特高压交流系统横向接地故障对直流系统谐波的影响研究

Research on the Influence of Transverse Grounding Fault of UHV AC on Harmonics of DC System

针对交直流混联系统中谐波的相互影响以及分析精度问题,提出了一种建立保护动作区域的快速校核方法.该方法以交流故障对保护影响特性为研究切入点,分析交流系统横向故障发生时直流侧谐波的特性,在此基础上,获取长时间间隔下交流故障参数,并建立起其对谐波影响的关联关系以及直流保护动作的运作机理.通过对故障影响定性和定量的分析以及保护动作特性分析,表明该方法在一定程度上提高了谐波的分析精度,对工程计算和整定校核具有一定的现实意义.

In view of the mutual influence of harmonics and the problem of analysis accuracy in AC-DC hybrid system,a fast check method of establishing protection action area is proposed.This method takes the influence of AC fault on protection as the research entry point,analyzes the harmonic characteristics of DC side when the transverse fault occurs in AC system,and on this basis,obtains the AC fault parameters under long time interval,and establishes the relationship of its influence on harmonic,combined with the operation mechanism of DC protection action.Through the qualitative and quantitative analysis of fault influence,as well as the analysis of protection action characteristics,it shows that the accuracy of harmonic analysis has been improved to a certain extent,which has a certain practical significance for engineering calculation and setting check.