question

Carlo avatar image
Carlo asked

ESS is not selling excess PV to the grid, while it is charing the battery.

System:

Two Quattros 10K-120V- setup in SplitPhase, ACin1 has a generator, ACin2 has the grid

Four MPPT SmartSolar 150/100 controllers with a total of 14 365W panels per string.

Large 1400Ah Lithium Battery managed by Batterie's internal BMS that communicates with Venus via CAN-BUS. The BMS is a REC-BMS.

Venus is configure:

ESS:

Mode:Optimized without BatteryLife

Grid metering: Inverter/Charger

Multiphase regulation: Total of all phases

Limit inverter per:OFF

Grid setpoint: 0W

Grid Feed-in:

AC-coupled PV:off

DC-coupled PV : ON

Limit system feed-in : ON

Max feed-in: 15000W

Scheduled charging: Disable

DVCC: ON; SVS:ON; STS:ON; SCS:ON;Temp:REC-BMS

Problems:

1- System will curtail the PV been generated to match the sum of the AC-load plus the BMS requires to charge the battery. When it should produce as much PV as it can and sell to Grid all that is not needed by the BMS to charge the battery.

2-Once the BMS has reached 100% SOC it sends parameter to Venus to charge at 1A, the system does not pay attention to it and send at least 20 to 50A, but now starts to allow the PV to produce the maximum PV and sells to the grid. Any variations in the AC-load make the battery charging amps to spike to up to 100A, at which point the DC Volt also rise to 65VDC. The batteries BMS send a voltage high ALARM and it it happens several times, the BMS goes into protection mode and disconnects the Battery. this also triggers an alarm38 in the Smart Controllers disabling them, and requiring a full disconnect.

MPPT ControllersMultiPlus Quattro Inverter ChargerESSVenus OS
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2 Answers
Warwick Bruce Chapman avatar image
Warwick Bruce Chapman answered ·

Please install an ET112 or ET340 energy meter as applicable.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

Hi @warwick

Please explain why an energy meter would be needed?

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Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @Carlo

I'm guessing LiFePO4 battery?

What charge voltage (CVL) are you sending to the system? and when battery is at 100%, is the battery well balanced?

Normally you should try to reach the CVL without needing to set CCL to a low value.

But if you really want to stop charging: use CCL=0, not 1

as for not feeding to grid: did you check all things from the manual?
(see Q9)

https://www.victronenergy.com/media/pg/6292-ESS_design_and_installation_manual-html5/en/faq.html

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Carlo avatar image Carlo commented ·

My current configuration has ESS Mode set to Optimized (without BatteryLife). Still do not know why Victron is not selling excess solar energy to the grid. It instead it pushes the SmartSolar MPPT controller to produce less PV, once the Battery's SOC is 100%.

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ Carlo commented ·

Hi @Carlo

What settings do you have for feed-in?

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Carlo avatar image Carlo Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

AC-coupled PV - feed in excess OFF

DC-coupled PV - feed in excess ON

Limit system feed-in OFF


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