I have recently installed another 8 panel string of 460W panels  and parralelled connecting it with almost identical string to MMPT1.  This two string are facing NE.  Another NW facing string of also 8 panels is on MPPT1 on Deye 8kw inverter.  I suspected clipping soon after installation but thought it was marginal and I thought the 9000w was just what I was getting from irradiation at that point.  Today I checked data directly on the inverter and noticed the following:  The MPPT1 input voltage started to run up to 20 amps and yielded about 6300W.  At that point MPPT2 started to catch up but when it got to 2700W  the total inverter output started to be clipped at 9000W.  As MMPT2 ran up further it was evident that MPPT1 was proportionally cutting back to maintain total output at 9000W (actually 8999W).  Amps on MMPT1 reduced from 20 to 18 and volts increased.   Ip_max is around 11.1 for panels so I was expecting clipping at 22A on the MMPT1.   Inverter rated DC input is 10400W.  I also does not seem to be max MMPT power (never read of such thing though) because it dot not clip MPPT1.    During the time, battery amps was well within range as load was around 7000W so there was no other constrains.  Max solar power setting was 10380W, which I lowered to about 10000W to see  if it would activate something.

Firmware is 6014-1724.  Inverter was installed in Oct 22 and I think it had only one firmware upgrade via installer after it showed some serious hunting on Solar Power inputs few months after installation. 

For reference I attached xlsx file with data dump.  Period under discussion is marked in yellow. 

 

2024-08-31~2024-08-31Inverter2207272408Report.xlsx

Where was the 9000W of power going too? Essential load / Non Essential load, feeding back to Grid.

Where the batteries fully charged, or taking some of the power?

Edit, after looking at spreadsheet.

I see your batteries were taking +- 85A(SOC 57%), and then about 20 minuets later, only 26A(SOC 61%), but the DC power was still 9000W.

I see your Max charge current is set to 150A, has it ever reached that limit? On the spreadsheet I see 120A.

On the DC bus the inverter can get to 10400W of power, but only if the batteries are taking the excess power(1600W), and the AC load is 8800W.

Never tested this on my inverter yet..🤔

 

Edited August 31, 20241 yr by TimCam

3 hours ago, JacquesStrydom said:

the total inverter output started to be clipped at 9000W. 

I have seen this on various occasions on the Sunsynk and Deye 8kw that the total output power between the 2 mppt's will not exceed 9000w. It will adjust the mpp so the current between the combined mppt's do not exceed 9kw. I know the sticker and the manual states 22A+22A 10400W but in reality the sum of the 2 mppt's will not exceed 9000w. 

I also had conformation from Deye that this is indeed the case. They send me an e-mail after i enquired about this 2 years ago (wording not very technical) but nevertheless conformation max pv power for the 8kw SS &Deye inverters 9000w pv output. 

3 hours ago, TimCam said:

Never tested this on my inverter yet..🤔

 

Edited August 31, 20241 yr by TaliaB

Thanks for the useful Update @TaliaB. 👍

Interesting  @TaliaB I looked through some of my old data and found more more the 9kw on my Sunsynk 8kw  (12,7kw of panels) a number of times, the highest production readings were during spikes. 

12 hours ago, TimCam said:

Where was the 9000W of power going too? Essential load / Non Essential load, feeding back to Grid.

Where the batteries fully charged, or taking some of the power?

Edit, after looking at spreadsheet.

I see your batteries were taking +- 85A(SOC 57%), and then about 20 minuets later, only 26A(SOC 61%), but the DC power was still 9000W.

I see your Max charge current is set to 150A, has it ever reached that limit? On the spreadsheet I see 120A.

On the DC bus the inverter can get to 10400W of power, but only if the batteries are taking the excess power(1600W), and the AC load is 8800W.

