中性点非有效接地系统遇到的问题与对策

Problems and Countermeasures of Neutral Point Non-effectively Grounded System

当电网发展到一定规模,张家口地区10 kV、35 kV系统出线总长度增加,配网电缆线路增加,对地电容较大时,单相接地电流就不容忽视。电网运行经验表明,当单相接地电流大于10 A时,电弧不易熄灭,容易产生间歇性弧光接地过电压,发展成相间故障,直接影响供用电可靠性。电力系统中性点接地是一个综合性技术问题,文章从张家口地区运行情况以及存在的问题,对地区电网调度管理、运行方式、中性点接地配置优化、季节变化、消弧线圈自动装置的正确投入等诸多问题提出解决措施与建议。

Along with the development of power grid, the length of 10 kV and 35 kV transmission lines and the distribution cable line are increasing. When the earth capacitance becomes bigger,the single phase ground current cannot be neglected. The grid operation experience showed that when the single phase ground current is greater than 10A, the electric arc is not easy to die out which directly causes intermittent arc to ground overvohage and developing into inter-phase failure and directly affecting the reliability of power supply. This paper analyzed the operation problems in Zbangjiakou area from the aspects of regional power grid dispatching management, operation mode, neutral point earth optimum configuration,season changing and correct operation of Peterson Coil automation device. Finally recommen- dations and solutions were put forward.