基于双端电流杰卡德相似度比较的柔性直流输电线路保护

Protection of Flexible DC Transmission Line Based on Double-end Current Jaccard Similarity Coefficient Comparison

为解决现有柔性直流输电线路保护难以应对噪声干扰及高阻故障场景问题,提出一种基于电流故障分量杰卡德相似度系数JSC(Jaccard similarity coefficient)的纵联保护方法。基于电流故障分量的越限实现电流量与逻辑量的变换,构建线路两端电流逻辑量的杰卡德相似度模型,基于区内高相似度完成线路故障识别;最后提出利用保护启动1 ms数据窗下的电流故障分量极间能量比值的差异构建故障极识别判据。仿真结果表明,该保护在噪声干扰和高阻故障下仍能可靠动作。

To solve the problem that the existing protection of flexible DC transmission line is difficult to cope with sce⁃narios with noise interference and high-resistance fault,a longitudinal protection method based on the Jaccard similari⁃ty coefficient(JSC)of current fault components is proposed in this paper.First,the transformation of current and logic volume based on the threshold value of current fault component is realized.Then,a JSC model based on the current and logic volume at both ends of the line is built,thus completing the line fault identification according to the high similari⁃ty in the zone.Finally,the use of polar energy ratio difference between the positive and negative polar current fault com⁃ponents under the 1 ms data window is put forward to formulate a fault polar identification criterion.Simulation results show that the protection is still reliable under noise interference and high-resistance fault.