Which connection types are used in a 3-phase system?

The correct answer is based on the commonly recognized connection types used in 3-phase systems. In three-phase electrical systems, the predominant configurations utilized for connecting the windings of transformers and generators are the Y (star) and Δ (delta) connections.

The Y (star) connection provides advantages such as having a neutral point, which can help in grounding and allows for the connection of single-phase loads alongside three-phase loads. It is characterized by one terminal of each phase winding being connected to form a common point, while the other terminals are connected to the load.

The Δ (delta) connection, on the other hand, connects the end of each phase winding to the beginning of the next, creating a closed loop. This connection type is advantageous for its ability to handle higher loads and provide better voltage stability under heavy loads since each phase directly benefits from the voltages of the other phases.

In some specific applications, the Z (zig-zag) connection is also used. However, it is less common than the star and delta connections and is primarily for grounding purposes or for the creation of specific phase shifts in voltage.

Therefore, the inclusion of Y and Δ in the response emphasizes the main types of connections found in most three-phase systems. The other options