基于线路残余能量的柔直输电线路极间故障重合闸

Pole-to-pole Fault Reclosing for DC Transmission Line Based on Residual Line Energy

在线路残余能量激励下,电弧会持续燃弧一段时间,现有重合闸等待瞬时性电弧自然熄灭后启动,耗时过长,不利于系统快速恢复供电。基于此,提出一种考虑主动消弧的自适应重合闸。提出引入接地开关,可增加线路电流分量,加快消散线路残余能量,降低电弧燃弧概率。针对瞬时性电弧熄弧速度的差异性,建立多次主动消弧方案。进一步借助皮尔逊相关系数表征差异性辨识故障性质。最后,在PSCAD软件中搭建柔性直流输电系统,与现有直流重合闸相比,提出的重合闸可加速降低线路残余能量,促进电弧熄灭,最长减少170ms的停电时间。

DC arcs continue to burn for a certain period under the excitation of line residual energy.The existing reclosing waits for DC arc to extinguish naturally and then starts,which is time consuming and not conducive to the rapid restoration of power supply.On this basis,a novel adaptive reclosing with an active arc suppression(AAS)is proposed.The grounding switch is introduced to increase the current component of the line,speed up the dissipation of the line residual energy,and reduce the probability of arc burning.A multi-level AAS scheme is established focusing on the variability in arc extinguishing speed for a non-permanent fault(NPF).Furthermore,the Pearson correlation coefficient is used to characterize the difference and identify the NPF and permanent fault(PF).Finally,a flexible DC transmission system is built in the PSCAD.Compared with the traditional DC reclosing,the reclosing proposed in this paper actively reduces the line residual energy,and promotes arc extinguishing,thus reducing the outage time by up to 170ms.