Analysis of single-phase earth fault mode in networks with combined neutral ground by means of wavelet transformation
The paper presents the technique for two stage identification of a line where the fault took places. Timely detection of the line with single phase ground fault increases reliability of power supply and reduces risks of defeat of personnel electric current. The first stage is based on the analysis of high frequency components arising under transients. The second stage involves an analysis of the steady-state mode of a single phase-to-ground fault. Based on the energy spectrum of higher harmonics a damaged line is detected. The proposed method can be implemented to organize digital protection against ground faults.