ESS not using PV power unless Grid setpoint set to negative. Then dumps.

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andre asked Dec 15, '18

ESS not using PV power unless Grid setpoint set to negative. Then dumps.

Dear Victron People,

Set-up: 5 kW 48 V Multi (2624430); CCGX (v2.22) ; 2 x SmartSolar Chargers MPPT (v1.37) and 4 x Pylontech US2000 batteries. ESS in Optimized (with BatteryLife) mode and Feed-in excess sloarcharger power enabled.

When Grid setpoint at 50 W a small amount of PV power is used to keep the batteries charged and the available PV power is not used to supply AC load or feed into the grid. Effectively the PV power is disabled.

I can only circumvent this by setting the Gird setpoint to a negative value equivalent to the available PV power. The Multi then inverts this amount of power to AC as grid feed-in using the PV power available and when not enough PV power at the time, by discharging the batteries until the Minimum SOC is reached. The PV power (and sometimes AC power!) is then used to recharge the batteries (but not to 100 %) and the cycle then repeats.

My understanding is that when ESS operates correctly the PV power should first be used to supply the AC load, then charge the batteries and then feed into the grid. I am migrating my systems to not grid-tie but not working.

It appears that the CCGX malfunctioning.

Is there another possible reason for this aberrant behaviour?

ESS CCGX Color Control Pylontech

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andre commented · Dec 16, 2018 at 12:31 PM

PS I am migrating my system to not grid-feed but run grid parallel. (This is prototype of first 4 kW, I have another 4.5 kW system on direct grid-tie waiting in the wings.) So want to run loads and charge battery in the day (and only then grid-feed), and use battery at night. I can't get ESS to do this.

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Answer 1 · 2018-12-15T20:46:28Z

mihair answered · Dec 15, 2018 at 08:46 PM

Please look in CCGX, MPPP properties, Networking. Should be controlled by BMS&ESS. If not, reset the MPPT

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andre commented · Dec 16, 2018 at 04:59 AM

Dear MihaiR, thank you for response.
I can confirm that MPPT is in State "ESS" and that Mode setting is "ESS & BMS".
The Pylontech batteries' BMS controls the MPPTs output current and voltage and the MPPT are functioning optimally but only with large negative Gird setpoint.
In the 48 hours that I have run the system with these settings the maximum battery SOC has been 83%, despite selecting Optimized (with BatteryLife) mode in ESS.

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Answer 2 · 2018-12-24T19:54:53Z

andre answered · Dec 24, 2018 at 07:54 PM

She Fixed!

CCGX behaving. ESS running like she should in Optimised (with battery life) ! Settings: Gird setpoint = 50.
Minimum SOC = 25%.
System selected Active SOC limit = Varies, thus far between 55 and 65 % depending on charge pattern in day. Batteries only charged from solar.
When sun comes up: Manages AC load - then Charges batteries (to 98%) - then Feed-in excess solarchager power.

Once sun gone discharges batteries to Active SOC limit and then switch to grid!

...some said slow feedback loop ?!

No idea why it took days and multiple trails before she worked!

Brilliant what she does! Will add 3 Kw Sunnyboy soon.

Happy Times!

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