The structural principle and performance influencing factors of transformer cores

The core is one of the key components of a transformer. Its main function is to conduct magnetic flux. As the main magnetic circuit of the transformer, it converts the electrical energy from the primary circuit into magnetic energy, and then transforms the magnetic energy into electrical energy for the secondary circuit. At the same time, it serves as the mechanical framework of the transformer, supporting all internal components such as windings and leads. Its performance directly affects the operating efficiency and stability of the transformer. 

The transformer core is composed of two parts: the core column and the yoke. The windings are wound on the core column, and the yoke connects the core column to form a closed magnetic circuit. A single-phase transformer has two core columns, while a three-phase transformer has three core columns. Since the magnetic flux in the core is an alternating magnetic flux, in order to reduce eddy current losses, the core is usually made of silicon steel sheets with a high resistivity. The silicon steel sheets are first cut into the required shapes as laminations, and then combined in an overlapping manner to ensure that the joints of each layer of the magnetic circuit are staggered, thus preventing eddy currents from flowing between the steel sheets. 

The factors influencing the performance of the iron core mainly include material selection, structural design and manufacturing process. In terms of materials, the quality, thickness and resistivity of silicon steel sheets directly affect the loss of the iron core. Cold-rolled grain-oriented silicon steel sheets can effectively reduce hysteresis loss and eddy current loss. In terms of structural design, the lamination method of the iron core, the setting of air passages or oil passages, affect the heat dissipation effect and magnetic conductivity of the iron core. Reasonable structural design can improve the heat dissipation efficiency of the iron core and reduce heat accumulation. In terms of manufacturing process, the accuracy of the laminations, the tightness of the laminations, and the control of clamping force, will affect the continuity of the magnetic circuit and mechanical strength of the iron core, and thereby affect the overall performance of the transformer. 

In practical applications, it is necessary to select the appropriate core material and structural design based on the type, capacity and usage scenario of the transformer, strictly control the manufacturing process, and ensure that the core performance meets the standards, thereby guaranteeing the stability and operation of the transformer.