The invention relates to a distribution network cable
hybrid direct distribution line fault
ranging method based on line side direction traveling wave
decomposition, which belongs to the technical field of power
system relay protection. When single-phase grounding fault happens to the distribution network cable
hybrid direct distribution line, a PCA-SVM is firstly adopted to recognize a line
hybrid line fault section; line mode traveling wave is obtained according to fault travelling wave data acquired at a measurement end, the obtained line mode traveling wave is applied and according to line side
voltage travelling wave and current travelling wave distribution in a fault region deduced by a Bergeron line
transfer equation, the line side
voltage travelling wave and the line side current travelling wave are subjected to line side direction traveling wave
decomposition, direction travelling wave for line side distribution is acquired, positive travelling wave is used to multiply backward travelling wave, integration is carried out in two sequential time window lengths for building a
ranging function, and finally, fault
ranging is carried out according to traveling wave
mutation distribution of the ranging function along a fault region
line length range. After theoretical analysis and the
simulation result, the method has good effects.