Current transformers have probably been heard, it is a commonly used device. The function is to convert a large current with a larger value into a secondary current with a smaller value for protection, measurement and the like. For a current transformer with a ratio of 400/5, the actual current of 400A can be converted into a current of 5A.
So what principle does this current transformer work on?
The principle of current transformer is based on the principle of electromagnetic induction. The current transformer consists of a closed core and a winding. Its primary side winding has few turns and is strung in the line of current that needs to be measured. Therefore, it often has a full current flowing through the line, and the number of turns on the secondary side is relatively large, which is connected in series to the measurement appearance and maintenance circuit. When the current transformer is in operation, its secondary circuit is always closed, so the impedance of the series coil of the measuring external and maintenance circuit is small, and the working state of the current transformer is close to short circuit. The current transformer is used to convert the primary side large current into the secondary side small current, and the secondary side does not open.