AC-coupled PV-inverter connected to Multiplus 2 - ZeverSolar

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xrstokes asked Oct 23, '18

AC-coupled PV-inverter connected to Multiplus 2 - ZeverSolar

Hi, I'm setting up a hybrid on/off grid system.

I aim to couple a zeversolar zeverlution5000[common in Australia] to the output of 2 parallel multiplus 2's. I'm hoping that via frequency shifting the multi's will be able to limit it's output when the batteries are full. There is a section in the settings where you can set a max frequency on the ZS so i'm confident it will be fine.

What is hybrid on/off grid you ask. We will stay on grid during the six warmer months of the year, where our feed in tariff will pay our fees plus put money in our pockets. But in the 6 colder months, our feed in will not cover the $200 connection cost. So we'll switch the AC input over to a generator and disconnect in the winter. Kind of the opposite of what you would expect, but our huge 6KW system made plenty extra last year in the winter and our 4days of battery should mean barely using the generator if at all.

My questions are these;

1, Can anyone confirm that the zever solar will work with the multi's?

2, Can I change the input from grid to generator in the menu without connecting laptop?

2a, If not, could I just change grid to zero feed in and start the generator manually to charge the batteries?

3, why bother with frequency shifting If the AC inverter will naturally lower it's output once the voltage gets to 253ish. Couldn't the multi just let the voltage float up that high?

4, does it matter if the AC invter on the output is set to leading or lagging?

5, since this config usually doesn't need the multiplus II external current sensor, could it instead be used to monitor the AC PV output? Then you would have more info on your loads. If not, this should be a feature request.

Thanks in advance, The reason i'm asking is because if ordered and payed for the multi's, but they want to configure them before shipping them out. Want to be sure they are 100% right.

Multiplus-II AC PV Coupling

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mvader (Victron Energy) answered · Oct 23, 2018 at 09:44 PM

1. Can anyone confirm that the zever solar will work with the multi's?

I can't. But as most modern PV Inverters work, this one will probably work as well. Perhaps someone else can confirm. And otherwise if you want to be sure, get a brand/model that we do confirm works. (SMA / Fronius mostly)

2. Can I change the input from grid to generator in the menu without connecting laptop?

No.

2a, If not, could I just change grid to zero feed in and start the generator manually to charge the batteries?

Depends on the quality of the generator: configure the MultiPlus-IIs to the Australian standard, and then see if they still accept the power quality that comes from the generator. If not, then you'll have to configure the MultiPlus-IIs to a different standard while connecting to the generator.

3, why bother with frequency shifting If the AC inverter will naturally lower it's output once the voltage gets to 253ish. Couldn't the multi just let the voltage float up that high?

Because thats how the world has chosen that an AC-coupled system should work. By frequency shifting. Its explained in detail here:
https://www.victronenergy.com/live/ac_coupling:start

4, does it matter if the AC invter on the output is set to leading or lagging?

I don't know what exactly Zeversolar means by that.

5, since this config usually doesn't need the multiplus II external current sensor, could it instead be used to monitor the AC PV output? Then you would have more info on your loads. If not, this should be a feature request.

No it can't. That external current sensor can only be used for what its advertised.

I hope that helps!

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Modifications Space

Node Red Space

Answer 1 · 2018-10-28T03:27:18Z

xrstokes answered · Oct 28, 2018 at 03:27 AM

thanks for the help mvader,

Where can I get info on communication with the venus GX. I've got an Arduino to get the info from the zeverlution inverter and display it on an LCD. How would the venus gx like to receive it? Do I just sit on the network and pretend to be an SMA inverter [by making a dummy Modbus or tcp server]. Does the Venus GX go and "get" the info? or can I push it to the venus from the Arduino? Can you point me in the right direction. Thanks.

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mvader (Victron Energy) ♦♦ commented · Oct 28, 2018 at 05:25 AM

Hi again; thats more a question for the developers list, please search that and ask remaining questions there.

Pasting a link doesnt seem to work, please search Google for victron-dev-venus.

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Answer 2 · 2018-11-08T03:32:13Z

xrstokes answered · Nov 08, 2018 at 03:32 AM

I've almost finished the code for connecting Zeversolar inverters on the output. Just one issue remains to fix. During bulk charge. The frequency shift works beautifully to cap the solar production during bulk. However, During absorption there appears to be a bug or PID difference problem. Because it as soon as the battery voltage hits about 58, the frequency shift shoots to 52+ which restarts the AC coupled inverter. This just continues and absorption goes nowhere because the inverter is of more than half the time. Here is a pick.

Thanks in advance.

capture.jpg (70.1 KiB)

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Answer 3 · 2018-12-11T14:49:40Z

dam answered · Dec 11, 2018 at 02:49 PM

Você resolveu o problema de ajuste de freqüência do zeversolar? Você acha que este investidor está trabalhando na saída do multiplus II? recomenda?

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Answer 4 · 2018-12-11T23:17:52Z

xrstokes answered · Dec 11, 2018 at 11:17 PM

I was able to get this working very well.

The files needed are here. https://groups.google.com/forum/#!searchin/victron-dev-venus/zever%7Csort:date/victron-dev-venus/3i_eToqSMMc/Gu8QpqB_BgAJ

The setting in the inverter can only be reached over lan cable.

zever-setting.jpg (25.5 KiB)

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Answer 5 · 2018-12-12T02:34:11Z

dam answered · Dec 12, 2018 at 02:34 AM

Obrigado.

O zeversolar que eu estava pensando em adquirir para conectar com o multiplus II, seria o 1500s zeversolar. Eu acho que já tem LAN e Wifi. Funcionaria bem da mesma maneira?

Ac acoplamento funcionaria ainda melhor com outros investidores?

Ou seria mesmo fronius, sma ou zeversolar?

Eu também tenho a chance de ter um garoto de sol.

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