高频传导干扰对配电网智能柱上开关保护的影响仿真研究

Simulation Study on Effect of High Frequency Conducted Interference on Intelligent Switch Protection On-column of Distribution Network

针对配电网故障隔离期间电弧重燃导致相邻馈线柱上开关保护误动或拒动问题,提出柱上开关并联电容器的方式以避免其保护误动,保障配电系统设备的正常运行。通过对故障电流暂态过程时域、频域的特征分析,发现暂态故障电流使断路器动作产生高频电磁干扰对智能柱上开关保护影响较大,故障暂态产生电快速瞬变脉冲群是导致柱上开关保护误动或拒动的主要因素。探讨了电快速瞬变脉冲群的幅频特性影响因素,发现馈线间耦合电感及分布电容对其影响显著,增加配电网馈线的分布电容可有效抑制电磁干扰对智能柱上开关保护的影响,基于该特征构建了智能柱上开关并联电容器的抑制高频干扰信号进入保护测量回路的方案。最后利用ATP-EMTP仿真计算,证实了该抑制方案的有效性。

In view of the problem of mal-operation or refusal operation on adjacent feeder column switch due to arc reignition during the fault isolation period of the power distribution grid,the way of parallel capacitor for the column switch is proposed to void its mal-operation in the protection and assure normal operation of equipment of the power distribution equipment.It is found throughout the analysis of the time and frequency domain of the fault current transient processthat the transient fault current causes the highfrequency electromagnetic interference in the operation of circuit breaker which has a great influence on the on-column switch protection,and that the main factor causing the mal-operation or refusal operation is that the fault transient generates an electrical fast transient pulse group.The influence factor of amplitudefrequency characteristics of the electrical fast transient pulse group is discussed.It is found that the influence of coupling inductance and distributed capacitance between the feeders on it is significant,and increasing the distributed capacitance of the feeders of the distribution network can effectively suppress the influence of electromagnetic interference on the switching protection of the smart column.On the basis of this feature,a high-frequency conduction signal suppression scheme for a switched-parallel capacitor on a smart column is constructed.Finally,the effectiveness of the suppression proposal is verified by the use of ATP-EMTP simulation calculation.