10 kV小电阻接地方式对变电站内保护配置的影响

The Effect of 10kV Low Resistance Grounding System on Relay Protection Configuration Scheme in Substation

近几年,随着城市配电网缆化工程的推进,电网电缆比例增大,系统对地电容电流随之增大,同时也带来了接地电弧易无法自熄的问题。福州仓山区电网由于供电半径大,系统电容迅增的现象尤为明显。文中探讨了小电阻接地方式的优点,并选取福州仓山片区一座220 kV变电站为实例,分析了该站10kVⅣ段母线改小电阻接地方式对站内保护的影响,并针对后续小电阻改造工程调试验收提出具体建议。

In recent years,with the construction of power cable in the urban distribution networks,the increasing proportion of power cables has led to increment of the in capacitive current-to-ground,which will eventually make the arc fail to extinguish by itself.Due to the large power supply radius of Cangshan District in Fuzhou,the highly increasing capacitance current is particularly serious.The advantages of the low resistance grounding system is discussed in the paper.The effect of low resistance grounding system on relay protection configuration scheme in substation is analyzed based on a 220 kV power station located in Cangshan area,which will adopt the low resistance grounding system to substitute the arc suppression coil grounding system,and specific suggestions for check and accept about the low resistance grounding system project are also proposed in the paper.