Scheduling discharge

Hi,

I have looked on the forum and as far as I can see have not found a 'Victron' based solution to schedule a discharge. The scheduled charging works great with firmware 3.0 so that you can use the correct timezones (GMT in my case).

The only piece that I can see that is missing is scheduled discharging.

I can programmatically force a discharge by setting the 'Grid Setpoint' to -5000 for the tme period that I need to force discharge my batteries, and checking that the 'State of Charge' does not go below a certain limit and that works fine.

A simple solution to this issue (as far as I can see) would be to include the 'Grid Setpoint' value within each 'Scheduled charge', and a low level 'State of Charge'. That way if the value is 0W the normal chargng of the battery occurs, but if you set the value to a negative value (-5000 in my case) the batteries would force discharge unitl either the time period expired or the low level 'SOC' was reached. Having the scheduling within the Inverter is a nice set and forget feature..

Please could I ask that you look at this as a new feature to your product.

Regards,

Graham.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

graham-willsher commented · Jun 15, 2023 at 05:40 AM

Hi @MarkEss,

Thanks for the offer. My email address is graham@grahamwillsher.co.uk. I have tried looking at the 'Victron Energy' Node Red palette but am a beginner at this and can't seem to find where/how to configure the connection node to the victron inverter, so any guidance that you could give would be great.

Having re-read the Venus OSv3.00 blog release, there is an item in there that seems to indicate that you can now discharge at set times as well...

'In Venus v3.00 there is a new ‘Self-consumption above limit’ option that allows an ESS system to discharge during a scheduled charging period as long as the SOC remains above the programmed SOC limit.'

Which, if I read it correctly, seems to mean that if your SOC limit is above X the batteries will discharge. I am going to try it later today to see what happens, but to get the victron to discharge we normally set the 'ACPowersetpoint' to a large negative number, and there does not seem to be any mention of this. Have you heard of this?

If this is correct that keeps all of the control (charging and discharging in the Victron), which means that I would not have to rely on another computer system to achieve the desired result, and makes things cleaner.

I tried this last night but could not get it to work without changing the grid setpoipnt value, which means it required manual intervention.

0 ·

markess graham-willsher commented · Jun 15, 2023 at 10:35 AM

Interesting to hear of the OSv3.00 changes to charging. I'm still in v2.92 so can't really comment on the ESS behaviour, but I would assume this means that the battery can now be used for self-consumption (not grid export) even if still within the charging window if you are above the set SOC.

I don't think forced discharged to grid is supported (and admittedly that is not an ESS objective) and for that you still need to modify the grid set-point as I understand it.

My Node-RED code monitors the battery current and adjusts the grid set-point dynamically (every 1 min.) to keep the battery current steady, so the result is everything (PV and battery) are exported. Then when it reaches SOC the same code keeps battery current at 0A, the affect being only and all PV is then exported. This behaviour only happens 4-7pm to take advantage of export tarrif, so at 7pm it switches back to conventional ESS.

I will email you the code.

Idea

Scheduling discharge

3 Comments

Your Opinion Counts

IDEA DETAILS

Related Ideas

Modifications Space

Node Red Space