What is a potential transformer (PT) used for?

A potential transformer (PT) is specifically designed to step down high voltages to a lower, more manageable level for measurement purposes. This is particularly important in electrical systems where high voltage can be hazardous and difficult to measure directly. By stepping down the voltage, the PT provides a safe and accurate way to monitor voltage levels for system diagnostics, control, and protection. The measured lower voltage can then be utilized by instrumentation and protective relays without exposing them to the dangers of high voltage.

The design and function of a PT inherently focus on voltage transformation rather than altering current levels, providing backup power, or converting alternating current to direct current. These other options involve different devices or functions not aligned with the primary role of a potential transformer.