基于纵联保护原理的直流输电系统接地极不平衡保护

Grounding Electrode Unbalance Protection for HVDC Based on Pilot Protection

直流输电系统接地极故障保护配置的不平衡保护动作触发条件和保护策略都存在一定的缺陷。针对存在的问题,介绍单极大地回线运行方式下接地极引线故障的运行实例。然后借鉴输电线路的纵联保护原理,在原保护基础上提出了基于纵联保护原理的不平衡保护改进方案。应用结果表明:改进的方案可根据接地极引线发生接地故障和断线故障时各电流值的变化规律来判断故障类型。

The DC power system’s grounding electrode fault protection doesn’t work perfectly at home and some defects can be found in trigger conditions of unbalance protection and protection strategies.Taking the grounding electrode’s wire fault as an example and basing on the principle of pilot protection,an improved un-balance protection scheme was proposed.The application results show that this method can determine the fault types according to the current variation of the grounding electrode while any failure occurs to the electrode wire.