Incorrect frequency and low voltage can both cause overheating. Low frequency is most damaging to electrical equipment that contains coils like transformers and motors because it allows more current to pass unimpeded. I doubt it will bother lightbulbs, but it will blow your computer power supply, fridge compressor, invertor transformer etc.
In places where the voltage is almost always low, lots of people like to play that trick with low voltage 220 fed into a 110 regulator. It works great until someone fixes the problem and you burn the regulator and sometimes every device in the house. I have seen more than one electrical fire caused by this.
Voltage regulators correct problems of low and high voltage. Here they usually work on the principle of a variable transformer. Some require the owner to adjust it manually, some have electronics that adjust it automatically. typically they can adjust from 90 - 140V and output at 110. Some also take 220 in. More expensive models have wider ranges and higher wattage ratings. They come in sizes as small as 500W up to 25K or much more. The small units come in a standard electric equipment box with meters and outlets on the front, larger units look very much like the transformers mounted on the utility poles. Ochoa can have them made to your specifications if you visit the electrical department. If you are on street power it is the second thing you should buy after you get your invertor.
I dont know of a good way to fix a low frequency problem. If your problem is really serious an inefficient way to fix it is to make a heavy duty battery charger that is rated at that frequency to charge your batteries and link your inverter to your batteries only and not to street power. This will decouple you entirely from the street power. If there is such a thing as a frequency shifter it would be nice if someone posted the info.
Not that it is important to this discussion but 220 is not actual 2 times 110 as you would mathematically expect. It is 2 phases out of a 3 phase system. A fourth wire would act as the neutral between the three phases. Connecting the neutral to any of the other 3 wires will give 110. This may not be true on a generator designed for 220 only but i am not sure.
I would like to note that i am not an electrical engineer.... It would be nice if one was around to correct any mistakes....