Which type of connections are more common for transformer primaries?

In electrical engineering, transformer connections refer to how the windings of a transformer are configured. For transformer primaries, the delta connection is particularly common, especially when discussing larger transformers used in industrial applications.

The delta configuration allows for several benefits that make it suitable for transformer primaries. One of the main advantages is that it facilitates the handling of three-phase power systems effectively. In a delta connection, each winding is connected end-to-end to form a closed loop, which helps balance the load across the phases, leading to improved system stability and reliability. Furthermore, the delta configuration helps in reducing the phase voltage across each winding, allowing them to share the voltage drop equally when heavy loads are present.

Additionally, delta-connected transformers can provide a path for third harmonic currents to circulate within the delta loop, which can minimize interference with other equipment in the power system. This is particularly beneficial when transformers are used in conjunction with non-linear loads that produce harmonics.

While other configurations like star (or wye) connections also have their uses—such as providing a neutral point or handling unbalanced loads—a delta connection is more common for transformer primaries in three-phase power systems, especially in industrial settings.