基于故障行波理论和IEC61850标准,研制了中性点非有效接地系统数字化变电站中的单相接地故障行波选线装置。介绍了单相接地故障行波选线原理,故障线路电流初始行波幅值最大,极性与非故障线路相反。建立了符合IEC61850标准的数字化变电站中通用选线装置模型,一个包括3个逻辑节点的逻辑设备。设计了基于故障电流初始行波的选线装置硬件方案和软件流程,包括基于小波变换的故障行波算法和基于小波变换模极大值的选线判据。并设计了符合IEC61850标准中制造报文规范(MMS)的通信单元。在某数字化变电站的成功投运,证明了装置的可行性。
A faulty feeder selector based on traveling wave theory and IEC61850 standard is developed for the single-phase grounding fault of digital substation in non-solid grounding power system.Its principle is presented: the amplitude of initial traveling wave on faulty feeder is higher than those on other feeders and its polarity is in inverse.General model of faulty feeder selector is established according to IEC61850,which is a logic device with three logic nodes.Its hardware scheme and software flowchart are designed,including the wavelet-transform-based traveling wave algorithm and modulus-maximum-based criterion,and especially the communication unit conforming to the MMS of IEC61850.Its successful operation in a digital substation verifies its feasibility.