35kV配电网中性点灵活接地方式的仿真研究

Simulation&Study on Flexible Neutral Grounding Mode in 35 kV Distribution Network

对35 kV中压配电网经消弧线圈接地方式下的瞬时性单相接地故障进行仿真分析,结果表明若故障点发生多次燃弧,仍可能产生高幅值弧光过电压。提出了中性点经消弧线圈与限压电阻、选线电阻组合的灵活接地方式。理论分析及ATP-EMTP仿真计算结果表明,这种灵活中性点接地方式在限制单相接地故障暂态过电压及故障选线方面优于谐振接地方式,可以提高中压配电网的供电可靠性和线路的设备安全性,可在雷电多发地区应用。

Transient single-phase grounding fault occurs in the neutral resonance grounding mode of 35 kV distribution network is simulated and analyzed,which shows that the repeatedly arc at the fault may still cause high amplitude arc overvoltage.In order to improve the neutral resonance grounding mode,a flexible neutral grounding mode which is a combined mode of Petersen-coil and limiting voltage and the line resistors is proposed.Theoretical analysis and ATP-EMTP simulation results both show that this flexible neutral grounding mode has the advantages of limiting the transient overvoltage and fault line selection of single phase to ground fault.It improves the reliability of power supply and the safety of power distribution network,which can be applied in the area of thunder and lightning.