Forcing Sunny Island on grid?

[Hedges]

Now that you mention it, what I need is a IMPORT power limit.

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.

When I tried that parameter, it did not disconnect to prevent export of excess power above the limit. Maybe your firmware handles it differently. Mine was an older 5048US, firmware not updated.

Just use that parameter. If battery gets low, set it back up to 55A until SoC is back up where you want. If your SI does disconnect due to excess export (does it then cycle on and off grid repeatedly?) set it to 55A until you are once again importing, then set back to 1A.

 

[Ai4px]

Why is the extra power coming from the grid and not the battery? I don't understand.

Do you have "GdPwrEna" set to enable or disable?

GdPwrEna would be great if I could switch it from canbus....... the sma wants to pull excess power from the grid rather than battery.

 

[1201]

What do you have these set at?


"Utility grid as generator: connecting the utility grid as soon as the loads request high power from the Sunny Island

You can configure the Sunny Island in such a way that it automatically connects to the utility grid once the connected loads request high power from the Sunny Island. To activate this function, set the parameter "232.42 GdPwrEna" to "Enable". The Sunny Island connects to the utility grid when the power requested by the loads is within the limits determined by the following parameters:

• "233.07 GdPwrStr" to "233.08 GdPwrStp"

 

[kommando]

I read my SI5048 data using yasdi2mqtt running on a PI, the PI also runs Node Red. In Node Red I monitor various readings held in the MQTT database including SOC, Frequency, battery voltage. When the frequency starts to go over 50.2 Htz (UK grid frequency) I get Node Red to fire on a Wemo Wifi switch with loads connected. With an extra load the SI drops the frequency back to 50 or below. I then use the Battery voltage to turn the same Wemo off once the voltage drops below the threshold. You can use the PI to control other relays so can't see why this could not be a relay to connect to the grid.

Also using Node Red I take the MQTT data and present it as Modbus data using the same register map as an SI8.0H-13 so my Solar-log data logger can record the data, it already uses RS485 for the Sunny Boys.

 

[1201]

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[1201]

I read my SI5048 data using yasdi2mqtt running on a PI, the PI also runs Node Red. In Node Red I monitor various readings held in the MQTT database including SOC, Frequency, battery voltage. When the frequency starts to go over 50.2 Htz (UK grid frequency) I get Node Red to fire on a Wemo Wifi switch with loads connected. With an extra load the SI drops the frequency back to 50 or below. I then use the Battery voltage to turn the same Wemo off once the voltage drops below the threshold. You can use the PI to control other relays so can't see why this could not be a relay to connect to the grid.

Also using Node Red I take the MQTT data and present it as Modbus data using the same register map as an SI8.0H-13 so my Solar-log data logger can record the data, it already uses RS485 for the Sunny Boys.

can you control the sunny island via yasdi?

 

[kommando]

can you control the sunny island via yasdi?

Yes you can, this are the commands available in the terminal.

Commands:
? : This help...
e : Start device detection (sync)
b : Start device detection (async)
z : Stop (async) device detection
d : Show device list
a : Show spot channel values
p : Show parameter channel values
t : Show test channel values
s : Set parameter
m : Remove device
l : Change access level
q : Exit

So s: Set parameter will change a parameter value

This is not part of Yasdi2mqtt functionality only in raw Yasdi.

 

[1201]

Yes you can, this are the commands available in the terminal.

Commands:
? : This help...
e : Start device detection (sync)
b : Start device detection (async)
z : Stop (async) device detection
d : Show device list
a : Show spot channel values
p : Show parameter channel values
t : Show test channel values
s : Set parameter
m : Remove device
l : Change access level
q : Exit

So s: Set parameter will change a parameter value

This is not part of Yasdi2mqtt functionality only in raw Yasdi.

How difficult would it be to set up a system that monitors the voltage and then starts the grid connection at high voltage (battery full) and low voltage(battery almost empty)?
Thanks

 

[kommando]

I do not know how to do that within a program, Yasdi runs in a text entry terminal that you type commands into. My setup only takes data and switches external wifi switches on or off and does nothing internally within the SI or change any parameters. A programmer could do it in say Python running on a Raspberry Pi but I am not a programmer.

 

[Hedges]

One approach is to command a lower battery voltage setpoint. Sunny Island should then invert and backfeed grid to draw battery down.

SMA had said that SI could serve as GT PV inverter if SCC drove battery to a higher voltage than SI wanted, and export was enabled (as it would be with Sunny Boys exporting.)

 

[1201]

I do not know how to do that within a program, Yasdi runs in a text entry terminal that you type commands into. My setup only takes data and switches external wifi switches on or off and does nothing internally within the SI or change any parameters. A programmer could do it in say Python running on a Raspberry Pi but I am not a programmer.

Still very cool that you are able to use the data to control switches via wifi. That might be an option for me

 

[kommando]

I used Node-red and it had a node to control Belkin Wifi switches, but they are no longer made, the UK ones can switch up to 13A, EU up to 16A. There will be other Wifi switches Node Red can control plus there are Hats you can fit to a Pi which can switch loads on and off of hi amps and Node red can handle these.

30A Relay HAT - PlasmaDan Electronics

Raspberry Pi HAT add-on board with dual 30A SPDT changeover power relays and built-in MCP23008 GPIO expander.

plasmadan.com

 

[1201]

One approach is to command a lower battery voltage setpoint. Sunny Island should then invert and backfeed grid to draw battery down.

SMA had said that SI could serve as GT PV inverter if SCC drove battery to a higher voltage than SI wanted, and export was enabled (as it would be with Sunny Boys exporting.)

That could work for feeding back the grid but the big problem is when there is no pv available, sunny island will continue to keep battery charged and supply loads from the grid instead of battery unless the grid is disconnected.

 

[Hedges]

Then maybe the mode grid as generator, only kicks in at some low SoC.
But some modes require a restart, not sure about that one.

Or, reduce allowed grid current to near zero. Raise back up if SoC gets too low.

 

[Ai4px]

must be careful changing settings every day with YASDI.... are we sure these changes aren't being written to NVRAM? don't wanna wear it out.

On a side note, I found that when changing the amps on my openevse I had to append the letter V to the end of a packet to make it NOT be written to NV RAM.

 

[Hedges]

A concern of mine.
NV could be EEPROM (1M cycles) or Flash (1K cycles, but hopefully wear-leveling algorithm.)
I think commanding power levels, at least for SB via Speedwire, is how SMA implements zero-export. That would be very frequent adjustments.
I think I heard they only store changes to NVM occasionally.
But we need to be sure, especially for SI.

Ahh, a programming trick - documented anywhere?

I do have one SB 10000TL-US-12 that has a reduced power setting in the 8kW range. Wasn't sure if that was left over from power control. I think it is the one with one fan failed, so maybe done for that reason? It would derate with temperature, but that would mean bouncing along max temperature.

 

[1201]

must be careful changing settings every day with YASDI.... are we sure these changes aren't being written to NVRAM? don't wanna wear it out.

On a side note, I found that when changing the amps on my openevse I had to append the letter V to the end of a packet to make it NOT be written to NV RAM.

Is this a concern changing settings via webbox? I'm changing settings via webbox 2x per day everyday- should I be concerned?

 

[1201]

Then maybe the mode grid as generator, only kicks in at some low SoC.
But some modes require a restart, not sure about that one.

Or, reduce allowed grid current to near zero. Raise back up if SoC gets too low.

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