question

alexyates avatar image
alexyates asked

ESS Grid Feed in questions

Hello

I've got a tricky question. I have a very good system in place.


2x Multigrid in Parrallel

20kwhr BYD BBOX

2x AC coupled Solar Systems one on the input and one on the output

3x DC coupled solar systes (all Victron) MPPT

1x Energy Meter

Colour Control


Works great, the minor issues and solutions I'm looking for are


1, On the colour control the Green AC load section has a PV inverter connected to it, which I cannot read with the Victron due to its locality, which I don't really mind but it only ever goes to 0W when in reality during the day it should display a negative reading. Can this be worked around or changed?

2. Where I am in Australia there is a maximum 5kw Grid feedback rule and unfortunately the Victron cannot do total export limitation to 5kw, controlling all inverters/mppts or can it? - Assuming it cannot as I don't think it can I have worked around this by having exactly 5kw of AC coupled solar and have turned off "Feedin excess charger power". This issue is during the day I would like the AC coupled to sell back and let the DC coupled power our loads but what actually happens is the DC coupled gets shutdown and the AC coupled powers the loads only providing a limited export. Any ideas on how I can get the AC coupled units to completely export and use the DC couple to power the loads?


Below is a photo of whats going on showing that DC's been ramped down and the AC coupled is powering everything, whilst the green AC load reads zero.


Thanks






ESS
1543632574206.png (170.1 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

2 Answers
Rob Duthie avatar image
Rob Duthie answered ·

Hi Alex

Is the Mulitgrid a model 2 or a plain Mulitgrid? as the Model 2 has a inbuilt Current Transformer.

To show AC loads you can set depending were the CT is in setting to change the location so it reads power etc.

4.3.2 Grid meter installation

Leave Off when no Victron grid meter is installed, and set to 'On' when such meter is installed.

All loads and (optional) grid-tie inverters must be installed on the AC out in a system without a Victron grid meter. See earlier in the manual for more information.

Also you can reduce the import current import setting so it will use more battery than grid

also you can change the Grid point. mine is set to zero so no importing of grid and use the battery first, if the load is to great in will pull from the grid etc.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi Alex,


For 1) no thats hardcoded to never show negative; because its meant to show loads. Sorry.


For 2a feed-in limit) indeed there is not such setting, yet. Its being worked on; thats the good news. I dont have a date for availability yet though.


For 2b) What you can do is let the PV Inverters produce maximum power; unlimited and always. Which is what they are doing already in your system. And the Multi+MPPT+Battery will help powering the loads if more power is needed.

Indeed by switching the Feedin excess solar charger power switch off.

but that will indeed, when there is enough power coming from the PV Inverters, and also the battery is full, cause the MPPT to reduce its power output.

I dont see a better solution now; sorry. Perhaps someone else does; and you might improve a bit by wiring part of the PV Inverters on the utility side of the Energy Meter. That way they’ll nornally export; unless Battery is empty; leaving more room for the mppt.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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