基于VMD-ApEn的输电线路两相接地故障诊断

针对现有电力系统输电线路故障信号分析方法中,存在故障信号特征遗失等问题,提出一种基于VMD-ApEn的两相接地故障诊断新方法。首先选取故障点处容易获取的相电压信号作为故障信号,然后对各相故障信号进行VMD分解得到其IMF分量,进一步提取各相IMF分量的近似熵值并作为一个特征向量,通过分析各相特征向量的模值,最终诊断出输电线路两相接地故障所在相。选取IEEE5节点标准测试系统验证,并与EMD-ApEn算法进行比较。实验结果表明,本文提出的VMD-ApEn方法准确可靠,避免了EMD分解时产生模态混叠的现象,更能有效地诊断出输电线路两相接地故障所在相,具有较好的实用性。

Two-phase Grounding Fault Diagnosis of Transmission Lines Based on VMD-ApEn

A new fault diagnosis method based on VMD-ApEn was proposed to solve the problem of failure signal feature loss in the fault signal analysis method of transmission line fault of existing power system. Firstly, the phase voltage signal easily obtained at the fault point is taken as the fault signal. Then, the IMF component was decomposed by VMD, and the approximate entropy of the IMF component was extracted and taken as an eigenvector. By analyzing the modulus of the eigenvector of each phase, the phase of the two-phase ground fault of the transmission line was diagnosed. The IEEE5-node standard test system was validated and compared with the EMD-ApEn algorithm. The experimental results show that the VMD-ApEn method proposed in this paper is accurate and reliable, which avoids the phenomenon of modal aliasing when EMD was decomposed, and can effectively diagnose the phase of the two-phase ground fault of the transmission line, and has good practicability.