Never tested this on my inverter yet..🤔

 

I ramped up essential load to about 7.5kw to make space for power import  while testing - that was why the battery amps  reduced.   I would have liked to have say 7kw on inverter and 3.4kw on battery if needed.  Had a few cases where I charged at close to 7kw. (3 x 5.12kw battery bank)

On 2024/08/31 at 7:13 PM, JacquesStrydom said:

I have recently installed another 8 panel string of 460W panels  and parralelled connecting it with almost identical string to MMPT1.  This two string are facing NE.  Another NW facing string of also 8 panels is on MPPT1 on Deye 8kw inverter.  I suspected clipping soon after installation but thought it was marginal and I thought the 9000w was just what I was getting from irradiation at that point.  Today I checked data directly on the inverter and noticed the following:  The MPPT1 input voltage started to run up to 20 amps and yielded about 6300W.  At that point MPPT2 started to catch up but when it got to 2700W  the total inverter output started to be clipped at 9000W.  As MMPT2 ran up further it was evident that MPPT1 was proportionally cutting back to maintain total output at 9000W (actually 8999W).  Amps on MMPT1 reduced from 20 to 18 and volts increased.   Ip_max is around 11.1 for panels so I was expecting clipping at 22A on the MMPT1.   Inverter rated DC input is 10400W.  I also does not seem to be max MMPT power (never read of such thing though) because it dot not clip MPPT1.    During the time, battery amps was well within range as load was around 7000W so there was no other constrains.  Max solar power setting was 10380W, which I lowered to about 10000W to see  if it would activate something.

Firmware is 6014-1724.  Inverter was installed in Oct 22 and I think it had only one firmware upgrade via installer after it showed some serious hunting on Solar Power inputs few months after installation. 

For reference I attached xlsx file with data dump.  Period under discussion is marked in yellow. 

 

2024-08-31~2024-08-31Inverter2207272408Report.xlsx 32.93 kB · 7 downloads

So on Deye inverters there is a setting for Max PV power or Max power, don't remember exactly. Mine was set to 2200W initially and I saw clipping of PV at that wattage, you might want to check your settings for what your limit is set to.

On 2024/09/03 at 9:50 AM, HendrikBigChief said:

So on Deye inverters there is a setting for Max PV power or Max power, don't remember exactly. Mine was set to 2200W initially and I saw clipping of PV at that wattage, you might want to check your settings for what your limit is set to.

Thanks, when I installed additional panels I increased the value to 10380W so it is not that. 

On 2024/08/31 at 11:04 PM, TaliaB said:

I have seen this on various occasions on the Sunsynk and Deye 8kw that the total output power between the 2 mppt's will not exceed 9000w. It will adjust the mpp so the current between the combined mppt's do not exceed 9kw. I know the sticker and the manual states 22A+22A 10400W but in reality the sum of the 2 mppt's will not exceed 9000w. 

I also had conformation from Deye that this is indeed the case. They send me an e-mail after i enquired about this 2 years ago (wording not very technical) but nevertheless conformation max pv power for the 8kw SS &Deye inverters 9000w pv output. 

 

I asked Deye yesterday to upgrade firmware and in follow up I asked about clipping.  The replied with:

Quote

 

hi，

Please refer to the parameter table, the maximum photovoltaic power is 1.3 times the rated power

Deye Wuli
Deye after-sales customer service

 

which works out to be 10400W which contradicts what they told you.

 

22 minutes ago, JacquesStrydom said:

I asked Deye yesterday to upgrade firmware and in follow up I asked about clipping.  The replied with:

which works out to be 10400W which contradicts what they told you.

 

I have also ask Deye for clarification on this issue again this morning as their previous response 2 years ago that the mppt's are clipped at 20A for safety reasons might have to do with temp rise on constant 10kw output. As @Sc00bsgraphs indicate spikes well above 10kw but constant output of closer to 9kw as i have also observed. Below response from Deye 2 years ago. Let see what response i get back from Deye.

