Validity analysis of prony algorithm on faulty feeder selection in distribution grids

When a single-phase earthed fault occurred in distribution grids, power system variables during transient process are composed of damped DC components and damped AC components (fundamental wave and harmonics). Prony algorithm can directly estimate the magnitude, phase, frequency and damping factor of all modes which damp exponentially. Such algorithm is more suitable to the character of power system transient variables and can produce high-accuracy fitting by least-square means. A simulation model of non-effectively earthed distribution grid is established and vast simulations under diverse fault conditions have been done. Prony fitting of ATP simulation data of single-phase earthed fault and the field fault data are analyzed by using Prony algorithm respectively, which all proved that the validity of Prony algorithm on faulty feeder selection in distribution grids.