对电缆受外力破坏引发频率异常保护拒动的分析

Analysis of the Relay Protection Malfunction of Abnormal Frequency Caused by the Cablet External Destruction

本文对某变电站出线电缆受外力破坏,发生接地、短路故障时,继电保护未正确动作切除故障的原因进行现场试验分析,得出故障时产生的高次谐波分量是导致继电保护装置频率异常告警、电流采样精度不够造成保护拒动的原因;并对此采取了相应的设备改造和技术防范措施,消减了电网此类故障的发生几率。

This paper analyzes the faults of a substation as outlet cable damage by external forces, grounding and short circuit, while the relay cannot cut the faults. Get cauises that high order component sends abnormal alarm of relay protection device frequency during faults and current sampling precision is not enough makes relay not to act, and takes the corresponding equipment reformation and technical preventive measure to reduce the fault probability of power grid.