3 minutes ago, TaliaB said:

mppt's are clipped at 20A for safety reasons

I suspected 20A clipping as well but from the data it seem there is 9000W clipping as well since during this time, the amps on the mppt starts to run down from 20A to 18A. 

For the last few days I ran into 20A limit before I ran into 9000W limit.  Fortuanately production is more than sufficient for load and recharging.  Just frustrate me that I carefully contemplate design to to be within spec  just to tripped up with misleading specs in the end.

Thanks for following up as well. 

On 2024/08/31 at 7:13 PM, JacquesStrydom said:

I have recently installed another 8 panel string of 460W panels  and paralleled connecting it with almost identical string to MMPT1.  This two string are facing NE.  Another NW facing string of also 8 panels is on MPPT1 MPPT2 on Deye 8kw inverter.  I suspected clipping soon after installation but thought it was marginal and I thought the 9000w was just what I was getting from irradiation at that point.  Today I checked data directly on the inverter and noticed the following:  The MPPT1 input voltage started to run up to 20 amps and yielded about 6300W.  At that point MPPT2 started to catch up but when it got to 2700W  the total inverter output started to be clipped at 9000W.  As MMPT2 ran up further it was evident that MPPT1 was proportionally cutting back to maintain total output at 9000W (actually 8999W).  Amps on MMPT1 reduced from 20 to 18 and volts increased.   Ip_max is around 11.1 for panels so I was expecting clipping at 22A on the MMPT1.   Inverter rated DC input is 10400W.  I also does not seem to be max MMPT power (never read of such thing though) because it dot not clip MPPT1.    During the time, battery amps was well within range as load was around 7000W so there was no other constrains.  Max solar power setting was 10380W, which I lowered to about 10000W to see  if it would activate something.

Firmware is 6014-1724.  Inverter was installed in Oct 22 and I think it had only one firmware upgrade via installer after it showed some serious hunting on Solar Power inputs few months after installation. 

For reference I attached xlsx file with data dump.  Period under discussion is marked in yellow.

Just to confirm:
The Deye 8k has 2 MPPT controllers.
You have connected the solar panels as follows:

• MPPT1: 8s+8s x 460W NE = 7360W
• MPPT2: 8s x 460W NW = 3680W

The reason I'm asking is I'm considering adding an additional string to my Sunsynk 8k.
Now:

• MPPT1: 8s x 400W N = 3200W
• MPPT2: 8s x 400W N = 3200W

Proposed:

• MPPT1: 8s+8s x 400W N = 6400W
• MPPT2: 8s x 400W E = 3200W

Sorry, not trying to go off-topic, but I think many are interested in adding more strings.
Thanks in advance.

8 minutes ago, system32 said:

Proposed:

• MPPT1: 8s+8s x 400W N = 6400W
• MPPT2: 8s x 400W E = 3200W

what  is your I_pmax and V_pmax for your panels?

You correctly stated the config of my panels - what I omitted to say is that NE is 8x455W +8x460 and NW is 8x455. V-I curves for the 455 and 460 are virtually the same to the exent it can be ignored.

Deye upgrade my firmware yesterday and I suspect it now limits my amps on the MPPT1 to 19.4 as oppsed to 20A I have seen before and 22A on spec sticker.

12 minutes ago, JacquesStrydom said:

what  is your I_pmax and V_pmax for your panels?

You correctly stated the config of my panels - what I omitted to say is that NE is 8x455W +8x460 and NW is 8x455. V-I curves for the 455 and 460 are virtually the same to the exent it can be ignored.

Deye upgrade my firmware yesterday and I suspect it now limits my amps on the MPPT1 to 19.4 as oppsed to 20A I have seen before and 22A on spec sticker.

I_pmax 9.62A
V_pmax 41.6V

I have 16 of these:

8 in series on MPPT1
8 in series on MPPT2
Am looking to put all 16 on MPPT1 configured as 8 series strings 2 parallel - North Facing
Then add 8 new panels (still to buy) on MPPT2 - East Facing

Just thought I'd report my take on this.

