特高压换流变压器支撑件的直流偏磁损耗计算

Eddy Current Loss Calculation of Supporting Parts of UHV Converter Transformer under DC Bias

根据抑制特高压换流变压器直流偏磁原因温升的需求,提出研究换流变压器铁芯钢质支撑件直流偏磁损耗的计算方法,为设计与制造抑制温升提供依据。根据换流变压器的短路阻抗大以及拉板、夹件结构的设计特点,采用Ansoft Maxwell仿真软件,建立了包括铁芯和油箱、拉板等支撑件的三维有限元模型,考虑短路阻抗和拉板、夹件等因素的影响,完成了励磁电流、涡流场分布及涡流损耗效应的计算。结果表明,与普通变压器相比,换流变压器直流偏磁油箱及铜屏蔽的涡流损耗增加得较快,以及铁芯拉板的开槽方式,也会造成拉板涡流损耗增大。

Based on the requirement of suppressing the tem. perature rise of UHV converter transformer caused by dc bias,a calculation method of eddy current loss of the transformer sup. porting parts is proposed in this paper,which can provide a ba. sis for the design and manufacturing to reduce the temperature rise. Considering the large short circuit impedance and special structure of the flitch plate,we established a 3D finite element model containing the iron core,oil tank and other supporting parts based on Ansoft Maxwell and Simplorer,and obtained both the excitation current and eddy current loss for the UHV converter transformer. The results show that the eddy current loss of oil tank and its shield for converter transformer increase more quickly compared with the normal transformer,and the loss of flitch plate is also higher due to its special structure.