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fellside avatar image
fellside asked

G100 testing UK

We are carrying out commissioning on the following Setup in the UK.

MultiPlus-II 48/5000/70-50 230V (v500 FW)

Cerbo GX

ET112 (grid meter)

SMA 4000 inverter 3.42Kw PV (on AC-Input 1)

ET112 (PV inverter)

BYD battery


The system is setup in ESS mode.

All G98 checks have been carried out and the everything works as expected.

The whole house is on AC-out-1.


The DNO has set a 6KA limit on export. So G100 test is required.


G100 requirement

“The ELS must detect an excursion and reduce the export to the Agreed Export Capacity or less within 5 seconds.”


Test:

Settings, ESS, Grid Feed-in

AC-coupled PV Feed in Excess (ON)

DC-coupled PV Feed in Excess (OFF)

Limit System Feed-in (ON)

Maximum feed-in(6000W) Temporarily set to 300W for test.

Feed-limiting active(NO)


In ESS mode the Grid set point was set to -500W. System ramped up to around 500W export and sat there. There was no change to “Feed-limiting active” that stayed at NO. We assumed that “Feed-limiting active” would change to (YES) and export would be restricted to “Maximum feed-in” 300W. This did not happen. Is this because we artificially forced export by setting Grid set point to 500W. Is there another way to Force export?

We tried this with the grid tied SMA inverter charging the battery and with the Grid tied inverter turned off.

We know that in ESS mode there should be very little export. Grid tied inverter can in theory (battery full and no House loads) export max 3.42kw and we have no control over that. There is no DC coupled PV. ENA site lists Multi 5000 as capacity of 4.4kw so DNO totals that as 7.82kw potential export.


Does Grid Feed-in work for anyone. What are we doing wrong. Any advise would be greatly appreciated.


In the document G100 Declaration Victron Energy ESS


https://midsummerwholesale.co.uk/pdfs/victron-g100-declaration-multi.pdf


Test 1

Removed wire from ET112 (grid meter) Multi Continues exporting. But shuts down inverter and goes into pass through at 60seconds. Not 3.6 seconds as in document as above.

Unplugging rs485 USB adapter has the same result.


Test 2

Disconnected VE.Bus cable (simulates power loss on Cerbo) Multi Continues exporting. But shuts down inverter and goes into pass through at 60seconds. Not 2.1 seconds as in document as above.


“The response time under loss of communications, or loss of power, response time is less than 3s”


So we are well outside the 3 seconds. Is this again because we are forcing the export by Setting Grid set point?


Have we missed as setting or a box is not ticked somewhere?


Any help would be very much appreciated.

Multiplus-II
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11 Answers
jamesstubberfield avatar image
jamesstubberfield answered ·

If your batteries were 100% SOC, and if you had DC coupled PV of around 3kW, and if you had no house loads, and if your SMA inverter was running at its maximum output, and if you had 'Export DC coupled PV' setting turned on in ESS, then perhaps you could test the 6kW export limit. Otherwise I am not sure how you are expecting to do so?

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fellside avatar image
fellside answered ·

DNO thinks I have the potential to export, SMA 3.42kw plus Multi 4.4kw = 7.82kw. The DNO has set an export limit of 6kw. The system is not fitted with any DC coupled PV at this time.

What we need to know is does "Grid Feed-in" work or how does "Grid Feed-in" work?

https://midsummerwholesale.co.uk/pdfs/victron-g100-declaration-multi.pdf

How were the disconnection times in the document obtained?


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wkirby avatar image wkirby ♦♦ commented ·

When ESS is installed on the system then yes, grid feed in from DC does work.
Grid feed in works by the inverter taking energy from the DC bus and converting it to AC synchronised with the AC from the network. It is possible for DC energy to come from the battery even if a DC coupled solar system is not producing anything.
The disconnection times in the document were measured with an oscilloscope, you can see the timings in the oscilloscope screen captures.

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spazpeker avatar image
spazpeker answered ·

As your PV is on AC1 output, and the Multiplus II is set to UK grid code then it wont export more than 3.68kw

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sharpener avatar image sharpener commented ·

My DNO (WPD, now NG) wouldn't accept that and requires me to limit the inverter power as well to 3.7 kW. However they seem to think this is all that is necessary (i.e. are not adding this 3.7kW to the 3.68kW of AC-connected PV as above), and were content to rely on the Victron G100 declaration so did not require a separate test.

No great consistency of approach among DNOs it would seem.



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fellside avatar image fellside commented ·

G98 is up to 3.68kw (16A) per phase. G99 is above 3.68kw is (16A) per phase. G100 if export is above 32A all at 230V.

Does the UK grid code actually restricted the inverter (in software) to 3.68kw (16A) G98


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apple047 avatar image
apple047 answered ·

Your SMA inverter is connected to AC input, therefore Victron doesn’t have any control over it. You could switch off MP ii and SMW would still generate, so not really covered by G100.

I would suggest connecting PV inverter to AC out (reconfigure ESS assistant accordingly)

MP than can monitor SMA generation via internal CTs, if batteries are full it would than disconnect from Grid (inverter still running) and increase frequency to ramp down/stop SMA inverter.

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fellside avatar image
fellside answered ·

Correct SMA inverter is connected to AC input and is in receipt of a FIT`s payment tariff. Therefore payments would be lost if moved to Ac out and throttled by frequency changing. I'm not sure if the 4000L can tolerate frequency control. SMA inverter is monitored by a ET112. So Cerbo knows and displays what the SMA inverter is doing.

