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mazo78

AXPERT INVEREX 5.2kw output watts problem

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i have instaedl inverex 5.2kw VM3 inverter its work good with battery and utility but problem on PV 

I get it when I check with the meter PV volts and amp ( on meter 180v and 14amp )

but Inverter only 850 watts output 

i have 12 panels 250 watts

 

 

2-strings.jpg

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Seems at 180V you are way over the MPPT range of  60 - 115 VDC according to the manual

Edit Apologies, brochure i seen shows MPPT 60-115 VDC, but manual says 150 - 450 VDC

May be 2 different models of Inverex

Edited by DaveSA

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Same problem with me,

 

Just bought 5.2 KW VM3 invrex ,

Installer 10 ×250 watt panels ,

I have not installed any batter yet .

So when my load is 300 watt ,PV out put shows around 200 watt out put,when I put more load like 1100 watts suddenly the PV out put reach around 860 watt.

I don't know what is the problem,

Any One can guide ?

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Ah, I misinterpreted "have not installed any battery yet" somehow as "the installation isn't quite finished" rather than "I don't intend to run it with a battery". [ Edit: I'm not used to an inverter-charger that can operate without a battery. ]

Without a battery, and without the ability to blend mains and PV power (correct me if I'm wrong there), [ edit: I am wrong here; see next post], there is nowhere to store PV energy. So you will always be limited by the load at any point in time.

I don't understand how the PV power seems to be less than the load, maybe it is some sort of lag effect. [ Edit: the difference is provided by the mains. ]

Edited by Coulomb
As noted.

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I'm not used to these newer models, which seem to have a powerful AC-DC converter, separate from the main inverter (an AC to DC converter). So they can combine mains and PV power, at the DC bus level (around 400-500 VDC). This is facilitated by the 450 V PV max models, which boost the PV voltage to 400-500 VDC, rather than buck it down to battery voltage.

It would seem that if there is plenty of PV power, there could be zero mains power. But maybe that's difficult to control, and maybe that's why PV power is less than load power in all the examples so far. I doubt that the PV power could ramp up to cover a sudden load increase, and maybe there are limits on how fast the AC to DC converter can ramp up the power as well. So maybe it's easier to have a few hundred watts of AC to DC converter power, so it's easier to ramp up or down in case of load changes. Perhaps sudden large load changes have to be handled by switching to pure bypass mode, as in a relay kicks in. But then, if it was a sudden large load decrease, and there was significant PV power which can't quickly be ramped down, where does the excess energy go? The DC bus capacitors would not have enough storage.

If a battery is present, it can provide the instantaneous power increase, so there is no need to keep some AC input power flowing, and no need to switch to bypass mode, unless of course the inverter is now overloaded.

But the power flow diagrams on the LCD (as depicted in the manual) seems to suggest that in line mode, the relay is always on (there is a direct straight line marked "BYPASS" from AC in to AC out). This suggests that the power blending occurs at AC (at the inverter output), not DC (at the inverter input), so it's a true AC coupled system. But then there is the usual problem where sudden decreases in load might cause brief exports of power, which I would imagine would not be allowed in this type of inverter, and in some locations it might be strictly prohibited (perhaps by a power meter tripping).

I'd be interested to hear the experiences of anyone running a VM III or other double conversion model without a battery; what is the experience like.

Edited by Coulomb
"AC transfer" -> "AC coupled"

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HI, I have a similar problem. I think my VM III is not reading PV input values correctly. 

However it is working OK. 

I am offgrid, any mains neither generator. Only 8x330w panels and one Pylontech US2000B module. 

My load is almost constant, around 150w, but when sun is up my inverter says that he is catching 0w from the battery and 8w from the pv solar panels. All my loads are working perfectly. 

It is not a lag. This behaviour is the same the whole day. Pv Watts are much lower than loads and all works. A imposible thing, so the pv Watts read should be wrong 

Screenshot_2019-08-08-00-31-40-299_com.android.chrome.thumb.png.08c78583bb7cbad36373a94a919725ab.png

Remember, there is not any other source of energy. No grid,and battery is aporting 0w

Edited by TomasCrespo

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1 hour ago, TomasCrespo said:

A imposible thing, so the pv Watts read should be wrong

I wonder if your monitoring software is using the "MPPT charging current" figure and multiplying it by battery voltage to come up with power. But this isn't total panel power, it's net power into the battery. The PV power figure from the LC Display (available from commands such as QPIGS) is the total panel power. If I recall correctly, the PV power figure comes from the Solar Charge Controller, but the PV net current figure is estimated using various assumptions.

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On 2019/08/08 at 2:04 AM, Coulomb said:

I wonder if your monitoring software is using the "MPPT charging current" figure and multiplying it by battery voltage to come up with power. But this isn't total panel power, it's net power into the battery. The PV power figure from the LC Display (available from commands such as QPIGS) is the total panel power. If I recall correctly, the PV power figure comes from the Solar Charge Controller, but the PV net current figure is estimated using various assumptions.

Hi! I'm using ICC as monitoring software. The graph is from emoncms, with the data that icc provides. The figure is pvwatts1, there is also a pvamps1, but I'm not logging that one. 

I'm not sure if the value of pvwatts1 in ICC is exactly the same showed in the Axpert LCD screen (PV Watts input) but I will check. 

Below a graph in the night, when thee is no solar production. You can see batterywatts instead pvwatts1. I think in this case the data is OK. 

IMG_20190809_112301.thumb.jpg.dabb113b8c0efbc4da3dbd5ff6bd7173.jpg

Edited by TomasCrespo

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Same graph, but with batterywatts in positive, to easy analyze.

