Hi All

I have an Deye 8kW hybrid inverter that was installed in December. On one of the MPPTs I have two PV strings paralleled. Now, according to the inverter datasheet, the current will be clipped at 22 Amps, what I am seeing in my data is that the current is being clipped at 20 Amps.

Has anybody else seen this happening? I suspect my inverter might need a firmware update or what else could be causing the issue?

Any advice would be appreciated.

Regards,

Freakazoid

 

What is the total kWp of all of your arrays?

2 hours ago, YellowTapemeasure said:

What is the total kWp of all of your arrays?

Hi @YellowTapemeasure

Sorry, I forgot to mention my PV arrangement. On the one MPPT, PV1, I have two strings of 5 panels each (East and North facing respectively). Then on the second MPPT, PV2, I have a single string of 6 panels (facing West). 

All 16 panels are JA 540W so I have total installed capacity of 8.64kW. As per the datasheet, each string of panels can deliver around 13 Amps. This means that, on PV1 with the 2 strings in parallel, the panels can deliver up to 26 Amps which the inverter would then cap at 22 Amps? Do you agree? 

Regards, 

Freakazoid 

On 2022/01/12 at 3:31 AM, Freakazoid said:

This means that, on PV1 with the 2 strings in parallel, the panels can deliver up to 26 Amps which the inverter would then cap at 22 Amps? Do you agree? 

Yes, but only under ideal conditions.

However, the top of your graph is very flat indeed. That suggests that the firmware is wrong, or at least out of step with the marketing droids. Most likely, the engineers are being a bit cautious, wanting to avoid warranty replacements for problems like the below (another brand, but the principle stands).

From this post: https://forums.aeva.asn.au/viewtopic.php?p=80051#p80051

Edit: I've since decided that the above wasn't excessive current, but arcing to the metal cover. So hopefully there is no need to be over cautious about PV current, as long as the budget allows for 100mm of electrical tape.

Edited January 13, 20223 yr by Coulomb

On 2022/01/11 at 5:31 PM, Freakazoid said:

Hi @YellowTapemeasure

Sorry, I forgot to mention my PV arrangement. On the one MPPT, PV1, I have two strings of 5 panels each (East and North facing respectively). Then on the second MPPT, PV2, I have a single string of 6 panels (facing West). 

All 16 panels are JA 540W so I have total installed capacity of 8.64kW. As per the datasheet, each string of panels can deliver around 13 Amps. This means that, on PV1 with the 2 strings in parallel, the panels can deliver up to 26 Amps which the inverter would then cap at 22 Amps? Do you agree? 

Regards, 

Freakazoid 

Thank you. Can you provide the link to the full specsheet of the panels, including Voc?

9 hours ago, YellowTapemeasure said:

Thank you. Can you provide the link to the full specsheet of the panels, including Voc?

Hi @YellowTapemeasure

 

Please see the attached datasheet, I have the JAM72S30-540/MR panels. Voc is listed as 49.6V

 

What are you trying to work out?

 

Regards,

JAM72S30_525-550_MR_Global_EN_20200904A.pdf

49 minutes ago, Freakazoid said:

Hi @YellowTapemeasure

 

Please see the attached datasheet, I have the JAM72S30-540/MR panels. Voc is listed as 49.6V

 

What are you trying to work out?

 

Regards,

JAM72S30_525-550_MR_Global_EN_20200904A.pdf 1.26 MB · 0 downloads

I am just double checking 😉

Imp (under load) is 12.97A, so the parallel string should be delivering 25.94A (at STC and all other perfect conditions).

OK, so we agree that clipping to 22A would probably occur, but just not at 20A (which your graph seems to show). Can you take a look at your sticker on the side? I am interested in the value of Isc. 

7 minutes ago, YellowTapemeasure said:

Imp (under load) is 12.97A, so the parallel string should be delivering 25.94A (at STC and all other perfect conditions).

yes, but...

On 2022/01/11 at 7:31 PM, Freakazoid said:

I have two strings of 5 panels each (East and North facing respectively).

so how do you propose to achieve the ideal conditions, last I checked you cant have the sun in 2 places at the same time...