I have my 1st string (MPPT1) as 2P8S of 365W Candian Solar PV pointing just West of North. 

Spec: Imp = 9.18A & Vmp = 39.8V. So in theory I should see 18.4A (say 18A with losses) and around 318V (say 305V with losses)

I chose those 4 years ago to match the mppt Max current of 18A, (8kW SS). 

Obviously, was peeved when some time later, the mppt limit was raised to 22A with firmware upgrade.

My 2nd string (MPPT2) is also 2P8S, but with 8S in the same direction as MPPT1, and the other 8S mounted much more Westerly, in order to get maximum afternoon generation.

What I'm actually seeing is the following:

Purple = MPPT1 & Blue = MPPT2. Max I've ever seen on MPPT1 = 16.7A (may go a bit higher, as it is not peak summer yet (new homegrown management system since winter). Voltages seem spot on @ 315V under max load. So efficiency = 16.7/18.4 = 90.1%

So in practice, my system is sort of under performing, as peak generation is only 8.5kW peak, with up to 10kW cloud effect have been observed.

I have as spare set of 16 x 545W JA Solar (Imp = 13.04A & Vmp = 41.8V), which would give 26.08*0.901=23.5A on MPPT1. Just too high and I don't like clipping.

Perhaps just replacing just MPPT2's strings might just be the right option, taking into account the 545W is quite a bit larger to mount, but fortunately, the rails of MPPT2 do have quite a bit of overhang. 

MPPT2 calc's: Efficiency = 15.1/18.4= 82%

Thus new panels should give 26.08*0.82 = 21.4A, within the MPPT limit, but at a voltage of 335V = 7160W peak.

Maybe I could add 4 panels to MPPT1 to get them to 2PS10. That will give me a Voc = 472V, leaving some headroom for Temp. drops to below 0.

Yes/No?

4 hours ago, system32 said:

Just to confirm:
The Deye 8k has 2 MPPT controllers.
You have connected the solar panels as follows:

• MPPT1: 8s+8s x 460W NE = 7360W
• MPPT2: 8s x 460W NW = 3680W

The reason I'm asking is I'm considering adding an additional string to my Sunsynk 8k.
Now:

• MPPT1: 8s x 400W N = 3200W
• MPPT2: 8s x 400W N = 3200W

Proposed:

• MPPT1: 8s+8s x 400W N = 6400W
• MPPT2: 8s x 400W E = 3200W

Sorry, not trying to go off-topic, but I think many are interested in adding more strings.
Thanks in advance.

I can try and simulate the expected clear sky output for a specific date for you if you give me approximate roof tilt and facing direction (if you have anything more detailed than just N or E.  -and maybe a system dump of the existing power  profile for the current installation for calibration.   Maybe PM me.

16 hours ago, Sidewinder said:

Thus new panels should give 26.08*0.82 = 21.4A

I guess the final answer depends on if your firmware will allow operating to 21.4A. As user reported here for Deye it is more like 20A.

If you are getting close to the limits on the 8Kw Inverter.

My suggestion would be have a look at adding a Grid-Tie inverter on the Aux Port. 

My understanding is that you can add up to a 4kw Grid Tie, so you can add another 2 x mppt controllers relatively cheaply and it also increases the max load on the inverter without going to the grid. 

One of my friends has this setup and he said that he regularly goes up to 9kw load when his grid tie is producing power without pulling any power from the grid. 

Seems like a good option if you are borderline on your 8kw as you can pick up a grid tie pretty cheap second hand off FB Marketplace

Hi. I have a 8KW Deye inverter Split phase. 9600w in solar panels. But the inverter just generates 7kw max. It seems that the inverter limites the power to 7kw. I want to know if there is a way to reach 8kw. 

I have a 8KW Deye inverter split phase. 9600W of Solar panels. The inverted is clipped to 7KW on the generated power from the solar panels. I want to know if there is a way to reach at least 8KW.