133233012_energyanalisysatnightABS2.thumb.PNG.9287666b1e61c0591202ffeb3cd84f6d.PNG

As far as I know, the Inverter autoconsume is not integrated in loadwatts, and it is about 50w. This is the small difference. I mean, the data is ok at night (batterywatts vs loadwatts) but not in the sunny hours (pvwatts1 vs loadwatts)

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Yesterday daylight hours:

icc-solar3.thumb.PNG.84a275ccd09a833b6be2b5119fc2bcaf.PNG

As you can see, until 13 the battery is charging and the the figures have sense, pvwatts1 = batterybatts + loadwatts. However when the battery is fully charged I can´t understand the figures; pvwatts1 is not enough to feed the loads, and battery is not apporting anything.

Detail from 13:00h:

icc-solar4.thumb.PNG.5b3cd6532d5cc7c8342788667ee1742d.PNG

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17 hours ago, TomasCrespo said:

However when the battery is fully charged I can´t understand the figures; pvwatts1 is not enough to feed the loads, and battery is not apporting anything.

If the graphs are correct, the rest has to be coming from AC-in. Is that possible? Is your inverter (in these conditions) in line mode? Like this:

1529420901_VMIIIlinemode1.png.1036ab36d8e1a069724a8a15f0bbf0aa.png

So basically, when it's doing this strange stuff, do you see that line from AC-in to loads with "BYPASS" under it?

In this mode, the loads seem to be able to be supplied from the battery and/or solar via the DC-AC inverter, and from the mains at the same time. I would not expect your inverter to be in line mode after just having charged the battery, but if so, that can probably be fixed with settings (either on the inverter itself, or on ICC).

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8 hours ago, Coulomb said:

If the graphs are correct, the rest has to be coming from AC-in. Is that possible? Is your inverter (in these conditions) in line mode? 

Absolutely not. I have no AC in. Not grid neither generator. Totally offgrid. 

Could it be that the inverter wrongly reads pvwatts when the value is small (< 100 Watts) and it reads correctly when the value is bigger? 

I will post inverter's lcd screen pics when I get there 

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On 2019/08/08 at 12:13 AM, TomasCrespo said:

My load is almost constant, around 150w, but when sun is up my inverter says that he is catching 0w from the battery and 8w from the pv solar panels. All my loads are working perfectly. 

Perpetum Mobile? You're so lucky!

 

On 2019/08/08 at 12:13 AM, TomasCrespo said:

I think my VM III is not reading PV input values correctly.

My 2cents.

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1 hour ago, TomasCrespo said:

Absolutely not. I have no AC in.

Sorry. I get confused between all the various posters.

1 hour ago, TomasCrespo said:

Could it be that the inverter wrongly reads pvwatts when the value is small (< 100 Watts)

Yes. I think that ICC probably uses the QPGS command to get most of its data, needed for paralleled units (I know you don't have paralleled units, but the same monitoring software has to work with singles and paralleled units). QPGS doesn't have the total PV power in Watts (a bad omission it seems to me), so the PV power has to be calculated from net charge current times battery voltage plus load power times a fudge factor for inverter efficiency. The net PV charge current is provided only in whole amps, so with a 52 V battery you will only see 0/52/104 charging Watts for 0/1/2 A of net charging current.

 

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On 2019/08/11 at 11:51 AM, Coulomb said:

Yes. I think that ICC probably uses the QPGS command to get most of its data, needed for paralleled units (I know you don't have paralleled units, but the same monitoring software has to work with singles and paralleled units). QPGS doesn't have the total PV power in Watts (a bad omission it seems to me), so the PV power has to be calculated from net charge current times battery voltage plus load power times a fudge factor for inverter efficiency. The net PV charge current is provided only in whole amps, so with a 52 V battery you will only see 0/52/104 charging Watts for 0/1/2 A of net charging current.

 

🙄

And what about Inverter's LCD screen? Should it show the right values?

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20 minutes ago, TomasCrespo said:

LCD screen? Should it show the right values?

Yes. But for technical reasons, it's hard to write a general monitoring program to get at those values, that works for paralleled as well as single machines.

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Inverter LCD screen values (pv input Watts) and ICC pvwatts are identical. 

So my problem is the same looking at ICC data or LCD screen data. 

My inverter show me less PV Watts than Load Watts 😱. Obviously this is impossible, because there is no mains and battery is apporting 0 Watts. 

 

@mazo78 Was this your problem? Was solved reflashing the unit? 

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On 2019/08/12 at 12:24 PM, Coulomb said:

Yes. But for technical reasons, it's hard to write a general monitoring program to get at those values, that works for paralleled as well as single machines.

Hi! Coulomb, finally the seller has confirmed that they are having this problem (erroneous pv input readings) in their VM III and King models. They told me that are speaking with voltronic to find a solution (firmware update perhaps), but they are not very confidendt about getting the firmware update.

It looks like other people its not having this problem with their King or VM III. I suppose because its another maker (Easus, Inverex...). Mine has no a specifc brand, but the seller is a trusted seller. I don´t think he sells clones.

Could it be possible to update my unit with the firmware of another one?

Currently my firmware is:

U1 20 25
U2 01 21
U3 00 21

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2 hours ago, TomasCrespo said:

Could it be possible to update my unit with the firmware of another one?

Currently my firmware is:

U1 20 25

There is version 20.59 for Axpert VM IIIs on this forum:

https://powerforum.co.za/files/file/25-axpert-vmiii-inverter-firmware/

It might fix your problem. The brand on the box, or who the reseller is, should not matter; it's just paint and a different sticker, the insides should all be the same (although Inverex seem to have models that no other reseller has, so either they are an exception to this rule, or I'm simply wrong).

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