GS 12kw has a 60v tap

[dickson]

Will a 72 volt lithium-ion  battery   syatem  work on a 60v tap transformer of the GS 12kw  and the max will be 80vdc  ?      My  48 volt  system  max out at  64vdc  on a ASL9,0  PJ transformer .    The  PJ  10.3  controlboard will blow up the FETs at 65 vdc  but the  11.1  control board  will  not let the inverter to  even start  but  shut down  if  the MPPT charge over 65vdc  .     PJ  no longer  sell the  good  11.1  control board  and  replace with the 11.3  control board  .    The 11.3 control board will blow up the FETs on all older PJ inverter and need the mainboard  cable modify by the  seller  so be careful  if trying to make older PJ inverter to work .   

[Sid Genetry Solar]

72v is not 60v...if you have a 72v nominal battery bank (= 20S Li-Ion or 24S LiFePo4), the "full charge" voltage will be 84-86v, which is too high.

The 80v limit is an absolute limit--if it's exceeded for even a spike, the power chips tend to blow out.  Main FET caps are 80v...and for that matter, the fans are rated to a maximum of 75v anyway.

So while the 12kw GS has the transformer ability for a 60v system, that's not 72v.

[dickson]

So while the 12kw GS has the transformer ability for a 60v system, that's not 72v.

The primary for the GS 12kw is 32vac  for 48vdc battery system     Will the 60v system  also has the primary at 32vac ?     A 72v or 96v battery system will need a different transformer  as there is no room for a separate  winding .      Look like  impossible  and need  a complete  re-design  to do 96vdc system .      Thank you .  

[Sid Genetry Solar]

1 hour ago, dickson said:

Will the 60v system  also has the primary at 32vac ?

No.  The 30v primary configuration is ideal for 48v usage.

60v "tap" configuration is 37.5v, providing a minimum pure sine voltage of 53vDC.  (The "60v" config is actually a byproduct of 36v support.)

 

96v would be possible with the exact same transformer and size, though it would need a different winding spec (twice the turns, half the strand count).  As a result, transformer losses will be exactly the same at 96v as at 48v.

but 96v would require 200v FETs (which have a considerably increased RdsOn), different DC filter caps (rated to 150 or 200v), and a 96v -> 48v step down converter to power the fans and logic.  Due to the increased FET slew rate (resulting from the doubled DC bus voltage), the Miller spikes will be a lot worse--which may necessitate redesigning the FET gate drive circuitry to force the FET gates negative in off state.

[NotMario]

I see lots of inverters for higher voltages like that in the industrial market.. At which point 130v is pretty common [substations], and then 480v, which then you're talking about 3-phase.
Almost no overlap with the off-grid community. Can't say i see much reason it would be worth the design investment - unless you want to make industrial inverters... haha

Edited September 19, 2022 by NotMario

[Sid Genetry Solar]

I have no interest in going into higher and higher DC voltages...simply because the safety risk goes up exponentially.  There's a reason UL requirements top at 50v nominal.  Besides, if you're getting into voltages that high, you might as well go HF.  (EDIT: UL permits higher DC voltages, but the rules get considerably more difficult to follow.)

60v is simply an unexpected side effect of supporting 36v--which to my knowledge no other established LF inverter manufacturer does.  Yes, we don't sell too many of them--but we have sold a decent number.  They're especially valuable to people trying to utilize EV battery packs, which often are at weird voltages that don't fit into 24v or 48v brackets.

[dickson]

60v "tap" configuration is 37.5v, providing a minimum pure sine voltage of 53vDC.  (The "60v" config is actually a byproduct of 36v support.)      They're especially valuable to people trying to utilize EV battery packs, which often are at weird voltages that don't fit into 24v or 48v brackets.

MY  16s  lithium-ion  ev battery will work with  your 60vdc  GS12 kw ?    Is  80vdc  the maximun for OVP ?   Do Sean  sell  the 60vdc GS 12kw  now after the pre-order ?  

[Sid Genetry Solar]

13 minutes ago, dickson said:

Is  80vdc  the maximun for OVP ?

80vDC is the red line, the cliff's edge, the absolute max before the inverter will likely fail.  EDIT: and that's with the power switch turned off.

A reasonably safe maximum would be 72v.

 

16S Li-Ion at full charge would be 67.2v, which is well within the safe range.  (16S nominal voltage is 57.6v)

[dickson]

A reasonably safe maximum would be 72v.

Thank you .    Is  the inverter  wired for  60vdc  done by Sean  or are all inverter wired 48vdc in China ?     

[dickson]

 The 30v primary configuration is ideal for 48v usage.

Sean  youtube   answer all the questions about the 60vdc  so 48vdc  is better  .  

[Sid Genetry Solar]

11 hours ago, dickson said:

Thank you .    Is  the inverter  wired for  60vdc  done by Sean  or are all inverter wired 48vdc in China ?

All final wiring is done by Sean.