基于故障类型的故障分量提取算法

提出了一种基于故障类型的故障分量提取算法,适用于中性点接地的高压系统。其原理是根据选相结果,先计算出保护安装处的负序及零序故障分量,然后根据故障类型特征计算出保护安装处的正序故障分量,最后按照对称分量理论,将各序故障分量合成得到故障相的故障分量。该算法弥补了目前方法由于只能获取故障发生最初短时的故障分量、只能用于快速保护的缺陷,采用该算法可以求得故障发生后任何时刻的故障分量,从而将故障分量引入后备保护。

Novel Algorithm Based on Fault Type to Extract Fault Components

This paper presents a novel method which is capable of extracting fault components at arbitrary time after fault occurrence. From the result of phase selection, this approach firstly calculates the zero sequence and negative sequence fault components at the location where the protection relay is installed. Then it calculates the positive sequence fault components in accordance with the fault boundary condition. Finally, phase fault components are obtained by synthesizing sequence fault components based on the symmetrical components theory. Comparing with the currently available methods that can only obtain the original short-time fault components, this novel algorithm can extract fault components at arbitrary time after fault occurrence. Hence it may be employed for the fault components in back-up protections to improve their performance.