Bronco6Gen said:

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Isn't the answer to just isolate the inverter from the grid with energy storage (battery)? On my residential system, the solar is just charging the batteries, and the inverter takes the DC from the battery and inverts it AC for the house. Battery technology is a lot better at detecting anomalies, I assume because there is usually some sort of "smart charging" circuitry applied to it that picks up on too low or too high voltage. You could use feedback from the battery system instead of the inverter to isolate problem sites?

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Battery storage relies on inverters too. It's the same thing.

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Isn't the answer to just isolate the inverter from the grid with energy storage (battery)?

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These are generation companies. The whole point is to sell power to the grid. Isolating them defeats the purpose.

RedHand said:

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Logos Stick said:

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I watch Practical Engineering all the time on YouTube and Brady discussed this on a vid a few months back. We've got a serious issue going forward with the move to renewables. Blackouts are going to become more frequent and widespread.

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I refuse to take any complaining about energy seriously until they start mentioning nuclear. It's the solution to the energy issues we have. Until then everyone is just blowing hot air, which tells me the issue isn't that serious.

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Policy makers vs engineers.

I fear we'll get 1/3 of the way into the renewable build out and folks will start to ask why they're getting less reliable energy for twice the cost. Transmission lines, interconnections, batteries, capacitors, synchronous condensers, extreme high voltage… it's going to cost numerous billions - a cost that'll be borne by rate payers and tax payer subsidies - while also giving them zero noticeable benefit in reliability.

Politicians are making promises for a 20 year build out that'll take 30+ and cost an order of magnitude more than advertised. I wouldn't be surprised if it becomes politically unpalatable within 10 and we end up pivoting to slapping in nukes at the end of the line segments we did manage to build.

If you're asking me, my undergrad at A&M was Ch E. So ????

I did take EE grad classes at another school, but couldn't stomach a mandatory antenna design class and bailed.

I usually attend this for Austin Energy but this year it was sandwiched in between DistribuTech conference and SWEDE so I didn't attend since going to the other conferences.

Thanks for sharing the links to the presentations

Seems overblown. There are lots of other countries with higher renewable penetration than the US. Denmark is like 90% renewable

Martin Q. Blank said:

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Quote:

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Isn't the answer to just isolate the inverter from the grid with energy storage (battery)?

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These are generation companies. The whole point is to sell power to the grid. Isolating them defeats the purpose.

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Well, I don't mean permanent isolation. My residential system sells power to the grid, but the battery storage is before the inverter, the battery acts as a "buffer" between the solar and the inverter/ grid, theoretically you could monitor the "buffer zone" instead of the inverter for anomalies to identify problem sites.

JobSecurity said:

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Seems overblown. There are lots of other countries with higher renewable penetration than the US. Denmark is like 90% renewable

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Make it happen!

IBRs are a hot topic, for sure. But, NERC is addressing these through multiple new standards and standards revisions, and PRC-029-1 specifically addresses keeping IBRs connected to the BPS during system disturbances. I am pretty confident that we can handle IBRs on the grid.

I am not so confident about excess generation capacity; our boss spoke at a conference this week and told everyone he is seriously concerned. We're dropping from 24% to 5% in our footprint by 2035, and he doesn't think we will create enough new generation to make up the difference. He's hoping that demand response will help, but if you're concerned about blackouts, don't blame IBRs, in my opinion.

As an aside, the good news is that new gas is still being built. I just saw an announcement there is a 4.5 GW facility that will be constructed in Pennsylvania for the express purpose of powering data centers. Granted, I'd hold my breath until it's up and running.

Blackout? I'll add that to my list of **** that never is going to happen.

Asteroid. Second coming.

Relay protection settings have ALWAYS been like walking a tightrope with a tradeoff between making things fail when they need to and avoiding catastrophic damage that takes a long time to recover from and the other end of the spectrum of nuisance tripping frequtntly shutting things down that don't need to be when you start protecting from anything and everything.

