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Posted (edited)

@plonkster

I am considering scheme expansion. The new panels will be a 80m away from the batteries and existing 5kVA Quattro.

My preference is for an ac -coupled Fronius unit that will operate at a higher voltage situated at the new panels, to avoid the cost of copper and associated losses from lower voltage power transfer.

I haven't priced a 5kVA Fronius but I think it'll be cheaper than 2 MPPT's and another 5kVA Quattro.

However, this statement raised a concern, I hope I am not taking you out of context,

"On the test bench where I have a Fronius tied to the output of a 3kva Multi, it is almost impossible to get it stable without the Fronius constantly disconnecting whenever there was a change in load which caused a slight disturbance in the output of the Multi."

The last thing I want is a finicky system, that I have to nurse.

I'd rather make another plan, if these two aren't the match made in heaven that they proclaimed to be.

Can you expound on your experience please?

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Edited by phil.g00
Posted
1 minute ago, phil.g00 said:

Can you expound on your experience please?

I think the system on my test bench is mismatched. It is a large Fronius on a somewhat large Multi, but with only a 12V LFP battery.

When running grid-connected there is no problem, it works perfectly. It only happens when the grid is disconnected, which is an indication that the Fronius isn't perfectly happy with the power quality of my Multi.

It looks like you can tweak these settings on the Fronius, though you might need an installer to do that (with a password and all).

Also, there are lots of systems like these running off-grid all over the world and they seem to work just fine, so my own experience seems to be unrepresentative.

  • 4 weeks later...
Posted (edited)

Thanks, my understanding so far is ( and I may be wrong cause it is an assembly of a lot of internet hearsay):

The power output of  SMA, Fronius and now ABB PV inverters can be gradually controlled by the frequency shifting of function of the Quattro in an off-grid scenario. (Huawei, and other brands I still dont know).

Micro-inverters (at least all at 50Hz), seem to be an all or nothing approach, when the frequency is shifted, as well as other PV string inverter makes.

It appears Magnum micro-inverters are doing something in this field but are all 60Hz at the moment .

I also don't know if the frequency-shifting is an accepted international conventional standard, or if it is every-one doing their own version. I have read of oblique references to a standard, but I cant find the actual standard on the WWW.

But, the difference is in an "On-grid" scenario, the frequency is dictated by the grid, and this is when you need the Victron ESS CCGX setup to step in and limit the PV power, and that seems to only talk to the Fronius brand. So with other brands exporting to the grid has to be allowed, otherwise the batteries could get overcharged if there was insufficient load.

SMA-Sunny Boy seem to also have a proprietry protocol that achieves the same thing as the Victron -Fronius combo.

That said, I have no firsthand practical experience that what I have just stated is not BS.

Anyone feel free to step in an correct any heresy, or add to the list, because it is information that is difficult find in one place on the WWW.

 

Edited by phil.g00
Posted (edited)

Hi Phil. 

Frequency shifting has always been possible. This is a by product so to speak of EU requirements that the inverter must be able to reduce power when the grid frequency goes out of range without immediately disconnecting. 

Since the last couple of weeks I have been working with @plonkster to make it possible to setup the ABB in ESS in the same way as Fronius. I say we, was mostly him working and me just testing. This makes it possible for the CCGX or Venus GX to limit export to the grid. 

Edited by anotherbrownbear
Posted (edited)

Good to know, but I don't doubt there are work around solutions, but will these combinations that will have manufacturer support?

( I also have an allergy to fiddly, finicky and temperamental solutions).

In terms of Grid frequency, and over-frequency condition is indicative of too much power on the grid and it is understandable that utilities would seek an approved grid tie converter to have this capability.

Rant alert.

Then the bureaucrats step in  to regulate the laws of physics so  that SA, Oz, the EU, USA, California and everyone else who wants to do their own approval. (And then ebay will sell you an all singing dancing firebomb version too).

Each inverter ends up with a multitude of certification codes, and special secret codes to tell the inverter which country it is in so it knows what to do where.

Take for example the Huawei inverter, it is by all accounts a reputable brand, I can find no reference to this capability, but compliance certs a plenty.

What I 'd also like to know is, which amongst the numerous compliance certification codes of each inverter, relates to this frequency shifting capability?

In other words, what can I look for on the tin that says " may contain nuts", without having study quantum physics in foreign language.

