He has found a potential problem:
That if a load of rich guys buy fancy EVs and all try to rapid charge them at the same time, you will have a problem.
IMO, it is a bit of a corner case, but is worth considering.

The solution is to stagger the charging times across the whole night. You could even imagine a dual charge scenario: a few kwH when you get home in case you need the car soon, and top it off later on during the night.
If the average person drives 34 miles / day, this is about 11 kwH / day, which should be easy as long as you can stagger it.
You need to implement a pricing structure that encourages this.
You might need some kind of connected charging system which negotiates with other local cars as to when they charge (or just charges at a lower rate).
If you have a "big battery" car with more than one day's driving in it, this should not be a problem.
A 60 KwH Tesla 3 should be able to store 5 average day's driving, and so should have considerable flexibility as to when it charges.

How is this different from having everybody in a neighborhood running maximum A/C and cooking dinner at the same time? Electric cars are less of an issue because they can be programmed to charge overnight.

@Bernard, it is different because if you want to cook a meal, you need to do it NOW- same with A/C.
However, you usually do not need to charge a battery right now, you just have to have ti charged before you need it the next morning. Thus, you could schedule it to charge from 4-6 AM (or whatever).
What you want is some system where all the local cars agree on when to charge so as to spread it across the night. Some people might want it right away - they would pay more.
Some might want it by 6am, some by 8am. You might pay less if you give more flexibility in terms of time.
You might pay even less if you allow them to take power from you as well as charging.
It sounds simple to me - the sooner you want it charged, the more you pay per KwH.

Voltage literally doesn't matter, Roger.  You can run voltage almost as low or high as you want by drawing or injecting reactive power.  The thing which gives you the grid's state of power surplus/deficit isn't voltage, it's frequency.

And yes, vehicles could sense this automagically and ramp their charging up or down depending on how the phase is changing relative to a known clock.  The problem there is that if you have a lot of load which is ramping up and down to try to keep frequency stable, you might have unwanted interactions with the grid's own AFC (automatic frequency control) which does the same thing from the generation end.  You really want a second data channel which can tell the loads what to do, preferably by particular zones in the grid.  But that one can have a lot more latency than the direct sensing of frequency.

As Conley and Mahoney write, we have energy storage.  It's called "fuel".

Pretty much that, Roger.  A computationally cheaper way than A/D with Fourier transform is to use a zero-crossing detector and just wait for its output state to flip.  Most microcontroller families have "timer capture" as an option on one or more pins, which grabs the value of the system's clock counter when the prescribed transition occurs (the program can read the value of the capture register at its leisure).  Sampling of system voltage can be done halfway between crossings, at the peak.  More sophisticated functions will require more data, of course.

Local problems can cause major undervoltages and connections going bad from e.g. overheating can cause flicker.  The latter is cause to shut down and raise a fault flag; you can just pause and wait for the former to go away.  The broader grid surplus/deficit condition is telegraphed by frequency, in other words the time between those zero crossings.  If that time suddenly starts getting longer, there's an energy-deficit condition on the grid and backing off on the charging rate might be in order.

You can potentially respond to such conditions within 1/2 cycle, or 8.33 msec at 60 Hz.

I wonder if this technique has been used more widely.

I don't know if it's being used anywhere yet.

I've mentioned the possibility as rational or logical for years but E.P's comment is the first time I've seen any reference.

I've seen references to it before, so it's not a new idea.  I may incorporate it in some patent claims that I'm revising almost as I write this.

From my perspective is simply the mirror end of e providers or grid operators supply quality assurance.

Yes, precisely.

On the numerous occasions I've tried to bring this question, the response has been silence. 0..?..No! can't be done. Not necessarily in that order.

The mentality of grid operators is that frequency control is done by generators, as it has been... to date.  They have not yet internalized that grid frequency is a balance between generation and load, and dynamic load control has just as much influence on frequency.  This will require an awakening on their part.

If the grid operator uses frequency shifting as a response to under capacity and that the supply guarantee is within +-1Hz that is corrected over 24hours

IIUC the frequency limits are far tighter than that, OTOO 0.15 Hz or maybe narrower.  Parts of the grid can have wider immediate tolerances than the average, because as power flows over lines reverse the phase relationship between the two ends necessarily reverses with them.  This means a shift in frequency over time at at least one end and probably both.

"Muratori also looked at the impact PEV charging might have on a residential distribution transformer.Even without large numbers of PEVs on the road, this clustering effect will significantly increase the peak demand seen by distribution transformers, thereby potentially requiring the upgrades, he found."

I'm sure the utility companies will have zero problem upgrading these transformers with the extra revenue from all that extra electricity they will be selling. That's how business works.

Of course they will try to put the onus on EV owners and require them to pay an extra fee and try to force them to charge only at off peak times so they don't have to upgrade equipment. That way they get to sell extra electricity AND don't have to spend any extra on upgraded equipment.

Frequency signals are IMO not a good idea as the same signal is given to all participants at the same time

Except it isn't.  The phase you measure at your end of a feeder depends on the phase shift over the lines between you and the generator.  That phase shift depends on the load.  If the load is increasing near your end you'll measure a frequency drop, and vice versa.  Changing transformer taps can cause abrupt phase jumps.

the operator may try to keep the frequency as stable as possible irrespective of what is happening on the grid.

That's one of the operator's jobs; there is only so high/low frequency can go before generator specs call for them to trip off the grid.  One of the possibilities with frequency-responsive charging is that chargers could back off as frequency sagged toward the control limits.  This automatic load-shedding could happen much faster than the grid's AFC, letting slow machinery catch up to rapidly-changing conditions.  This is a substitute for mechanical inertia which is being lost as wind and PV increasingly displace conventional generation.

Ideally, you want a schedule which is automatically worked out such that everyone who wants to charge can do so.

Handling of the broad-scale grid condition and the load on the local distribution transformer are related but different problems.

Frequency signals are IMO not a good idea as the same signal is given to all participants at the same time

Except it isn't.  The phase you measure at your end of a feeder depends on the phase shift over the lines between you and the generator.  That phase shift depends on the load.  If the load is increasing near your end you'll measure a frequency drop, and vice versa.  Changing transformer taps can cause abrupt phase jumps.

Remember that grid frequency is what the generators use to sense if they should ramp power up or down.

the operator may try to keep the frequency as stable as possible irrespective of what is happening on the grid.

That's one of the operator's jobs; there is only so high/low frequency can go before generator specs call for them to trip off the grid.  One of the possibilities with frequency-responsive charging is that chargers could back off as frequency sagged toward the control limits.  This automatic load-shedding could happen much faster than the grid's AFC, letting slow machinery catch up to rapidly-changing conditions.  This is a substitute for mechanical inertia which is being lost as wind and PV increasingly displace conventional generation.

Ideally, you want a schedule which is automatically worked out such that everyone who wants to charge can do so.

Handling of the broad-scale grid condition and the load on the local distribution transformer are related but different problems.

Can I even comment on this post?  3 comments I've tried to post have vanished.