Your power is likely going so high because:
- the generator torque in your model is constant for speeds higher than rated speed (Region 3 control),
- the aerodynamic torque is higher than the rated generator torque, and
- you don't have active blade-pitch control to reduce the aerodynamic torque at high winds to regulate the speed,
You'll need another means of control to operate in Region 3 e.g. active blade pitch control.