Dear All
Let me list my system out first so there’s no confusion.
My system is grid disconnected (relay) between 5:30am and midnight. MP2's are set to deliver 240v rather than 230v. Currently testing out DESS, but even before this same results.
System: https://betavrm.victronenergy.com/installation/224457/share/db360fff
3 phase set up, 3x MP2 48v10KVA
- With perfect DC wiring and completely balanced busbar
- PV cabling is all 6mm
- 16x Pylon US5000 4.- 8kWh batteries, wired in sets of 2x
- 2x RS450/100 charge controllers (see attached for string layout)
- All of the above using the following panels; 18x JAM72S20 460/MR - Max theory output = 8.280kw
- All of the above using the following panels; 18x JAM72S20 460/MR - Max theory output = 8.280kw
- AC Inverter: Solis S5-GC-30k
- AC solar panels in 3x strings
- All of the above using the following panels; 24x JAM72S-30-555-GR-F30-EVO2 - Max theory output = 13.32kw
- There are Tigo optimisers (TS4-A-O) on all of string 2, 3 and some on string 1 where it's possible to get tree shading (not sure this is even needed). These Tigos are not TAP connected and I have no monitoring (but I will be setting this up soon).
Attached:
- DC panel layout
- AC panel layout
- Wiring diagram
The issue(s):
1) It could be me but 90-95% of the time the AC panels wattage output seems to match the DC panel output, very rarely will is be vastly different.
This seems to be regardless of battery SOC (Noting that frequency shift shuts down AC/DC as needed if when SOC is nearly full)
There appears to no difference to this when AC load is high or low.
The 'AC/DC matching' occurs when frequency is below 50hz
There are times when the AC over-shoots the DC PV system; but only happens for a few minutes in most cases.
Could there be an issue with Frequency shifting causing this apparent sync?
2) On the DC panels, panel 4 can get shading after midday and morning sun; but I wonder would I get better results combining strings 1 and 2 for a higher voltage?
3) Anyone have any AC suggestions for me to get better output?
4) Tigo Optimisers - I've have been watching and reading so many comments/tests. As mentioned above, they are not TAP connected but I've purchased one so will be checking the firmware on the Tigo's to see if there is any buggy firmware present.
Reference 1
Reference 2
Reference 3
5) Tigo Optimisers - I'm unable to determine if they even work correctly with my panel type or not. Again if anyone has suggestions that would be good.
Thank you.