These things cost too much money to adopt a "suck it and see" approach, on the other hand there are genuine savings to be made by buying the approved Chinese clone of the German inverter, rather than buying the German brand inverter that's made in China.

Rant over.

 

 

 

Edited by phil.g00
Posted (edited)
24 minutes ago, phil.g00 said:

These things cost too much money to adopt a "suck it and see" approach, on the other hand there are genuine savings to be made by buying the approved Chinese clone of the German inverter, rather than buying the German brand inverter that's made in China.

Well, one thing is sure. ABB Solar inverters are not manufactured in China.

 

Attached is a white paper for the operation of ABB with OF derating. 

Inv_Str-All_OFActivePowerLimitation_2015-06-26.pdf

Edited by anotherbrownbear
Posted
1 hour ago, anotherbrownbear said:

Since the last couple of weeks I have been working with @plonkster to make it possible to setup the ABB in ESS in the same way as Fronius

OK then! Now I know exactly who you are :-)

Your company is also well-recommended in these parts :-)

Posted
1 hour ago, anotherbrownbear said:

Well, one thing is sure. ABB Solar inverters are not manufactured in China.

 

Attached is a white paper for the operation of ABB with OF derating. 

Inv_Str-All_OFActivePowerLimitation_2015-06-26.pdf

Interesting reading, thank you.

I'd be interested to know if ABB end up with ESS support to control on-grid power output.

On an aside,

Not that I was checking up on you, (I was actually reading looking for the current ABB inverter manual),  but I ran across this, indicating some ABB inverters are indeed chinese made.

https://www.solarmarket.com.au/tips/top-5-solar-inverters/

image.png.8282cfef45da2092c57c9139c6548cdc.png

Posted
11 minutes ago, phil.g00 said:

I'd be interested to know if ABB end up with ESS support to control on-grid power output.

Already tested and implemented. Scheduled to be included in the next beta release of 2.30. POC tested at @anotherbrownbear's home. 

Posted

Also, I think that link you got is a bit outdated. The inverters are from 1.2kw to 175kw string inverters. Manufacturing in South Africa was only for some MW projects for central inverters. This also only consisted of installing auxiliary supply to the MW stations, not the actual inverter manufacturing. 

Posted
21 minutes ago, phil.g00 said:

I will definitely being evaluating the ABB vs the Fronius at that time if this is a runner.

The one major thing to keep in mind -- and I am not dissing ABB here, this is just something I stress a little about -- is that Fronius is well tested and understood while ABB is a newcomer and might yet throw a surprise or two. If the surprise is particularly big, the only reasonable response (given that there is essentially one man working on this... and that guy has other work too) might be to pull support for power limiting.

So simple facts: It does appear to work. It uses the WMaxLimPct register in Sunspec model 123 and it is properly implemented. Time will tell and I am excited about it because I too like ABB. I really hope we don't run into any surprises.

So far there's been two small ones, but they were good ones. On the initial tests the inverter would log 655KW values in the early morning and late afternoon. Seasoned firmware people instinctively react to numbers starting with 655 or 327 (because 65535 and 32767 are "special" in the binary sense) so the bug was found very quickly, but it did show one minor difference between Fronius and ABB: The Fronius never logs a negative number, whereas the ABB will show when it is consuming power (which happens when there is too little sun to compensate for the consumption of the inverter itself). It is unclear whether the Fronius wakes up a bit later, or whether it simply doesn't tell you about its own power draw...

Now this difference might cause some side effects in some calculations. We'll just have to see :-)

Posted
On 2018/11/27 at 8:44 AM, plonkster said:

that Fronius is well tested and understood

@plonkster  I have another question that concerns the 1:1 rule. I fully understand why the 1:1 rule exists.

And I hope with your familiarity with the Fronius, you maybe able to answer this.

I'd like to know is a Fronius primo's output can be throttled back to make it comply with the 1:1 rule?

For instance if I had 2 x 5kVA Quattro's in parallel, and also in parallel with an 8,2 kVA Fronius on the AC outs, the 1:1 rule would be satisfied.

But if one of the Quattro's went faulty, could I throttle back the Fronius to a 5kVA output to satisfy the 1:1 ratio, while the repair took place or would I be down the wole 5+8,2kVA?

The reason I ask is there considerable economy of scale price-wise between a Fronius 8.2kVA unit and 2 x Fronius 5kVA units.

