Introduction to current transformers

A current transformer is an instrument that converts a large current on the primary side into a small current on the secondary side for measurement based on the principle of electromagnetic induction. A current transformer consists of a closed iron core and windings. Its primary side winding has few turns and is connected in the line of the current to be measured.

Therefore, it often has all the current of the line flowing through it, and the secondary winding has a large number of turns. It is connected in series in the measuring instrument and the protection circuit. When the current transformer is working, its secondary circuit is always closed, so the measurement The impedance of the series coil of the instrument and the protection circuit is very small, and the working state of the current transformer is close to a short circuit. The current transformer is to convert the large current on the primary side into a small current on the secondary side for measurement, and the secondary side cannot be opened.