Just a question about PV assistant being installed on a stand alone 3000w/24v Multiplus but NO micro inverters hooked up to the AC output.
24v 12kWh lithium battery pack with internal BMS, but no communication to the Multiplus.
Will the Multiplus vary the output frequency based on the battery voltage getting close to full charge from the ‘external’ DC sources even though there are NO micro inverters sourcing the load? (System has an MPPT controller, plus an external battery charger.)
Does the frequency swinging response require the Multiplus to have ‘figured out’ that there is an external source of AC power FIRST and be using that ‘extra’ energy to charge the battery pack before the frequency shift to throttle kicks in?
Thanks,
Steve
Ok, just tested the Multiplus by charging the batteries from the MPPT and an external power supply and NO micro inverters.
Multiplus charger is set for:
Lithium Batteries
Absorption @27.95
Float @ 27.70
Charge Current 70a
Curve Adaptive
Repeated Absorption time .25 hour
Repeated Absorption interval 45 days
Max Absorption Time 1 hr.
I just accepted the PV assistant defaults:
Solar converter will:
Start Reducing output at 60.2Hz
Output power will reduce to minimum at 62.7Hz
Converter will disconnect over 63Hz
(I have NO IDEA what the frequency vs output defaults actually are on the DS3 at this point, and I’m waiting for a 3kva 120v/240 transformer to show up so I can actually try it with my 120v Multiplus.)
Multiplus Freq shift on output, while Slowly Raising Voltage from the point where the Multiplus is outputting 60Hz.
Volts Hz
27.97 60.3
27.98 61.0
=======
Multiplus Freq shift on output, while Dropping the Voltage from the point where the Multiplus is outputting 62.8Hz.
27.94 62.4 Slowly Dropping from a higher voltage value
27.92 61.8 Slowly Dropping from a higher voltage value
27.91 60.5 Slowly Dropping from a higher voltage value
It appears that the frequency shift is exaggerated if the voltage overshoots and it is on the way back down.
Once the transformer gets here, I can actually test the DS3 and see how it acts.