When stacking transformer cores, there are three different seam methods. One is direct seam, which is characterized by convenient processing and stacking, large overlap area, and therefore the stacked core structure has good strength, strong integrity, and is not easily deformed. However, it can only be used for hot-rolled silicon steel sheets. If used for cold-rolled oriented silicon steel sheets with good magnetic properties along the rolling direction, the magnetic flux at the joint does not pass along the rolling direction, resulting in a deterioration of magnetic properties and an increase in no-load losses.

Another type is semi straight and semi oblique joint, used for cold-rolled oriented silicon steel sheets. The characteristic of this type of joint is that direct and oblique joints are replaced in the core laminations. When the width of the core column piece and the iron yoke piece are the same, the oblique joint has a 45 ° overlap area accounting for 50% of the corner. The magnetic performance is significantly improved compared to direct joint, the structure is reliable, and the cutting and stacking are also convenient. The utilization rate of silicon steel sheets is high. However, due to the fact that there are still some direct seams that do not fully utilize the directionality of cold-rolled oriented silicon steel sheets, the no-load loss of the iron core cannot be reduced to a very small level.

Another type is full oblique joint. In order to further reduce the no-load loss of the iron core and fully utilize the characteristics of cold-rolled oriented silicon steel sheets, full oblique joint should be used. This can align the direction of magnetic flux with the rolling direction of the silicon steel sheets, resulting in minimal iron core loss. But this joint process is complex, and the overall integrity of the stacked iron core is poor.

Article source: Transformer silicon steel sheethttp://www.cheungshun.com/