Also the main graph only shows current, what is the voltage at the same time and thus the power produced? The 20A or so limit you are seeing can only be a limit if both the 5 panel strings are pointing in the same direction, I would imagine.

8 minutes ago, Kalahari Meerkat said:

yes, but...

so how do you propose to achieve the ideal conditions, last I checked you cant have the sun in 2 places at the same time...

Also the main graph only shows current, what is the voltage at the same time and thus the power produced? The 20A or so limit you are seeing can only be a limit if both the 5 panel strings are pointing in the same direction, I would imagine.

Good point, we are getting there. I just want to confirm with the sticker, but my money is on the firmware update to solve the problem. That graph is just too flat, the only other way it might be achieved is if the inverter's WiFi bombed out and it skipped a couple of updates...  so perhaps we should be looking at the raw data as well...

Hi Guys

Thanks for all the comments.

I will have a look at the sticker on the side of the inverter later today but I do remember that is lists 22A + 22A.

Here are the graphs of the DC Current, DC Voltage and DC Power. I doubt whether it was a WiFi issue as there is data available in the "flat" section of the DC Current graph and there is a variation in the other parameters around this time. The curve is just to consistent for it not to be due to the current being clipped... What's the process for updating the firmware on a 8kW Deye??

 

Regards,

You sure you did not limit production by consumption / charging rate during the period in question? Current is flat but voltage and subsequenlty power still varies, so many it is just the MPPT doing it's job?  

Edited January 13, 20223 yr by Scubadude

It seems it may be mostly charging the battery at that flat current stage, but I still think having 5 panels east - high power production early in the day and 5 panels north not so much power production until later in the day, may be the real problem.

Hi Guys

This is becoming a really interesting discussion...

You are right, at this time of day, it is mainly the batteries being charged (max set to around 5kW for charging). It might be that it is the MPPT busy doing its job but the fact that the curve is perfectly flat and always flattens out at 19.89A just seems like too much of a coincidence?? Since I've had my system I have not see the PV1 DC current exceed this value...

5 hours ago, Kalahari Meerkat said:

It seems it may be mostly charging the battery at that flat current stage, but I still think having 5 panels east - high power production early in the day and 5 panels north not so much power production until later in the day, may be the real problem.

@Kalahari Meerkat, I'm not sure that I understand your comment regarding that the fact that the north-facing panels only produce most of their power later in the day and that that may the the real problem... Would you mind explaining what you mean?

Thanks for all your comments.

 

3 hours ago, Freakazoid said:

@Kalahari Meerkat, I'm not sure that I understand your comment regarding that the fact that the north-facing panels only produce most of their power later in the day and that that may the the real problem... Would you mind explaining what you mean?

If you expect double the current for the 2 X 5 panels, then they should all be facing the sun at the same time... if the east facing bunch deliver 13 A @ around 200V, 2.6kW, (It'll be less than this) then the the north facing ones will probably do half that, I'm guessing... and once the sun moves and the north facing ones produce closer to maximum smoke, then the east facing ones will be down on their production, so if the panels come up to 13A for each string, but one is east facing and the other north facing, you will never ever see 26A out of them combined, unless you face all 10 panels in the same heading... facing the sun at the time...

Thanks @Kalahari Meerkat

Yes, I agree with you that it is unlikely that the north and east facing panels will be running at peak production at the same time and we're very unlikely to see a total of 26A on my PV1 string...  This was my reasoning when putting these two strings together. Losing capacity due to clipping should be negligible... 

However, I don't think it is unreasonable to expect a current in the region of 20A to 22A on PV1. It does however look like my system is clipping the current at 20A and not 22A as indicated in the datasheet. 

2 hours ago, Freakazoid said:

Thanks @Kalahari Meerkat

Yes, I agree with you that it is unlikely that the north and east facing panels will be running at peak production at the same time and we're very unlikely to see a total of 26A on my PV1 string...  This was my reasoning when putting these two strings together. Losing capacity due to clipping should be negligible... 

However, I don't think it is unreasonable to expect a current in the region of 20A to 22A on PV1. It does however look like my system is clipping the current at 20A and not 22A as indicated in the datasheet. 

Yes I agree that flat portion starting at 08h00 is clipping. It would be interesting to know why once you have solved the problem.

