改进的消弧线圈故障期间调谐方法

An Improved Method for Arc Suppression Coil Tuning During Single-Phase to Earth Fault

正确调谐是消弧线圈正常工作的前提。传统调谐方法只针对正常运行时线路对地电容的大小,而对单相接地故障期间消弧线圈如何调谐的研究鲜见报道。在现有方法的基础之上,考虑到系统不平衡对馈线负序电流的影响,提出种基于馈线负序电流增量和的故障期间调谐新方法。通过分析单相接地故障期间馈线的负序电流,证明了馈线负序电流增量和也能够跟踪接地点残流的变化,提出在故障期间可以调节消弧线圈使馈线负序电流增量和小以保证消弧线圈达到佳补偿位置。仿真结果验证了该方法的可行性。与原方法相比,该方法不要首先判断故障线路且避免了系统不平衡因素的影响。

Correct turning of arc suppression coil （ASC） is related to whether normal operation of ASC can be ensured. In traditional coil turning methods only capacitance between wire and ground under normal operation of transmission line is considered, and the research on the turning of ASC during single phase to earth fault is seldom reported. Based on existing methods and considering the impact of unbalance in power grid on negative-sequence current in＇ transmission lines, a new ASC turning method based on the sum of increments of negative-sequence currents in all transmission lines during single phase to earth fault is proposed. By means of analyzing negative-sequence currents of transmission lines during single phase to earth fault it is proved that the increment of negative-sequence currents in all transmission lines can trace the change of grounding residual current, and it is proposed that to make the sum of increments of negative-sequence currents in all transmission lines minimum during single phase to earth fault by adjusting ASC to ensure the best compensation effect of ASC. The feasibility of the proposed method is verified by simulation results. Using the proposed method, it is not needed to judge that which line is in fault at first and the impact of imbalance factors in power grid can be avoided.