I am busy with an off-grid installation that has a Goodwe GW15KN-DT PV inverter on AC-Out of a set of Quattros. The PV Inverter assistant is configured and frequency shifting works as expected as the battery approaches full. The Goodwe is supposed to be VDE4105 compliant and the suppliers assured me before purchase that it was able to reduce power in response to frequency shifts. In practice the Goodwe does not respond appropriately to the increases in frequency. It does cut-off once the threshold for frequency error is crossed. But it does not throttle back for lower frequency increases.
A long period of troubleshooting with the suppliers and including Goodwe HQ has not produced results beyond establishing there is a problem and that a firmware fix is somewhere in the pipeline. They are not able to provide any information on when this may be.
In the meantime the Goodwe and it's array sit idle!
Would it be possible to implement the export limiting function in the Goodwe such that it will not export back in to AC-Out on the Quattros and only follow the loads on the distribution side? i.e. the CT clamp is positioned between the PV Inverter and the Quattros.
I understand that if this is not 'a very bad idea' for technical reasons then the Goodwe would not contribute to battery charging. This would be acceptable at least until a more robust solution is devised by Goodwe.