DC coupled ESS system not grid feeding the full PV potential

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solartronics asked May 2, '19

DC coupled ESS system not grid feeding the full PV potential

I have a 250/100 with 5.36kWp of PV installed. The system can grid feed. The daytime loads are relatively low, but it looks like the charge controller is limiting to 2.5kW (50A). Charge current limit is disabled.

I have tried Keep Batteries Charged as well as optimized with batteries at 100%.

Charge controller float voltage 54.4V

Inverter charge setting 53.6V

Charge controller firmware version v1.39

Color Control firmware v2.23

Does the country standard affect the amount of power that can be grid fed? Country code: Other

MultiPlus Quattro Inverter Charger ESS grid

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solartronics commented · May 04, 2019 at 04:35 PM

I replaced the 150/100Tr in a Easysolar 5000 with a 250/100Tr, any ideas on what the problem could be @Guy Stewart (Victron Energy Staff)?

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Modifications Space

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Answer 1 · 2019-05-02T11:33:18Z

Murray van Graan answered · May 02, 2019 at 11:33 AM

Note that the MPPT will follow the charge parameters set in veconfig. So setting the inverter different to the MPPT will cause the MPPT to charge at the voltages you set in the inverter. Please see below ESS manual for information:

https://www.victronenergy.com/live/ess:design-installation-manual

Once ESS is set up correctly, let me know how it behaves!

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solartronics commented · May 02, 2019 at 03:01 PM

I dont think the voltages are the problem, it looks like the current is being throttled as can be seen below.

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Answer 2 · 2019-05-02T16:00:20Z

Murray van Graan answered · May 02, 2019 at 04:00 PM

That might be true, but read the whole ESS manual and do the settings correctly. For instance, have you disabled storage mode? Also, how about the settings in ESS menu? Those could also cause the system to throttle PV production.

Can you provide more info?

Veconfig settings, and CCGX system setup and ESS settings. What batteries are you using?

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solartronics commented · May 03, 2019 at 10:25 AM

Lead Acid batteries

-Gridcode other

-UPS function

-Storage mode is disabled yes

-DVCC on

-SVS on (tried both on&off)

ESS settings

-Keep Batteries Charged (Tried optimized 100% aswell)

-No gridmeter installed

-Feed in access Solar power enables

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Answer 3 · 2019-05-04T17:30:09Z

boekel answered · May 04, 2019 at 05:30 PM

what firmware is loaded in the multi?

Can you look into the MPPT parameters?

like this:

Also: check the temperature of the unit, heat can also be an issue, do you have pictures of the installation?

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solartronics commented · May 06, 2019 at 08:04 AM

The firmware version is 2624433

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boekel ♦ solartronics commented · May 06, 2019 at 01:50 PM

Ok. if you try to set a higher (negative) grid-setpoint? does it go feedback more?

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solartronics boekel ♦ commented · May 07, 2019 at 02:05 PM

If the keep batteries charged setting is used there is no option for grid set point. I have however already tried under optimized 100% SOC, set the grid setpoint to -5500. This didn't make a difference.

I tried 90% today. Usually PV starts decreasing at around 3000W (9:50 roughly) today it went up to 3500W (10:30) once thebattery got closer to full the PV decreased. No cloud cover. At about 13:00 I changed it back to keep batteries charged.

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boekel ♦ solartronics commented · May 07, 2019 at 04:37 PM

I think you're at the feedback-limit of your inverter, this limit might vary a bit with temperature and DC voltage, but 3000-3500W for a 5000VA inverter sounds about right to me.

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