Ungrounded Lightening Rod makes some good points. 11 kW @ 120 volts is pretty ridiculous. We have dual Xantrex SW Plus 4024's powering our off-grid home, stacked for 240 split phase. The heavy loads (electric range, clothes dryer, welder, water heater, well pump) are all 240 volt, which automatically keeps the inverters balanced when any of those loads are running.
We have a Xantrex/Trace T240 balancing transformer that powers our 120 volt loads. Even with my wife's hair dryer, electric toaster, crockpots, slow cookers, microwave, 'fridge, freezer, and numerous smaller loads like computers, TV and lights - the T240 has never had a problem powering those 120 volt loads.
Before I'd try to find a 90 amp 240->120 step down transformer (what kind of wiring you got in your walls that can even handle that?) I think I'd do it right and rewire motors and heavy loads for split phase.
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Chris