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Powerwall 2 + UPS Connundrum - and solution
- Thread starter NinjaVece
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- ups 65 hertz
So, um, when you say "altered" you mean in a positive way, right?
Bruce.
Bruce, I sure hope so. Testing will bear it out one way or another - which I hope we can all do soon...
I have a separate issue (from the frequency problem) where the comms antenna in my TEG is misbehaving. It's dropping my cell signal and the wifi won't connect. I could potentially run something temporarily to get it connected and updated but I want to leave it for troubleshooting.
And now that I've heard this I may do so anyway
Hello everyone,
1 month after installing 4 nice founders PWs, I ofcourse realized that I also do have the 66Hz issue as well.
I run 1.37.1 and I would appreciate if you guys tell me where we stand on this?
I already raised this issue with Tesla and now await.
I do not plan to buy new UPS's to accommodate their bugs.
1 month after installing 4 nice founders PWs, I ofcourse realized that I also do have the 66Hz issue as well.
I run 1.37.1 and I would appreciate if you guys tell me where we stand on this?
I already raised this issue with Tesla and now await.
I do not plan to buy new UPS's to accommodate their bugs.
Last edited:
ai4px
Wes
Solar inverters requie steady state power for 5 straight minute before switching to making power. I’m puzzled by an inverter like Tesla power wall or other hybrid type inverter making a steady 65 hz.... that’s going to play hell with your clocks in the house. It would seem to me that the “pilot” inverter would occasionally glitch the frequency to >62 hz for one or two cycles, then short to 58hz for another one or two cycles.... just often enough for the solar inverters to inhibit turning on. When the hybrid inverter wants the solar inverters to come on it simply has to steady state 60hz for 5 minutes.....
The UPSs are not to accommodate a PW2 ‘bug’. They deal with the reality that the mechanical relay in the Gateway is not instantaneous and that some electronics are very sensitive to even a few cycles of lost power before they fault.
This is of no concern to your typical fridge or HVAC system but can affect a NAS or router you want to keep running without reset.
The 66 Hz issue is a separate issue from the relay delay on creating an islanded circuit in the house should the grid power fail.
Ding ding ding! If you look back on this thread, this is somewhat the proposal I’ve made to Tesla to solve this this problrm. A short term ‘blast’ of 66 Hz followed by a steady state of 63 Hz until it is acceptable for solar input during an islanded circuit would mitigate much of this issue.
Linking back here to my update on another thread that my issues with the frequency are resolved: My grid outage frequency issue is resolved!
ai4px
Wes
I would think a “blast” of 66 hz might trip out other devices, but ok.... just counter any high frequency excursion with a corresponding low frequency event... My nightstand clock doesn’t need to run fast just because the batteries are full.
The concept is for the 66 Hz period to last 5-10 seconds filled further by the lower 62-63 Hz for the time the PW2 needs to inhibit the solar inverters from transmitting power.
Events like these where the grid is down and the PW2 has a very high SoC are exceedingly rare so shouldn’t affect your clocks timing in any meaningful way.
This would only occur if your circuit was islanded and the PW2 maintained a high SoC for long periods of time. If your solar panels regularly put out a lot more than your house uses, then that will happen.
But again, for most folks power outages are a rare occurrence. If you see it a lot, you might have to get a clock that checks the internet for actual time as opposed to using the 60 Hz of the power supply.
As many of you know, PG&E deliberately cut power to large parts of Northern California last week in a Public Safety Power Shutoff. I don't want to debate the various aspects of that action (there are plenty of other threads for that). I observed something unexpected, related to the AC frequency adjustments in this thread, with my Powerwalls during this incident (which lasted for about 36 hours in our case).
