基于暂态特征突变量的配电网故障选线方法研究

Abstract

本文对于配电网络常见的单相接地故障，提出了一种基于暂态特征突变量的综合选线方法。首先，对故障后各线路的暂态零序电流进行小波分解；然后，由小波分解系数求得低频能量占总能量的百分比来区分为强故障或弱故障；最后，在强故障情况下采用小波包系数极性法，在弱故障情况下采用暂态零序能量法来选择故障线路。通过MATLAB进行了大量的仿真验证，结果表明该方法具有很好的选线能力，即使发生母线故障、相电压过零故障，高阻接地故障时也能正确选线。 For the single-phase grounding fault in the power distribution, a method to select fault line was proposed in the paper. Firstly, wavelet decomposition was used to transient zero-sequence current of each line after fault; then, the percentage of the low frequency energy to the total energy, which were calculated by the wavelet coefficients, was used to distinguish strong or weak fault; finally, the fault line was selected by comparing the polarities of the wavelet packet decomposition coefficient in the strong fault situation, but comparing the transient zero-sequence energy in the weak fault situation. The MATLAB simulation results show that the method is proposed has good ability to carry out the fault line. The criterion can keep the high reliability when the circuit is bus-bar, high resistance or voltage zero grounding.