Hi! I am having issues with 2No. SMA STP 25 X, coupled to the AC output of 10kVA Quattro inverter/chargers (60kVA - 3phase). The system is off-grid, but has a diesel genset, to only work when the battery SOC is below 20%. Now, when the battery SOC reaches 100%, the SMA do not throttle down quickly and end up causing the entire system to shut down (often due to high temp on the DC bus). Which settings should I pay particular attention to on the SMAs and VEConfigure, or any other area which i have missed?
I have a similar problem, not as big a system but also off grid with SMA. Today my batteries were fully charged for the first time in a very long time and the load was not covering the solar yield. The Victron did raise the system voltage but at one stage of low solar production the frequency jumped to 53.3 Hz at the same time the Ve.Bus reported a High DC Ripple which was at 0.4V and the Battery Voltage spiked to over 60V. The power dipped briefly but was noticeable. Previously I’m sure the Victron did a reset or something as the power was down for a minute or so.
How that happens I’m not sure. Maybe this will help someone to be able to comment.
My system is a Quattro 10000, with a SMA Sunnyboy 5000 on the output and 5300Wp CS Solar panels. I also have another 1740Wp CS Solar panels feeding a Victron 250/85 Charge controller charging four LiFePO4 batteries totalling 1176Ah . Charging upto a max of 55.2V.
What frequency ranges are you using in the PV assistant to control power?
It looks like the SMA has quite the operational frequency range so the usual 53hz might not be enough?
It may be worth using ac2 out to connect and disconnect the PV inverters. Or contactors that are opened and closed.
@Alan
Your batteries tripped or the contactors opened and closed
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Thank you for the reply. I presume you are talking about the BMS contactors? I do know that two of the batteries probably switched off, but they are only 30% of the capacity of the whole system. I can switch them off to test with the remaining batteries.
Yes. Likely the contactors or fets disconnected. Hence the DC bus voltage rise. And the sudden frequency shift to protect everything.