Quattro exporting 12kW leads to high voltage

[Andy]

I expected this to happen at some point. I have an export limit of 13kW and in the winter I was exporting 12kW and hitting around 249V. Now that it is summer and it was windy in the area as well I spotted I was hitting 260V once the batteries were full. My SolarEdge used to trip at 253V. That was installed with G58/2. Now G99 limits are 262.2V. However, I really don't want 260V in my house hold so a bit of coding later and I have this.

It might be useful for someone with a bigger Victron system. The inputs to the node should be self explanatory. The output on msg5 (was my 5th output) sets the ESS maximum feed in. This limits the export preventing the high 'push back' voltage.

Code: Select all

var feedIn = context.get("feedIn")
var vDiff = 250-voltageIn
var gridDiff=feedIn+grid
var correction =0
 
if (vDiff<0) {
    // Greater than the voltage we want. make a big correction
    feedIn=feedIn+vDiff*800
} else if (vDiff>.55 && gridDiff<500 ) //.55 stops continued hunting due to viltron discrete steps of 100watts on feed in.
{
    // Creep up on the export figure from below. Can go faster at the start.
    correction=(30 *Math.pow(vDiff,2))
    feedIn=feedIn+correction
}
//node.warn(feedIn+":"+vDiff+":"+gridDiff+"c:"+correction)
feedIn = clampValue(feedIn, 0, 13000)
context.set("feedIn",feedIn)
msg5.payload=feedIn

It makes a big change to the export limit if over voltage but otherwise more slowly increases the export until within .5 volts of the required maximum. In this case I am using 250V.

In node OnStart you will need to set your initial export figure.

Code: Select all

context.set("feedIn",5000) // Initial allowed export of 5000

This shows the voltage nicely capped just below 250V and you can see the changing set point for export.

[Andy]

An interesting corollary is that if I was expecting to earn money from SEG I would not be able to export the full amount once the batteries are full blowing all the calculations for any return. The way round it might be to limit the battery charging and export some solar the whole day based on the anticipated daily production.

I can't request the transformer be tapped down as I am already bouncing at the bottom end of the voltage range in the winter whilst charging everything in the house.

[Andy]

I'm curious what voltages others with larger single phase systems are experiencing when the batteries are full and you are at full export. Do you find it limits you?

[Fintray]

Andy

I've just looked at my voltage when on import of just over 14kW (during the night) and the voltage was at 239V.
During the day I have changed the parameters in my Solaredge inverters to limit output if the voltage rises too far.

[Andy]

Andy

I've just looked at my voltage when on import of just over 14kW (during the night) and the voltage was at 239V.
During the day I have changed the parameters in my Solaredge inverters to limit output if the voltage rises too far.

It's strange, I couldn't find any way in the Victron of doing that apart from using the export limit. You can do so much with them but that seems to be missing. The grid settings are the only way that the voltage is controlled and the settings don't appear to be individually editable.

I want to leave my SolarEdge running at full pelt as my deemed export is based on that. Although I make no money from my Victron exports I am continuing to export for 'the greater good'.

[Fintray]

Andy

I've just looked at my voltage when on import of just over 14kW (during the night) and the voltage was at 239V.
During the day I have changed the parameters in my Solaredge inverters to limit output if the voltage rises too far.

It's strange, I couldn't find any way in the Victron of doing that apart from using the export limit. You can do so much with them but that seems to be missing. The grid settings are the only way that the voltage is controlled and the settings don't appear to be individually editable.

I want to leave my SolarEdge running at full pelt as my deemed export is based on that. Although I make no money from my Victron exports I am continuing to export for 'the greater good'.

In the Solaredge it comes under active power configuration then P(V) power voltage " This is used when voltage-based power reduction is required. This defines a linear graph set by six points (available from inverter CPU version 3.1808). The inverter de-rates power according to the defined graph, until the voltage reaches the trip value and the inverter disconnects."
It would probably be better if the voltage from the mains transformer was lower though!

[Andy]

In the Solaredge it comes under active power configuration then P(V) power voltage " This is used when voltage-based power reduction is required. This defines a linear graph set by six points (available from inverter CPU version 3.1808). The inverter de-rates power according to the defined graph, until the voltage reaches the trip value and the inverter disconnects."
It would probably be better if the voltage from the mains transformer was lower though!

I tried using the voltage control when switching a relay to signal when on a generator and it would not work. Despite having instructions for it and following them the solar edge would not respond. Support washed their hands of it in the end. I should see if it works for the grid.

[Fintray]

I did find it a bit awkward to get the settings ok for the voltage control side of things, hope you get yours to work.

[marshman]

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[nowty]

The voltage at Nowty Towers is top end, its now around midnight, no import or export and the grid voltage here is 255V+.



It fluctuates throughout the day, lowest is 247V and the highest (without export) is 256V, but its worse at night, maybe because neighbours are consuming less at that time.

Like marshman I could complain but its typically 253V (legal max) most of the time and I'm not awfully keen on the DNO coming round.

I've heard anecdotally that if you have solar the DNO is not interested unless your voltage is over 257V which sort of makes sense as I find my voltage increases by 1V per 1kW exported so of I export the standard 3.68kW thats nearly 4V to add to the legal maximum of 253V.