The technical community eventually figures out power quality signatures to do a better job with tripping off vs not tripping. Sounds like the current crop of "experts" still has some work to do with identifying the numerous, suttle variations between similar but different invertor event signatures. About the time they get that figured out some mnfg will develop some new invertor design that the current protection doesn't account for. Rinse and repeat....its been that way for quite some time with electronic equipment. If you are a PQ/Protection type engineering consultant there is a lot of money to made on both sides of the figure out the solutions and be that guy....or prolonging the problem as long as you can for more billable hours.

I'm no power guy but would one solution be to sync the grid frequency to GPS time signals and require all producers to match that frequency? I know we shift grid frequency to help match small variations in load but could we just let the grid voltage vary more instead?

Thats a good way to damage sensitive equipment

I'm not saying drop the voltage into the 80s but they probably manage it a lot tighter than required.

For decades we had 110v systems. Then somewhere along the way they just decided to change the standard to 120v and I don't think they had to retrofit much on the user side. But even with the 120v standard they're allowed to vary the voltage between 114v-126v and even between 110v-127v in off nominal situations.



There are probably reasons we prefer to let the frequency sag instead voltage, but if I understand the OP, it seems that the issue with inverters is that as soon as they no longer have a frequency to sync with, they will each go back to 60.0+/- Hz and phasing be damned. So when the circuit breakers trip and the grid fragments into lots of isolated mini-grids, you can't just close the breakers and reconnect the isolated grids because they're now all out of phase.

Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

Great read.

techno-ag said:

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Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

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These comments are revolting.

IIIHorn said:

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techno-ag said:

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Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

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These comments are revolting.

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Figured you'd have a line for this. More power to ya.

Get a synchronous generator that automatically isolates from the utility … problem solved ….as long as you have fuel.

Dr. Venkman said:

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I just returned from the 78th annual relay conference at Texas A&M. This conference was started in 1948 as a way for electrical engineers to collaborate on the best way to design and set protection relays for generators, transmission and distribution lines, and industrial loads.

The past couple of years has been dedicated to how to deal with inverter based resources (IBRs). These are generating units that rely on inverters for generation (solar, wind, and battery storage). The problem with inverters is they do not act in a predictable fashion like synchronous machines (turbine generators).

If there is a fault on the system, synchronous machines slow down gradually, provide a lot of fault current, and provide predictable "signatures" in the fault current so that relays are able to detect the fault and isolate it with minimal loss to electric customers.

Inverters do not do this. They rapidly change frequency to protect themselves, provide very little fault current, and do not provide a "signature" so that our relays are not able to distinguish a true fault from normal load current. This is a problem because the relays may not trip breakers when they need to. Or they'll trip when they're not supposed to.

If you look at the papers from the past three years, about 1/3 - 1/2 are dedicated to this problem and proposals to how to solve it.
https://na.eventscloud.com/website/78210/archive/

From listening to the presentations this week, it can be summed up from one such presentation by PG&E.
https://na.eventscloud.com/file_uploads/c215cc72a075d4060a5016e0e13df5c7_1-EventAnalysis-InnovativeToolsandStrategiesforProtectionEngineers.pdf

The relevant section is about half way down: Inconsistent IBR Fault Current Contributions. We may do our best to come up with a way to model IBRs and set our relays in a way we think they will behave. But this was a real world example of the SAME inverter during two faults behaving in two entirely different manners.

I believe the US is due for a regional blackout and it will be caused by this issue. One of the last papers yesterday was by Entergy presenting on line protection solutions for IBR interconnections.
https://na.eventscloud.com/file_uploads/b8e0753fbd9fe32e19801d92f3b48c7f_4-LineProtectionSolutionsforMultipleIBRInterconnectionsinanIncumbentUtilityInfrastructure.pdf

In passing they mention they are moving from 2% renewables in 2023 to 25% by 2030. As it stands, we have sufficient synchronous machines with enough inertia for the relays to see and isolate faults, but unless we require inverter manufacturers to design their products to address this issue, we're going to have a problem when more of these are connected to the grid.

