What is the main function of a voltage transformer (VT)?

The main function of a voltage transformer (VT) is to reduce high line voltage to a proportionally lower voltage. This is crucial for various applications, especially in electrical systems where high voltages need to be measured or monitored safely. By stepping down the voltage, VTs allow for accurate voltage readings and safe operation of measurement equipment without the risk of exposure to high voltages.

In addition to ensuring safety, this reduced voltage also allows for easier handling and integration into control and protection systems. Lower voltage levels are manageable for devices such as meters and relays, which would be damaged by high line voltages.

Other options do not align with the primary role of a VT. Raising voltage is not a function of a voltage transformer, and serving as a primary winding or increasing power factor describes functions associated with different types of transformers or electrical devices. Therefore, the correct understanding of a voltage transformer's function lies in its capability to safely and effectively reduce voltage.