I’m currently in the planning phase of building a 3-phase Energy Storage System (ESS), using 3 x Multiplus II units, Pylontech batteries, a Cerbo GX, and more.
Recently, we experienced a grid fault where one phase went down.
This got me wondering: what happens to the ESS system if one of the phases fails?
Will the entire 3-phase ESS shut down, or will the remaining two phases continue to operate?
This is important to know, as I may need to implement protection for the ESS against such scenarios.
If one of the phases from the grid fails, the system will switch to off-grid mode and continue to supply 3 phases to connected loads. This is assuming the grid is connected to the AC input and loads to AC output.
If one of the units fail, the other 2 units will go into an error state (and power to loads would stop on all 3 phases).