Low-resistance grounding system fault location method based on zero-sequence break variable gradient

The invention discloses a low-resistance grounding system fault location method based on zero-sequence break variable gradient, and relates to the technical field of power distribution network single-phase grounding fault location. The method comprises the following steps: setting a plurality of detection points in a power distribution line; collecting a first parameter of each detection point during normal operation; after the single-phase earth fault occurs, acquiring a second parameter of each detection point, and calculating a third parameter; dividing upstream and downstream detection points of a fault point according to a fault section positioning result; determining the number of downstream detection points of the fault point; the fault point upstream zero-sequence voltage break variable gradient is calculated; and finally calculating and determining the position of a fault point according to the first parameter, the third parameter and the zero-sequence voltage break variable gradient. According to th