> However, variable renewable sources, such as solar photovoltaic, do not have this capability. They generate direct current which is converted to alternating current at 50 Hertz, but they cannot react automatically to frequency variations.
This part didn't make sense to me.
The rotating machinery of hydroelectric, or nuclear's steam generators, produce the frequency of AC in synchronization with their mechanical rotation, but the inverters converting solar's DC into AC are making a purely synthesized waveform under control of high speed digital electronics.
I would think they should be the most able to modify the AC sine wave they are generating.
I remember reading an article about exactly that some time last year: https://spectrum.ieee.org/electric-inverter The technology is grid forming inverters, unlike the normal grid following converters. I'm definitely not an expert, but I think the part you're quoting is hinting at the following:
> Grid-following inverters operate only if they can “see” an existing voltage and frequency on the grid that they can synchronize to. They rely on controls that sense the frequency of the voltage waveform and lock onto that signal, usually by means of a technology called a phase-locked loop. So if the grid goes down, these inverters will stop injecting power because there is no voltage to follow. A key point here is that grid-following inverters do not deliver any inertia.
From the linked ieee articale ..... Not yet commercially available ....
For photovoltaics and wind, grid-forming inverters are not yet commercially available at the size and scale needed for large grids, but they are now being developed by GE Vernova, Enphase, and Solectria......
You are very right about electronics being much more capable than electromechanical systems. We can sychronize the frequency much better with GPS for example. This wasn't an issue for small scale solar, so apparently nobody implemented it to keep things low cost. We are at a point that we need these.
The beauty of it is the electronics can be connected and controlled much better with each other too, so more optimized control algorithms for supply and demand balancing is possible. Bad thing is, this will incentivize to solve problems by over the air updates. As we know software reliability has gotten so much worse, which makes it more prone to bugs being pushed. Obe should expect weird outages due to someone pushing something buggy.
You’re not wrong, it’s not that they can’t, it’s just that they currently don’t do it well. The concept is known as as grid forming if you want to read about it.
This part didn't make sense to me.
The rotating machinery of hydroelectric, or nuclear's steam generators, produce the frequency of AC in synchronization with their mechanical rotation, but the inverters converting solar's DC into AC are making a purely synthesized waveform under control of high speed digital electronics.
I would think they should be the most able to modify the AC sine wave they are generating.
Maybe someone can comment and correct my logic...