What is current transformer?

There are various types of transformer such as power transformer, distribution transformer, earthing transformer and current transformer. Among all, the current transformer is relatively small in size and yet widely used in electrical system.

What is current transformer?

A current transformer (CT) is a measurement device designed to provide a current in its secondary coil proportional to the current flowing in its primary.

The current transformer had been created due to difficulties in constructing an ammeter, current coil of wattmeter, energy meters and relays designed to carry the full magnitude of current of higher than 100A of ac current.

Since the accuracy of the output current is the main concerned, some factors like burden, rating factor, physical CT configuration etc are to be designed accordingly to improve the accuracy of current transformer. The co-ordination of these factors is essential for the proper functioning of current transformers.