电力变压器铁心硅钢片振动与微观变形特性研究

Vibration and Microscopic Deformation Characteristics of Silicon Steel Sheet of Power Transformer Core

电力变压器本体噪声主要来源于铁心硅钢片的磁致伸缩产生的振动。依据实际50 MVA/110 kV变压器铁心结构,搭建了四角铁心模型,研究了变压器铁心不同区域,不同方向的振动情况以及铁心硅钢片磁致伸缩机理。结果表明:硅钢片中心区域的振动值明显小于硅钢片接缝区域的数值,平行方向振动值小于垂直方向;在硅钢片中心区域,垂直方向上振动峰值频率主要出现在100、200、300、400 Hz等频段,平行方向上为100、200、600 Hz等频段;在硅钢片接缝区域,垂直方向上振动峰值频率主要出现在100、200、300、500 Hz等频段;平行方向上为100、200、300、600,700 Hz等频段;铁心硅钢片在施加磁场后的平面中心区域与接缝区域磁致伸缩均由晶界移动、晶粒变形和转动行为引发。

The noise of power transformer is mainly caused by magnetostriction of its core silicon steel. According to the actual structure of 50 MVA/110 kV transformer core,an equivalent four-angle core model is constructed to investigate the vibration of different areas and directions of the transformer core as well as the magnetostriction mechanism of the core’s silicon steel sheet. The results show that the vibration of the central region of the silicon steel sheet is significantly less than the joint region,and the vibration in parallel direction is less than that in vertical direction. In the central region of silicon steel sheet,the peak frequency of vibration in vertical direction mainly appears in the frequency bands 100,200,300,and 400 Hz,while in parallel direction it appears in the bands 100,200,and 600 Hz.In the joint area of silicon steel sheet,the peak frequency of vibration in vertical direction mainly appears in the frequency bands 100,200,300,and 500 Hz,while in parallel direction,it appears in100,200,300,600 and 700 Hz.The magnetostriction in plane center area and joint area of the silicon steel sheet with magnetic field applied is caused by grain boundary movement,grain deformation and rotation.