Wind inverters

[Raul Castagnino]

Does anybody know if Aurora and Sunny Boy wind inverters can be ordered or configured for a three phase network? If so, would they be much more expensive?

[Rob Beckers]

Hi Raul,

First, to state the obvious, you can run 3-phase by using 3 single-phase inverters (each feeding one phase). In case of the Power-One Aurora inverters you'll also have to add an isolation transformer to two of the three inverters.

Power-One makes 50kW 3-phase wind inverters as well. Those are available (with some caveats). There should be 10kW 3-phase wind inverters early next year too.

-RoB-

[Jim White]

Hi Rob,
Regarding connection of Aurora inverters to a 3-phase supply. I appreciate that in theory you should only require two isolation transformers for the three inverters, but I have heard of the "Master" (without the TFX) having a lot of GFI trips. It was cued by adding a third isolation TFX. Also, the P1 documentation for connecting to three phase shows either a three phase isolation transformer or three seperate transformers. Do you have any further experience?

[Rob Beckers]

Jim, you're correct that there are many cases where the un-isolated inverter is throwing ground faults. To the best of my knowledge they're real though, and often caused by things like turbine's controller leaking to ground (in particular, with a number of Chinese turbines we found that the controller's power supply was the cause, putting a small transformer in line with that would solve it). In any event, this has gotten to the point where I now usually tell people not to bother with saving the extra transformer, and just put one in with every inverter (or use a 3-phase isolation transformer and put the inverters on each leg). It's not worth the time and aggravation of chasing down illusive ground faults to save on a transformer.

Raul, Power-One now has 10kW 3-phase isolated wind inverters available. Those can be stacked without transformers.

-RoB-