Fault line detection using waveform fusion and one-dimensional convolutional neural network in resonant grounding distribution systems

Effective features are essential for fault diagnosis. Due to the faint characteristics of a single line-to-ground (SLG) fault, fault line detection has become a challenge in resonant grounding distribution systems. This paper proposes a novel fault line detection method using waveform fusion and one-dimensional convolutional neural networks (1-D CNN). After an SLG fault occurs, the first-half waves of zero-sequence currents are collected and superimposed with each other to achieve waveform fusion. The compelling feature of fused waveforms is extracted by 1-D CNN to determine whether the fused waveform source contains the fault line. Then, the 1-D CNN output is used to update the value of the counter in order to identify the fault line. Given the lack of fault data in existing distribution systems, the proposed method only needs a small quantity of data for model training and fault line detection. In addition, the proposed method owns fault-tolerant performance. Even if a few samples are misjudged, the fault line can still be detected correctly based on the full output results of 1-D CNN. Experimental results verified that the proposed method can work effectively under various fault conditions.