基于相模变换的互相关故障定位方法

Cross-correlation Fault Positioning Based on Phase-mode Transformation

对容易受故障影响的配电网,若直接使用三相电流量进行定位,互相关算法定位故障效果不明显。为解决该问题,采用Clarke变换对多个监测点的三相故障电流进行解耦,得到的三个电流模量更能反映各种故障的特征。为了避免单一模量不能反映所有故障特征,结合三个电流模量通过最大值对其进行筛选,选用合适的模量进行互相关算法分析,得到的相关系数反映两个监测点信号波形的相似度,相关系数与配电网各监测点位置结合分析可有效地定位普通故障与雷击故障,提高配电网运行的稳定性。使用PSCAD/EMTDC软件进行仿真,经过大量的仿真数据验证,以上方法可以准确有效地定位故障。

If directly using three-phase current magnitude for positioning power distribution network susceptible to fault, there is no obvious fault positioning result by means of cross-correlation algorithm.For solving this problem,Clarke trans-formation was used to carry out decoupling for three-phase fault current of several monitoring points and get three current modulus which were able to reflect characteristics of various faults.For avoiding failure to reflect all faults characteristics by single modulus,by means of maximum value combining with three current modulus,it was able to screening it and carry out cross-correlation algorithm analysis.The relevant coefficients were able to reflect similarity of signals wave of two monito-ring points.Meanwhile,by combining relevant coefficients and position of each monitoring point of the power distribution network,it was able to effectively positioning common faults and lightning faults which might improve stability of the power distribution network.By using PSCAD/EMTDC software for simulation and on the basis of great deal of simulating data,it was verified that the above method was able to correctly and effectively realize fault positioning.