Phase transformation can be accomplished by the use of:

Phase transformation refers to the process of changing the number of phases in an electrical system. Conventional transformers are designed specifically for this purpose, as they can step voltage up or down across different phases using magnetic coupling between windings. When an alternating current (AC) passes through the primary winding, it generates a magnetic field, which induces a voltage in the secondary winding. This allows for adjustments in voltage levels while simultaneously transforming the phase characteristics of the system.

The concept of phase transformation is particularly critical in AC systems where different applications may require different phase configurations. Conventional transformers can facilitate transformation from single-phase to three-phase systems or vice versa, depending on how they are constructed and connected. This functionality is a fundamental aspect of electric power distribution and is essential for optimizing the efficiency and reliability of electrical systems.

Other options, like inverters and rectifiers, serve different purposes such as converting DC to AC or altering the form of current rather than changing the phase directly. Switchgear, on the other hand, is primarily concerned with controlling and protecting electrical circuits, rather than performing phase transformation. Therefore, the conventional transformer stands out as the essential device specifically used for phase transformation in electrical systems.