For what purpose is a current transformer specifically used?

A current transformer is specifically designed to reduce high current levels to a lower, manageable amount, which can then be measured and monitored safely. This is especially important because many electrical systems operate at high currents that are too large to be directly measured by standard meters or instrumentation. By stepping down the current, the transformer allows for accurate metering and protection without the need for direct connection to the high-current circuits.

In the context of electrical systems, the primary function of current transformers is to provide a scaled down replica of the line current for measurement by meters and for use in protective relaying. This ensures the safety of the equipment and personnel while facilitating precise monitoring of current flow within the electrical distribution system.

The other purposes mentioned, such as voltage regulation, current interruption, and grounding, relate to different components or processes in electrical systems and do not pertain specifically to the function of a current transformer.