基于ATP-EMTP的输电电缆护层多点接地故障研究

Research on Multipoint Grounding Fault of Transmission Cable Sheath Based on ATP-EMTP

输电电缆在实际运行中因外力影响导致外护层破损,易形成金属护层多点接地故障。金属护层接地后,护层环流会显著升高,从而会导致护层温度升高,芯线能量损耗加大,长时间运行会加快电缆绝缘老化速度,大大缩短电缆安全运行年限,对电力系统安全稳定运行造成威胁。首先对电缆金属护层环流的产生进行理论分析,然后通过仿真软件对电缆护层多点接地故障等情况进行仿真分析,对比不同影响因素对护层环流值的影响,为输电电缆状态在线监测和护层绝缘性能研究提供一定的参考依据。

In the actual operation of the transmission cable,the outer sheath of the cable is damaged due to the influence of external force,and it is easy to form a multi-point grounding fault of the metal sheath.After the metal sheath is grounded,the circulating current of the sheath will increase significantly,which will cause the temperature of the sheath to rise and the energy loss of the core wire.Long time operation will accelerate the aging speed of cable insulation,greatly shorten the safe operation life of cable,and pose a threat to the safe and stable operation of power system.Firstly,the generation of circulating current in cable metal sheath is theoretically analyzed,and then the multi-point grounding fault of cable sheath is simulated and analyzed by simulation software.The effects of different influencing factors on sheath circulation value are compared,which provides a certain reference basis for on-line monitoring of transmission cable condition and Research on sheath insulation performance.