城市中压配网中性点小电阻接地方式分析

摘要

中性点接地方式直接关系城市配网的安全运行.针对中压配电网小电阻接地方式,基于Matlab仿真与运行示例分析中性点经小电阻接地方式的运行特点,从绝缘配合、人身安全、供电可靠性与继电保护配置方面综合考虑提出相应的接地电阻选取原则,结果表明接地电阻对中性点电压偏移具有很好的抑制作用.因此,中性点小电阻接地系统可以适应一定范围内电网运行方式变化及发展要求,对进一步探索接地方式并提升系统安全稳定运行具有重要意义.%The high-speed development of urban economy and society have higher requirement on the running reliability of medium-voltage power grid,which is directly influenced by the neutral grounding mode.In this paper,the low-resistance grounding mode for medium-voltage power grid is analyzed,based on the consideration of insulation coordination,personnel safety,power supply reliability and relay protection.Based on the running characteristics of low-resistance grounding,the selection principle of low resistance is proposed.The obtained results show that the low resistance can have better inhibition on the neutral voltage offset,which makes non-fault phase have little higher stead-state voltage.Therefore,the low-resistance neutral grounding system is suitable to the developing need and running variation of urban power grid,which is helpful to further investigate the more effective grounding mode and to promote the safety and reliability of power system.