Forcing Sunny Island on grid?

[Hedges]

If EEPROM, might wear out in 1000 years.
If Flash, we hope there is wear leveling. Should last plenty long then.
(Something like Windows, which downloads Gbytes of updates nightly, obviously need Tbytes of SSD to withstand such abuse.)
But parameters are such a small amount of data, a dedicated sections of Flash could be used.
Are Germans good engineers?

 

[Hedges]

It's complicated- grid as generator would only export when soc seeing is active and could pull unwanted power from the grid. Also maxes out at 95% soc and disconnects from grid, presumably when the battery is about full and I'm ready to start exporting

How about "reduce allowed grid current to near zero (during hours of no PV output). Raise back up if SoC gets too low" ?

 

[1201]

If EEPROM, might wear out in 1000 years.
If Flash, we hope there is wear leveling. Should last plenty long then.
(Something like Windows, which downloads Gbytes of updates nightly, obviously need Tbytes of SSD to withstand such abuse.)
But parameters are such a small amount of data, a dedicated sections of Flash could be used.
Are Germans good engineers?

I don't know how any of this works. I change the same two settings 2x a day. Could this be bad somehow?

 

[1201]

How about "reduce allowed grid current to near zero (during hours of no PV output). Raise back up if SoC gets too low" ?

That would be awesome if I could automate that somehow. Afaik there is no time adjustment for GdCurNom

 

[Ai4px]

It's complicated- grid as generator would only export when soc seeing is active and could pull unwanted power from the grid. Also maxes out at 95% soc and disconnects from grid, presumably when the battery is about full and I'm ready to start exporting

now that I think about it, it probably uses the last 5% in the battery as a buffer for the lag in frequency shift power control. There's a ramp rate for how fast sunny boys will change power output and all that excess power has go to so somewhere quickly.

 

[Ai4px]

How about "reduce allowed grid current to near zero (during hours of no PV output). Raise back up if SoC gets too low" ?

again, I think this is a NV ram value. The canbus converter actually changes the permitted battery charge current based on nearing full and cell deltas. The cell delta thing is done via node red, so it's NOT a sure bet if node red goes down.

 

[Hedges]

That would be awesome if I could automate that somehow. Afaik there is no time adjustment for gdcurnom

You would have to stuff a value from outside.

I don't know how any of this works. I change the same two settings 2x a day. Could this be bad somehow?

Only bad if storage is Flash and system was designed assuming updates would only be done a few hundred times.
Flash wears out around 1000 write cycles, and that even includes SSD used in computers.

Modern application of Flash, including thumb drives, has wear leveling, your permanent data gets moved elsewhere on occasion so that area of flash can suffer its share of wear.

Somebody reported Tesla was logging engineering data even in implementation shipped to customers, causing flash to fail and cars to stop working. Don't know for sure if that was true, or FUD spread by a short.

As for what you need to know, "I don't know for sure if SMA products can withstand daily updates." I don't even know if parameters are stored in Flash or in EEPROM. So I worry about implementing such automated control.

again, I think this is a NV ram value. The canbus converter actually changes the permitted battery charge current based on nearing full and cell deltas. The cell delta thing is done via node red, so it's NOT a sure bet if node red goes down.

In which case you either buy power you didn't mean to, or battery drains to the point of system shutdown.
Either way, hopefully not the end of the world.

Wish we had a bit more feature programmability in SI, even a state machine or ladder logic we could program inside it.

 

[1201]

now that I think about it, it probably uses the last 5% in the battery as a buffer for the lag in frequency shift power control. There's a ramp rate for how fast sunny boys will change power output and all that excess power has go to so somewhere quickly.

I'm not sure but either way I don't see a way to do this automatically without some type of relays

 

[Ai4px]

You would have to stuff a value from outside.



Only bad if storage is Flash and system was designed assuming updates would only be done a few hundred times.
Flash wears out around 1000 write cycles, and that even includes SSD used in computers.

Modern application of Flash, including thumb drives, has wear leveling, your permanent data gets moved elsewhere on occasion so that area of flash can suffer its share of wear.

Somebody reported Tesla was logging engineering data even in implementation shipped to customers, causing flash to fail and cars to stop working. Don't know for sure if that was true, or FUD spread by a short.

As for what you need to know, "I don't know for sure if SMA products can withstand daily updates." I don't even know if parameters are stored in Flash or in EEPROM. So I worry about implementing such automated control.



In which case you either buy power you didn't mean to, or battery drains to the point of system shutdown.
Either way, hopefully not the end of the world.

Wish we had a bit more feature programmability in SI, even a state machine or ladder logic we could program inside it.

The Tesla thing was real... I had a 2014 Model S that had to get a new head unit because of that issue. It was a real issue. And while we might say that modern flash could have wear leveling or last 100,000 cycles, do those apply to inverters that were designed in 2016/17? Actually, I'm not sure when the sunny island was spec'ed and the design committed.

 

[Ai4px]

You would have to stuff a value from outside.



Only bad if storage is Flash and system was designed assuming updates would only be done a few hundred times.
Flash wears out around 1000 write cycles, and that even includes SSD used in computers.

Modern application of Flash, including thumb drives, has wear leveling, your permanent data gets moved elsewhere on occasion so that area of flash can suffer its share of wear.

Somebody reported Tesla was logging engineering data even in implementation shipped to customers, causing flash to fail and cars to stop working. Don't know for sure if that was true, or FUD spread by a short.

