Synchronizing AC generators -- Part 4 (phase deviation) 

Yeah!

Thats why im here! I would love to see a demonstration of different failure modes

I want to see an out of sync close as well

If this were tried in 2 5000w generators, I wonder if the 20a breaker would be enough to protect from pole slip. And if there would be any other items that may not like connecting this way, like an automatic voltage regulator module

This is EXACTLY what I want to know! When I was in the Army, we had a pair of generators mounted on one trailer. One had twice the capacity of the other, so they were in a 1/3 - 2/3 ratio. We would service one while the other carried the bare minimum base load, then start it up, sync them with a mysterious sync box that had a neon sync lamp in the panel, and then shut down the other one for servicing. At least one of them was running 24/7 for an entire year! That was a lot of fuel, but we had reliable power. I never understood until now how that magic box worked. I can see having something like a 1,000W lithium + solar system providing baseload to a camper, then syncing a 2,000 - 3,000W gas generator for when you had heavier short-term loads.

We opened up the alternators and simply wired three 12-gauge conductors to the input terminals of the bridge rectifier assembly, then ran those wires out some of the holes that were already in the Delco-Remy alternator case. Some heavy-duty alternators such as Leece-Neville units already have three studs on the back pre-connected to the stator windings, but since I'm building six of these generator stations going with expensive Leece-Neville units would have broken my budget.

As far as I understand: Solar inverters cause some problems in a grid, as they dont have a rotating mass, there is no inertia, which is what enables the 2 motor/generators to come to an agreement of whose motoring and whose generating. I cant think of an easy way to add (like batteries) ac voltages un synchronized. Totally possible if their on the same shaft, they're physically in sync, can series or parallel windings all day. Roll any voltage you have windings for. Id think you'd want to parallell your 110v, as your 'grid', n then use a stepup transformer to get your 220v. I only have experience with 240v systems, but where 110 is common, perhaps autotransformers of adequate size are a thing? It'll be big tho. I was actually having this conversation at work today, very large isolation transformers. A ghetto solution would be a few stick welder transformers. We were talking 2 back to back. But a 110v transformer stick welder bolted to a 220v stick welder might just work. Or 3x 110v units. But that gives you an idea of the size of this beast. Could work... To continue the thought experiment tho, I have seen a lashup job with a 1kw standalone battery backed system that ran as the generator, with a 5kw grid connect inverter attached. With sun, there was 6kw of power, but at night dropped to 1kw off the batteries. Could run washing machine, oven, AC, etc during the day via the grid connect inverter, but at night that circut was disconnected leaving the fridge, lights n tv running off the 1 kw battery system. Very custom and hackish, but appeared to work. They just made lunch the big meal of the day, n had a cold roast sandwich for dinner. Off grid, thats easy enough. Do your washing during the day, n open the Windows at night. Tl;dr, no, i dont think you can series your inverters, unless they are specifically designed to do so. I run 2 solar strings, 2 chargers, 1 battery n 1 big inverter here, but i dont run AC either. The human body can adapt to most temperatures, its better to just acclimatise. You dont need to be 24 degrees every day of the year. The AC is nice to have in a heatwave, run it of a generator if you must. Last year, i think i ran the AC 4 or 5 nights? Priceless when you need it, but is no way a daily need.

The blinking speed is determined by the difference in the frequency between the 2 generators.

In normal use in a vehicle, the AC from the alternator is rectified by diodes so the electrical system only sees DC. So this sort of AC synchronization doesn't apply.