【摘要】 输电线路发生接地故障时,可能因零序电压不满足灵敏度要求,而导致零序方向元件误动或者拒动。针对上述问题,本文通过分析零序电压和故障相电压之间的相位关系,提出了一种新的基于故障类型的方向元件。当零序电压低于门槛值时,依据选相结果,该元件采用保护安装处故障前的故障相电压代替零序电压,进行零序功率方向判别。经现场故障数据验证,该元件正确、可靠,已应用于750kV线路微机保护装置。更多还原

【Abstract】 Grounded faults occur on transmission lines, may cause malfunction of currently available zero sequence directional element when zero sequence voltage can’t meet the sensitive requirement. By analyzing the phases’ relation between zero sequence voltage and voltage of faulted-phase, a novel directional element based on faulty type is proposed in this paper to overcome the defects above. When the zero sequence voltage is below the threshold, this element adopts the recorded voltage of the faulted-phase to replace the zero sequence voltage, and then determine the zero sequence power direction. The simulations use recorded fault data show that this element is correct and reliable. The element proposed has been applied into 750kV transmission line digital relaying更多还原