摘要
三相变四相电力变压器是一种新型平衡变压器,由此可以实现四相输电方式,也可以用于电气化铁道的 AT供电方式。该文基于该变压器的结构、磁势平衡方程、中性点接地和三相输入阻抗平衡条件,导出了该变压器四相侧的等值电路。分析了 AT 牵引网不同区段发生故障时变压器的负载阻抗特性,得到变电所处不设自耦变压器会影响三相侧的对称性和增加变压器的设计容量的结论。为了准确反映电力机车的负载电流或短路电流,应将接触导线和正馈线上的电流互感器次边差接。
Three-phase to four-phase power transformer with four-limb structure is one kind of novel balance transformer. The transformer may be applicable to either four- phase transmission system or AT power supply system in electric railways. On the basis of its structure, magnetic balance equations, grounding condition, and balance condition of three- phase input impedance of the transformer, an equivalent circuit of the four-phase side of the transformer is proposed. The load impedance characteristics of the transformer are analyzed when the faults occur in different sections in AT power supply network. From the theoretical analysis, it can be concluded that the symmetry of the transformer in the three-phase side is getting worse and its designing capacity of the transformer should be larger in the case of no autotransformer installed in the substation. In order to measure accurately the load of electric locomotives and short circuit current, the secondary side of CTs connected with catenary and feeder should be connected in differential mode.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2004年第3期174-177,共4页
Proceedings of the CSEE
