Based on FTU with Wavelet Decomposition Waveform Adaptive Area Calculation for Single-phase Ground Fault Line Selection in Distribution Network

Using wavelet to achieve fault line selection, many traditional methods used single module extreme point to describe the amount of transient current mutation. However, influenced by the diversity of fault modes and the complexity of transient frequency components, such single point method has the poor anti-interference ability, thus causing wrong judgment. Based on analyzing fault transient characteristics, the new perspective that ¿representing the amount of transient current mutation by the wavelet decomposition waveform area value¿ is first proposed in this article. Using wavelet irregularity to detect fault moment, then line selection interval and characteristic band can self-adaptively determined by fault moment. The line that area value of wavelet decomposition waveform in this interval is maximum is the fault line. The paper introduces the basic hardware features of FTU and expounds on the detailed fault line selection flow based on FTU. Theoretical analysis and many dynamic experiments results show that the new method can accurately and reliably select fault line under different system operations and different fault conditions.