Method and system for line loss grading calculation and fault location of low-voltage transformer area

The invention discloses a line loss grading calculation and fault positioning method for a low-voltage transformer area, which comprises the following steps of: establishing a line model of a low-voltage power grid for describing structures and related parameters of each lead, a transformer and a power distribution equipment object in the low-voltage power grid; performing fitting processing on the line according to the line data and the error function by adopting a selective weighted least square integral error technology, and establishing a hierarchical line loss model; monitoring current, voltage and power parameters of the low-voltage power grid in real time, and determining the current working condition of the low-voltage power grid; and selecting an error function corresponding to the current working condition, performing calculation to obtain a line loss calculation result, and performing fault positioning. The invention further discloses a corresponding system. By implementing the method, the precisio