Research On New Way Of Single Phase To Ground Fault Detection For Power Distribution Systems

Most faults in power distribution systems are single phase to ground faults. Most methods now are based on the steady zero sequence currents, which are effected by arcing, operating manner, etc. The accuracy of fault line selection is not satisfied. On the basis of farther research about abstracting transient fault information to detect fault line in neutral indirectly grounded systems, a novel fault line identifying principle based on theory of single singularity detection with the wavelet transform modulus maxima is presented in this paper, which can acquire abundant characteristic information from transient fault signal more detailedly. The wavelet transform is used to decompose the transient electrical quantities, and the distinct information of modulus maxima in some scale is abstracted to compose a new criterion. Theoretical analysis and lots of simulation show that the proposed method can reliably and exactly detect the fault line in single phase to ground fault and it is suitable for various distribution systems with different neural grounding modes.