The principle of current transformer is based on the principle of electromagnetic induction. The current transformer is composed of a closed core and windings. Its primary winding has very few turns, which is stringed in the line of the current that needs to be measured. Therefore, it often has all the current flowing through the line. The secondary winding has a relatively large number of turns. It is serially connected to the measuring instrument and the protection circuit, and the current mutual inductance When the transformer is working, its secondary loop is always closed, so the impedance of the series coil of the measuring instrument and the protection loop is very small, and the working state of the current transformer is close to short-circuit.
The function of the current transformer is to convert the primary current with a larger value into a secondary current with a smaller value through a certain transformation ratio, which is used for protection, measurement and other purposes. For example, a current transformer with a transformation ratio of 400/5 can convert an actual current of 400A into a current of 5A.
There are two types of iron cores for current transformers: laminated square iron cores and round iron cores. The advantage of the former is that the coil is easy to wind and install, but the disadvantage is that there is an air gap in the magnetic circuit of the iron core, the magnetic performance is poor, the magnetic leakage of the coil is large, and the lamination is more troublesome. The advantage of the latter is that the structure has no air gap and the magnetic performance is good, but the disadvantage is that it is difficult to wind the coil.
current transformer core
The function of the current transformer is to convert the primary current with a larger value into a secondary current with a smaller value through a certain transformation ratio, which is used for protection, measurement and other purposes. For example, a current transformer with a transformation ratio of 400/5 can convert an actual current of 400A into a current of 5A.
There are two types of iron cores for current transformers: laminated square iron cores and round iron cores. The advantage of the former is that the coil is easy to wind and install, but the disadvantage is that there is an air gap in the magnetic circuit of the iron core, the magnetic performance is poor, the magnetic leakage of the coil is large, and the lamination is more troublesome. The advantage of the latter is that the structure has no air gap and the magnetic performance is good, but the disadvantage is that it is difficult to wind the coil.
current transformer core