基于漏磁补偿的变压器结构件损耗与磁通分布研究

Research of Structure Loss and Flux Distribution of Transformer Based on Leakage Flux Compensator

为研究电力变压器内部由导磁钢板和取向硅钢片组成的屏蔽构件在漏磁场激励下的电磁性能,提出并设计了基于漏磁补偿的试验模型,考察了不同磁屏蔽结构中的杂散损耗和磁通分布。通过试验研究和数值计算获得了电力变压器不同类型屏蔽结构中的杂散损耗和磁通密度分布情况,并进行了对比分析。提出了采用等效均匀化磁导率、电导率处理方法计算电力变压器磁屏蔽构件杂散损耗的实用措施。在不同激励条件下,测量得到的损耗结果和仿真结果具有很好的一致性,说明了提出的结构件杂散损耗试验研究和仿真分析方法的有效性。试验和仿真结果同时表明:在相同的漏磁通激励条件下,立式磁屏蔽相对平式磁屏蔽的损耗值更低,以磁屏蔽中心工作磁通密度1.5 T为例,立式磁屏蔽的损耗约为平式磁屏蔽损耗的20%左右。

Normally the shielding structural parts in transformer are composed of magnetic steel plates and grain-oriented silicon steel. In order to study their electromagnetic properties, we developed a test model with leakage flux compensation, by which we obtained the distribution of iron loss and magnetic flux. The stray loss and flux of different typed shunts were also obtained experimentally, and then were compared with their calculated counterparts. Then we proposed some practical engineering-oriented approaches to solve the problems of stray loss, including the homogenization of magnetic and electric conductivities. All the calculated and measured results of the iron loss and magnetic flux for different magnetic shunts are in good agreement, showing that the loss of the vertical magnetic shielding is much lower than that of the flat-type magnetic shielding, e.g., when the work magnetic flux density is 1.5 T, the loss of the vertical magnetic shielding is about 20% of that of the flat-type magnetic shielding.