Fast identification of inrush current using a weighted morphological approach

This paper proposes an approach using weighted mathematical morphology (WMM) to effectively identify inrush current. The identification is based on the feature that the waveform of inrush current is quite different from sinusoid whereas internal fault current is nearly sinusoidal. Compared with the traditional method based on the second harmonic, the proposed approach reduces the data window from a cycle to half a cycle, leading to faster identification. In order to verify the performance of the proposed approach, data collected from laboratory test are employed in simulation studies. The simulation results demonstrate that the proposed approach can reduce the identification time to a great extent, and achieve a better accuracy rate.