交直流碰线故障对变压器差动保护影响的实证分析

在实际工程中,目前较为常见的是交流、直流线路交叉跨越的情况,特别在南方地区交流线路错综复杂,南方电网作为多个直流工程的落点,交直流交叉跨越现象更加明显。文中以金中换流站实用的PSCAD仿真模型为基础,搭建了交直流系统共存的仿真模型,并选取220 k V,500 k V交流系统作为典型场景进行分析,仿真交流变压器区外发生金属性的交直流碰线故障。根据仿真波形的分析结果,给出了交直流碰线故障时变压器差动保护的特性分析结果。

Empirical Study of the Influence of AC/DC Touch Fault on Transformer Differential Protection

In practical engineering,the cross and crossing of AC and DC lines are more common at present.The communication lines are complex,especially in the South.With many DC projects,the cross over phenomenon of AC and DC in the China Southern Power Grid is more obvious.This paper is based on the practical PSCAD simulation model of Jin-Zhong converter station,built a simulation model of AC and DC concomitant systems,and selecte 220 kV and 500 kV communication systems as typical scenarios for analysis by simulation of metal touch faults outside the AC transformer protection range.According to the simulation waveform,the characteristic analysis results of transformer differential protection are given in the end.