Posted
1 hour ago, phil.g00 said:

I'd like to know is a Fronius primo's output can be throttled back to make it comply with the 1:1 rule?

I have no idea. I think there is such a configuration option (on the Fronius), but I really don't know right now.

Posted

OK, I'll write to Fronius. It appears you can limit your feed-in with a Fronius smart meter and that meter doesn't really know where it is, so if I put 1 on the output that should work.

 I was just wondering if the ESS system had the capability as I understand the smart meter and ESS are incompatible.

Alternatively, swapping the Fronius from AC out to AC in for the duration of the repair would free up the full capability as well, I suppose.

Posted
21 minutes ago, phil.g00 said:

Alternatively, swapping the Fronius from AC out to AC in for the duration of the repair would free up the full capability as well, I suppose. 

I was just about to suggest that.

I'm pretty sure you can limit it in config, and I could go to the garage and turn on the Fronius on the test bench to check... but don't have time right now, and I'm going to forget later :-)

  • 2 weeks later...
Posted
On 2018/11/28 at 6:33 PM, phil.g00 said:

OK, I'll write to Fronius. It appears you can limit your feed-in with a Fronius smart meter and that meter doesn't really know where it is, so if I put 1 on the output that should work.

 I was just wondering if the ESS system had the capability as I understand the smart meter and ESS are incompatible.

Alternatively, swapping the Fronius from AC out to AC in for the duration of the repair would free up the full capability as well, I suppose.

The test release is available now for CCGX and Venus GX to implement ESS with ABB. Ongrid limiting is possible through th CCGX and is also possible to limit the inverter with an ABB meter if you only grid-tie. 0% export algorithm is built into the inverter.

  • 4 weeks later...
Posted

Just getting back to this topic and my previous post about having some trouble on the test bench. It turns out it was a combination of issues, some of which might be of interest to forum members.

1. Unknown to me, there was an isolation transformer installed between the Fronius and the grid, which has to do with capacitors in the wrong place and a tripping RCD... I removed this device and had no issues. This improved the performance of the Fronius with the Multi, but it still wasn't stable.

2. I realised there is some special configuration you have to do on the Fronius. You have to go into the country selection menu (it's hidden, but google will find details on how to get there), and select MG50 (microgrid 50hz).

3. While all of this helped, it was still not stable. I then got new firmware from Fronius (with improved microgrid functionality) and now it is stable as a rock!

So in conclusion, tying a Fronius to the output of a Multi works very well. While the ABB inverters is now supported for ESS, at the moment I don't know how they will work in a microgrid setup.

  • 2 months later...
Posted

@plonkster, I am facing the same issue at this time after upgrading to firmware 28500. I have written to fronius about this but no reply yet. Can you share update file for me to upgrade mine as well.

 

Thanks 

  • 6 months later...
Posted

Thanks for this interesting and useful forum. Does anyone out there have some experience with the Sunsynk hybrid type inverters (5kw or 8kw) which are touted as superior to the Axpert Voltronic / Mecer type of inverters with all the bells and whistles.

I first installed a Victron Energy Quatro 5 kva with 4 x FNB Excis batteries (not ideal but 4 years ago got them for a good price) as back-up where I live - the place is renowned for power interruptions - DB split into essential and non-essential loads - inverter fitted to one phase of my three phase home grid power supply. Later fitted a Fronius 10 kw three phase grid tie inverter with 15 x 410 Watt Sunpower panels - system is running fine for now - had to clean the panels though following substantial soiling in a very dusty environment. I am keen on AC coupling but it will be a costly excercise for a three phase system and the 1 to 1 power factor rule will limit my power output / consumption if I fit 3 x Victron 3 kva Multis on each phase.

I am keen to try out the Hoymiles Micro grid tie inverters, assisting someone else, and link them to 5kw Sunsynk inverter's bi-directional generator port with a lithium battery incorporated - according to the supplier this system works well - anyone with experience / recommendations on this particular combination. I am aware that the Sunsynk inverter alsso has a built in MPPT solar charge controller of I think about 60  Amp but I am tempted to do a AC coupled / DC coupled mix by fitting one 1200 Watt Hoymiles micro grid tie inverter with its own 4 panels to the generator port of the Sunsynk inverter due to its higher efficiency / less loss through AC wiring. The Sunsynks built in MPPT will then be used to link the other panel string. 

Any ideas and comments will be welcome

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