三相变压器的不对称运行问题分析与研究

以＂Y,y_n＂连接的三相变压器在三相电源对称时三相负载不对称情况下的运行为例,讨论了有零序分量时三相变压器的不对称运行;以各序等效电路为基础,利用对称分量法及叠加原理对此做了详细的分析,推导出计算三相变压器原、副边相电流的表达式,并且利用相量图来说明原、副边电流的关系以及不对称运行产生中点浮动对选择三相变压器结构的影响。

Analysis and Research of Three-phase Transformer Asymmetric Operation Problem

When three-phase power supply is symmetrical and three-phase load is asymmetric, taking the operation of the three- phase transformer with the connection of ＂Y,yo＂ as an example, this paper discusses the asymmetric operation of the three-phase transformer with zero sequence components. Based on each sequence equivalent circuit, the expression of the original and deputy edge phase current in the three-phase transformer is deduced by using symmetrical component method and superposition principle. The paper discusses the relationship between the original and deputy edge phase current, and also explains the effect of midpoint floating caused by the asymmetric operation on the three-phase transformer structure using phasor diagram.