Larger three-phase alternators control output via their SALIENT POLES EXCITATION CURRENT.
Google the terms: Salient Pole, Excitation Current ( it's DC, BTW )
The Poco -- all of them -- run Infinite Busses -- i.e. you can consider their output as coming from one alternator -- or thousands of perfectly tuned alternators.
Tesla was the inventor of this system. His Alternating Current 3-phase machines solved Edison's Number One Headache: DC generators would keep 'hunting' up and down voltages -- swinging from generation to motoring.
Edison couldn't follow Tesla's theories. Edison then screwed Tesla over a mere $50,000 -- a bonus promised if Tesla could solve this back breaking problem. Until Tesla solved it, Edison couldn't built an infinite bus. He couldn't scale up.
The very best load following prime movers are hydroelectric dams. Between their excitation and water flow -- they can stay load-matched.
Nuclear power stations are the WORST load followers. So they are always base loaded prime movers.
Iran's new nuke at Bushehr is taking weeks to come up to full power. That is entirely typical.
If Reactive Power is needed the traditional Poco solution was a Synchronous Capacitor. This is always the latest state-of-the-art Synchronous Alternator -- with Zero Loading. It's sole function is to inject rotary capacitance by way of OVER EXITED SALIENT POLES.
This provides Reactance in mega-quantities. ( Think giga-watts-reactive )
The Canadian - New England/ New York inter-tie famously has a monster Synchronous Capacitor at the border. By the terms of the deal -- the Canadians must provide juice with virtually 100% power factor. This, then, shunts the maximum amount of real power possible over the Very High Voltage long distance power lines.
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Rather than propound novel electrical theories -- use Bing/ Google to find what the inventor-brains have said.
BTW, it wasn't just Edison -- until Tesla Wrote His Book -- and worked up the mathematics of AC power -- no one else could follow it.
( Witness this forum. )
To understand AC you need to get up to speed on Complex Numbers, Trig and Vector Calculus. That's what's taught to EE's in college.
McGraw-Hill has a fantastic summary of the electrical engineering art -- try and get a copy -- even second hand.
You can study homopolar generators, railroad traction motors, and complex double-headed power delivery to major industrial plants.
It still details technology that is now out to pasture.
EE is so big a field you can spend your entire life in it and not reach the end.
Cheers.
