function ydot = f2(t,y)
Um=13/100*400e3/sqrt(3)*sqrt(2);
Omega=314.16;
Rk=3.2;
Ls=0.26464;
Lh= 1052.0;
pom1=Ls/2+Lh;
pom2=Ls/2+Lh-Lh^2/pom1;
ydot=zeros(2,1);
ydot(1)=(Um*sin(Omega*t)-y(1)*Rk/2-Lh*y(2)*Rk/2/pom1)/pom2;
ydot(2)=(Lh*Um*sin(Omega*t)/pom1-Lh*y(1)*Rk/2/pom1-y(2)*Rk/2)/pom2;
