一种配网单相接地选线的频带自适应获取方法

小电流接地系统单相故障选线中,目前频带的选择方法中被广泛采用的是首容性频带方法,但是这种方法易受配网运行方式、线路参数不精确等因素的影响。为了克服以上缺点,提出一种基于矩阵束算法的配电网单相接地选线频带自适应获取方法。频带下限在不接地系统中为0,经消弧线圈接地为150 Hz;频带上限的确定方法为首先通过矩阵束算法提取各出线零序电流的共有频率以及对应的相位,然后找到满足相位关系的最大频率,此最大频率就是频带的上限。PSCAD仿真和故障录波验证了该方法在各种故障情况下的有效性。此方法有望提高小电流接地系统单相接地故障时的选线正确率。

A novel frequency band self-adaptive selection method of fault line selection in distribution network

In the non-solid earthed network fault line selection, nowadays the frequency band selection method is based on special frequency band (SFB). However, this method is liable to be influenced by the distribution network operation type and line parameters. To overcome the disadvantages, a new selection method of frequency band based on matrix pencil algorithm is proposed. In ungrounded distribution network, the minimum frequency is 0 Hz, in compensated distribution network, the minimum frequency is 150 Hz. The maximum frequency of frequency band is determined by the way as follows: first the common frequencies and phases of all line transient zero sequence current are extracted by the matrix pencil method. Then the maximum frequency that meets a certain relationship is found and the maximum frequency is the maximum of the frequency band. The simulation on PSCAD and the recording data analysis verify that the method proposed is effective. The method is hopeful to improve the accuracy of the fault line selection.