Delta Inverter ( Source ) to a TT Grid

[ShadiGhabboun]

Hi All

I was wondering what are the limitation regarding the connection of a Delta Connected Inverter ( SMA STP60-10 ) to a TT Grid?

the datasheet and design sheet for the inverter states that it is a Balanced Delta Source with only 3 phase terminals and a PE terminal ,but the electrical company here has some concerns about the reference point since the reference is the neutral line and this inverter does not have one.

so does produce a problem or any concern at all ?

sorry for the long post and thanks alot

 

[waross]

You can use three dry type lighting transformers in a wye delta configuration to generate an artificial neutral.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ShadiGhabboun]

Thanks for your reply waross

i know that it is possible to use a wye delta transformer but i wanted to know what is the problem or the consequences of connecting the delta to the TT Grid.

thanks

 

[waross]

I would expect that the delta inverter will contribute to the positive sequence loads but that the grid will be the sole supply of the zero sequence component.
I may be wrong. Wait for other posters to confirm this.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[pwrtran]

Any type of transformer can be use as the utility-DG interconnection transformer. Grounded Wye as the primary on utility side cause desensitize L-G protection if the utility source is weak. Delta on utility side will cause TOV concern on unfaulted phases. Either high current contribution or high voltage contribution, one or the other.