分形理论在中压电网故障辨识中的应用

通过对中压电网常见的几种故障(铁磁谐振、消弧线圈串联谐振以及单相接地)发生后各馈线零序电流暂态过程的特点进行分析,得出"不同故障情况下电网暂态过程中出线零序电流具有不同分形特征"的结论.基于这一结论,提出了具有学习功能的故障概率函数测度法来实现故障的分类辨识.通过ATP仿真,对一电压等级为10 kV的配电网模型进行验证计算,结果表明该算法的正确性和可靠性,并且可在现有故障选线的硬件平台上实现.

Application of Fractal Theory in the Fault Classification for Distribution Systems

Distribution system with neutral point ineffectively earthing is analyzed under different types of faults, viz. ferromagnetic resonance, resonance caused by Peterson-coil in series and single-phase earth fault. It is found that the fractal dimensions of outlets' zero-sequence transient currents differ from the variety of fault happened in terms of the fractal theory applied in processing the abnormal signals during the fault. Therefore, an algorithm for fault-classification is proposed to develop a normal-distributed probabilistic function in accordance with those fractal dimensions. In the paper a 10 kV distribution system model is established to test the proposed algorithm. Simulation result on different faults with different parameters has shown that the algorithm has high validity and reliability. In addition, the algorithm can be easily realized using the currently available fault-detection equipment.