箔式绕组双分裂变压器损耗异常分析

Analysis of Loss Anomalies in Foil-winding Double-split Transformers

本文所讨论的是一台采用箔式绕组的双分裂变压器,在分裂运行试验下负载损耗远大于计算值。对分裂运行负载损耗偏大的原因进行了分析并进行了磁场仿真,发现分裂运行时箔式绕组中电流分布严重不均匀。在两个箔式绕组相对应的端部,电流密度达到平均电流密度的近40倍,导致箔式绕组中损耗大大超过计算值。将低压绕组改为纸包扁线绕制,分裂运行的负载损耗得到明显下降,与计算值预期相符,说明在某些情况下,轴向双分裂变压器的低压绕组不适宜采用箔式绕组。

This paper discusses a double-split transformer with foil-windings,and the load loss under the split operation test is much larger than the calculated value.The reasons for the high load loss in split operation are analyzed and magnetic field simulation is carried out,and it is found that the current distribution in the foil-winding is very uneven in split operation.At the opposite ends of the two foil-windings,the current density reaches nearly 40 times of the average current density,resulting in the loss in the foil-winding greatly exceeding the calculated value.By changing the low-voltage windings to flat wire windings,the load losses in split operation are significantly reduced,which corresponds to the calculated values as expected,indicating that in some cases foil-windings are not suitable for the low-voltage windings of axial double-split transformers.