基于SSI的超高压线路单相自适应重合闸故障判别方法

针对带并联电抗器的超高压输电线路发生单相瞬时性故障时存在的拍频现象,提出了基于随机子空间(SSI)的单相自适应重合闸故障性质判定域的自动识别方法。该方法以故障相端部恢复电压为特征量,经EMD预处理、稳定图定阶、SSI辨识,获得系统的特征根。根据两种故障性质的特征根在复平面的分布特点定义了故障性质的判定域,该判定域以系统正常运行时的特征根为参考点,以系统频率允许偏差为半径。经SSI辨识获得的特征根全部落在判定域内判定为永久性故障,否则判定为瞬时性故障。文中同时给出了故障判别的定量指标,以实现故障性质的自动识别。大量仿真实验表明,该方法能有效、准确的判别故障性质,不受过渡电阻、故障位置等因素的影响,且判别结果无交叉区域。

Identification method of single-phase adaptive reclosure in the EHV transmission lines based on SSI

For the EHV transmission lines with shunt reactors, the recovery voltage of fault phase exists the beat frequency phenomenon when transient fault occurred. The paper proposes a new automatic recognition scheme of single-phase adaptive reclosure based on Stochastic Subspace Identification(SSI). The scheme uses the recovery voltage of fault phase as characteristic quantity. Achieve system eigenvalues through EMD, stabilization diagram, SSI. Based on the distribution characteristics of system eigenvalues in the complex plane, define a decision space of fault characteristics, using the system eigenvalues as a reference point and permissible deviation of frequency as the radius. If the eigenvalues of fault signal all locate in the decision space, then the fault type is permanent fault, otherwise the fault type is transient fault. The quantitative index using to distinguish fault type is given in the paper in order to achieve automatic recognition of fault properties. Simulation results show that the proposed scheme can judge the fault property correctly and reliably without cross-regional discrimination results.