I am running the Microgen Stirling Engine in an off-grid setup with a MultiPlus 3kW.
The Stirling Engine is a 60Hz-type so I have set the AC out frequency to 60Hz (@230Vrms).
This Stirling Engine has a frequency-operating-range of 60.0 +/- 0.5Hz. Our software has built-in protection: it stops the Stirling Engine when the grid-frequency goes outside these limits for more than 1 second.
We have quite a number of commercial setups with Victron MulitPlus's out there, all set up to 50Hz, all working fine.
But, when set up to 60Hz, a customer and I too, see unexpected frequency-jumps when the Stirling Engine is running. When this happens, the Stirling Engine stops and there is an error reported by the software. I have seen this error also appear in a system in my lab when the Stirling Engine is not running. There is nothing going on in these systems that would warrant frequency-jumps: there are no large loads being switched that could cause a frequency-jump.
Could there be a bug in the inverter software that only shows when set to 60Hz?