Locating method and device for one-phase earth fault of power distribution network based on transient state signal wavelet transformation

The invention discloses a locating method and device for a one-phase earth fault region of a power distribution network. The locating method comprises the following steps of: accurately acquiring zero sequence current transient state signals within two periods before and after a zero sequence current exceeds a starting value through terminals arranged in different positions on a line; carrying out wavelet transformation and reconstruction on the zero sequence current transient state signals by the terminals; and analyzing a fault point region according to an approximation coefficient integral value of a detail component after the reconstruction. The locating device disclosed by the invention consists of a terminal and a master station, wherein the terminal is arranged on an overhead line tower or in a cable ring network cabinet, the input end of the terminal is used for receiving a phase current signal at the secondary side of a distribution line CT, the phase current signal is synthesized to obtain a zero sequence current signal, and the terminal is connected with the master station through optical fiber communication or mobile communication; and the master station is arranged in a converting station or dispatching center, composed of an optical fiber communication module and a mobile communication module and used for receiving a signal sent by the terminal. The locating method and device are matured in technique and high in reliability.