A new method of fault location for small current to ground system

A new principle of fault location is proposed in this paper, which utilized the transient zero-mode power when the fault occurred. The waveforms of transient zero-mode power are similar at the two ipsilateral points of fault point, and the correlation coefficient is close to 1; but the initial polarity of transient zero-mode power is opposite at the two sides of fault point, so the correlation coefficient is close to 0. The value of correlation coefficient is compared with the threshold value. If it is greater than threshold value, the section is considered as health section; on the contrary, it is considered as fault section. Besides, the error caused by non- synchronised data acquisition is avoided through calculating the maximum correlation coefficient. The validity of this method is proved by the simulation.