Synchronous machine simulation on simscape

How can I simulate a synchronous machine with the following points?

• I want to start it with a initial condition of rotating speed - so that it has to pass from 0 to N rotor rotation speed
• Then I stop the power supply (short-circuit test) - i want to see the velocity linked to the machine's inertia discrease progressively

At the moment I'm using the model from the "Capture.PNG" file attached to this post. Another problem is that the output of the speed corresponds exactly to the same input of speed.

Thanks in advance for your help.