Transformer

An inductive transformer is a device used for the measurement and protection purposes in a power system. It is an instrument transformer that is designed to provide a scaled-down replica of the voltage in a High Voltage (HV) line and isolate the measuring instruments [1], meters, and relays from the high voltage of the power system. The transformer’s secondary winding is usually connected to a measuring instrument, such as a voltmeter or an ammeter, to provide an accurate reading of the voltage or current in the HV line. The inductive transformer is also used for relaying purposes, where it provides signals to protective relays that isolate faulty line sections of the power system. The basic working principle of an inductive transformer is based on Faraday’s law of electromagnetic induction, which states that an electromotive force (EMF) is induced in a conductor when exposed to a varying magnetic field.

References:

[1] https://www.arteche.com/en/high-voltage-inductive-voltage-transformers