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I see your renewable issue problem and raise you a cyber attack by a nation state. I was at the TEEX Cyber Readiness Summit last week and participated in a table top exercise simulating an attack on a local power company. It was bad. Don't want to hijack your thread, but let's just say there are signs that the bad guys have been surveilling and preparing for a major attack.

Like to hear more about this if you're able to share. I work for Austin Energy cybersecurity is big on our list.

BurnetAggie99 said:

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Like to hear more about this if you're able to share. I work for Austin Energy cybersecurity is big on our list.

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Have company coming over for final four and I need to get the pit going but I will start a thread tomorrow.

Tailgate88 said:

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BurnetAggie99 said:

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Like to hear more about this if you're able to share. I work for Austin Energy cybersecurity is big on our list.

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Have company coming over for final four and I need to get the pit going but I will start a thread tomorrow.

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Much appreciated

the 1977 New York blackout was insane

techno-ag said:

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IIIHorn said:

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techno-ag said:

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Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

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These comments are revolting.

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Figured you'd have a line for this. More power to ya.

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Welcome to the resistance

IIIHorn said:

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techno-ag said:

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IIIHorn said:

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techno-ag said:

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Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

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These comments are revolting.

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Figured you'd have a line for this. More power to ya.

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Welcome to the resistance

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Have you switched sides or are you a transformer? Maybe that's a loaded question.

IIIHorn said:

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techno-ag said:

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IIIHorn said:

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techno-ag said:

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Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

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These comments are revolting.

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Figured you'd have a line for this. More power to ya.

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Welcome to the resistance

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So correct me if I'm wrong, traditional electrical generation relies on spinning mass to act as an inertial buffer to the grid. The mass of the generator behaves in ways we can easily model because of physics of big heavy things rotating. Historically, this generation style has fewer, larger drums to keep the 60Hz beat with (power plants). And an obvious manner on how you're going to produce the next beat (keep rotating a physical spinning mass).

Invertors require no such limitation. They can whip their electrical signal all over the place to keep the 60z drum beat. They can listen to the drum beat, and respond with their own beat with way less inertia. But also fall out of sync faster. So millions smaller invertors collectively creating a less precise drum beat as they all try to whip their way to be perfectly in sync. But fewer signal leaders, more listeners.

Isn't the option A) demand larger solar panel farms implement a physical mass to attach to the grid
or
B) demand all control logic of inverters actually only be able to control with PID loops that mirror rotating masses.

GeorgiAg said:

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Whatever Venkman, I said shut it down.

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Ha!

lb3 said:

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IIIHorn said:

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techno-ag said:

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IIIHorn said:

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techno-ag said:

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Old Sarge said:

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Well, this is not shocking news.

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Gotta stay current.

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These comments are revolting.

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Figured you'd have a line for this. More power to ya.

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Welcome to the resistance

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Have you switched sides or are you a transformer? Maybe that's a loaded question.

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Static

Great thread OP. I share this concern as well. There have been several events with IBRs in ERCOT where the IBRs tripped unexpectedly.

Now we have another concern on the load side of the equation with the massive demand for AI data center load wanting to connect. These loads are highly unpredictable in that they can ramp up from 0 to 100% instantly, or switch to backup power unexpectedly which takes them off the grid, and this makes managing the frequency problematic. On top of this, it doesn't seem like utilities really understand how to model the behavior of these AI data center loads in order to properly plan for them, but they so badly want this load on their systems for revenue, and these are companies like Microsoft and Google which don't like being told that no, we can't support your data center load the grid at this time.

Overall, it seems like the demand for large data center loads is outpacing our ability to build the generation and transmission capacity to support it.

So PG&E, the CA producer of energy predicted this? Did CenterPoint in Houston give a presentation on storm preparedness and how to bounce back? It would be equally convincing.

They're experts at calamities, who better to tee up the next one?