If a transformer has a delta primary and a wye secondary, what is this transformer called?

A transformer with a delta primary and a wye secondary is referred to as a delta-wye transformer. This type of transformer configuration is common in three-phase systems and serves various purposes such as voltage transformation and phase conversion.

In this setup, the delta connection on the primary side allows for higher current capacity and less voltage drop, while the wye connection on the secondary side facilitates a neutral point, which is useful for grounding and providing a return path for unbalanced loads. This configuration also allows for phase shift, which can be beneficial in certain applications.

The distinction in terms of connections not only influences how voltage and current behave through each side but also impacts overall system stability and performance. Delta-wye transformers are frequently used in power distribution systems to adapt high-voltage transmission to lower voltages for residential or commercial use, ensuring efficient energy transfer and improved reliability.