Which transformer configuration is used when a neutral point is required?

The configuration that provides a neutral point is the Wye connection. In a Wye configuration, each of the three phases is connected to a common neutral point, which allows for the safe grounding of the system and provides a reference point. This neutral point can be particularly important for systems that require single-phase loads, as it allows for balanced load conditions and can support both three-phase and single-phase loads simultaneously.

Additionally, having a neutral point is helpful for protecting the system and maintaining voltage stability; it enables conditions like phase-to-ground fault detection. In contrast, Delta configurations do not have a neutral point since the phases form a closed loop, which is advantageous for certain applications but does not provide the grounding options that a Wye configuration allows.

Other configurations like split-phase typically refer to specific two-wire systems common in residential settings, mainly not designed for three-phase applications. Parallel typically refers to the arrangement of transformers or circuits rather than a specific transformer configuration providing a neutral. Thus, the Wye configuration is indeed the optimal choice when a neutral point is required.