Thank you very much Mr. Madhavan. I have found and downloaded the paper that you suggested. I actually find it very helpful. My thesis is about the development of DC Circuit Breakers in MVDC onboard grids. So i am trying to simulate a fault in order to observe how the Circuit Breaker model that i am investigating operates.
My suggestion is that you should consider ETAP software for this purpose. It is much more convenient than simulink. If you need help with that, feel free to contact me.