question

juan-sebastian-pfeiffer avatar image

Pylontech - MPPT Yield Limited

Hi everyone,


This is my first post in the community and our first Victron installation so please excuse me if I miss something.

Before posting, following the Forum guidelines, I looked at these posts but I just could not find the answer to our issue.

https://community.victronenergy.com/questions/65147/maximum-charge-current-of-multiplus-ii-3-x-pylonte.html

https://community.victronenergy.com/questions/55513/strange-charging-behavior.html

https://community.victronenergy.com/questions/61350/multiplus2bluesolar-limitedthrottled-solar-product.html

We have a DC coupled PV ESS:

  • Quattro 48/3000/35-50/50 120V
  • Smart Solar 250/100 VE Direct
  • 5.4 kW PV Modules (3 strings of 5 x 360 W Modules)
  • 2x Pylontech US2000
  • Cerbo GX
  • System recently installed, setup in VE Config and all firmware uptated to latest version

We have noticed that the PV Yield is limited to around 1200-1300 W, regardless if we have 1 or the 3 strings connected. Currenty there are limited AC loads but while comissioning we tested and increased loads and the PV Yield increased up to 2000 W with the additional loads (~800 W)

We set up everything as per the manual and Pylontech specific instructions.

Looking at the different posts and manual, it looks like the Battery BMS of the battery is limiting the PV output. I looked into the parameters of the battery in VRM (screenshot attached) and it shows CCL is ony 10 A, while DCL is 50 A.

Pylontech Params

batteri-parameters.jpg


MPPT Params1608727960214.png

The DCL of 50 A confirms that the system is reading the 2x Pylontech batteries correct? The CCL of 10 A with the 120 Volts ~ i.e. 1200 W would to confirm to me that this is the reason why it's limiting to 1200 W with no loads. The MPPT Charge current param is 50 A. There are no extreme cold conditions, the battery temp range sbetween 14 deg C to around 20 deg C during the day. Should 14 deg C already limit the CCL to only 10 A?

If this is the case, then, my questions are:

  • Why if the battery is fully charged, it limits the PV output. We can feed back to the grid and we have played with it enabled and disabled for testing purposes, however the PV yield is limited to the 1200 W. The plan for the system is to feed back all excess to the grid as a regular grid-tied PV inverter even if there's no load but the 1200 W is currently only 25% of the capacity!
  • Could anyone suggest more trouuleshooting stepts to resolve this issue?

Thank you very much for your support.


Cheers,


Juan

ESSPylontech
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2 Answers
nickdb avatar image
nickdb answered ·

Having the same issue with Pylon. In ESS optimised modes PV is being severely throttled. If you change to keep batteries charged then PV production works fine - 250/100 CAN MPPT and MP2 5kVA.

2 comments
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@Guy Stewart (Victron Community Manager) I see from some posts you have dealt with related issues. Any thoughts on why PV is being limited and only in the optimised ESS modes? (it's not an inverter limit, that's disabled).

pt.jpeg

pt.jpeg (91.9 KiB)

To add to the above, disabling the schedule in ESS optimised mode also results in proper PV usage.

There seems to be an issue with pylon and scheduled charging which is throttling PV usage and instead pulls from grid.

@Daniël Boekel (Victron Energy Staff) any ideas?

Alexandra avatar image
Alexandra answered ·

@Juan Sebastian Pfeiffer

Are you feeding back at all? Have you set it to feedback in the color control?

ESS - Grid feed in (then enable appropriate settings)

1608734712867.png

I also see you have a flashing triangle notification. What is it? It may be related to the problem.

My advice to you though if it is a new system give it a few days to let it sort out the battery balancing before setting yourself to feedback. It will take a few days before your pylons say 100%. At least this has been my experience with them.


1608734712867.png (26.9 KiB)
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