The iron core is an important part of the power transformer. It undertakes the important tasks of conducting magnetic flux, reducing losses, and improving the efficiency of the transformer. During the working process of the transformer, the processing method of the core has a direct impact on its performance. Generally speaking, the core processing methods can be mainly divided into two categories: punched cores and wound cores. Each processing method has its applicable materials, process characteristics and application scope.

Punch core is a common core processing method, suitable for materials with steel plate (strip) thickness above 0.1mm. The processing process is mainly completed through the stamping process. The process is simple, high-efficiency, basically no waste, and the cost is relatively low. Stamped iron cores are widely used in fields such as low-power power transformers and audio transformers.

In particular, the EI type shell punched core has been widely used in power transformers. Due to the small size of the EI type punched core, the shear stress has a greater impact on the performance of the core material. In the magnetic circuit of the EI type core, a part is perpendicular to the orientation direction of the steel plate (strip). When processed with oriented silicon steel plate (strip), the magnetic properties will be reduced due to the influence of anisotropy.

Wound core is another common core processing method, which is made by continuously winding a steel strip of a certain width or a variable width on a suitably shaped core. During the processing of the wound core, the orientation direction of the steel strip is completely consistent with the direction of the magnetic flux, so the performance of the core material can be fully utilized.

The introduction of various high-performance oriented silicon steel strips has made the application of wound cores in power transformers increasingly widespread. These silicon steel strips have excellent properties such as low hysteresis loss, low eddy current loss and high magnetic permeability, which can significantly improve the efficiency and performance of the transformer. Therefore, wound cores have become an important choice in power transformer design, bringing higher energy utilization and more reliable power transmission systems. These high-performance oriented silicon steel strips not only have lower hysteresis loss and eddy current loss, but also have higher magnetic permeability and permeability coefficient, which can significantly improve the efficiency and performance of the transformer.

Stamped cores and wound cores are two common core processing methods. They each have their own advantages and disadvantages and are suitable for different application scenarios. When selecting a core processing method, factors such as material characteristics, process requirements, cost-effectiveness, etc. need to be comprehensively considered to ensure that the final product has excellent performance and stable quality.