Current transformer

The current transformer (CT) serves to measure alternating current with large values. Together with the voltage transformer, they belong to the class of measuring transformers. Current transformers are used in circuits where the current is too large for direct measurements with ammeters. Through it, the measured current from the network is converted into one with a proportionally smaller value, and thus the current in the circuit is determined with standard measuring devices. The current transformer also galvanically isolates the measuring equipment from any high voltage in the measured circuit. Current transformers are mainly used for current measurement in electric power systems and in their relay protection.