question

jackcactus avatar image
jackcactus asked

MP 2 ac coupled with solax inverter

Is it possible to ac couple the solax pv inverter to MP II

MPPT Controllers
2 |3000

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

3 Answers
Petr P avatar image
Petr P answered ·

Any news about this topic? has someone test it?



2 |3000

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

innoboreal avatar image
innoboreal answered ·

We have been able to connect SolaX and Victron Multiplus in AC coupling, but still work in progress, so let us know your results if you try it.


It works without the current sensor on PV production from the inverter, but you cannot see the PV production on the GX diagram, so you only see the flow from or to the batteries. It is recommended to use the current sensor, as it seems it helps to properly regulate the frequency and for what it costs, it's worth it.


First of all, you need to use a grid configuration on the SolaX that has Droop control.

https://en.wikipedia.org/wiki/Droop_speed_control

For example, EN50438_NL has this possibility, but I prefer VDE4105, it's faster.

You can choose plenty of parameters and configurations. We decided to use the default settings on the Victron AC Coupling to start with something:

- 50.20Hz as the frequency at which the solar converter will start reducing its output power.

- 52.70Hz as the frequency at which the output power will be reduced to a minimum (we assume 0W here).

- The converter (SolaX) will disconnect when the frequency is higher than 53Hz.


So we go to the SolaX configuration on EN50438_NL or VDE4105 and we set:

- Fac Upper : 53Hz

- Fac Upper slow : 52.9Hz (you could put here 52.7Hz, but like this you have some margin).

- FreqSetPoint: 50.2Hz

- FreqDropRate: 5% (I'm not sure, but this parameter should be similar to (52.7Hz-50.2Hz)/50Hz)




1 comment
2 |3000

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

kw4np avatar image kw4np commented ·

I've used the details from this post, and I had trouble with the FAC Upper Slow being set at 52.9Hz. 52.7Hz worked much better and stopped issues with flickering and grid instability. Also for the settings to be effective, the grid mode should be set to User Defined, otherwise the settings don't seem to work correctly. So the settings that have been working for me were:

User Defined Grid Settings

FAC Upper 53Hz

FAC Upper Slow 52.7Hz

FreqSetPoint 50.2Hz

FreqDropRate 5%

0 Likes 0 ·
kyuketsuki avatar image
kyuketsuki answered ·

Hi, where is configuration for FreqSetPoint and

FreqDropRate?

I can't find it on my Solax app.

My Solax is preconfigurated for Spain.

The Solax manual is very bad.

Thanks

2 |3000

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