I ran 800 feet # 2 wire 240 volt 30 amp. I looking for a transformer that will stabilized the voltage at 240 volt. When a big load like chop saw and table saw it drain the power.

this is a good example of what happens when starting a motor load. Typically the load (or current) you see in then first second or two may approach 600% of the rated load amperes. In this case at 30 amps / 240 volt / #2 awg / 800 feet the voltage may drop as much as 30 volts.
If your equipment will not start due to this voltage drop, you might consider - increasing the wire size, Installing a transformer at each end of the circuit to reduce the IR drop, a soft start or frequency drive....
I would recommend consulting a local professional as your location may limit the options available.

Increasing wire would fix. The size and cost of the wire may be large.
A Generator may be a Solution. Temporary? Permanent?