On 2022/01/13 at 9:49 AM, Freakazoid said:

What's the process for updating the firmware on a 8kW Deye??

It updates automatically once connected to your wifi network.

On 2022/01/11 at 7:31 PM, Freakazoid said:

Hi @YellowTapemeasure

Sorry, I forgot to mention my PV arrangement. On the one MPPT, PV1, I have two strings of 5 panels each (East and North facing respectively). Then on the second MPPT, PV2, I have a single string of 6 panels (facing West). 

All 16 panels are JA 540W so I have total installed capacity of 8.64kW. As per the datasheet, each string of panels can deliver around 13 Amps. This means that, on PV1 with the 2 strings in parallel, the panels can deliver up to 26 Amps which the inverter would then cap at 22 Amps? Do you agree? 

Regards, 

Freakazoid 

Not 100% sure but the max of the Sunsynk inverters on the spec sheet is 18A which they upgraded to 20A.

I assume that the DEYE is the same.

7 hours ago, Sc00bs said:

Not 100% sure but the max of the Sunsynk inverters on the spec sheet is 18A which they upgraded to 20A.

I assume that the DEYE is the same.

Thanks @Sc00bs, I checked the sticker on the side om my 8kW Deye and it clearly states 22A+22A for the "PV input current".

@Scubadude, my inverter has been constantly connected to our WiFi for more than a month and I don't think it has ever done a firmware update... My device software details are as follows

HMI : Ver c34c

MAIN1: Ver 3881

MAIN2: Ver 717

How does it compare to yours? What is the latest version?

@Freakazoid, you have to request a firmware update from Deye support, I don’t have details on how to contact Deye as I have a Sunsynk

12 hours ago, Freakazoid said:

HMI : Ver c34c

MAIN1: Ver 3881

MAIN2: Ver 717

How does it compare to yours? What is the latest version?

Same ... Except mine is c34b.

Solarman buisness gives this option, suposedly to be able to push manual updates ...

... but with no package options so pretty useless.

Edited January 16, 20223 yr by Scubadude

So, I learnt something new today about my inverter  

Sunsynk 8kw specs say 10400W Max solar power. 

I learnt that the 10.4kw limit is actually split between the MPPT's @ 5200Watts per MPPT

Saying this however, the max amount of power I have produced on one MPPT is 5400watts, perhaps since the firmware update, there does however seem to be a cap per mppt as mine pull back on the power at 5.4kw.

Not sure what the DEYE specs say but assume that there are similar limits to the amount of power you can put through each MPPT

 

On 2022/01/13 at 7:43 PM, Kalahari Meerkat said:

If you expect double the current for the 2 X 5 panels, then they should all be facing the sun at the same time... if the east facing bunch deliver 13 A @ around 200V, 2.6kW, (It'll be less than this) then the the north facing ones will probably do half that, I'm guessing... and once the sun moves and the north facing ones produce closer to maximum smoke, then the east facing ones will be down on their production, so if the panels come up to 13A for each string, but one is east facing and the other north facing, you will never ever see 26A out of them combined, unless you face all 10 panels in the same heading... facing the sun at the time...

@Kalahari Meerkat You need to take into account the different voltages of the East & North facing panels as well as you will loose efficiency on the mppt

2 hours ago, Sc00bs said:

So, I learnt something new today about my inverter  

Sunsynk 8kw specs say 10400W Max solar power. 

I learnt that the 10.4kw limit is actually split between the MPPT's @ 5200Watts per MPPT

Saying this however, the max amount of power I have produced on one MPPT is 5400watts, perhaps since the firmware update, there does however seem to be a cap per mppt as mine pull back on the power at 5.4kw.

Not sure what the DEYE specs say but assume that there are similar limits to the amount of power you can put through each MPPT

 

Ok, looks like the info I was given is actually incorrect

Here I am generating the maximum solar energy of 10.4kw

 

4.2kw from the East Panels and 8.18kw from the West Panes. 

 

So not sure what the actual power limit is on the MPPT controllers. 

 

 

5 minutes ago, Sc00bs said:

So not sure what the actual power limit is on the MPPT controllers. 

 

Usually whatever you can practically fit within the voltage and current limit. So probably around 80% of max voltage * max current. So roughly 8.8kW per MPPT?