一起海陆缆混合线路接地电流异常原因分析

Abnormal Grounding Current Analysis of Land and Submarine Cable Hybird Line

接地电流是判断高压电缆接地方式是否正确的重要指标之一。笔者介绍了一起220 kV海陆缆混合线路接地电流异常事件,分析了该线路陆缆段中间接头和海陆缆对接头多处接地电流存在严重的三相不平衡现象产生的原因,并给出了接地方式优化方案。线路消缺后接地电流恢复正常,验证了所提出的处理措施的正确性。该起接地电流缺陷及其处理方案为采用海陆缆对接方式线路的接地方式选择提供了经验。

The grounding current is one of the important indexes to judge whether the grounding mode of HV cable is correct or not. The author introduces a grounding current defect of 220 kV land and submarine cable hybird line. The grounding currents of the middle joints of the land cable and the joints between the land and submarine cable of this line were seriously unbalanced. The reasons of unbalanced grounding currents were analyzed. Then,the optimization scheme of grounding mode was proposed. After eliminating the defeats,the grounding current returns to normal,and the correctness of the proposed treatment measures is verified. This grounding current defect and its treatment provides valuable experience for the grounding mode selection of land and submarine cable hybird lines.