基于小波包的配电网单相接地故障判别

Selection on single-phase to ground fault line based on wavelet packets

基于故障产生的暂态零序电压电流在特定频段内分量呈容性关系,应用小波包良好的频域分频特性,以适当频率带宽对配电网发生单相接地故障后暂态电气量进行分解,得到其在不同频段下的输出。对于中性点接地方式不同的配电网,按照能量的观点,在SFB频段内选择不同的频带利用波形识别技术来实现故障选线。理论及大量的仿真试验表明,该方法可以准确、可靠地实现单相故障接地选线,适合于接地方式不同的电网。

According to the capacitive relationship between transient zero sequence voltage and current components in a selected frequency band （SFB） produced by earth fault, applying the good property of frequency division of wavelet packets, transient electrical quantities, which appears in the distribution networks occurring a single phase to ground fault, are decomposed to obtain the outputs of different frequency bands. In view of energy, using waveform recognition, the different frequency band is chosen corresponding to the distribution system with the different neutral grounding mode in SFB. Theoretical analysis and simulations show that the proposed method can reliably and exactly choose the faulty line in single phase-to-ground fault and it is suitable for various distribution systems with different neutral grounding modes.