How can I manage to feed in excess solar power during absorption phase as well?
- Octo GX
- 3 pcs MultiPlus-II (3 phase connection)
- 3 pcs DC Coupled MPPT Solar charge controller
- 2 pcs AC inverters from SMA connected to the UPS side of the MultiPlus each per one phase (L2 and L3) but not yet measured with energy meter.
- 48V lead GEL battery
how the system behaves, see image below
- battery is in absorption, so DC voltage constantly 57.5V in this phase
- AC power from SMA inverters on L2 and L3 is used to charge the battery
- excess AC coupled PV power is feed to the grid so far so good
- but DC coupled PV charger power is drastically reduced in order not to exceed 57.5V (in the image below reduced to 236W but often to as low as around 50W)
- The available DC coupled PV power at the time would have been around 1.5kW
- As soon as absorption phase is completed the DC coupled PV power goes up to the maximum as per solar input and the system starts feeding excess solar power to the grid.
- see second image as well, this was an overall clear and sunny day. so no need to reduce solar pv power on lunch time. should be a "nice" daily full power PV curve.
- DVCC enabled
- SVS enabled
- STS enabled
- feed in excess solar power enabled
- battery monitor is MultiPlusII on VE Bus