It seems like you're referring to the concept of a "Star-Star Connection" in the context of transformers. However, as of my last update in September 2021, I'm not aware of any specific technical or engineering term called "Star-Star Connection" related to transformers. Transformers are devices used to transfer electrical energy between two or more circuits through electromagnetic induction.
If you could provide more context or details about what you're referring to, I'd be happy to help you understand or provide information to the best of my knowledge. If this concept has emerged after my last update, I might not have information about it. Please feel free to provide more information or ask about any other topic!