用于中高压弱馈线路的方向距离继电器

摘要

Based on two fault cases of weak-infeed lines,where the metal grounding fault happened on line”s back outlet,this article analyzed the cause of unwanted operation of grounding distance relay on non-fault phase when the value of the first stage of the grounding distance protection is based on over range setting and the line carries a light load.Furthermore,it is proved that it is reliable to prevent unwanted operation using zero sequence directional component to block the first stage of the ground distance relay.%弱馈线路是一种比较常见的电网接线运行方式。文中结合电网中的两个故障案例，分析了当接地距离Ⅰ段的定值若按超范围整定，且运行线路空载或负荷很轻时，在线路背后出口发生接地故障时非故障相的接地距离继电器误动的原因。通过分析证明可用零序方向元件闭锁接地距离Ⅰ段继电器以防止误动的可靠性。