高压电力电缆轨迹法在线监测方法

Research on online monitoring system based on locus method of HV power cable

实时掌握电力电缆运行状况能够及时发现高压电缆线路故障,为此该文提出一种基于金属护层参数轨迹法的交联聚乙烯电缆在线监测的方法。通过采集同一时间点的电力电缆护层接地环流和护层感应电压信号,将2个信号进行拟合绘出轨迹图,根据轨迹图特征参数的变化作为判据来判断电力电缆线路是否存在故障。最后,以此设计出一套高压电缆线路故障在线监测系统,它包括前端信号采集单元、主控单元以及后台数据分析处理单元。实验结果表明:运用该方法可及时预警高压电缆线路故障,防止高压电缆线路发生安全事故。

Real-time monitoring of the power cable's operation condition can timely detect the faults in high-voltage cables. This paper proposes an online monitoring method for cross-linked polyethylene (XLPE) cable based on the locus method of metal sheath parameters. Firstly, the signals of earthing circulating current and induced voltage in the sheath of power cable are measured synchronously. Then these two signals are fitted to draw a locus diagram. Based on the analysis of the characteristic parameters of the locus diagram, the insulation condition of the power cable is identified. Finally, a new type of on-line monitoring system for cable insulation is designed. It consists of a front signal acquisition unit, a main control unit and a data analysis system. The actual monitoring results show that the proposed online monitoring system can truly detect and warm the insulation faults in power cables.