First, with Storm Watch active, the Powerwalls were charged to 100%. When the power cut out, the AC frequency went up to 65.2Hz. The effects this has on common UPSs is well known in this thread, but in the middle of the night we weren't using a lot of power and I calculated the UPSs would run out of battery before the Powerwall SOE got down to 96-97%, which is what I'd thought the frequency shifting threshold was. (Note that for my inverter, a Fronius IG Plus, only 60.5Hz is needed to make it shut down...this was confirmed by Fronius tech support and experimentally verified, ironically, a few hours before the first PSPS warnings went out.)
I found out during this outage that the point at which the Powerwalls would begin increasing the AC line frequency was more like 83%. I wound up charging my Model S at various times to soak up energy from the Powerwalls to keep them below this level, and we didn't observe any other problems for the remainder of the outage (the AC line frequency was nominal at 60 Hz).
I put in a phone call and an email to Tesla Energy support to figure out what's going on.
Today (Sunday 13 October) I tried to recreate this situation with an off-grid test...my intent was to make a video demonstrating this problem. Of course under these circumstances, it behaved as expected...while the AC frequency shift was still much higher than necessary (or desirable) for my setup, it went back to nominal below about 97% SOE. I had the Powerwalls do a couple of cycles around this point, letting them shut down and start up the inverter, and each time it was right about 96-97% SOE. This much better than how the system worked during the actual grid outage.
I'm a little confuzzled as to the difference in the threshold. The only difference I can think of is that Storm Watch was active during the actual grid outage, and not in the tests.
Also of note is that the Level 2 support person my technician was working with, was extremely reluctant to make any adjustments to the AC frequency to solve this problem. If they could just lower the the maximum adjusted frequency below 63 Hz, I'm pretty sure the inverter would still shut down as required, since we already have multiple instances of it doing this at a lower frequency (and Tesla knows exactly what inverter I have since it was originally a Solar City install).
I was trying to get someone at Tesla Energy to help resolve this during the outage, but that didn't happen. Still going to try to press them on this, even though the urgency has passed...I want things working better for future outages. For unrelated reasons, a couple of my existing UPSs need replacing, so I decided to try the Eaton UPSs mentioned upthread for better frequency tolerance.
Bruce.
PS. As a part of troubleshooting the Insteon gear, I called Insteon tech support to see what the frequency tolerance was. The uninformed but trying-to-be-helpful tech support rep would only say "50-60Hz", which was completely useless. Experimentally I'd seen flickering lights attached to SwitchLinc Dimmers at 66Hz but the constant flickering went away below about 64.5Hz. At around 63.5 Hz and below, I observed powerline communication working, although there was still flickering of lights during powerline communication.
First, with Storm Watch active, the Powerwalls were charged to 100%. When the power cut out, the AC frequency went up to 65.2Hz. The effects this has on common UPSs is well known in this thread, but in the middle of the night we weren't using a lot of power and I calculated the UPSs would run out of battery before the Powerwall SOE got down to 96-97%, which is what I'd thought the frequency shifting threshold was. (Note that for my inverter, a Fronius IG Plus, only 60.5Hz is needed to make it shut down...this was confirmed by Fronius tech support and experimentally verified, ironically, a few hours before the first PSPS warnings went out.)
I found out during this outage that the point at which the Powerwalls would begin increasing the AC line frequency was more like 83%. I wound up charging my Model S at various times to soak up energy from the Powerwalls to keep them below this level, and we didn't observe any other problems for the remainder of the outage (the AC line frequency was nominal at 60 Hz).
I put in a phone call and an email to Tesla Energy support to figure out what's going on.
Today (Sunday 13 October) I tried to recreate this situation with an off-grid test...my intent was to make a video demonstrating this problem. Of course under these circumstances, it behaved as expected...while the AC frequency shift was still much higher than necessary (or desirable) for my setup, it went back to nominal below about 97% SOE. I had the Powerwalls do a couple of cycles around this point, letting them shut down and start up the inverter, and each time it was right about 96-97% SOE. This much better than how the system worked during the actual grid outage.
I'm a little confuzzled as to the difference in the threshold. The only difference I can think of is that Storm Watch was active during the actual grid outage, and not in the tests.