As for what you need to know, "I don't know for sure if SMA products can withstand daily updates." I don't even know if parameters are stored in Flash or in EEPROM. So I worry about implementing such automated control.



In which case you either buy power you didn't mean to, or battery drains to the point of system shutdown.
Either way, hopefully not the end of the world.

Wish we had a bit more feature programmability in SI, even a state machine or ladder logic we could program inside it.

and aw heck, if I could get into it to program it, I would have changed the peukert compensation value and not needed the doggone can bus / bms converter device!! ha!

 

[1201]

.

Wish we had a bit more feature programmability in SI, even a state machine or ladder logic we could program inside it.

This is the reason why I'm considering a victron system for when these eventually expire

 

[Hedges]

Oh, do they have a space for user programming?

I've gone all in for SMA, lots of spares on the shelf.

do those apply to inverters that were designed in 2016/17? Actually, I'm not sure when the sunny island was spec'ed and the design committed.

2007 or earlier. I think the SI 5048US I just commissioned said 2007 in the firmware.
It accepts same code as 6048US.

Hardware could be different in the new model if it did some switching regarding part numbers/functions and the like. But I suspect architecture and chipset identical. Just battery terminals and power transistor differences.

Software of course could implement a new algorithm.

 

[Ai4px]

Oh, do they have a space for user programming?

I've gone all in for SMA, lots of spares on the shelf.




2007 or earlier. I think the SI 5048US I just commissioned said 2007 in the firmware.
It accepts same code as 6048US.

Hardware could be different in the new model if it did some switching regarding part numbers/functions and the like. But I suspect architecture and chipset identical. Just battery terminals and power transistor differences.

Software of course could implement a new algorithm.

I have a spare pair of sunny islands on the shelf as well. These things are built like tanks.... but support stinks from SMA overall. Over the past several years, I've done away with all "spike" starting loads in the house so the original need for these particular inverters has passed... but I'm well down the rabbit hole.

On a side note... was prepping to have friends come over two weekends ago to add 20 more panels to my roof and once I set up a scaffold I got a chance to look UP my shingled roof. ....and it's time for a roof. So that was put on hold. Entirely by luck a friend found us 134 370w panels for .16/watt and we're splitting the lot of them three ways. I'll ground mount them. I had resisted ground mounting the ones on the roof because there would be 80 of them in the yard... too much space. But 48 panels is doable.

 

[1201]

Before you say it, there is a parameter where you set how much current can come from the grid connection GdCurNom (232.03) (for example mine is set to 55amps)... If I set it to 1 amp then I can only push OR pull 1amp. So I have to set this to 55amps. So that won't limit import power without also limiting export power.

It seems the one parm we missing is GdRvPwr's evil twin .... GdFwPwr. or if I could put a negative number in GdRvPwr.

here is a wacky idea.
we know that if you set GdCurNom to say 1 amp it will only import one amp. but if you try to export more than 1 amp it will trip and lockout for the time set at ExtLkTm, whose default is 20min.

what if, and here is the wacky idea, we set extlktm to 0. maybe that would force the inverter to not shut down the grid connection and would allow us to limit the incoming amps, but not limit the outgoing amps?

 

[Ai4px]

here is a wacky idea.
we know that if you set GdCurNom to say 1 amp it will only import one amp. but if you try to export more than 1 amp it will trip and lockout for the time set at ExtLkTm, whose default is 20min.

what if, and here is the wacky idea, we set extlktm to 0. maybe that force the inverter to not shut down the grid connection and would allow us to limit the incoming amps, but not limit the outgoing amps?

I could try it.... let me look in the menus... but my spidy sense tells me it'll just rapid cycle.

 

[1201]

I could try it.... let me look in the menus... but my spidy sense tells me it'll just rapid cycle.

You are probably very right. Thanks for volunteering

You may have to set grid reverse power and time as high as possible too. Good luck and please let us know how it goes

 

[Hedges]

At least one of mine, 5048US, will export 13A even when set for 8A max. Maybe older firmware.
Unusual system, 3-phase setup with 3x 5048US, coupled to TriPower which was delivering PV power, but only Master SI was connected to grid.

I could try it.... let me look in the menus... but my spidy sense tells me it'll just rapid cycle.

Because when disconnected, less than the limit. Lockout becomes period of cycle.

 

[Samste]

Ahhhh sorry.... I'll explain better.... first thing in the morning, I'll start off grid with a battery that is not 100%.... PV AC coupled inverters will charge my battery. As soon as battery is full, the frequency will blip to 61hz. When that happens I'll command the grid connection. From then for the rest of the day (or until consistency cloudy), I'll stay locked to 60hz. The trick will be recognizing when I'm buying power and dropping the grid.... but the initial connection to the grid will probably be based on 61hz. Hope this makes more sense!

would this work for you ?

CATCH Solar Relay | Installer I CATCH Power

Export Limiter, Inverter Control, Load Control, Energy Meter all in one device! Fronius, Sungrow, Goodwe, Ge, SolaX, Sunways, Sofa, Growatt, Solis, Hauwei

www.catchpower.com.au

 

[kommando]

would this work for you ?

Only cover Sunny Boys with modbus TCP not Sunny Islands

 

[Samste]

Only cover Sunny Boys with modbus TCP not Sunny Islands

tech docs say you can program freq limits for on/off relay ? inc voltage limits and thresholds etc