What type of transformer bank is described if it is a delta-connected bank?

A delta-connected transformer bank is characterized by its three transformers connected in a triangular configuration, where each transformer is connected to two others, forming a closed loop. This connection allows for certain beneficial properties, such as the capacity to handle higher loads and the ability to provide phase-to-phase voltage outputs that are higher than those seen in wye configurations.

In a delta-delta transformer bank, the primary and secondary windings are both connected in a delta formation. This arrangement supports balanced three-phase loads and can also provide lower current ratings on the primary side, which can enhance efficiency when dealing with variable loads. Additionally, a delta connection allows for the elimination of harmonic currents and helps in improving the stability of the system.

The other options present different configurations: star-star (wye-wye) connections would involve both primary and secondary windings being connected in a wye configuration, which behaves differently compared to delta connections. Delta-wye and wye-delta connections involve different configurations that serve specific purposes, particularly in balancing loads and managing phase shifts.

Choosing the delta-delta configuration aligns effectively with the definition of a delta-connected transformer bank, providing advantages in efficiency and load handling.