Still waiting for the DNO. They seemed to think we had not returned our quote/offer acceptance form. We had, and had a record. Latest email says they will contact us within 5 day. That was a week ago, nothing!!! They could be waiting for the ENA multiplus approval. Victron, ENA, DNO nightmare.

The customer is very unhappy. I cannot believe why Victron think it is good for customer relations and for future sales to not communicate with their customers. Communication is key to a good business. We will soon be getting to the point where customers will start looking for ways to get a refund. Not sure I will be fitting Victron again. To much stress.:)

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benlongcross avatar image
benlongcross answered ·

@Fellside Just wondering if you ever managed to get the fail safe criteria of the G100 test to work - I have the same issue in that loss comms ET112 meter does not fail safe within 5 seconds - same issue on loss of CT.

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mjs500 avatar image
mjs500 answered ·

loss comms ET112 meter is comms hard wired ? or wireless link and how are you determining inverter switch off time i hop not over VRM (processing time delays between two devices )


have tested hundreds G59 to G59-3 much old test for mains decupling relays for generator you always read trip time at sore i.e. point mains decupling - mains mccb for backup generator with parallel soft return and so on for all uk DNO and over sea

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fellside avatar image
fellside answered ·

benlongcross

Have you read the first post at the top of this thread. Well we never did get any of the tests to come close to being within spec.

We were advised to submit the Victron G100 Declaration doc as others had done. At the time our DNO (ENWL) never questioned it and the system was approved. I`ve no idea how Victron got the figures they did in that document.

After the Type approval problems that went on and on (I found it quiet stressful) I have lost faith a bit in Victron. Its a great system and I like working with it. Various hardware faults, software that is always just getting there. Or seems to be in beta (EV charger) There is a lot of other good kit on the market now. Customers want reliable kit that works out of the box and software that does what they want, such as works with Octopus.

And don’t even think of comments like “you can do that in Nod Red, have fun” A customer would really love that. Sorry rant off:)

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benlongcross avatar image
benlongcross answered ·

@Fellside Thanks for your response. Yes, I have searched the forum for G100 testing and found your original post - I do think this is an issue that Victron need to confront as the DNOs will be looking to see this being demonstrated on site going forward.

As it stands, I can't offer Victron as a G100 compliant element of a system, which is a shame as the equipment and interface are very good in my experience so far.

To address the issue in the short term I am looking to rely on the export limitation and fail safe of another (Growatt) AC coupled PV inverter in the system seen as the Victron inverter rating is below the export capacity limit. Therefore, even if the export limit function fails on the Victron I can't exceed my export limit - as long as the PV inverter with export limit function has a working fail safe.

Just a little bit odd that I need to rely on the PV inverter, that is half the price of the Victron, for this important function.. My rant over :-)

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fellside avatar image
fellside answered ·

I agree entirely with your comments.

I'm looking at Sunsynk SYNK-5K-SG04LP1 Listed on ENA as G99 and G100 compliant.

https://portal.segensolar.co.za/reseller/docs/G1008.8.pdf

https://www.sunsynk.org/_files/ugd/50e58b_489ee58affde495bbf8d25894de7ec7a.pdf

So is the DNO now wanting witness test as Victron is not G100 compliant or is this the norm now for G100.

Or can we assume that inverters that are compliant such as Sunsynk will not require a witness test.

As a matter of interest what DNO ar you dealing with?

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benlongcross avatar image benlongcross commented ·

I am dealing with SSEN - I suspect the witness test was required as Victron do not seem to have a G100 compliance on the ENA type test register. However, they wanted to witness my G99 operation also despite this being on the ENA register.

I can imagine that the witness test is at some discretion by the DNO. There are all sorts of variables at play with export limitation schemes – from the location of the remote CT to the individual config of the inverter so this is probably why they want to check.

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jonstret avatar image jonstret commented ·
FYI Sunsync (last time I checked) are also not compliant with G100 Issue 2 amendment 2. They may be compliant with Issue 1 (as was Victron as this was a declaration not a test). We have passed witness testing with Victron setup but it is not an entirely comfortable situation. Just about every G99 application we submit requires a G100 export limit so we are having to reconsider using victron. We and our customers love the system so this is really really frustrating. If we can pool our experience here maybe we can come up with a solution or maybe Victron have some advice @Guy Stewart (Victron Community Manager)
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Jona Aal avatar image
Jona Aal answered ·

@Fellside @benlongcross

I am just having the same issues here with a system that has been installed by me for a customer who bought as lart of DIY buying group and then was out of his depth..

I did the G99 appliction for him, got approval, did the install but am now trying to tick the boxes and not getting anywhere close to satisfying the disconnection times.

Training on G98/99/100 from someone like C&G or EAL would probably be a good thing to push for since this aspect of installs seems to cause confusion and ultimately very variable installations when the very thing these standard s are trying to do is promote safety.

Like you say the old 'fix it in node red' is ridiculous and (in my opinion) should be replaced with 'see our training video on g99 comissioning tests'...


Maybe i'll start a new thread secifically dealing with these tests/methods/typical outcomes? I'm not experienced enough to put anything really useful on it though...

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benlongcross avatar image benlongcross commented ·

I managed to demonstrate the G99 function to the DNO okay - the problem I had was with the export limitation, G100. What are the disconnection issues you are getting on the G99 test ?

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