线路单相接地故障熄弧时刻捕捉算法  

Approach to detect arc extinction time of single-phase transient fault in transmission lines

作　　者：李娜[1] 江亚群[1] 黄纯[1] 高云鹏[1] 江辉[2] 

机构地区：[1]湖南大学电气与信息工程学院,长沙410082 [2]深圳大学光电工程学院,深圳518060

出　　处：《仪器仪表学报》2017年第7期1660-1667,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(51677060);广东省自然科学基金(2016A030313041)项目资助

摘　　要：针对带并联电抗器的电力线路瞬时性单相接地故障,为确保自适应重合闸成功并最大限度缩短非全相运行时间,提出了一种基于单频信号全相位快速傅里叶变换(ap FFT)相位谱平坦特性的熄弧时刻捕捉算法。对故障相端电压信号进行全相位FFT计算,分析二次电弧熄弧前后故障相端电压信号的全相位FFT频谱特征,在二次电弧熄弧前,由于过渡电阻的高度非线性,故障相端电压中有剧烈变化的高频信号,其全相位FFT相位谱不具平坦性;二次电弧熄灭后,过渡电阻消失进入恢复电压阶段,高频信号平稳变化,其全相位FFT相位谱较平坦。通过分析高次谐波相位谱平坦特性的变化,可准确捕捉二次电弧熄弧时刻。ATP-EMTP仿真结果表明,该方法计算简单,受故障位置、过渡电阻、功角等因素影响小。实际故障录波数据的分析结果验证了所提方法的有效性。In order to improve the success rate of adaptive reclosure and minimize the incomplete phase operative time, a method based on flatness characteristics of all-phase FFT （apFFT） spectrum is presented to detect the arc extinction time for transient single-phase earth faults in transmission lines with shunt reactors. The apFFT spectrum of the terminal voltage of faulty phase is analyzed. It is found that, before the secondary arc extinguishes, the apFFT phase spectrum is not smooth, because of outstanding variation of high-frequency components caused by the highly non-linear transition resistances. After the secondary arc extinguishes, the apFFT phase spectrum is flat, because the transition resistance disappears and high-frequency signals change smoothly. Utilizing the difference of the flatness characteristic in high-order harmonic apFFT phase spectrum before and after the secondary arc extinguishes, a reliable method is proposed to identify the arc extinction time accurately and effectively. Simulations using ATP-EMTP verify the correctness and effectiveness of the proposed method. The proposed method is almost insusceptible to fault location, transition resistance and power angle. The validity of the method is verified by the analysis of the actual wave data.

关 键 词：输电线路 自适应重合闸 全相位快速傅里叶变换 高频暂态分量 熄弧时间 

分 类 号：TH89[机械工程—仪器科学与技术]