感应滤波器对新型换流变压器短路阻抗的影响

摘要

换流变压器的短路阻抗是高压直流输电系统中一项重要技术参数。与传统的换流变压器相比,新型换流变压器具有独特的绕组联结方式。本文针对新型换流变压器拓扑结构的特殊性,分别推导阀侧短路阻抗ZK,网侧短路阻抗Zk与滤波器阻抗Zf的数学关系。通过分析短路阻抗和滤波器阻抗的关系,在未投入和投入感应滤波器的情况下,短路阻抗值的变化较小,表明滤波器的阻抗对短路阻抗的影响较小。而通过对比短路阻抗ZK和Zk,可知网侧短路和阀侧短路时得到的短路阻抗值基本上是相等的,说明新型换流变压器的阻抗是对称的。最后通过对理论计算值、仿真结果和实验结果的对比分析,验证了本文理论分析的正确性。%The short-circuit impedances of converter transformer are important technical parameters in HVDC system.Compared with the traditional converter transformers,the new converter transformer has unique windings connection mode.Based on the peculiar topological structure of the new converter transformer,this paper establishes the mathematical relations of the valve side short-circuit impedance ZK,the grid side short-circuits impedance Zk and the filter impedance Zf,respectively.According to the analysis of the relation of the short-circuit impedances and the filter impedance,the results show that the short-circuit impedance change a little whether or not with filters,so that filters have little effect on the short-circuit impedances,And according to the comparison between the short circuit impedance ZK and Zk,it shows that the both short-circuit impedance are almost the same,so that the short-circuit impedance of the new converter transformer are symmetrical.Finally,the theoretical calculation,simulation and experiment results verify the correctness of the theoretical analysis.