Hello Akhtar,
running open loop on a grid connected simulation would often not work since it won't by synchronized with the grid. It is possible in simulation but you'd need to often tweak a number of phase ofsets and frequencies to ensure it actually worked, which is probably more work than just synchronizing it to the gril with PLL and closed loop controller given the examples that are available. There are shipping examples of how this works grid connected:
Regards,
Joel
