The big function of miniature transformer and its core form

Miniature transformer is a collective term for current transformer and voltage transformer. It can turn high voltage into low voltage and large current into small current, which can be used for measurement or maintenance system. Its function is mainly to convert high voltage or high current into standard low voltage or standard small current according to the share, so as to complete the standardization and miniaturization of measuring appearance, maintenance equipment and automatic control equipment. Miniature transformers can also be used to isolate high-voltage systems to ensure the safety of people and equipment.

In order to transmit electric energy, the electric power system often uses communication voltage and high-current loops to send electric power to users, which cannot be directly measured by appearance. The effect of the miniature transformer is to reduce the communication voltage and high current to a value that can be directly measured by the surface according to the share, which is convenient for direct measurement by the surface, and provides power for relay maintenance and automatic equipment.

In order to improve the accuracy of the miniature transformer, the fault of the current transformer is generally compensated. In this way, in addition to the above-mentioned primary and secondary windings and cores, some also wind auxiliary coils or participate in auxiliary cores. Its core has two types: square and circular.

Square, also laminated. A square core is formed by stacking silicon steel sheets one by one. The advantage of this kind of iron core is that it is convenient to wind the coil. The winding can be wound on the machine in advance and then put on the silicon steel sheet iron core to become a winding; the defect is that there is an air gap between the iron cores, the magnetic function is low, and the winding magnetic leakage is large. Moreover, the lamination and the device are both more troublesome.

At the beginning of the toroidal iron core, silicon steel sheets are used to punch them into rings and stacked one by one. Now, most of them are directly wound with silicon steel strips. The advantage of this kind of iron core is that there is no air gap, the magnetic function is high, and the winding is also very convenient. If the winding is evenly wound, the leakage flux is very small. Therefore, fine current transformers of class 0.2 and above are selected for this kind of band-wound core. Its defect is that it is difficult to wind the winding, especially the winding of thick wire, and it is not easy to complete the mechanized winding.