Power is developed due to two things, one is about motor unit recruitment while the other is about doing the rep as fast as possible. They cannot be trained simultaneously, but they both work the on the shift left in the force velocity curve started by max strength work. In the weight room you have to use heavier and lighter reps to develop power. On the track it's kind of like the difference between skipping and bounding.
i still dont understand the point to work on power in the weightroom with sprinters maybe for football, basketball and throwers. i do use jump squats in the weight but i would never spend 4-6 weeks just on a so call power phase.