I want to build in simulink a specific circuit that includes an asyncronous machine (DFIG) connected to the grid. I have saw some examples on the internet and in most of them, it's used buses like the one pointed by the red arrow in the image bellow. My question is, why use these buses instead of a straight connection? What would be the difference if the bus "B_stator" was erased? What is the name of this bus?