主接地网接地电阻对变电站安全运行的影响

对变电站主接地网接地电阻值、故障时对地电流值以及主接地网接地电位升高等问题进行分析。结合设计规程对变电站主接地网接地电阻值的计算方法和是否合乎现场判断进行论述,指出应该正确理解有关技术标准对变电站主接地网接地电阻值的规定。某变电站母线故障引起的连锁事故说明,在设计中应该明确主接地网接地电阻值概念,运行中应该加强对变电站主接地网接地电阻管理,消除变电站主接地网存在的问题和事故隐患,提高电网安全运行水平。

Influence of grounding resistance value of main grounding grid on substation safe operation

The problems were analyzed about the grounding resistance value of the substation main grounding grid, the phase-to-ground fault current value and the grounding potential rise of the main grounding grid. Combined with the design regulations, the calculation method of the grounding resistance value for the substation main grounding grid and the judgment to meet the actual operation condition were discussed. It is pointed out that the relational technique regulation of the grounding resistance value for the substation main grounding grid must be rightly comprehended. A series accidents caused by the bus failure of one substation in Tanjin further shows that electric operators should be clear about the conception of the grounding resistance value of the main grounding grid, and should attach more importance to the grounding resistance of the substation main grounding grid and strengthen the management. Thus existing problems and latent troubles of the substation main grounding grid would be eliminated, and further safe operation level of power grid can be improved.