Also of note is that the Level 2 support person my technician was working with, was extremely reluctant to make any adjustments to the AC frequency to solve this problem. If they could just lower the the maximum adjusted frequency below 63 Hz, I'm pretty sure the inverter would still shut down as required, since we already have multiple instances of it doing this at a lower frequency (and Tesla knows exactly what inverter I have since it was originally a Solar City install).
I was trying to get someone at Tesla Energy to help resolve this during the outage, but that didn't happen. Still going to try to press them on this, even though the urgency has passed...I want things working better for future outages. For unrelated reasons, a couple of my existing UPSs need replacing, so I decided to try the Eaton UPSs mentioned upthread for better frequency tolerance.
Bruce.
PS. As a part of troubleshooting the Insteon gear, I called Insteon tech support to see what the frequency tolerance was. The uninformed but trying-to-be-helpful tech support rep would only say "50-60Hz", which was completely useless. Experimentally I'd seen flickering lights attached to SwitchLinc Dimmers at 66Hz but the constant flickering went away below about 64.5Hz. At around 63.5 Hz and below, I observed powerline communication working, although there was still flickering of lights during powerline communication.
Actually if you think about it we should be on the threshold of not using 120V/60Hz at all for equipment like this. After all, the PowerWall starts off with DC power, converts it to 120V/60Hz, sends it maybe 50 feet to a computer, which promptly converts if to 5V/12V DC (etc).
Blue sky thinking perhaps, but the whole system would be more logical and efficient if it simply output the DC power needed my modern devices directly (and yes I’m aware of DC-DC converter issues and losses at Lowe voltage/high current, but we’re not talking space heaters here.
Blue sky thinking perhaps, but the whole system would be more logical and efficient if it simply output the DC power needed my modern devices directly (and yes I’m aware of DC-DC converter issues and losses at Lowe voltage/high current, but we’re not talking space heaters here.
SSonnentag
埃隆•馬斯克
Have you ever seen the wiring requirements for sending the 200W-500W the 50-70 feet to my computer?
SSonnentag
埃隆•馬斯克
Since your entire house is on battery backup, the only real requirement is for UPS systems on devices that may be damaged or cause data loss by the 0.5-1.0 second of power loss during the switch over to Powerwall power during an outage. In my case, that's only one computer that isn't on most of the time anyway. For that computer I bought one of the Eaton UPS systems that can handle up to 67Hz on the input side. The laptops and other electronics are fine with the tiny power drops during outages.
At this point, only our induction cooktop stove has issues with the increased frequency coming out of the Powerwalls when their batteries are nearly full. I'm working on a solution for that as well.
https://www.amazon.com/gp/product/B00KPX2MOO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
@bmah check out this post I made back in June: Utility outage simulation data dump
Originally I thought that the Powerwall flips from 60hz to the max at some charge threshold. From the data, it looks like the AC frequency that the Powerwall sets is actually a scaling function of multiple values: charge level, load wattage, and maybe solar input. I couldn't figure out via a simple linear solver what the function is but an example would be that 1% of charge means 0.1hz of frequency (again an example, not the actual amount). The more recent updates, I believe, allows Tesla to tweak each of those values depending on the customer need.
I'm guessing the higher charge state that Storm Watch provides (even if the UI doesn't really show it) causes the frequency to be higher, which is why you saw the off grid test w/o Storm Watch behave differently.
Well yes I noted that in my post. But how many people have a 500W computer? Yes, I;m sure it plays great games, but these days most people use laptops .. more like 100W max. My point was that there is a significant loss in going medium voltage DC -> AC -> low voltage DC.
Right...I get that the UPSs only need to be there to protect electronic devices that won't handle that little blip when the Powerwalls cut in. My computer and network setup at home sounds somewhat different than yours, with multiple always-on servers in various parts of the house. Anyway, the Eaton units that I will be getting will require much less energy capacity than the APCs that I'm replacing (still need outlets and power output though).
Thanks,
Bruce.
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