Scott接线平衡变压器数学模型与阻抗匹配的实验验证

从磁势平衡方程、绕组接线方程和电压传递方程出发分析Scott接线平衡变压器的运行特性,阐明为使Scott接线变压器三相-两相平衡变换性能达到理想状态应满足的设计条件;推导出用绕组间短路阻抗表达的阻抗匹配关系式;试制了一台50 kVA小容量模型,实际测试结果验证了相关分析的正确性。讨论了Scott接线变压器的励磁电流特性;给出Scott接线变压器的二次侧两相端口电压输出方程、两相等值电路和相坐标下的节点导纳矩阵,以便同电力系统和牵引网接口进行有关问题的分析计算。

Experimental Verification of Mathematical Model and Impedance Matching of the Scott Connected Balance Transformer

On the basis of the magnetomotive force balance equations,winding connection equation and voltage transfer equations,the operational characteristics of the Scott connected balance transformer are analyzed.The design requirements for ideal balance transformation performance between the three-phase and two-phase for a Scott transformer are clarified.An impedance matching equation expressed with winding-winding short circuit impedances is derived.The validity of relevant analyses is verified by experimental measurements on a trial-produced 50kVA Scott transformer model.The properties of magnetizing currents of Scott transformers are discussed.The two-phase output voltage equations,two-phase equivalent circuit and nodal admittance matrix of Scott transformers are presented,which can be used for calulation for interfacing between the three-phase power system and traction networks.