Wye-Wye transformers, also known as Star-Star transformers or Y-Y transformers, are another type of transformer configuration commonly used in three-phase electrical systems. In this configuration, both the primary and secondary windings are connected in a Wye or Star arrangement.
The primary and secondary voltages of a Wye-Wye transformer have the same phase shift, making it a no-phase-shift transformer. The voltage ratio between the primary and secondary sides remains the same as in other transformer configurations.
One drawback of the Wye-Wye transformer configuration is that it does not provide a path for zero-sequence currents (unbalanced currents) to flow on the primary side, which might lead to some challenges in mitigating certain unbalanced load conditions. However, in most applications, this is not a significant issue.
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