Variating rotor speed problem.

Hello! I'm working on some electrical machines (generators) models and I'm needing to use a variating speed at the rotor based on the actual time of the simulation. My idea is to use a velocity input that looks like a wind variation speed in order to use a frequency inverter to guarantee the 60hz output.

Is there any way that I can use a variating speed at the rotor, not a constant value?

Thanks in advance!