That's an interresting project.
Of course some points have to be refined.
The best would be that you post the complete diagram of the system including inventory of motors, mechanical parts, control unit, ect...
the first questions I think about are :
Does it have to be connected to a computer or should it operate standalone (sometimes even if not needed, an old $100 computer helps simplifying the remaining hardware)
What kind of motors DC, AC, how many phases, how many poles, top speed.
What kind of switching ? relays (only on/off) or semi-conductors (possibility of smooth varyation)
why do you talk about voltage increasing ? when you switch a motor on, without an inverter or a variator, the voltage stays at its maximum value, simply the current is very high and can even damage the motor and the control unit.
are you planning to use regular motors like generators ? if yes, there are some changes to implement (if DC, put DC in the rotor like for a car alternator, if AC, send reactive power with an inverter)
which accuracy do you expect in input voltage detection ? if high, then an analog to digital conversion is a must. if low (more or less 20 percents) an analog comparision would be enough and cheaper but less flexible.
your project seems somehow unconventional, so teach us your idea so we can help you. No one will stole your idea here.
I assume your budget is too low to implement the full control unit. If you need a semi-conductor-based switching, the transistor to switch 600V with 200 if they exist are completely out of price. I've bought a little inverter/variator for a three-phased 11 kilowatts motor, it costs around $2000 and the 6 output transistor can give only 20 amps.
maybe we should define a board with a standard output level like TTL or low power relays and you complete it with extra high power relays to fit your application.