun = @(t,y)scriptname(t,y,A,B,C);

% dummy values for tspan and y0
tspan = [0 1];
y0 = zeros(1, 5);

% ode solver
sol = ode45(myfun,tspan,y0);
h = figure;
% plot
for i = 1:3
    subplot(3,1,i);
    plot(sol.x,sol.y(i,:));
    xlabel('time');
    ylabel('Current');
    title(['stator current # ',int2str(i)]);
end
g = figure;
for i=3
    plot(sol.x,sol.y(i,:)*30/pi);
    xlabel('time,s');
    ylabel('Speed, rpm');
    title('Mechanical Angular Speed');
end

function dydt = scriptname(t,y,A,B,C)

inertia = 0.05;
Wr = 2*pi*50;
p =2;
% evaluation of A and B (numerical) with theta = y(3)
Cn = double(subs(C,y(5)));
for i=1:3
    I(i,1)=y(i);
end

Te = 1/2*p*I'*Cn*I

if t<0.75
    Tl=0;
else
    Tl=7.31;
end

V = [1.4142*400/sqrt(3)*cos(Wr*t);
    1.4142*400/sqrt(3)*cos(Wr*t+2.*pi/3.);
    1.4142*400/sqrt(3)*cos(Wr*t-2.*pi/3.);
    (Te-Tl)/inertia;
    y(4)]

% evaluation of A and B (numerical) with theta = y(3)
An = double(subs(A,y(5)));
Bn = double(subs(B,y(5)));
dydt = An\V-(Bn*y);
end

while running this code, it is giving below error

Warning: Failure at t=7.854990e-01.  Unable to meet integration tolerances without reducing the step size below
the smallest value allowed (1.776357e-15) at time t. 

And waveforms are coming like this

Can anyone tell me where did i went wrong.

[darova]

What hapens if you reuce tspan?

tspan = [0 0.7];

[Bathala Teja]

it is working fine if i put tspan = [0 0.7];

i know the issue with that if condition.

what i need to change now, i want that condition???

[darova]

Honetsly i don't know. Maybe @Walter Roberson will suggest you something

Maybe you have stiff ode: LINK